Citation
Preparation of sic-based fibers from organosilicon polymers

Material Information

Title:
Preparation of sic-based fibers from organosilicon polymers (I) Effects of polyvinylsilazane on the characteristics and processing behavior of polycarbosilane-based solutions and (II) synthesis, characterization, and processif of polymethylsilanes
Creator:
Saleem, Mohamed, 1965-
Publication Date:
Language:
English
Physical Description:
xxii, 435 leaves : ill. ; 29 cm.

Subjects

Subjects / Keywords:
Absorption spectra ( jstor )
Heat treatment ( jstor )
Molecular weight ( jstor )
Nitrogen ( jstor )
Polymerization ( jstor )
Polymers ( jstor )
Polysilanes ( jstor )
Pyrolysis ( jstor )
Solvents ( jstor )
Viscosity ( jstor )
Dissertations, Academic -- Materials Science and Engineering -- UF ( lcsh )
Materials Science and Engineering thesis, Ph.D ( lcsh )
Genre:
bibliography ( marcgt )
non-fiction ( marcgt )

Notes

Thesis:
Thesis (Ph.D.)--University of Florida, 1998.
Bibliography:
Includes bibliographical references (leaves 425-434).
General Note:
Typescript.
General Note:
Vita.
Statement of Responsibility:
by Mohamed Saleem.

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
Copyright [name of dissertation author]. Permission granted to the University of Florida to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Resource Identifier:
029546497 ( ALEPH )
40154079 ( OCLC )

Downloads

This item has the following downloads:


Full Text










PREPARATION OF SIC-BASED FIBERS FROM ORGANOSILICON POLYMERS:
(I) EFFECTS OF POLYVINYLSILAZANE ON THE CHARACTERISTICS AND
PROCESSING BEHAVIOR OF POLYCARBOSILANE-BASED SOLUTIONS AND
(II) SYNTHESIS, CHARACTERIZATION, AND PROCESSING OF
POLYMETHYLSILANES













By


MOHAMED SALEEM


A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY



UNIVERSITY OF FLORIDA


1998














ACKNOWLEDGMENTS


I am grateful to Dr. M.D. Sacks for his invaluable guidance and support. I am

thankful to Drs. C.D. Batich, J.H. Simmons, E.D. Whitney, R. Drago, and D. Talham for

serving on my committee. I would like to thank Dr. S. Bates, Dr. A. Morrone, R.

Crockett, W. Acree, and E. Lambers for their help in use of various analytical

instruments.

I would also like to thank G.W. Schieffele, J.H. Dow, Y.J. Lin, K. Wang, R.

Raghunathan, T.J. Williams, and G. Staab for their assistance in carrying out various

experiments in this study. I am grateful to Drs. Rajiv Bendale and Priya Bendale for

many useful technical discussions throughout the course of this study. Thanks are also

due to U. Mahajan, S. Lathi, M. Lakshmipathy, and J. DePuy for their help in compiling

this dissertation. I would aiso like to thank P. Raghunathan, R. Raghunathan, J.

Sethuraman, J.H. Dow, V. Shenoy, U. Shenoy, N. Srinivasa, A. Srinivasa, H. Kannan,

D. Kuruvilla, E. Naveen, R. Parikh, C. Parikh, and V. Srinivas for their friendship

throughout the course of my stay in Gainesville.

Finally, my special gratitude goes to Anuradha and Prakash Krishnans, for their

friendship, support, and encouragement, and for providing an atmosphere of home

away from home.















TABLE OF CONTENTS

AC KNO W LEDG M ENTS ................................................. ........ ........ ........ ii

LIS T O F TA B LE S ............................................. .......................... ................. vii

LIST OF FIGURES ....... .............................................. .............. ................. xi

A B S T R A C T ............................................. ......................................................... xxi

1. INTR O D U C TIO N ................................................. ....................................... 1

2. LITERATURE REVIEW .............................................................. ................ 5
2.1. Background ........... ................................................ ...... ......... ...... 5
2.2. Polysilane synthesis ............................ ................... 7
2.2.1. Wurtz-coupling of dichlorosilanes with alkali metal ......................... 7
2.2.1.1. M echanism ....................................... ... .............. 7
2.2.1.2. Mode of addition of reagents .................. ...................... 10
2.2.1.3. Effect of alkali m etal ......................................... .. ............. 12
2.2.1.4. Solvent effects ........................................ ..................... 14
2.2.1.5. Temperature effects ....................................... ................ 23
2.2.2. Ultrasonically activated Wurtz-coupling reactions ........................... 25
2.2.3. Polymerization of monoalkylchlorosilanes ...................................... 26
2.2.4. Polysilane copolym ers .................................... ......................... 28
2.2.5. Dehydrocoupling ............................... ................. 28
2.2.6. Redistribution/substitution reactions ...................................... 37
2.3. Pyrolysis behavior ............................................. ....................................... 42
2.4. Cross-linking of polysilane polymers ....................... ........................ 60
2.4.1. Oxidative cross-linking ........................................... ............. 60
2.4.2. Room temperature vulcanization ..................................... .... 60
2.4.3. Photo-cross linking ........................................ ......................... 62
2.5. Applications of Polysilane Polymers ..................................... ....... 63
2.5.1. Precursor for p-SiC ................... ................... ...................... 63
2.5.2. Photoinitiators for radical polymerization ..................................... 68
2.5.3. Photoresists in microelectronics .................................... ..... 69

3. EXPERIMENTAL PROCEDURE .................................................................... 72
3.1. Role of polyvinylsilazane as a spinning aid for polycarbosilane ..................72
3.1.1. Polymer synthesis ............................................... ................ 72
3.1.2. Spin dope preparation, fiber spinning, and fiber heat treatment ...... 74
3.1.3. Characterization of PCS polymer solutions .................................. 77
3.1.4. Characterization of fibers ............................................ ........... 82
3.2. Synthesis and characterization of polymethylsilane (PMS) polymers ....... 84








3 .2 .1. S tarting m materials .............................................. ....................... 84
3.2.2. Procedure for polymerization ..................................................... 84
3.2.3 Determination of polymer yield .................... .......... .......... 89
3.2.4. General procedure for heat treatment of PMS-based polymer
solutions .................................. ............. ................... 90
3.2.5. Procedure for fractional precipitation of PMS polymers .................. 91
3.2.6. Characterization of polymers and samples prepared by heat
treatment of the polymers ................................................... 92
3.3. Spinning and characterization of fibers prepared from PMS-based
po lym e rs ........................................ ........ .......... .................... ... ....... 9 5
3.3.1. Spin dope preparation, fiber spinning, and fiber heat treatment ..... 95
3.3.2. Fiber characterization .......................................... ............... 98

4. RESULTS AND DISCUSSIO N ....................................................................... 100
4.1. Effect of PSZ as a cross-linking/processing aid for spinning of fibers
from P C S solution ................................................................. ................. 100
4.1.1. Fiber spinning characteristics .................................................. 100
4.1.2. Polymer solution characteristics................................................... 107
4.1.2.1. Molecular weight and intrinsic viscosity measurements..... 107
4.1.2.2. Studies on rate of evaporation of solvents from PCS
and PCS+PSZ solutions ..................... ............. 111
4.1.2.3. Contact angle measurements ........................................ 114
4.1.2.4. Surface tension measurements ....................................... 126
4.1.3. Characterization of fibers ............................................... 137
4.1.3.1. Characterization of fibers by FTIR .................................. 137
4.1.3.1.1. FTIR spectra of PCS fibers during heat
treatment in nitrogen ........................................ 143
4.1 3.1.2. FTIR spectra of PCS fibers heat-treated in air..... 151
4.1.3.1.3. FTIR spectra of air-heat treated PCS fibers
during heat treatment in nitrogen ...................... 155
4.1.3.1.4. FTIR spectra of PSZ during heat treatment
in nitrogen ............................. ............................ 162
4.1.3.1.5. FTIR spectra of PCS+PSZ fibers during heat
treatment in nitrogen ......................................... 172
4.1.3.1.6. FTIR spectra of air-heat treated PCS+PSZ
fibers during heat treatment in nitrogen .............. 184
4.1.3.2. Mechanical properties of fibers ........................................ 195
4.2. Synthesis and characterization of polymethylsilane polymers ............... 216
4.2.1. Effect of synthesis conditions on molecular weight .................... 220
4.2.2. Effect of synthesis conditions on polymer yield ............................. 229
4.2.3. Characterization of PMS polymers and ceramic residues resulting
from pyrolysis .................. ..... ................... ................ 225
4.2.3.1. Weight loss behavior ............................................... 233
4.2.3.2. FTIR spectroscopy studies on PMS polymers .............. 236
4.2.3.3. XRD characteristics ................................................ 252
4.2.3.4. EMA analysis .................................................. 256
4.2.4. Sensitivity of PMS polymers to oxygen contamination ............... 260
4.3. Preparation of silicon carbide fibers from polymethylsilane polymers...... 265
4.3.1. Methods to increase molecular weight of PMS polymers .............. 268








4.3.1.1. Heat treatment of PMS polymers ................................... 268
4.3.1.2. Fractional precipitation ................... .................... 289
4.3.2. Spinning of fibers from PMS-based polymers ............................. 299
4.3.2.1. Spinning of fibers from as-prepared blends of PMS:PCS
polym ers ........ ..... ... .............................................. 299
4.3.2.2. Spinning of heat-treated PMS polymers and PMS:PCS
polymer blends .............................................................. 306
4.3.2.3. Spinning of fibers from fractionally-precipitated PMS
polym ers ............. ....... ..... ....... ............ ..... .... ............ 331
4.3.3. Fiber extension experiments on PMS polymer spin dopes
containing PSZ .................................................... 339

5. SUMMARY AND CONCLUSIONS .................................. 346


APPENDIX A


APPENDIX B


APPENDIX C


APPENDIX D


APPENDIX E

APPENDIX F


APPENDIX G



APPENDIX H


APPENDIX I



APPENDIX J



APPENDIX K


RHEOLOGICAL CHARACTERIZATION OF PCS AND
PCS+PSZ POLYMER SPIN DOPES................................... 351

FIBER SPINNING CHARACTERISTICS FOR PCS AND
PCS+PSZ SPIN BATCHES ................. ... ................... 357

FIBER EXTENSION DISTANCES FOR PCS AND PCS+PSZ
SPIN DOPES ...................................... ..................... 362

INTRINSIC VISCOSITY CALCULATIONS FOR PCS,
PCS+PSZ AND PMS POLYMERS ................ .............. 365

RESULTS OF SURFACE TENSION MEASUREMENTS ..... 371

TEMPERATURE AND WEIGHT GAINS FOR HEAT
TREATMENT OF PCS, PCS+PSZ FIBERS IN AIR ........... 376

WEIGHT LOSS DATA FOR PCS, PCS+PSZ FIBERS
(AIR-HEAT TREATED AND NON-AIR HEAT TREATED)
AFTER PYROLYSIS AT 1150C IN NITROGEN .............. 378

TENSILE STRENGTH DATA FOR PYROLYZED PCS AND
PCS+PSZ FIBERS ...............................................................380

GPC MOLECULAR WEIGHT DISTRIBUTIONS FOR PMS
POLYMERS FRACTIONALLY-PRECIPITATED BY ADDITION
OF ALCOHOLS ...................................... .................. 400

GPC MOLECULAR WEIGHT DISTRIBUTIONS FOR PMS
POLYMERS FRACTIONALLY-PRECIPITATED BY ADDITION
OF ACETONE ............... ................. .... ................... 403

CALCULATIONS FOR EXCESS SILICON AND CARBON
IN SIC FIBERS ........ ....... ................................... .. 413








APPENDIX L


APPENDIX M


APPENDIX N


CHARACTERISTICS OF PMS POLYMERS SYNTHESIZED
FROM MDCS MONOMER .................................................415

CHARACTERISTICS OF PMS POLYMERS SYNTHESIZED
FROM MDCS AND MTCS MONOMER MIXTURE ..............417

CHEMICAL FORMULAS FOR MONOMERS USED IN
WURTZ-COUPLING POLYMERIZATION ........................ 424


REFERENCES ............................................... ..................................................426














LIST OF TABLES


Table Page

2.1. Effect of diglyme and heptane additions on polymerization of some
dichlorosilane m onom ers .............................................. ............. 17

2.2. Effect of temperature on polymerization of methylphenyldichlorosilane ....... 24

2.3. Effect of sonication time on molecular weights and polydispersities
of polymethylphenylsilane ............. ............................. ................ 26

2.4. Summary of methylsilane polymerization by catalytic dehydrogenation
reactions ...... ........... ....... ..... .................... .................. 30

2.5. Effect of time and temperature on polymerization of phenylsilane in the
presence of a lanthanoid complex ................................ ...... ............. 35

2.6. Ceramic yield and chemical compositions upon pyrolysis of polysilane
homopolymers, copolymers, and terpolymers ........................................ 43

2.7. Synthesis conditions and characteristics of PMS polymers prepared by
W ood .................. ..................... ............................................ .... 48

2.8. Pyrolysis results for catalytically cross-linked polysilane polymers .............. 50

2.9. Peak assignments for IR absorption spectra of vinylic polysilanes .............. 56

2.10. Ceramic yield characteristics and decomposition temperatures for
polysilane polymers synthesized by Abu-Eid et al. ................................... 59

2.11. List of polysilanes that can be used in radical polymerization .................. 69

3.1. Properties of reagents used in synthesis of polymethylsilane polymers ...... 85

4.1. Fiber spinning characteristics for PCS and PCS+PSZ spin dopes spun
under identical conditions ............. ............................................... 104

4.2. Average fiber extension distances for PCS and PCS+PSZ spin dopes at
the same viscosities used in the fiber spinning experiments.................... 108

4.3. Surface tension values for PCS and PCS+PSZ solutions in toluene at
different solids-loadings ....... ..... .................................................. 128








4.4. FTIR peak assignments for polycarbosilane (PCS) fibers ............................ 139

4.5. FTIR peak assignments for polydimethylsilane (PDMS) polymer ............... 141

4.6. FTIR peak assignments for PCS fibers (batch 65s) heat-treated in air
at 1870C .................................... ...................... .... .. ....... 153

4.7. FTIR peak assignments for polyvinylsilazane (PSZ) polymer ....................... 166

4.8. FTIR peak assignments for PCS+PSZ fibers (batch 70s)......................... 174

4.9. FTIR peak assignments for PCS+PSZ fibers (batch 70s) heat-treated in air
a t 17 7 C ...................................................................................................... 18 6

4.10. Average tensile strengths and rupture strains for PCS and PCS+PSZ fibers
(green, heat treatment in air at 180 10C, heat treatment in nitrogen at
400C, and heat treatment in air at 180 10C followed by heat
treatment in nitrogen at 4000C) .............................. ................. 196

4.11. Tensile properties of as-spun and air-heat treated (187C) PCS fibers,
heat-treated to various temperatures between 200 and 1150C in nitrogen .203

4.12. Tensile properties of as-spun and air-heat treated (177C) PCS+PSZ
fibers, heat-treated to various temperatures between 200 and 1150C
in nitrogen ................. ............... .................... .................... 204

4.13. Properties of SiC fibers spun from PCS ................................ ................. 211

4.14. Properties of SiC fibers spun from PCS+PSZ ........................................ 211

4.15. Synthesis conditions and characteristics for PMS polymers ...................... 219

4.16. FTIR peak assignments for polymethylsilane polymer PMS-F (batch
PMS-256) ....... ...................... ............ ........ .............. .. 239

4.17. FTIR peak assignments for polymethylsilane polymer PMS-C (batch
PMS-263) ...... .................. ....... ..................... .. ................ 240

4.18. d-spacings and 20 Bragg angles for Si and 3-SiC .................................... 257

4.19. Crystallite sizes for Si and SiC calculated by Scherrer's formula for various
polymers pyrolyzed at 1350C in nitrogen at 10C/min with no hold ........... 258

4.20. Results of Electron Microprobe Analysis (EMA) on pyrolyzed ceramic fibers
from PM S polym ers ...................................................... ................... 259

4.21. Conditions for heat treatment for PMS polymers containing PSZ, DCP,
and D B ....... .... .................................................................... .................. 270








4.22. Nomenclature of PMS polymers used in the heat treatment experiments ... 271

4.23. Conditions and results of heat treatment for PMS/PCS polymer blends ...... 282

4.24. Molecular weight distributions for PCS polymers used in the heat treatment
of PM S/PC S blends ........................................................ ................ 283

4.25. Conditions for fractional precipitation of PMS polymers ............................. 290

4.26. Results of EMA analysis on fractionally precipitated 1150C-pyrolyzed
(nitrogen) polym ers .................................................................................... 295

4.27. Conditions for fiber spinning experiments from as-prepared PMS/PCS
polymer blends (non-heat treated) ....................................... ................ 300

4.28. Tensile strengths of SiC fibers spun from as-prepared PMS:PCS polymer
b le nd s ... .. ...................... ..................... ........... ....... ............................... 30 5

4.29. Conditions and qualitative results for fiber spinning experiments from
heat-treated PMS and PMS/PCS polymer blends .................................... 307

4.30. Tensile strengths of SiC fibers spun from heat-treated PMS polymers and
PMS/PCS polymer blends .............................. ........................ 323

4.31. Elemental analysis by EMA for SiC fibers prepared from heat-treated PMS/
PCS polymer blends .................... ............... ..................................... 332

4.32. Conditions and qualitative results of fiber spinning experiments for
fractionally-precipitated PMS polymers...................... ............... 333

4.33. Tensile strengths of SiC fibers spun from fractionally-precipitated PMS
polym ers ...... ................................................... 336

4.34. Elemental analysis by electron microprobe for SiC fibers prepared from
fractionally-precipitated PMS polymers .............................................. 336

4.35. Results of fiber extension experiments for PMS polymers containing PSZ. 341

D-1. Intrinsic viscosity calculations for PCS and PCS+PSZ solutions in toluene 365

D-2. Intrinsic viscosity calculations for PMS polymer in toluene ....................... 368

D-3. Intrinsic viscosity calculations for PMS polymer in toluene-1,4 dioxane
mixture (50:50 by volume) ....... .............. ..................... 369

E-1. Results of surface tension measurements ....................................... 371

F-1. Air-heat treatment temperatures and weight gains for PCS and PCS+PSZ
fi be rs .............................................................. .............................. ........ 3 7 6










G-1. Weight loss data for PCS, PCS+PSZ fibers (air-heat treated and non-air
heat treated) after pyrolysis at 1150C in nitrogen ............................ 378

H-1. Tensile strength data for pyrolyzed PCS fibers (batch 63s) .................... 380

H-2. Tensile strength data for pyrolyzed PCS fibers (batch 64s) ................... 381

H-3. Tensile strength data for pyrolyzed PCS fibers (batch 65s) .................. 384

H-4. Tensile strength data for pyrolyzed PCS fibers (batch 69s) .................. 387

H-5. Tensile strength data for pyrolyzed PCS+PSZ fibers (batch 67s)............. 390

H-6. Tensile strength data for pyrolyzed PCS+PSZ fibers (batch 68s) .......... 394

H-7. Tensile strength data for pyrolyzed PCS+PSZ fibers (batch 70s) .......... 397

L-1. Results of characterization of PMS polymers synthesized from MDCS ...... 415

M-1. Results of characterization of PMS polymers synthesized from MDCS and
M TC S (70:30 w t% ) .......................................................... ................. 417














LIST OF FIGURES


Figure Page

2.1. Schematic showing mechanism of Wurtz coupling polymerization............ 8

2.2. Effect of reactant addition rate on molecular weight distribution of phenyl
m ethylsilane ....................... .................................... .............. ........... 11

2.3. Effect of sodium surface area on the rate of consumption of hexylmethyl-
dichlorosilane ................................ .. ............................................ 13

2.4. UV-Vis Diffuse reflectance spectrum of purple solid isolated during Wurtz
polymerization ....................................... .......................................... 15

2.5. Chemical formulas of polar solvents used in Wurtz polymerization .......... 16

2.6. Schematic illustration of the influence of solvent on the polymer/sodium
particle interaction during Wurtz polymerization ............................... 20

2.7. Rate of disappearance of monomer n-hexylmethyldichlorosilane as a
function of time and weight percent of 15-Crown-5 ether ....................... 22

2.8. GPC of polymethylsilanes synthesized by Mu and Harrod ..................... 32

2.9. Scheme for redistribution/substitution reactions of chlorodisilanes ......... 39

2.10. Structure of methylchloropolysilane polymer .......................................... 40

2.11. IR spectral changes during pyrolysis of a polysilane polymer ................. 45

2.12. Changes in intensities of pendant groups based on IR spectra for polysilane
polymer ... ........................................ ......... .................................... 46

2.13. TGA plots for polymethylsilane polymers, prepared by Zhang et al. .......... 51

2.14. FTIR spectra of PMS polymer, prepared by Zhang et al. ..................... 53

2.15. TGA and DTA plots for a VPS polymer heated in nitrogen at 200C/min to
12000C ...... ............. .... .... .......... .......................... ...................... 55

2.16. IR spectra of VPS polymer:(a) 25C (b) 250C (c) 400C (d) 650C
(e) 1000C ................................................................. .... ...................... 57










2.17. FTIR spectrum of polymethylsilane polymer, prepared by Abu-Eid et al. ... 61

2.18. Scheme for photo cross-linking reactions of polysilane polymers ............ 64

2.19. Comparison of single layer photoresist process vs. multilayer photoresist
process ....... ............................................. 71

3.1. Structure of 1,3,5-trimethyl-1,3,5-trivinylcyclotrisilazane .......................... 72

3.2. Schematic of reaction assembly for PSZ synthesis .................................. 73

3.3. Definition of terms in Young's equation and schematic illustration of the
geometry for determination of the contact angle by the sessile drop
method.................... ............... .............. ... 79

3.4. Schematic of reaction assembly for synthesis of polymethylsilane ............ 87

4.1. Plots of (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
PCS spin dope (solids concentration ~68 wt%) ...................................... 101

4.2. Plots of (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
PCS+PSZ spin dope (solids concentration ~70 wt%) ............................ 102

4.3. Schematic illustration of globule formation during spinning of fibers from
PCS spin dope .............................................. ................. 106

4.4. GPC molecular weight distributions: (A) PCS (B) PSZ ............................. 109

4.5 Plots of Ti,/c vs. c for (A) PCS (B) PCS+PSZ (C) PSZ ............................ 110

4.6. (a) Percentage change in weight of PCS and PCS+PSZ spin dope as a
function of time due to evaporation of toluene, and (b) Absolute weight
change of PCS and PCS+PSZ spin dopes as a function of time due to
evaporation of toluene ......... .. ........ ........... ................. 112

4.7. Advancing and receding contact angles for water on: (A) teflon substrate
(B) stainless steel substrate as a function of cumulative drop volume ...... 115

4.8. Advancing and receding contact angles for toluene on teflon substrate
as a function of cumulative drop volume ................................. ............ 117

4.9. Advancing and receding contact angles for toluene on stainless steel
substrate as a function of cumulative drop volume............................... 118

4.10. Advancing and receding contact angles for PCS (33 wt%)/toluene solution
on stainless steel substrate as a function of cumulative drop volume ...... 119








4.11. Advancing and receding contact angles for PCS+PSZ (33 wt%)/toluene
solution on stainless steel substrate as a function of cumulative drop
volume ...... ............................ .. .................... 120

4.12. Advancing and receding contact angles of PCS (33 wt%)/toluene solution
on teflon substrate as a function of cumulative drop volume .................... 121

4.13. Advancing and receding contact angles of PCS+PSZ (33 wt%)/toluene
solution on teflon substrate as a function of cumulative drop volume ......... 122

4.14. Advancing and receding contact angles for PCS (33 wt%)/toluene solution
on a stainless steel substrate coated with PCS as a function of cumulative
drop volume .................................. ... ............ ................. 124

4.15. Advancing and receding contact angles for PCS+PSZ (33 wt%)/toluene
solution on a stainless steel substrate coated with PCS+PSZ as a function
of cumulative drop volume ... ............................. .............. 125

4.16. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
33 wt% PCS solution used in surface tension measurement ................... 129

4.17. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
50 wt% PCS solution used in surface tension measurement ................... 130

4.18 Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
66 wt% PCS solution used in surface tension measurement ................... 131

4.19. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
33 wt% PCS+PSZ solution used in surface tension measurement ............ 132

4.20. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
50 wt% PCS+PSZ solution used in surface tension measurement ............ 133

4.21. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
66 wt% PCS+PSZ solution used in surface tension measurement ............ 134

4.22. Surface tension as a function of concentration for PCS and PCS+PSZ
so lutio n s ............................. ................................... .................. ..... 13 5

4.23. Surface tension as a function of viscosity for PCS and PCS+PSZ
solutions ...................................................................... ........ 136

4.24. Room temperature FTIR spectra of green PCS fibers ............................. 138

4.25. Room temperature FTIR spectra of polydimethylsilane (PDMS) .............. 140

4.26. FTIR spectra of PCS fibers during heat treatment to 6000C at 1*C/min in
nitrogen atm osphere ...................................................... ................ 144








4.27. Intensity vs. temperature from FTIR spectra for PCS (green) fibers ........ 145

4.28. Subtraction spectra for PCS fibers (69s) heat-treated in nitrogen,
600-40C ...... ............. ............. ............................................ 149

4.29. Comparison of FTIR spectra of PCS fibers before and after heat treatment
at 600C in nitrogen ........................... ....... ................................. 150

4.30. Room temperature FTIR spectra for PCS fibers heat-treated in air at
18 7 .C .................................................... ........................ 152

4.31. Subtraction spectra for PCS fibers heat-treated in air at 187C (65s)
and PCS green fibers (69s) ...... ..................... ..... ............... 154

4.32. Comparison of FTIR spectra of PCS fibers at 40C before and after heat
treatm ent in air ....................... ............................. ............................. 156

4.33. FTIR spectra for air-heat treated (187C) PCS fibers during heat
treatment to 600C at 1 C/min in nitrogen ............................................ 157

4.34. Intensity vs. temperature from FTIR spectra for PCS (air-heat treated
at 187C) fibers during heat treatment in nitrogen to 6000C ................... 158

4.35. FTIR spectra of air-heat treated Nippon PCS fibers during heat treatment
in nitrogen to 500C (from Ichikawa et al.) ........................................ 160

4.36. Comparison of FTIR spectra of air-heat treated (187C) PCS fibers
before and after heat treatment at 6000C in nitrogen ............................ 163

4.37. Subtraction spectra for air-heat treated (187C) PCS fibers heat treated
in nitrogen (600-40 C) .................. ... ........................................ 164

4.38. Room temperature FTIR spectra for PSZ polymer (batch 0831A)............. 165

4.39. FTIR spectra for PSZ polymer during heat treatment to 600C at 1C/min
in nitrogen ...................................... ............ ............................. 167

4.40. Intensity vs. temperature from FTIR spectra of PSZ ............................. 169

4.41. Room temperature FTIR spectra of PCS+PSZ green fibers (batch 70s).. 173

4.42. FTIR spectra of PCS+PSZ green fibers during heat treatment to 600C in
nitrogen ........................................... 175

4.43. Intensity vs. temperature from FTIR spectra of PCS+PSZ fibers ............ 176

4.44. Comparison of FTIR spectra of PCS+PSZ fibers (70s) before and after
heat treatment at 6000C in nitrogen ....................................... .......... 179








4.45. Subtraction spectra for PCS+PSZ fibers (70s), 600-40C ........................ 180

4.46. Subtraction spectra for PCS+PSZ and PCS fibers at 40C ...................... 181

4.47. Subtraction spectra for PCS+PSZ and PCS fibers at 6000C .................... 182

4.48. Room temperature FTIR spectra of PCS+PSZ fibers heat-treated in air at
177 C ............... .... .. ........... ................................. ....... ... ............. 185

4.49. FTIR spectra of air-heat treated PCS+PSZ fibers during heat treatment
to 600C in nitrogen ...................................... ................................... 188

4.50. Intensity vs. temperature from FTIR spectra of air-heat treated PCS+PSZ
fibers ....... ....................... .... ........... .... 189

4.51. Comparison of spectra for air-heat treated PCS+PSZ fibers before and
after heat treatment at 600C in nitrogen ................... ................. 191

4.52. Subtraction spectra for air-heat treated PCS+PSZ fibers, 600-40C ......... 192

4.53. Comparison of spectra for air-heat treated PCS fibers (batch 65s)
and PCS+PSZ fibers (batch 70s) at 400C ...................... ............... 193

4.54. Comparison of spectra for air-heat treated PCS fibers (batch 65s)
and PCS+PSZ fibers (batch 70s) after heat treatment in nitrogen ............ 194

4.55. Average tensile strength for PCS, PCS+PSZ fibers, as-spun and after
heat treatment in (i) nitrogen at 400C (ii) air at 180 10C (iii) air at
180 10C, followed by nitrogen at 400C .................................... 197

4.56. Average rupture strain for PCS, PCS+PSZ fibers, as-spun and after
heat treatment in (i) nitrogen at 400C (ii) air at 180 10C (iii) air at
180 10C, followed by nitrogen at 400C ............................. ......... 198

4.57. Plots of (a) tensile strength vs. heat treatment temperature (b) %
elongation vs. temperature for polyacrylonitrile (PAN) fibers .................. 200

4.58. Schematic of structural changes taking place in PCS during heat
treatment in air at 180 10 C ............................ ..... .............. 202

4.59. Average rupture strain vs. temperature for: (A) PCS (batch 69s) and
(B) PCS+PSZ fibers (batch 70s) ..................................................... 206

4.60. Average rupture strain vs. temperature for fibers heat-treated in air:
(A) PCS (batch 65s/ 187C air heat treatment), and (B) PCS+PSZ (batch
70s/ 177C air heat treatm ent) ................. ................ ................... 207

4.61. Average tensile strength vs. temperature for (A) PCS (batch 69s), and
(B) PCS+PSZ fibers (batch 70s) ...................................................... 208








4.62. Distribution of tensile strengths for fibers after pyrolysis at 1150C in
nitrogen (A) PCS (B) PCS+PSZ ................ .......................................... 212

4.63. Distribution of diameters for fibers after pyrolysis at 1150C in nitrogen
(A) PCS (B) PCS+PSZ ...................................... .............. 213

4.64. Average tensile strength vs. temperature for fibers heat-treated in air:
(A) PCS (batch 65s/ 187C air heat treatment), and (B) PCS+PSZ (batch
70s/ 177C air heat treatm ent) ................................ .... ............... 214

4.65. Schematic for Wurtz polymerization of (a) MDCS (b) MDCS and MTCS
(70:30 wt%) .. ................. ........................... 217

4.66. (a) Gel permeation chromatograms for polymers prepared from MDCS
(A) toluene (B) Toluene:THF (95:5 vol%) (C) Toluene, dioxane (50:50 vol%)
(b) Gel permeation chromatograms for polymers prepared from
MDCS:MTCS(70:30 wt%) (A) toluene (B) Toluene:THF (95:5 vol%)
(C) Toluene, dioxane (50:50 vol% ) .................................................. 221

4.67. Effect of cosolvents on molecular weight of PMS polymers A,B, and C
(prepared using 100% MDCS) ....................... ......... .............. 223

4.68. Effect of cosolvents on molecular weight of PMS polymers D,E, and F
(prepared using MDCS/MTCS (70/30 wt%)) ........................ .............. 224

4.69. Plot of ns,/c vs. C for polymer F (batch PMS-256) (MDCS/MTCS (70/30
wt%); toluene/1,4-dioxane (50/50)) in toluene .......... ....... ............... 226

4.70. Plot of ri,/c vs. C for polymer F (batch PMS-256) (MDCS/MTCS (70/30
wt%); toluene/1,4-dioxane (50/50)) in a mixture of toluene and 1,4-dioxane
(50:50 vol% ) ...................................... ........................... .. 227

4.71. Schematic illustration for solvent effects in polymerization of MDCS (a) in
toluene (b) in a 50:50 mixture of toluene:1,4-dioxane .............................. 228

4.72. Effect of cosolvents on yield for PMS polymers D,E, and F (prepared
from MDCS/MTCS (70/30 wt% )) .................................. ................ 230

4.73. Effect of cosolvents on yield for PMS polymers A,B, and C (prepared
from 100% MDCS) .......................... ... .......... ..... ............... .. 232

4.74. TGA plots (% weight vs. temperature) for polymers prepared with 100%
MDCS ............ .... ............... .... .. .............................. 234

4.75. TGA plots (% weight vs. temperature) for polymers prepared with 70:30
wt% MDCS:MTCS ................... .................... ..................... 235

4.76. Room temperature FTIR spectra of PMS polymer C (batch PMS-263)
(prepared from 100% MDCS in toluene/dioxane solvent) ..................... 237








4.77. Room temperature FTIR spectra of PMS polymer F (batch PMS-256)
(prepared from 70:30 wt% MDCS:MTCS in toluene/dioxane solvent)...... 238

4.78. FTIR spectra of PMS polymer C (100% MDCS; toluene, dioxane (50:50
vol%)), 40 to 600C at 5C/min in nitrogen ............... ....... ............... 242

4.79. Intensity vs. temperature from FTIR spectra for PMS polymer C ............. 244

4.80. FTIR spectra of PMS polymer C, 750 to 1150C at 50C/min in nitrogen .... 247

4.81. FTIR spectra of PMS polymer F (MDCS, MTCS (70:30 wt%)), toluene,
dioxane (50:50 vol%)), 40 to 600C at 50C/min in nitrogen .................. 248

4.82. Intensity vs. temperature from FTIR spectra for PMS polymer F ............. 250

4.83. FTIR spectra of PMS polymer F, 750 to 1150C at 50C/min in nitrogen ... 253

4.84. XRD patterns for PMS polymers prepared from monomer MDCS: (A) 100%
toluene, (B) toluene:THF (95:5 Vol%), and (C) toluene:dioxane (50:50
vol%) .......................... ...... ............... .................. 254

4.85. XRD patterns for PMS polymers prepared from monomers MDCS:MTCS
(70:30 wt%): (A) 100% toluene, (B) toluene:THF (95:5 Vol%), and (C)
toluene:dioxane (50:50 vol% ) ................................. .............. 255

4.86. FTIR spectra of PMS polymer C (100% MDCS; toluene/dioxane
(50:50 vol%)) exposed to air, shown as a function of time ................... 261

4.87. Intensity vs. time of exposure to air from FTIR spectra for PMS polymer C. 262

4.88. Gel permeation chromatograms for PMS-231 polymer: (A) after 3 days
of storage, (B) after 260 days of storage, and (C) after heat treatment
(PMS-231-H) ........... ............ .......... ........... 273

4.89. Polydispersity index vs. molecular weight for PMS polymers containing
5-14.5 wt% PSZ (and 0.5-1.5 wt% DCP) as additives ........................... 274

4.90. GPC molecular weight distributions for: (A) PMS-214-A (B) PMS-214-A-H 275

4.91. GPC molecular weight distributions for: (A) PMS-216-A (B) PMS-216-A-H...277

4.92. GPC molecular weight distribution for PMS-216-A2-H ............................ 278

4.93. GPC molecular weight distributions for: (A) PMS-219-A (B) PMS-219-A-H.. 280

4.94. GPC molecular weight distributions for: (A) PMS-223-AD2-A
(B) PM S-223-AD2-H ........................................... ........................... 281

4.95. GPC molecular weight distribution for PMS-216-AP-H ............................ 285








4.96. GPC molecular weight distribution for PMS-217-AP-H .............................. 285

4.97. GPC molecular weight distribution for PMS-217-AP2-H ............................ 286

4.98. GPC molecular weight distribution for PMS-218-AP-H ............................ 286

4.99. GPC molecular weight distribution for PMS-220-AP2-H .......................... 288

4.100. GPC molecular weight distribution for PMS-221-AP2-H ....................... 288

4.101. GPC molecular weight distribution for PMS-240 polymer (A) before and
(B) after fractional precipitation with alcohol mixture................................. 293

4.102. Plot of non-solvent to polymer ratio vs. final Mw for polymers precipitated
using acetone as non-solvent ................................... 296

4.103. GPC molecular weight distribution for PMS-250 polymer (A) before and
(B) after fractional precipitation with acetone ........................................ 298

4.104. SEM micrographs of as-spun fibers (batch 24s) prepared from PMS/PCS
blends (non-heat treated) showing necking....................... ........ ........ 303

4.105. SEM micrographs of pyrolyzed fibers (batch 26s) prepared from
PMS/PCS blends (non-heat treated) showing necking ............................ 304

4.106 Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
U F-33s spin dope ......................................................... ....................... 3 11

4.107. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-35s spin dope ............ ..................................................... 312

4.108. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-36s spin dope ......................................... ................. 313

4.109. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-45s spin dope ........................... .. ............................ 316

4.110. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-42s spin dope ....................... .............................. 318

4.111. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-56s spin dope ................................................................ ................. 319

4.112. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-54s spin dope ................................. ................. 321

4.113. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-52s spin dope .......................................................... 322


xviii








4.114. SEM micrographs of pyrolyzed fibers (batch 42s) prepared from
heat-treated PMS/PCS polymer blends showing necking between fibers ... 324

4.115. SEM micrographs of UF-35s fibers after heat treatment at 1700*C in argon:
(A) and (B) surfaces, (C) fiber cross section ....................... .................. 326

4.116. SEM micrographs of fracture surfaces of UF-35s fibers after heat treatment
at 1700 C in argon ........................ ........................... ............................ 328

4.117. GPC molecular weight distribution for PMS-242 polymer: (A) before and
(B) after fractional precipitation .......... ........................... 342

4.118. Average extension for fibers drawn from PMS-based polymers as a
function of amount of PSZ 0908A added .......................................... 344

A-1. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
64s spin dope (PCS) (solids concentration -67 wt%) ............................... 351

A-2. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
65s spin dope (PCS) (solids concentration ~66 wt%) ............................... 352

A-3. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
69s spin dope (PCS) (solids concentration -66 wt%) ............................... 353

A-4. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
67s spin dope (PCS+PSZ) (solids concentration -69 wt%) ...................... 354

A-5. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
68s spin dope (PCS+PSZ) (solids concentration -70 wt%) ...................... 355

C-1. Fiber extension distances for PCS spin dope ....................................... 362

C-2. Fiber extension distances for PCS+PSZ spin dope ................................. 363

I-1. GPC molecular weight distributions for PMS-241 (A) before and (B) after
fractional precipitation with alcohols .................... ................. ... ............ 400

1-2. GPC molecular weight distributions for PMS-243 (A) before and (B) after
fractional precipitation with alcohols .................................... ................. 401

J-1. GPC molecular weight distributions for PMS-245 (A) before (B) and (C)
after two fractional precipitations with acetone ........................................ 403

J-2. GPC molecular weight distributions for PMS-246 (A) before and (B) after
fractional precipitation with acetone ........................................................ 404

J-3. GPC molecular weight distributions for PMS-247 (A) before and (B) after
fractional precipitation with acetone .................................... .................. 405








J-4. GPC molecular weight distributions for PMS-248 (A) before and (B) after
fractional precipitation with acetone ..................................................... 406

J-5. GPC molecular weight distributions for PMS-249 (A) before and (B) after
fractional precipitation w ith acetone .......................................................... 407

J-6. GPC molecular weight distributions for PMS-251 (A) before and (B) after
fractional precipitation with acetone ..................................................... 408

J-7. GPC molecular weight distributions for PMS-252 (A) before and (B) after
fractional precipitation with acetone ..................................................... 409

J-8. GPC molecular weight distributions for PMS-253 (A) before and (B) after
fractional precipitation with acetone .................................... 410

J-9. GPC molecular weight distributions for PMS-254 (A) before and (B) after
fractional precipitation w ith acetone ......................................................... 411














Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy


PREPARATION OF SIC-BASED FIBERS FROM ORGANOSILICON POLYMERS:
(I) EFFECTS OF POLYVINYLSILAZANE ON THE CHARACTERISTICS AND
PROCESSING BEHAVIOR OF POLYCARBOSILANE-BASED SOLUTIONS AND
(II) SYNTHESIS, CHARACTERIZATION, AND PROCESSING OF
POLYMETHYLSILANES

By

Mohamed Saleem

August 1998

Chairman: Dr. Michael D. Sacks
Major Department: Materials Science and Engineering

The effect of the addition of polyvinylsilazane (PSZ) on the characteristics (i.e.,

spinnability, theological behavior, wetting behavior, evaporation behavior, etc.) of

polycarbosilane (PCS) solutions was investigated. Spinnability of PCS solution was

characterized by number of breaks occurring during spinning and amount of fibers

formed after spinning. PCS and PCS+PSZ solutions were characterized by measuring

surface tension, contact angles and rate of solvent evaporation. Effect of PSZ on

mechanical properties of SiC fibers prepared from PCS and PCS+PSZ solutions was

also investigated. Chemical changes taking place in PCS and PCS+PSZ fibers during

heat treatment from 40-600C in nitrogen were studied by Fourier transform infrared

spectroscopy (FTIR).

Addition of PSZ to PCS greatly improved spinnability of PCS solutions.

Significant differences in wetting characteristics were observed for PCS solutions and








PCS+PSZ solutions deposited on stainless steel and teflon substrates, as well as on

PCS-coated and PCS+PSZ-coated stainless steel substrates. The rate of evaporation of

solvent was higher for PCS solution than for PCS+PSZ solution at identical polymer

concentrations. As-spun PCS and PCS+PSZ fibers developed similar tensile strengths

and rupture strains. After heat treatment at 400C in nitrogen, PCS+PSZ fibers showed

higher tensile strength and rupture strain compared to PCS fibers. Based on FTIR

spectra of PCS and PCS+PSZ fibers during heat treatment from 40-600C, it is

suggested that PSZ acts as a cross-linking aid for PCS. PCS+PSZ fibers developed

higher tensile strengths than PCS fibers at all heat treatment temperatures between

200-1150C.

SiC fibers were fabricated from polymethylsilane (PMS) and PMS/PCS polymer

blends. PMS polymers were synthesized by a Wurtz-coupling polymerization of

methyldichlorosilane (MDCS) and methyltrichlorosilane (MTCS) in 70:30 wt% proportion

with sodium in refluxing toluene. The addition of polar solvents (i.e., THF and 1,4-

dioxane) to toluene improved yields and increased the molecular weight of PMS

polymers. As-prepared PMS polymers with additives were heat-treated to increase

molecular weight to permit fiber spinning. As-prepared PMS polymers were also

fractionally-precipitated to isolate higher molecular weight fractions suitable for fiber

spinning. The heat treatment approach was ineffective in obtaining molecular weight

increases reproducibly. Fractionally- precipitated PMS polymers were useful in

preparation of high strength pyrolyzed SiC fibers. These fibers, however, exhibited poor

thermal stability at high temperatures. More investigations will be needed to address this

problem.














CHAPTER 1
INTRODUCTION



There has been much interest in the preparation of ceramic materials from

organosilicon-based preceramic polymers. Polycarbosilane (PCS) polymers, in

particular, have been shown to be useful for producing SiC-based ceramic materials,

particularly fibers. Continuous SiC fibers with fine diameter and high strength are of

considerable interest for the development of ceramic-matrix composites for high

temperature applications. Commercially available fibers (e.g., NicalonTM, Nippon Carbon

Company, Tokyo, Japan and TyrannoTM, Ube Industries, Tokyo, Japan) are not pure

stoichiometric SiC, i.e., the fibers contain relatively high concentrations of excess carbon

and oxygen. (In addition, TyrannoTM fibers are actually Si-Ti-C-O fibers.) As a

consequence, these fibers degrade extensively at high temperatures. This degradation

is associated with the presence of oxygen (-8-15 wt%) and excess carbon (-15 wt%) in

the fibers. At high temperatures, carbothermal reduction reactions occur between

carbon and siliceous material in the fibers, leading to large weight losses and

degradation in mechanical properties. The fibers contain excess carbon as a result of

the high C:Si ratios in the starting materials. (PCS has a high C:Si ratio, as it is formed

by pressure pyrolysis of polydimethylsilane (PDMS) which has a C:Si ratio of -2. (PDMS

is produced from dimethyldichlorosilane, (CH3)2SiCI2, which, in turn, also has a C:Si

ratio of 2.) The high C:Si ratio in the preceramic polymer, PCS, leads to excess C in the

SiC-based fibers after pyrolysis.) The oxygen in SiC-based fibers, such as NicalonTM and








Tyranno", is a result of an oxidative curing step that is used to render the fibers

infusible during pyrolytic conversion to SiC.

There has been considerable interest in recent years in producing SiC-based

fibers with improved thermomechanical properties. Much of the effort in this area has

been directed toward fabrication of fine-diameter, high-strength, polymer-derived fibers

which have low oxygen content [Lip91A; Lip91B; Lip94A; Lip94B; Lip95; Tak94; Tak95;

Tor92A; Tor92B; Tor94]. The development of such fibers with both carbon-rich and

near-stoichiometric compositions have been reported by several research groups,

including those at Nippon Carbon Co. (Hi-NicalonTM and Hi-NicalonTM Type S fibers

[Tak94; Tak95], Dow Corning Co. (SylramicTM fibers) [Lip95], and the University of

Florida (UF and UF-HM fibers) [Tor94; Sac95A; Sac95B]. All of these fibers show

improved thermochemical stability and thermomechanical properties compared to fibers

which contain large amounts of oxygen, such as NicalonTM and TyrannoTM fibers.

The approach developed at the University of Florida is based on using a high-

molecular-weight PCS polymer which is infusible. Hence, an oxidative curing step is

unnecessary during pyrolysis. In producing SiC-based fibers from the high-molecular-

weight PCS polymers, Toreki et al. [Tor90] reported that the addition of a

polyvinylsilazane (PSZ) polymer to a PCS-based spinning solution (in amounts up to

14.5 wt%) improved fiber spinnability and produced fibers with improved mechanical

properties. The reasons for these improvements were not investigated.

There are two major areas of investigation described in this dissertation. The first

area of investigation concerned the effects of PSZ on both spinnability and mechanical

properties of the SiC-based fibers prepared using the University of Florida method.

Fibers were spun from PCS solutions by dry spinning with and without PSZ. Mechanical

properties of these fibers were evaluated after heat treatment at various temperatures








up to 1150C. Fourier transform infrared spectroscopy (FTIR) was used to study the

chemical changes occurring in these fibers during pyrolysis. In an effort to understand

the effect of PSZ on spinnability of PCS solutions, polymer solutions were characterized

using several methods, including measurements of surface tension, contact angles,

theological characteristics (e.g., intrinsic viscosity), and the rate of evaporation of

solvent from the solutions.

The second major area of investigation was the synthesis and processing of

PMS (polymethylsilane) polymers for the fabrication of SiC-based fibers. There has

been limited work on the preparation of SiC fibers from organosilicon polymer blends.

SiC fibers may be fabricated by using PMS polymers and PMS/PCS polymer blends.

PMS polymers generally produce an excess of elemental Si (in addition to SiC) upon

pyrolysis. As indicated earlier, PCS polymers form an excess of elemental C upon

pyrolysis. Therefore, a combination of these two polymers might potentially be used to

form SiC fibers with controlled stoichiometry.

PMS polymers were synthesized in this study by Wurtz-coupling polymerization

of methyldichlorosilanes (MDCS) and methyltrichlorosilanes (MTCS) with sodium (Na) in

refluxing solvent/solvent mixtures. One of the major disadvantage of this method is poor

polymer yields. Polymer yields and molecular weight distributions are quite sensitive to

substituents (pendant groups) in the monomers, order of reagent addition, solvent

additives, reaction temperatures, etc. It has been reported that addition of polar solvents

promote anionic polymerization (such as Wurtz-coupling polymerization) and increase

polymer yields [Mil93; Gau89]. In this study, effects of addition of polar solvents THF

and 1,4-Dioxane on polymer yield and molecular weight were investigated.

One of the main drawbacks of PMS polymers for use in fiber fabrication is that

they are liquids at room temperature and generally have low molecular weight (M, <








1,000 and M_ < 2,500). In order to form fibers from these polymers, an increased

molecular weight and an increased extent of cross-linking are needed so that the

polymers are solids at room temperature (and remain solids during pyrolysis).

Investigations were carried out to increase the molecular weight/cross-linking of these

polymers as well as produce a solid polymer with sufficiently high molecular weight to

permit fiber spinning. Two approaches were utilized to raise the molecular weight/cross-

linking of the polymer: (1) polymerization and cross-linking by heat treatment with

additives and (2) fractional precipitation of higher molecular weight fractions by addition

of nonsolvents. The additives used consisted of polyvinylsilazane (PSZ), dicumyl

peroxide (DCP), and decaborane (DB). The nonsolvents used were a mixture of

methanol and 2-propanol, and acetone. Fibers were spun from heat-treated PMS,

PMS/PCS polymer blends, and fractionally-precipitated PMS polymers, and converted to

SiC fibers by pyrolysis at 1000-1150C in a nitrogen atmosphere.













CHAPTER 2
LITERATURE REVIEW




2.1 Background

There has been much interest in recent years in the preparation of ceramic

materials by pyrolysis of organometallic polymers. A wide range of ceramic materials

can be produced by this method, such as SiC, Si3N4, B4C, BN, SiO2, A1203 and AIN. In

this review, only silicon-based preceramic polymers, viz., polysilanes are discussed.

Polysilanes are a class of polymers with Si-Si backbone in their main chain. The interest

in polysilanes stems from a number of commercially attractive applications such as

precursors to p-SiC fibers, photoresists in multilayer microlithography and photoinitiators

in radical polymerization. Despite the commercial significance of these polymers,

polysilane technology suffers from the lack of well-controlled and reproducible methods

for synthesis of polysilanes with high yields, high molecular weight, and narrow

polydispersity.

A number of factors need to be considered when selecting a polysilane polymer

for a specific application: (1) nature of the ceramic material (chemical composition and

crystal structure) produced after further processing (e.g., heat treatment), (2) elemental

composition of the starting polymer (which influences the final stoichiometry of the

ceramic produced), (3) molecular architecture of the polymer (linear vs. cross-linked

polymer, which strongly influences the ceramic yield), (4) sensitivity to air (i.e., oxygen

and water vapor) of the polymer, (5) starting molecular weight, (6) capacity of the








polymer to be cross-linked at some stage in processing, and (7) solubility in common

organic solvents. As indicated in (1) above, pyrolysis conditions (temperature,

atmosphere, and heating rate) play a very important role in determining the

characteristics (yield, elemental composition, and crystal structure) of the ceramic

produced. The ceramic yield (i.e., weight percentage retained after polymer-to-ceramic

conversion) is an important consideration when discussing the suitability of a polysilane

polymer as a precursor for silicon carbide. As indicated in (3) above, molecular

architecture also has great impact on the ceramic yield of the polymer synthesized.

Cross-linked or branched polymers give much higher ceramic yield than their linear

counterparts. However, excessive cross-linking is generally not desirable, as it would

make the processing of the polymer difficult (i.e., the polymer will be less likely to melt or

to be soluble in common solvents). It is sometimes desirable that the final composition

of the ceramic produced be that of near-stoichiometric silicon carbide. A convenient

method of achieving this is to start with a polymer which has a 1:1 Si:C ratio, such as

polymethylsilanes. This can be contrasted to polyphenylsilanes, for example, which

have Si:C ratios of 1:6, and, therefore, result in SiC/C mixtures upon pyrolysis.

Polysilane polymers were first synthesized by Kipping [Kip21] in the early 1920's

by condensation reaction of diphenyldichlorosilane with sodium. This polymer was not

useful in practical applications since it was intractable (i.e., not processable into useful

articles because of poor solubility and infusibility). Subsequently, in 1949, Burkhard

[Bur49] reacted dimethyldichlorosilane with sodium to produce poly(dimethylsilane),

which also was insoluble in common organic solvents and infusible. In 1975, Yajima and

coworkers [Yaj75; Yaj78A; Yaj78B] were able to convert poly(dimethylsilane) to a

tractable form of polycarbosilane (PCS) by pressure pyrolysis in an autoclave at 450*C.

The polycarbosilanes were then melt spun into fibers which were subsequently heat








treated to form SiC-based ceramic fibers. The conversion process of polydimethylsilane

to polycarbosilane takes place by Kumada rearrangement reactions and is described in

detail elsewhere [Shi58].



2.2 Polysilane Synthesis

The prominent methods of synthesis of polysilanes are:

(i) Wurtz-coupling (dehalocoupling) reactions of chlorosilanes with alkali metals.

(ii) Dehydrocoupling of primary organosilanes in the presence of a catalyst.

(iii) Redistribution/substitution reactions of chlorosilanes.



2.2.1 Wurtz-coupling of dichlorosilanes with alkali metal

2.2.1.1 Mechanism

Wurtz-coupling of dichlorosilanes with an alkali metal is a strongly exothermic

and heterogeneous reaction. The reaction can be represented as follows:



R1 R2 SiCI2 + 2Na solvent. Reflux (R1 R2 Si)n + 2NaCI (2.1)

where R1, R2 can be H, CH3, CHs5, C6H13, etc.



The detailed reaction chemistry is shown in Figure 2.1 fBen91]. Although many

polymers are produced by this route, it suffers from the disadvantages of poor

reproducibility, polymodal molecular weight distributions, and low polymer yields. Poor

reproducibility arises because it is difficult to control the exothermic and heterogeneous

reaction (i.e., the reaction is heterogeneous in that it involves liquid and solid reagents

[Zei86A]). In addition, some reaction variables, such as the purity of the chlorosilanes,

and the state of dispersion of sodium, are difficult to control [Mar92].













Initiation


Cl-Si-CI
12
R


+ 2Na -0


Cl-Si Na+
I-,


Propagation


R1

-Si-Na+ +
12
R


R1 R1 R1
1 1 1
I I I
CI-Si-CI -- Si-Si-CI
12 12 12
R RR


(Rate determining)


1 1
RR
I I
- Si- Si- CI
1 2 1 2
122
RR


+ 2Na -


1 1
R R

- Si- Si Na+
I 2R
R R


(Fast)


Figure 2.1. Reaction scheme for Wurtz-coupling polymerization reaction


+ NaCI


(2.2)


+ NaCI


(2.3)


+ NaCI


(2.4)








Polymer yields and molecular weight distributions are quite sensitive to

substituents (pendant groups) in the monomers, order of reagent addition, solvent

composition, reaction temperatures, etc. The reaction is usually carried out at

elevated temperatures (~1000C) using a suitable alkali metal dispersion. Sodium,

potassium or lithium could be chosen as alkali metals but sodium is usually preferred

because potassium and lithium are relatively more flammable and hazardous. In the

Wurtz-coupling reaction, sodium is normally employed as a dispersion in an appropriate

solvent such as toluene, xylene, THF, etc. As discussed in section 2.2.1.4, the choice of

solvents plays an important role in determining the polymer molecular weight

distribution and polymer yields.

Equation (2.1) is indicative of the fact the polymerization reaction proceeds by

condensation type mechanism. However, Worsfold [Wor88] and Miller et al. [Mil91]

reported, based on the characteristics of the polymers produced during the reaction, that

it proceeds by an addition type mechanism. In an addition type polymerization reaction,

high molecular weight polymer fractions form very early in the reaction and the formation

of high molecular weight polymer is not affected by the stoichiometry of the reagents

(i.e., high molecular weight polymer forms even when one of the reagents is in excess).

Worsfold demonstrated these characteristics for Wurtz-coupling polymerization of

hexylmethyldichlorosilane (carried out in the "normal mode" (see section 2.2.1.2) in

which monomers are added to molten sodium) by isolating high molecular weight

polymer (-105) in the early stages of reaction. The rate determining step in Wurtz-

coupling polymerization is the reaction between silyl radical and monomer, as shown by

equation (2.3) in Figure 2.1. The reaction between chlorine-ended chain and sodium

takes place rapidly (equation (2.4) in Figure 2.1). Weyenberg [Wey69] et al. have








demonstrated by gas chromatography that molecules containing sequences of Si atoms

react faster than molecules containing single atoms.

2.2.1.2 Mode of addition of reagents

At the beginning of the reaction, molten sodium (melting point of sodium =

98.5C) can be added to dichlorosilanes dissolved in a suitable solvent at the reflux

temperature of the solvent ('inverse' mode of addition) or dichlorosilanes dissolved in a

small amount of solvent could be added to the molten sodium dispersed in the inert

solvent ('normal' mode of addition). The inverse mode of addition usually leads to higher

molecular weight polymers with lower polymer yields compared to the normal mode of

addition. The former method is also more hazardous (i.e., due to handling of sodium)

and difficult to control.

Zeigler [Zei86A; Zei87] investigated the effect of rate of monomer addition (in the

normal mode) and sodium addition (in the inverse mode) on the polymodality of the

molecular weight distribution in the synthesis of polymethylphenylsilane. Zeigler

concluded that the rate of reagent addition (monomer or sodium) and the mode of

addition had an important role in determining the molecular weight distribution because

of its influence in controlling the rate of diffusion of reactive species to and from the

sodium surface. When the rates of addition of Na or monomer were kept constant (for a

range of addition rates 80-640 meq/min (i.e., moles equivalent per min)), the molecular

weight distributions were nearly monomodal and the average molecular weights

remained approximately constant at 600,000 for inverse mode of addition and 4000 for

normal mode of addition. However, when the addition rate was varied, there was a

tendency to form a bimodal molecular weight distribution. Figure 2.2 shows the effect of

the rate of Na addition (inverse mode) on the (PhMeSi)n molecular weight distribution.




































106105 104 103102
MW


Effect of reactant addition rate on (PhMeSi)n molecular weight
distribution [Zei86].


Figure 2.2.









(Zeigler et al. did not provide plots of the molecular weight distributions obtained by

using different monomer addition rates (normal mode)).

2.2.1.3 Effect of alkali metal

As indicated earlier, sodium, potassium or lithium could be chosen as the alkali

metal for the polymerization reaction. Based on ease of handling (for example, sodium

is available as 3-5 mm pellets where as potassium and lithium are available as blocks of

materials and need to be cut into smaller sizes for accurately weighing) and flammability

considerations, sodium is normally preferred over the other two. Alternatively, alloys of

sodium and potassium of varying composition could be used but these alloys often

cause degradation of polymer molecular weight and form cyclic oligomers at elevated

temperatures (~1000C) (Na/K alloy promotes hydrogen abstraction from solvent and

causes chain transfer) [Mil93].

The polymerization reactions take place very close to the alkali metal surface

and, hence, the surface area of the alkali metal plays a very important role in

determining the molecular weight distribution of the polymer formed. Worsfold [Wor88]

studied the effect of sodium surface area on the molecular weight of polymers formed

during the polymerization of hexylymethyldichlorosilane and found that rate of

consumption of monomers increased as the sodium surface area increased (Figure 2.3)

(The monomer consumption was monitored by removing small amounts of the reaction

contents periodically during the course of reaction and analyzing the samples by gas

chromatography (GC).) Therefore, to obtain good polymer yield in a reasonable time, it

is important to use a fine dispersion of sodium in the reaction solvent.

The plots in Figure 2.3 show a sigmoidal behavior. The incubation period is

interpreted as the time during which initiation occurs, i.e., according to equation (2.2) in






13










1.0



S0.8-

ro

0.6-
.-


0
E



S0.64
0
o





E 0.2




0 10 20 30 40
Time, min







Figure 2.3. Effect of sodium surface area on the rate of consumption of
hexylmethyldichlorosilane [Wor88]; A: 0.20 m2, 0 : 0.67 m2, o: 4.64 m2
per mole of dichlorosilane








Figure 2.1. It might be expected, based on equation (2.2), that the rate of initiation would

be dependent upon the available sodium surface area. The results in Figure 2.3 are

consistent with this interpretation in that the incubation period decreases with increasing

sodium surface area.

The Wurtz polymerization reaction is strongly exothermic and the initially clear

reaction mixture changes to purple or dark blue color quickly. Miller et al. [Mi191]

attributed this blue color to 'defects' in sodium chloride, i.e., color centers produced by

incorporation of sodium ions in the interstitials of precipitating sodium chloride. Benfield

et al. [Ben91] suggested, based on spectroscopic studies, that the blue color is due to

colloidal Na particles (submicron) formed during the reaction. They collected diffuse

reflectance ultraviolet-visible (UV Vis) spectra of the products formed during the reaction

and found that there were two absorption bands for polysilanes, a sharper band below

400 nm and a broader band centered around 560 nm (Figure 2.4). Comparing this

spectra with published results of sodium colloids and defect centers of sodium chloride,

the authors concluded that the absorptions in the UV-Vis spectra were due to colloidal

sodium formed during the reaction.

2.2.1.4 Solvent effects

The influence of types of solvents on Wurtz-coupling reactions of dichlorosilanes

with sodium was first noted by Miller et al.[Mil93] in the preparation of

polycyclohexylmethylsilane (normal mode). They reported that when diglyme

(diethyleneglycol dimethylether, see Figure 2.5) was added to the reaction mixture of

sodium and monomers, overall polymer yield and molecular weight distribution are

affected (see Table 2.1). When diglyme was added in low concentrations (-10 vol%) in

the polymerization of cyclohexylmethylsilane, there was a significant increase in polymer































30 ';5 s O 700 900
Wavelength (nm)




Figure 2.4. UV-Vis Diffuse Reflectance spectrum of purple solid isolated during Wurtz
polymerization [Ben91].










/o
0 0



15-Crown-5 Ether (CH2)1005
(1,4,7,10,13-Pentaoxacyclopentadecane)


/o\


H2C


H2C

0


CH2

CH2


1,4-Dioxane


H2C CH2

H2 rorn H2



Tetrahydrofuran (THF)


(CH30CH2CH2)20
Diethyleneglycol dimethylether (Diglyme)


Figure 2.5. Chemical formulas of polar solvents used in Wurtz-coupling polymerization








Table 2.1: Effect of diglyme and heptane
dichlorosilane monomers [Mil91].


additions on polymerization of some


Polymer toluene:diglyme Yield, % Mw x103 R
(vol%)
(c-HexSiMe)n 100:0 20 804, 4.5 b 8.7

(c-HexSiMe)n 90:10 35 1477, 24.8 b 0.12

(c-HexSiMe)n 75:25 32 23.1 a

(c-HexSiMe)n 25:75 33 16.5a ...

(n-dodecylSiMe), 100:0 8 1345, 8.4 b 2.73

(n-dodecylSiMe), 70:30 33 476, 40.7 b 0.74

(n-Hex2Si), 100:0 5.9 1982, 1.2 b 3.12

(n-Hex2Si), 95:5 34 1008, 22.3 b 3.4

(n-Hex2Si), 90:10 36 1358, 26.6 b 2.6

(n-HexSi)n 70:30 37 1073, 31.7 b 1.42

(n-dodecyl2Si)n 100:0 3 521, 14.1 b 5.2

(n-dodecylSi), 70:30 34 570, 27.4 b 2.3

(PhMeSi)n 100:0 25 383, 16 b.

Polymer toluene:heptane Yield, % M, x10-3 R
(vol%)
(n-Hex2Si), 84:16 27 1386, 1.1 b

(PhMeSi), 85:15 9 1390, 10.5 b ...


" monomodal; b bimodal; c ratio of amounts of high molecular weight to low molecular weight fractions









yield and average molecular weight. At higher concentration of diglyme (-25 vol%),

polymer molecular weight distribution became monomodal and overall molecular weight

of the polymer decreased drastically. The polymer yield remained relatively high (32%).

The effect on polymer yield of diglyme additions was particularly significant in the case

of polysilane polymers derived from symmetric dialkylsilane monomers (e.g., dicholoro-

di-n-hexylsilane, dichloro-di-n-dodecylsilane) (see Table 2.1). In the case of poly(di-n-

hexylsilane), a typical dialkyldichlorosilane derived polymer, the yield of the polymer was

only 5.9% when synthesized in toluene alone as a solvent The polymer yield increased

approximately six fold (~34-37%) when diglyme was added in amounts of 5, 10, and

30% by volume of toluene. The addition of diglyme also resulted in lower average

molecular weight of the polymer. In the case of dichloro-di-n-dodecylsilane, the addition

of 30% diglyme resulted in large increase in the polymer yield (from 3 to 34%), while the

average molecular weight increased slightly for each mode in the distribution. Also, the

high molecular weight proportion of the polymer decreased significantly.

Table 2.1 also shows the effect of addition of a non-polar solvent (i.e., heptane)

on polymerization of diakyldichlorosilane monomers (dicholoro-di-n-hexylsilane) and

arylakyldichlorosilane monomers (phenylmethyldichlorosilane). Addition of heptane

caused an increase in polymer yield for the case of polymerization of dicholoro-di-n-

hexylsilane and a decrease in polymer yield for the case of polymerization of

phenylmethyldichlorosilane. The heptane addition resulted in lower average molecular

weight in the former case and higher average molecular weight in the latter case. Miller

et al. explain that polymerization of arylalkyldichlorosilanes is highly exothermic and

takes place rapidly because arylalkyldichlorosilanes are not sterically hindered unlike

dialkyldichlorosilanes. Solvent effects on polymerization of arylalkyldichlorosilanes are








not well understood because of the difficulty in obtaining controlled kinetic data (due to

the rapid polymerization rates).

Miller et al. attempted to explain the observation of increased polymer yield for

dialkyldichlorosilanes in the presence of polar cosolvents such as diglyme, crown ethers

etc., by suggesting the presence of silyl anion radical intermediates (such as shown in

equation (2.2) in Figure 2.1) as the main propagating species in the polymerization. It is

well known that polar solvents aid in the transfer of electrons from metal to monomer,

promoting formation of silyl anion radicals [Gau90; Mi193; Bil83]. A large number of

radicals formed would mean a large number of initiation sites and this would favor an

increased polymer yield. However, Miller et al. [Mil91] reported the same beneficial

effect (i.e., improved yield) when 16 vol% of non-polar solvent (i.e., heptane) was added

to toluene in the polymerization of dialkyldichlorosilane (such as dichloro-di-n-

hexylsilane).

Zeigler et al. [Zei87] have developed a model concerning the bulk solvent effects

in the polymerization of dialkyldichlorosilanes when monomer is present in excess

compared to sodium (inverse mode of addition). According to their model, yield and

molecular weight are determined by effective monomer concentration at the sodium

surface. This depends on the rate of diffusion of monomer to the sodium surface, which,

in turn, depends on degree of coverage of the sodium by growing polymer chains (see

Figure 2.6). In a "good" solvent (i.e., in which the difference in polymer and solvent

solubility parameters, A6 = 8p-s,, approaches zero), polymer-solvent contacts are highly

favored and the polymer coils are relatively extended in the solvent. Thus, polymers

tend to remain in the solvent phase and tend not to adsorb on the sodium particle

surfaces. The monomer continues to have easy access to sodium surface and






















"GOOD SOLVENT"





(R1R2S 2 ]


(I- Spl I SMALL)


"POOR SOLVENT"



Op

C(RR2SCW2 18


(ISs- SpI LARGE)


Figure 2.6. Schematic illustration of the influence of solvent on the polymer/sodium
particle interaction during Wurtz polymerization [Zei87].








new initiation reactions can occur readily. This tends to result in high polymer yield

(because monomer is "consumed" readily) and low average molecular weight. (Because

there are a large number of chains, the amount of chain extension is limited since the

supply of monomer is fixed.) In a poor solvent on the other hand, polymer coils are

contracted and there is a much greater tendency for the polymer chains to absorb on

the sodium particle surfaces. Since the direct path of monomer to the sodium surface

(through the solvents) is impeded now, the monomer is forced to diffuse through

polymer chains. This tends to promote propagation reactions (at the reactive chain

ends) (i.e., causes formation of longer chain polymers) and leads to lower polymer yield

and higher overall polymer molecular weight. In the extreme case when the solvent is

'too poor', the polymer would tend to precipitate out of solution, which is not desirable.

Thus, Zeigler et al. model suggests that there is an optimum A8 for a given polysilane

polymer-solvent system which would dictate the yield and overall molecular weight of

the polymer.

Gauthier and Worsfold [Gau89] investigated the influence of cosolvent 15-crown-

5 ether ('phase-transfer catalyst') on the Wurtz-coupling polymerization of n-

hexylmethyldichlorosilane (Figure 2.5 shows structure of 15-crown-5 ether). The primary

solvent used was toluene and the amount of 15-crown-5 ether used was in the range of

0.25-4 mol% (of hexylmethyldichlorosilane). They also found that in the presence of the

cosolvent, the polymer yield becomes high, the overall molecular weight of the polymer

decreases, and the molecular weight distribution changes from bimodal to monomodal.

Figure 2.7 shows the amount of monomer consumed as a function of time in the

study by Gauthier and Worsfold. They suggested that silyl anionic intermediates (shown

























I-
U-


Z-
60 -



40


0.25%\
1%
20 -




0 20 40
REACTION TIME (min)





Figure 2.7. Rate of disappearance of monomer n-hexylmethyldichlorosilane as a
function of time and weight percent of 15-crown-5 ether [Gau89].








by equation (2.2) in Figure 2.1) are involved in the polymerization of n-

hexylmethyldichlorosilane and claimed that 15-crown-5 ether accelerated the

occurrence of initiation reactions. Although data is limited, it is evident that the rate of

monomer consumption is increased with small additions of 15-crown-5 ether.

2.2.1.5 Temperature effects

Miller et al. [Mil93] investigated the effect of temperature on the molecular weight

distribution and yield for polymers produced from diaryl and dialkyl substituted

chlorosilanes. They found in the case of polymerization of methylphenyldichlorosilane in

toluene that lowering the reaction temperature to 65C (from the refluxing temperature

of 110C) decreased the total yield from 25% to 10%, while causing an increase in

molecular weight of the polymer. In addition, the molecular weight distribution changed

from bimodal to monomodal (Table 2.2). However, in the presence of a polar solvent

(i.e., 15% diglyme), lowering the reaction temperature to 65C (instead of the reflux

temperature) resulted in the opposite trends from what is noted above, i.e., the

polymer yield increased slightly and the polymer molecular weight decreased. (The latter

changes may have been within the limits of experimental error.)

When polymerization was carried out in a blend of toluene/15% heptane,

lowering the reaction temperature to 65C had no effect on polymer yield or overall

polymer molecular weight. Miller et al. also reported that low temperature (650C)

polymerization of alkyl substituted chlorosilanes (such as dichloro-di-n-hexylsilane) took

place sluggishly. The typical change in color to purple or dark blue was conspicuously

absent. In addition, the yield for such a polymerization was less than a percent (i.e.,

essentially no polymerization occurred).

Jones et al. [Jon94] investigated polymerization of methylphenylsilane in THF at

low temperatures (-79"C) using a sodium/electron acceptor complex. The electron











Table 2.2. Effect of temperature on polymerization of methylphenyldichlorosilane [Mil93].


( PhMeSiCI2 + Na


--(PhMeSi)n)


Solvent Temperature,OC Additive Yield, % Mw x 10-3 M x 10-3

Toluene Reflux 25 383, 16 a 267, 8.1
a
Toluene 65 10 1073b 377b
Toluene/15% Reflux 9 1390,10.5 375, 6"
Heptane a
Toluene/15% 65 9 1367 b 580 b
Heptane
Toluene/15% Reflux Diglyme 25 23.8 b 9.7 b
Heptane (15%)
Toluene/15% 65 Diglyme 28 14.2 b 6.7 b
Heptane (15%)


a bimodal; b monomodal








acceptors used in the polymerization were naphthalene, anthracene and tetraphenyl

ethene, and were used in stoichiometric excess to disperse sodium. The disadvantages

of typical Wurtz-type polymerization (e.g., low polymer yields, poor reproducibility)

persisted, but polydispersities of the polymer produced were much lower (1.5-3) than

that of typical Wurtz-type polymerization (> 5).

2.2.2 Ultrasonically-activated Wurtz-coupling reactions

Matyjaszewski et al. [Mat88; Mat91; Kim88] pioneered the use of ultrasonic

energy in the Wurtz-coupling synthesis of polysilanes (derived from aryl-substituted

monomers) having high molecular weight and monomodal distributions. Use of

ultrasonic energy enabled reactions to be performed at low or ambient temperatures.

The principle of ultrasonic polymerization is based on the implosive collapse of cavities

with very high pressures and temperatures existing locally for short duration of times

[Pri94]. The ultrasonic energy is generated using an immersion-type probe or ultrasonic

bath. The reasons for obtaining monomodal and high-molecular-weight distributions for

the polymers synthesized by ultrasonic method is attributed to the formation of high

quality sodium dispersions which are continuously regenerated during the coupling

process with continuous removal of sodium chloride byproduct from the sodium

surfaces.

Matyjaszewski et al. report that polymer molecular weight distribution becomes

broader and the average molecular weight decreases as the reaction temperature

increases. It was also observed that prolonged sonication (both during and after the

addition of monomer) results in degradation of high-molecular-weight components, as

shown in Table 2.3. (This results in polymers with lower average molecular weight and

lower polydispersity.)








Table 2.3: Effect of sonication time on molecular weights and polydispersities of
polymethylphenylsilane [Kim88].

Molecular Sonication time (min) Sonication time (min)
Weight During addition of monomers After addition of monomers
5 10 15 30 60 80 120
Mn. 10-5 3.8 2.24 2.30 1.82 1.48 1.06 0.40
Mw. 10- 17.3 6.68 6.35 3.73 2.57 1.57 0.47
MJMn 4.5 2.98 2.71 2.05 1.73 1.48 1.17



Matyjaszewski et al. also observed that ultrasonic polymerization of dialkyl-

substituted chlorosilanes occur sluggishly when compared with that of diaryl-substituted

dichlorosilanes and that cosolvent additions (e.g., diglyme) and higher temperatures

were required to obtain any meaningful yield of polymer. In general, polymer yields for

ultrasonic synthesis of polysilanes are low when compared to those of classic Wurtz-

coupling reactions performed at high temperatures (i.e., the reflux temperatures of the

solvents). Furthermore, the ultrasonic synthesis method is amenable only for aryl-

substituted dichlorosilanes. However, it has better potential for control of polymer

molecular weight and is less hazardous to perform, since the reactions are carried out at

or near ambient temperatures.

2.2.3 Polymerization of monoalkylchlorosilanes

Although a lot of information is available on the Wurtz-coupling reactions of aryl-

substituted and dialkyl-substituted chlorosilanes, information is scarce on the

polymerization of monoalkylchlorosilanes. Seyferth et al. [Sey92] have synthesized

polymethylsilanes by condensation of methyldichlorosilanes with sodium (normal mode)

in a solvent mixture of hexane and THF (7:1 by volume) at reflux for 16 h. The polymer

was a liquid with a composition of ((CH3SiH)0,8(CH3Si)0o2) (elucidated by NMR








spectroscopy) and was produced in high yields (i.e., 60 to 70%). Average molecular

weights for these polymers were reported to be low (620-690). When the polymerization

was carried out in THF instead of a mixture of THF and hexane, the resulting polymer

apparently had higher molecular weight (absolute numbers were not reported) and more

cross-linked structure. The latter conclusions were based on NMR studies (showing a

lower concentration of Si-H bonds) and thermogravimetric analysis (TGA) (showing

higher ceramic yield). When the reaction was carried out in xylene (under refluxing

conditions), the yellow-colored polymer was produced with a yield of 40%, molecular

weight in the range of 520-600 (Mw), and structure of ((CH3SiH)04(CH3Si)o36)

(determined from NMR).

Qiu and Du [Qiu89A; Qiu89B] prepared polymethylsilane polymers by

condensation of methyldichlorosilane with sodium (normal addition mode) in a blend of

toluene and dioxane (33:67 vol% ratio). It is expected that dioxane, a dipolar solvent, will

promote polymerization of MeHSiCI2 (i.e., higher reaction rate). (The effect of polar

solvents on Wurtz-coupling reaction of dichlorosilanes with sodium was discussed in

section 2.2.1.4) The polymerization was carried out at the reflux temperatures of the

toluene-dioxane solvent mixture. The end point of polymerization was determined by

testing for the acidic nature of the reaction contents. The reaction was stopped when the

reactions contents did not test acidic (pH=6-7). The reaction contents were separated

from the NaCI precipitates by filtering and the polymer was isolated by evaporation of

the polymer solution under vacuum. The polymer was fractionated by adding, drop by

drop, a mixture of methanol and 2-propanol with vigorous stirring. The precipitate was

collected and dried in a vacuum oven at room temperature for 2 h. The polymers

synthesized by this method were used in studies involving oxidative cross-linking, photo








cross-linking, and room temperature vulcanization. The polymer was produced in ~45%

yield and had an appearance of pale yellow waxy solid with M, -1,800.

2.2.4 Polysilane copolymers

As discussed in section 2.1, when dialkyldichlorosilane is reacted with sodium in

a refluxing solvent, polydimethylsilane polymer is formed which is infusible and insoluble

in common organic solvents (e.g., toluene, benzene, xylene, etc.). West et al. [Wes81;

Wes86A] discovered that when phenylmethyldichlorosilane was added to

dialkyldichlorosilane in a 1:1 proportion by volume, and the reaction was carried out

under same conditions, the resultant polysilane copolymer was highly soluble in

common organic solvents (e.g., toluene, xylene, etc.). West et al. referred to this

copolymer as "poly(silastyrene)" (PSS). The copolymerization reaction can be

represented as:



CH3 C6H5
>100C I I
(CH3)2SSiCII + 6 5C3Si2 Na -(--Si Si- (2.5)

CH3 CH3




The PSS copolymer had a bimodal molecular weight distribution with modal values of

-15,000 and -300,000.

2.2.5 Dehydrocoupling

Harrod et al. [Har88; Mu91A; Mu91B; Ait89; Ait87; Ait85] were the first to report

a catalyst-based synthetic route for polysilanes prepared from primary organosilanes








(e.g., RSiH3, where R is an alkyl or aryl group) with the evolution of hydrogen. The

reaction can be represented as



R
Catalyst I
nRSiH3 -- -(- Si -- + H2 (2.6)
20-65C n

H


The catalysts used were early transition metal complexes of titanium and zirconium,

namely, bis(rl-cyclopentadienyl) dimethyltitanium (CpTiMe2)(Dimethyl Titanocene,

DMT) and bis (r5-cyclopentadienyl) dimethylzirconium (Cp2ZrMe2) (Dimethyl

Zirconocene, DMZ). Mu and Harrod [Mu91A] have investigated polymerization of

methylsilane by dehydrocoupling in the presence of DMT catalyst and reported

significantly higher yield of polymer in the form of a glassy solid in comparison to that

produced by classic Wurtz-coupling reactions. Table 2.4 shows polymerization

conditions (temperature, catalysts, solvents, time, amount of monomer used) and

characteristics of the polymers produced (yield, molecular weight, etc.). Their method,

however, suffers from the following disadvantages: (i) the reaction must be performed at

9-10 atm at 500C because methylsilane is a gas at room temperatures; enhancing

reaction rate would require working at higher pressures, which in turn requires

sophisticated instrumentation in order to perform the experiments safely and (ii)

handling methylsilane is dangerous since it is spontaneously flammable in air.

The monomer, methylsilane, was synthesized from methyltrichlorosilane.

Methyltrichlorosilane was reacted with a suspension of lithium aluminum hydride in THF

at 50C for 3 h and then reaction products were cooled under liquid N2 temperature to









Table 2.4. Summary of methylsilane polymerization by catalytic dehydrogenation reactions [Mu91A].


Run Solvent Catalyst MeSiH3 T, "C Time, Amount of Yield, % Mw C Mn MJ/Mn %
# (psi x Lb) days PMS, g Cyclicsc
1 cyclohexene DMT 120 x 0.12 20 6 1.52 90 1590 790 2.01 0.4
toluenea (50 mg)
2 cyclohexene DMT 130 x 0.12 20 9 1.82 -100 6350 1200 5.30 1.6
+toluene" (50 mg)
3 cyclohexene DMT 140 x 0.12 20 12 1.96 -100 10100 1250 8.10 3.4
+toluene" (50 mg)_
4 cyclohexene DMT 120 x0.12 45 4 1.68 -100 7890 1240 6.36 0.5
+toluene" (50 mg)
5 cyclohexene DMT 110 x0.12 65 1 1.53 -100 12990 1260 10.30 0.5
+toluene" (50 mg)
6 Toluene DMT 100 x0.12 20 9 0.37 26 830 560 1.48 4.6
(50 mg)
7 cyclohexene DMZ 110 x0.12 20 5 1.43 -92 1730 800 2.16 ...
+toluene" (60 mg)
8 cyclohexene DMZ 130 x0.12 20 7 1.81 -100 6010 1080 5.56 0.8
+toluene" (60 mg)
9 cyclohexene DMZ 125 x0.12 20 9 1.75 -100 9990 1350 7.40 2.5
+toluene" (60 mg)_
10 cyclohexene DMZ 100 x0.12 65 1 1.40 -100 Insoluble
+toluene" (60 mg)
11 Toluene DMZ 110 x0.12 20 7 0.99 64 1020 620 1.65 3.8
(60 mg)
* Cyclohexene:toluene proportion 70:30 (Vol %); b Volume of silane gas used
c Based on the assumption that the low molecular weight species in the gel permeation chromatograms are cyclic oligomers.








trap methylsilane. The subsequent polymerization of polymethylsilane was carried

out in cyclohexene solvent which helps to avoid build up of hydrogen produced during

reaction by promoting hydrogenation of cyclohexene to cyclohexane.

Molecular weight characteristics of some of the polymers synthesized by Mu and

Harrod are illustrated by the GPC profiles in Figure 2.8. (The chromatograms are for

samples associated with the entries in Table 2.4. The "A" chromatograms, from top-to-

bottom, correspond to run #s 3,2,1, and 6, respectively, and the "B" chromatograms,

from top-to-bottom, correspond to run #s 9,8,7, and 11, respectively.) The bimodal

distributions that develop with longer reaction times are reported to be typical of

dehydrocoupling of primary organosilanes. The lower molecular weight peak (appearing

as a shoulder in most chromatograms in Figure 2.8) is attributed due to cyclic oligomers.

The high polydispersity of these polymers can be attributed to branching/cross-linking

that occurs at residual SiH3, SiH2 and SiH groups during prolonged reaction.

Mu and Harrod also studied polymerization of phenylsilane by dehydrocoupling

using the aforementioned catalysts The polyphenylsilane polymer synthesized with

DMT and DMZ had average degrees of polymerization of 1,000 and 2,000, respectively

(corresponding to molecular weights of 46,000 and 92,000, respectively). In both cases,

gel permeation chromatograms did not suggest the presence of cyclic oligomers (i.e.,

low molecular weight oligomers were not observed). Harrod et al. also report that

secondary organosilanes (e.g., phenylmethylsilane) do not polymerize easily under

similar reaction conditions and form only dimers and trimers. Brown-Wensley [Bro85;

Bro87] has shown that a good catalyst for conversion of secondary silanes (R2SiH2) to

dimeric silanes (HR2Si-SiR2H) is a (Ph3P)3RhCI complex.

While Harrod's work on the synthesis of poly(arylsilanes) (e.g.,

poly(phenylsilane)) indicated that cyclic oligomers do not form, Campbell and Hilty

















































3060 2M :20 1 87 0.16S .-:'


F'-40 :63 22.0 1.A7 0.16 xtlC


Molecular Weight






Figure 2.8. GPC of polymethylsilanes synthesized by Mu and Harrod [Mu91A]. A: DMT
catalyst B: DMZ catalyst








[Cam89] have shown by gas chromatography that they are the main products in the

polymerization of alkylsilanes (e.g., n-butylsilanes) catalyzed by DMZ. This is attributed

to the ability of DMZ to promote reversible reactions for both primary and secondary

silanes. In the case of polymerization of methylsilane, Campbell et al. reported the

presence of a small amount of cyclic oligomers (n=5 to 10), in agreement with the

results of Mu and Harrod. Thus, it can be concluded that formation of cyclic oligomers is

inevitable in the polymerization of alkylsilanes by dehydrocoupling.

In general, DMZ and DMT catalysts are effective for polymerization of primary

organosilanes. However, as shown by Mu and Harrod [Mu91A], polymerization rates for

primary silanes are about ten times faster using DMZ compared to using DMT.

Nevertheless, molecular weight characteristics of the polymers synthesized with the

two catalysts are essentially identical. The DMT-catalyzed polymerization exhibited a

pronounced induction period and a complete reduction of titanium to Ti (III). In contrast,

an induction period was absent for DMZ catalyzed reactions and a slight auto-

acceleration in the reaction rates was observed in the reactions at low catalyst or

monomer concentrations.

The mechanism of catalytically activated dehydrocoupling of organosilanes is

complex. Harrod [Har88] suggested (based on NMR studies) that the mechanism

involved formation of titanium (IV) silylhydride ( Cp2Ti(H)(SiH2R) ) which decomposed by

elimination of a-hydride from the SiH2R group, followed by release of H2 from the

complex to give Cp2Ti=SiHR (silylene) complex. A number of metallocene (catalyst)

derivatives are formed during polymerization that can be isolated and these compounds

are presumed inactive in the polymerization cycle. Propagation then occurred by

repetitive insertion of the silylene into a Ti-Si bond (a rapid addition mechanism) in which

the intermediates are not observable because they are short-lived or because they are








spectroscopically 'silent' (i.e., absent in NMR because of paramagnetic nature). At

present, a mechanism for chain termination is not elucidated, although catalyst-induced

chain scission has been observed in the polymerization of cyclohexasilanes.

Since early transition metal complexes are not effective for dehydrocoupling of

secondary silanes, other catalysts have been investigated. Corey et al. [Cor91]

synthesized disilanes through pentasilanes by using a Cp2ZrCI2-nBuLi mixture as a

catalyst for dehydrocoupling of phenylmethylsilanes in toluene at 90C. (This

temperature is higher than that used for dehydrocoupling of primary silanes.) This

condensation reaction of secondary silanes is sensitive to steric effects (i.e., steric

hindrance) of the substituents, as observed by the sluggish reaction of Ph2SiH2

compared to PhMeSiH2 [Cor91].

Sakakura et al., [Sak91; Sak93] have developed a method for producing

polysilanes by dehydrocoupling of primary organosilanes using a lanthanoid complex

(1.5 wt%) as a catalyst. They reported that lanthanoid complexes have higher activity

and selectivity than early transition metal complexes used by Harrod et al. In this case,

the dehydrogenative reactions of phenylsilanes were performed at temperatures

ranging from 200C to 1600C and in the presence of a solvent such as toluene or

benzene, with reaction times extending from several hours to several days. The authors

reported that higher polymerization temperatures and longer reaction times lead to

higher polymer molecular weight. The effect of the above variables in the polymerization

of phenylsilane in the presence of hydrobis(pentamethylcyclopentadienyl)-neodymium

catalysts (lanthanoid complex) is illustrated in Table 2.5.












Table 2.5: Effect of time and temperature on polymerization of phenylsilane in the
presence of a lanthanoid complex [Sak93].

Temperature, C Time, days Product M" Mn
_Appearance
25 15 oil 520 1.26
80 2 gum 780 1.37
100 2 gum 990 1.54
130 2 solid 1600 1.91
130, 160 a 2, 7 a solid 4380 3.09
" 2 days at 130"C followed by 7 days at 160"C.








Berris [Ber92] has also developed a process for synthesizing polysilane

polymers with a M, of -1000-1500 by dehydrogenative coupling of primary

organosilanes in the presence of (1-1.7 wt%) dimethyldialkylphosphine nickelhalide

(e.g., 1,2-bis(dimethylphosphine) ethanenickel(ll)chloride, dmpe NiCI2) at temperatures

of 20C to 500C in the presence of an inert solvent. The reaction time varied from 1 h to

10 days, depending on the temperature used (i.e., lower reaction times were used at

higher temperatures). The dmpe NiCI2 catalyst was reported to have a much higher

activity than the early transition metal complexes used by Harrod et al.[Har88].

Seyferth et al. [Sey88; Sey90; Sey92; Sey93] have used dehydrogenative

coupling to cross-link low molecular weight polymethylsilanes (containing multiple

secondary or tertiary Si-H bonds) which had been synthesized by the Wurtz-coupling

reaction of methyldichlorosilane with sodium in hexane/THF. This resulted in polymers

that could be pyrolyzed to produce near-stoichiometric SiC with high yield (in the range

of 95-98%). The low molecular weight polymethylsilanes were reacted with ~3 wt%

cyclopentadienyl zirconium hydride catalyst in an inert solvent (such as hexane) at reflux

temperatures. (Hexane was chosen because it readily dissolves the catalyst and it has a

low reflux temperature.) Seyferth et al. [Sey93] observed that the products of the

dehydrogenative coupling reaction of low-molecular-weight polysilanes with

cyclopentadienyl zirconium hydride catalyst ranged from oil to solid (both orange

in color) depending upon time-temperature conditions of the reaction. In order to impart

infusibility to articles prepared from these cross-linked polymers (e.g., fibers), photolysis

is required which can be accomplished by UV irradiation in hexane for 2 hours.

Tilley [Til91; Til93] developed a method of producing cross-linked, high-

molecular-weight, silicon-rich polymers by dehydrogenative coupling reactions of

organosilanes. The reaction of more than one Si-H group per silicon center caused








cross-linking of chains and increased molecular weights. A wide range of homopolymers

with different structures were prepared by modifying the reaction conditions to vary the

degree of branching (cross-linking) or chain extension. For example, when 1,3-

disilylbenzene(1,3-(H3Si)2C6H4) or 1,3-dimethylsilyl benzene (1,3-(CH3H2Si)2C6H4) was

reacted in the presence of cyclopentadienyl zirconium hydride catalyst (Cp2(ZrH2)2), the

resulting polymer was highly cross-linked and high in molecular weight. The disilyl

monomers (1,3-disilyl benzene or 1,3-dimethylsilylbenezene) developed by Tilley were

prepared by reacting tetraethoxysilanes (Si(OEt)4) or methyl triethoxysilanes

(CH3Si(OEt)3) with dibromobenzene and magnesium in an inert solvent, followed by

reduction of the intermediate compound (1,3-di(triethoxylsilyl)-benzene or di-

(trimethoxysiloxy)-benzene) with lithium aluminum hydride. The dehydrogenative

polymerization was then carried out by adding organosilanes (containing multiple Si-H

groups per silicon center) drop by drop to a benzene solution containing the catalyst and

stirring for 24 hours at 20-650C under nitrogen. Many of the polymers prepared by

Tilley's method were highly cross-linked and were insoluble in common solvents (e.g.,

toluene), indicating difficulty in controlling cross-linking reactions. The soluble polymers

exhibited Mw ranging from 5,500 to 90,000 and Mn ranging from 1,300 to 2,200.

2.2.6 Redistribution/substitution reactions:-

Baney et al. [Ban82; Ban83; Ban85] prepared another class of polysilane

polymers, methylpolysilanes (MPS polymers) by catalytic redistribution reactions

involving Si-Si/Si-CI bonds of methylchlorodisilane mixtures' The methylchlorodisilane

mixtures, comprising 55 wt% [MeCI2Si]2, 35 wt% Me2CISiSiMeCI2, and 10 wt%



1 Methylpolysilane (MPS) polymers, as described by Baney et al. have a structure of [((CH3)2Si)x(CH3Si),],.
They are different from polymethylsilane (PMS) polymers discussed earlier, which have a structure of
[(CH3SiH),(CH3Si),Ln-








(Me3CI3Si2), were obtained as fractions from an industrial process for manufacture of

methylchlorosilanes. The catalyst used for the redistribution/substitution reactions of

methylchlorodisilane mixtures was tetrabutylphosphonium chloride. The proposed

reaction scheme for these reactions is shown in Figure 2.9.

The rearrangement of disilanes into a monomer/polymer mixture occurred when

the disilane mixture was heated to 250C. Additional monomeric methylchlorosilanes

formed even after the starting disilanes reacted completely. This occurred by the

reaction of any Si-CI bond with a terminal Si-Si bond in the polysilane backbone. The

amount of monomers formed and the extent of polymerization were controlled by

manipulating the heating schedule and final reaction temperature. The resulting yellow-

colored methylchloropolysilane polymers (MCPS) were soluble in toluene and had

polycyclic structures with seven rings per molecule ((Me2Si)3(MeSi),17CI)) as determined

by gas chromatography (see Figure 2.10). The Si-CI bonds in the

methylchloropolysilane polymers were highly reactive and permitted easy chemical

modification (such as reaction with Grignard reagents (alkyl-magnesium halide or

phenyl-magnesium halide) to form methylpolysilane polymer (MPS). According to

Baney et al., MCPS polymer reacts readily with Grignard reagents to replace the

reactive Si-CI groups with more stable Si-R groups. The modified polymers can be melt

spun to form fibers which can be subsequently pyrolyzed to SiC as discussed in section

2.4.

The chemical modification of methylchloropolysilanes (MCPS) can also be

accomplished by reducing MCPS over a slurry of lithium aluminum hydride under an

inert blanket in a refluxing solvent such as toluene [Ban83]. The excess reducing agent

is neutralized by adding water and aqueous NaOH and the solution is subsequently

filtered to give a yellow-colored polymer of composition ((CH3)2Si)o0(CH3Si)04),).
















Si- CI + Me- Si- Si- Me ~250
I I Catalyst
Cl CI


CI

- SSi-S Me + MeSiCI
CI
CU


CI Me CI
25I
&Si-CI + Me-Si- Si-Me CaaSi-Si-Me + MeSiCL

CI CI CI

CI Me Me
I I
~250"C
Si CI + Me- Si- Si-Me Clyst Si-Si-Me + MeSiCI
I I Catalyst
CI CI CI


Figure 2.9. Scheme for redistribution/substitution reactions of chlorodisilanes.


(2.7)





(2.8)





(2.9)



















Me


*MeSi


Figure 2.10. Structure of methylchloropolysilane polymer [Ban83].








(Information on oxygen incorporation into the polymer due to the addition of water and

NaOH was not reported.)

The main disadvantage of Baney et al. MPS polymers from the point of view of

subsequent processing for ceramic articles (e.g., fibers) is their poor oxidative stability

(MPS polymers are pyrophoric). Burns [Bur90] attributed this tendency for spontaneous

oxidation to a large number of Si-H groups in the polymer structure. The polymer

develops a cross-linked structure upon oxidation due to the formation of Si-O-Si

networks. Burns developed a remedy to the problem of oxidative instability in these

MPS polymers by inserting multiple unsaturated bonds (such as acetylene or phenyl

acetylene or diene compounds). According to Burns, by selectively inserting multiple

unsaturated bonds in the Si-Si backbone, the final Si:C stoichiometry can also be

controlled (unmodified MPS polymers typically yield silicon-rich ceramic residue). The

insertion reaction can be carried out by reacting MPS polymers with ~8 wt%

unsaturated compounds (e.g., phenyl acetylene) in the presence of a transition metal

catalyst (e.g., tetrakis (triphenylphosphine) palladium or tris(tri-phenylphosphine)

rhodium chloride) in an inert solvent such as toluene at reflux temperatures for ~20

hours. In addition to better oxidative stability and control of stoichiometry, Burns' method

presents opportunities to synthesize polycarbosilanes by introducing unsaturated

moieties between Si-Si bonds. An example of such a synthesis is reported as the

reaction between 1,3-butadiene with a linear polysilane polymer [Bur90].

Bujalski et al. [Buj90] developed an alternate method of synthesis of chlorine-

containing polysilanes. These polymers were prepared by reacting a mixture of 70-99

wt% of one or more of chlorine-containing disilanes (e.g., ((CH3)2CISi)2,

(CH3Si)2CISiSiCI2CH3, (CH3CI2Si)2 etc.) with one or more of monoorganosilanes (e.g.,

C6H5SiCI3). The reaction required 0.1 to 2 wt% rearrangement catalyst (e.g., quaternary








ammonium halide, quaternary phosphonium halide, etc.) at temperatures ranging from

100C to 340C. The polysilanes (solid at room temperature) were easily converted to

silicon carbide by pyrolysis at elevated temperatures (at >1000C). According to Bujalski

et al., the use of a monoorganosilane (of structure R'SiX where R' is methyl, phenyl or

octyl groups and X is chlorine) (or a mixture of monoorganosilanes) permits control of

the glass transition temperature T, of the polysilanes as well as the stoichiometry of the

silicon carbide produced. Their work suggests using monoorganosilanes with silyl

groups R'Si (where R'=n-octyl) allows a greater reduction in Tg of the polymer compared

to using monoorganosilanes R'SiX (where R'=phenyl). Bujalski et al. reported that all the

n-octyl groups are lost as olefins upon pyrolysis and this results in a carbon-deficient

ceramic. In contrast, polymers with pheny! groups produce a carbon-rich ceramic after

pyrolysis. However, the final Si:C stoichiometry also depends significantly on the

presence of methyl radicals in the polysilane (CH3Si or (CH3Si)2Si), which are generally

not lost upon pyrolysis. Bujalski et al. indicated that presence of the n-octyl or phenyl-Si

units enabled "fine tuning" of the silicon and carbon contents in the ceramic.



2.3. Pyrolysis Behavior

Carlsson et al. [Car90] have studied the pyrolysis behavior of various silicon

backbone polymers such as polyphenylsilanes, poly-n-2-hexylsilanes, and

polydimethylsilanes by means of thermogravimetric analysis (TGA) and Fourier

transform infrared spectroscopy (FTIR). Polymers for the TGA study were heated at

10C/min with 10 min isothermal holds at 200C, 400C, 600*C and 1000C. Polymers

for FTIR study were heated at 3600C, 454C, 650C, and 1200C, with a 90 min hold at

each temperature. Their results are summarized in Table 2.6. The effect of pendant

groups (such as phenyl) on pyrolysis yield is particularly noticeable. For example,











Table 2.6. Ceramic yields and chemical compositions of polysilane homopolymers,
copolymers and terpolymers [Car90].

Batch Polymer" Yield (wt%) Inorganic Residue Analysis (wt%)
Theor.b Observed' Cd Si d Calculated SiC Yield
SiC Yielde (%Theor)'

Homopolymers
I (CH3-Si-CH3)n 69 1.0 42 58 0.8 1.2
II (C6Hs-Si-CH3)n 33 24.6 55 39 13.7 41.5
III (CeH13-Si-CH3)n 31 5.8 32 67 5.6 17.5

Copolymers
IV (C6Hs-Si-CH3)10
(CH3-Si-CH3)10 51 13 62 51 7.1 15.4
V (C6Hs-Si-CH3)1.0
(C6H13-Si-CH3)1.0 32 8 49 49 5.9 17.9
VI (CH2=CH-Si-CH3)1.0
(C6Hs-Si-CH3)9o 36 39.1 65 38 19.5 54.5
Terpolymers (5:5:1)
Vila (C6Hs-Si-CH3)
(C6H13-Si-CH3)
(CH2=CH-Si-CH3)9 36 7 47 54 5.3 15.6
VIIb (C6Hs-Si-CH3)
(CH 13-Si-CH3)
(CH2=CH-Si-CH3)h 36 22 53 42 14.8 41.2
VIII (C6Hs-Si-CH3)
(CH3-Si-CH3)
(CH2=CH-Si-CH3) 52 27 61 45 15.1 29.1
IX (C6Hs-Si-CH3)
(C6H,3-Si-CH3)
(CH2=CH-CH2-Si-CH3) 51 21 61 47 11.6 22.8

a The functional groups shown are attached to Si as side groups.
b Theoretical conversion to SiC (for e.g., (CH3-Si-CH3)n --- SiC is 69% conversion).
c Observed ceramic yield.
d C+Si total in some cases exceed 100%. The totals appeared as such in the paper and presumably reflect
experimental error in the measuring technique.
e The ceramic residue consists of SiC and C. The percentage of SiC is calculated by multiplying the
experimentally observed yield by the factor (100-C)/70 wt% where C is the carbon content of the residue.
(Note that the theoretical composition of SiC is 70 wt% Si/ 30 wt% C.)
S[Calculated SiC yieldd/theoretical SiC yieldb]xl00.
g low MW viscous oil.
" high MW fraction.








polydimethylsilane with methyl groups as substituents gives high theoretical yield

(69%) but low pyrolysis yield ( ~1%). (Experiments by Wood [Woo84] and West et al.

[Wes81] also confirm this observation.) Replacement of a methyl substituent by a bulky

phenyl group (as in polyphenylmethylsilane) results in improved pyrolysis yield, ~25%

(presumably due to the retention of some phenyl groups during pyrolysis). (It is also

possible that high yield depends on the ability to develop a Si-C-Si-C backbone with

sufficient cross-linking.)

Figure 2.11 shows the FTIR spectra of a polysilane terpolymer (polymer Vllb

shown in Table 2.6) during pyrolysis to 12000C. The polymer was cast as a thin film on a

silicon wafer and heated under argon atmosphere and spectra were collected at

different temperatures. The typical absorptions for the as-prepared polysilane occurred

at 3050 cm'1 (due to the C-H stretching vibration of Si-CH=CH2), 1428 cm-' (due to the

CH2 bending vibration of Si-C6Hs), 1468 cm-' ( due to the CH bending vibration of Si-

CH,1) and 2100 cm-1 (due to stretching vibration of Si-H), and 1247 cm'1 (due to the

rocking vibration of Si-CH3). Figure 2.12 shows the changes in concentrations in residual

pendant organic groups calculated based on the IR spectra, allowing for reduction in

thickness of the film which occurred during pyrolysis. The slight increase in the Si-H

group intensity is attributed to methylene insertion reactions taking place between 200C

and 450C. (This observation was also confirmed by Schilling [Sch84; Sch88] and

Schmidt [Sch91] by NMR studies and resembled reactions occurring during the

conversion of polydimethylsilane to polycarbosilane [Has83].) Carlsson et al. indicated

that no significant changes occurred during the pyrolysis up to 300C but rapid

elimination of -CH3, -C6H, and -C6H13 groups occurred between 300C and 450C. The

increase in the absorption intensity at 1030 cm-1 corresponded to formation of Si-(CH2)n-

Si linkages and network.



















o


Uj


C1


LU

















4000


1000 600


Figure 2.11.


IR spectral changes during pyrolysis of a polysilane polymer (Vllb in Table
2.6) [Car90]; A: initial film; B: 360"C (1.5 h hold); C: 454C (1.5 h); D:
650C (1.5 h); E:1200C (1.5 h); F: dispersion of single crystal SiC
whiskers in KBr for comparison.


3000 2000 1500
WAVENUMBER (cm-t)






46












70



60
"E



E
O
U










20 -
Z 00 30 cm 0
0U 0
CJ
S1800 cm w,





+
0 200 400 600 800 1000 1200
FIRING TEMPERATURE (C)








Figure 2.12. Change in intensities of pendant groups based on IR spectra for polysilane
polymer (Vllb in Table 2.6) [Car90] : o: p(CH3) from Si-CH3; 0: 5 (CH2) of
Si-C6Hs; l: 8 (CH) of Si-C6H13; +: 8 (CH2) of Si-(CH2)n-Si ; A:v (Si-H) ; V: v
(Si-C)








Wood [Woo84] studied the pyrolysis behavior of three different polymethylsilanes

(designated as PMS-I, PMS-II and PMS-III) prepared by Wurtz-coupling reactions of

dichlorosilane with sodium in the presence of hexane, hexane/THF (7:1 volume)

mixture and THF, respectively. Table 2.7 gives a summary of the synthesis conditions

and characteristics for the three polymers. PMS-I showed very low ceramic yield (~25%)

upon pyrolysis to 1000C. The low ceramic yield was attributed to the loss of Si by

volatilization of low molecular weight components (which was confirmed by mass

spectral analysis of the pyrolysis species). X-ray Diffraction (XRD) analysis of the

ceramic residue obtained from pyrolysis of PMS-I showed peaks due to excess Si as

well as SiC peaks. The pyrolyzed ceramic had an overall composition of 67% SiC and

33 wt% Si (calculated based on the Si/C ratio determined by elemental analysis).

Polymer PMS-II showed a ceramic yield of ~27% The XRD analysis of the pyrolyzed

ceramic residue showed no Si peaks (for unknown reasons) although elemental

analysis revealed silicon-rich composition (77 wt% SiC and 23 wt% Si). PMS-III showed

a much higher ceramic yield of 60% compared to the other two PMS polymers and had

an elemental composition of 75 wt% SiC and 25 wt% Si. (XRD analysis showed both Si

and SiC peaks.) The differences in the pyrolysis yields were attributed to differences in

cross-linking in the three polymers. Based on NMR data, both PMS-I and PMS-II

contained higher number of Si-H functionalities (which are potential cross-linking sites)

compared to PMS-III. (This suggested that cross-linking was more extensive in PMS-III

due to consumption of Si-H moieties by condensation reactions. Recall that a polar

solvent such as THF aids in the anionic polymerization of methylchlorosilanes with

sodium and leads to formation of polymers which are rich in Si-H groups; these Si-H

groups undergo condensation causing extensive cross-linking in the polymer).













Table 2.7. Synthesis conditions
Wood [Woo84].


and characteristics for PMS polymers prepared by


Polymer Synthesis Molecular Ceramic Composition
Designation Conditions Weight Yield ,%"
PMS-I Reflux, Hexane 520 25 67 wt% SiC,

33 wt% Si
PMS-Il Reflux, 620-690 27 77 wt% SiC,

Hexane:THFa 23 wt% Si

PMS-ll Reflux, THF ---b 60 75 wt% SiC,

25 wt% Si


" 7:1 Volume proportion
b Insoluble in benzene, hence cryoscopic determination of molecular weight could not be carried out.
c Pyrolyzed to 1000"C in nitrogen atmosphere at 10C/min








Seyferth at al. [Sey93] have significantly enhanced pyrolysis yields of PMS polymers

prepared by Wood's method by dehydrogenatively cross-linking the polymers in the

presence of early transition metal complex catalysts (zirconocene and titanocene) (see

section 2.3). The ceramic yield of PMS polymers increased from ~25% (for

unmodified polymer) to 74% (for cross-linked polymer). The ceramic residue after

pyrolysis for a typical cross-linked polysilane polymer had an elemental composition of

98% SiC, 1.6% ZrC and traces of elemental Si (as opposed to 74% SiC and 26% Si

for an unmodified polymer). Table 2.8 shows pyrolysis results for a number of cross-

linked polymethylsilane polymers prepared under different processing conditions (i.e.,

varying catalyst concentration, solvent, and reflux time). It is evident from the table that

the type of solvent used for the catalytic cross-linking plays an important role in

determining the ceramic yield of the polymer produced. For example, it appears that

hexane and benzene are good solvents for cross-linking in comparison with

polar solvents ether and THF. (This is not to be confused with the effect of polar

solvents on Wurtz-coupling of dichlorosilanes. For example, Wood reported higher

ceramic yield using THF and lower yield using hexane. Seyferth et al.'s results indicated

that non-polar solvents are useful in dehydrogenative cross-linking of low molecular

weight polysilanes prepared by the Wurtz-coupling method.) Furthermore, there

appears to be a level of catalyst concentration above which the pyrolysis yield does not

change significantly, but below which the pyrolysis yield decreases.

Zhang et al. [Zha91; Zha94A; Zha94B] studied the pyrolysis behavior of

polymethylsilane polymers prepared by dehydrocoupling of methylsilane in the presence

of a DMZ (Dimethyl Zirconocene) catalyst. Ceramic yields were ~60% when the polymer

did not contain any processing additives and ~75% when 5-20% processing additives

were added (Figure 2.13). (The chemistry of the processing additives was not specified.)













Table 2.8. Pyrolysis results for catalytically cross-linked polysilane polymers [Sey93]a.

% Catalyst Solvent Reaction Polymer Pyrolysis yield, %
(DMZ) mol% condition appearance

1.0 Hexaneb 30 min/reflux Orange solid 62
0.57 Hexaneb 30 min/reflux Orange solid 74
0.54 Hexaneb 30 min/reflux Orange solid 81
0.14 Hexaneb 30 min/reflux Yellow wax 40

0.56 Benzenec 30 min/reflux Orange solid 72
0.37 Etherd 30 min/reflux Yellow Oil 23
0.38 THFe 30 min/reflux Yellow Oil 31
0.48 Hexane 16 h/ 25" C Yellow solid 67
0.47 Hexaneb 2 h/reflux Orange solid 62

Reflux temperatures: b 68.7"C; c 80.1*C; d 34.9*C; 0 66*C
a The polymethylsilane polymer used for these experiments was PMS-I, prepared by Wood by Wurtz-
coupling reaction of methyldichlorosilane with sodium in hexane. The ceramic yield for this polymer was
-25 wt%.


































Temperature (oC)


Figure 2.13. TGA plots for polymethylsilane polymer prepared by Zhang et al. [Zha94]








The pyrolyzed ceramic residue had an elemental composition of 69 wt% Si/ 31wt% C

(i.e., close to stoichiometric composition). The bulk of the weight loss is shown to occur

between 200C and 600C in a gradual manner. This weight loss behavior is

different from that of Wood's polymethylsilane polymers (prepared by Wurtz coupling

reaction), where weight loss is reported to occur between 130C and 410C. (The

heating rates were comparable, i.e., 10C/min to 10000C.) Zhang et al. also studied the

chemical evolution of the polymethyslilane polymer during pyrolysis to 1100C using

diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Figure 2.14

shows DRIFT spectra of polymethylsilane polymer heated to selected temperatures

at 1 C/min in nitrogen and held at temperature for 0.5 h. The 400C spectra shows

the appearance of a strong peak at ~1350 cm-1 attributed to the bending

vibration of Si-CH2-Si group. (This is analogous to the thermal rearrangement taking

place during the conversion of polydimethylsilane to polycarbosilane.) Schmidt et al.

[Sch91] have reported similar observations. At 600C, the polymer is shown to lose well-

defined molecular structure with the only peaks remaining attributed to v (C-H) of CH3

(2896 cm-1), v (Si-H) (-2068 cm-'), and 6 (CH2) of Si-CH2-Si (at 1354 cm-'). These peaks

disappeared at temperatures >800C, and the spectra showed absorptions in the

region of 400 cm-1 to 1000 cm-' corresponding to 3-SiC.

Recall that linear polysilanes prepared by the Wurtz-coupling reaction of dialkyl

or monoalkyl chlorosilanes have ceramic yields of only up to < 25% [Bur49; Qiu89;

Woo84]. Schilling and Kanner [Sch88] reported that when olefinic halosilanes are

used as monomers in the Wurtz-coupling reaction with sodium, the resultant polysilanes

contain olefinic groups which act as backbone branching sites and cause in-situ cross-

linking. This resulted in relatively higher ceramic yields (38-50%) for these polymers.












































1_,
1 400 OC




200 0C



RT




4000 3000 2000 1000
400.0
Wavenumbers


Figure 2.14. DRIFT Spectra of PMS polymer, prepared by Zhang et al. [Zha94].








The olefin groups in olefinic halosilanes do not react with sodium and, therefore, are

retained in large amounts in the polymer.

Schmidt et al. [Sch91] have studied the pyrolysis characteristics of vinylic

polysilane (VPS) (manufactured by Union Carbide Corporation, Tarrytown, NY based on

Schilling and Kanner's patent [Sch88]). The polymer was prepared using Me3SiCI,

Me2SiClI, CH2=CHSiMeCI2 monomers in 0.85 :0.3: 1 proportion under refluxing

conditions in a xylene/THF mixture (7:1 wt ratio). The TGA profile of the VPS polymer is

shown in Figure 2.15. The pyrolysis process can be divided into three distinct regions

based on the TGA of profile: (i) ~ 50-300*C, where thermal cross-linking occurred

without much loss of weight, (ii) ~300-750C, where major weight loss occurred due to

polymer degradation, and (iii) above 750C, where small weight losses were observed.

The ceramic yield was ~58%, which is slightly higher than that reported by Schilling and

Kanner. The DTA showed a strong exotherm at around 2500C, corresponding to cross-

linking reactions, and a weaker exotherm (at about 4500C) during regime of large

weight loss. Schmidt et al. suggested that the exotherm at about ~1100C may be

indicative of partial crystallization of silicon carbide. Elemental analysis of the ceramic

formed after pyrolysis at 1000C showed a composition of 55% Si, 40% C, 2.7% 0, and

less than a percent each of H and N. The presence of excess carbon (-17 wt%) in the

ceramic is not surprising, considering the fact that vinylic groups are retained in the

polymer backbone due to early cross-linking reactions at temperatures less than 300*C.

The transmission IR spectra of as-received VPS and VPS heat-treated at temperatures

of 2500C, 4000C, 650C and 10000C in nitrogen atmosphere are shown in Figure 2.16.

Table 2.9 [Qiu89B; Col64] lists the IR peak assignments for the VPS polymer. The VPS

polymer undergoes following changes upon heating to 250C: (i) decrease in






















105


-5

4

3

-2

o ?
0
2





-1


1500


Temperature (oc)









Figure 2.15. TGA and DTA plots for a VPS polymer heated in N2 at 20C/min to 1200C
[Sch91].








Table 2.9. Peak assignments for IR absorption spectra of vinylic polysilanes [Qiu89B;
Col64]


Peak (cm-')

3048 (m)

2952 (s)

2894 (s)

2078 (s)

1732 (w)

1582 (w)

1397 (s)

1246 (vs)

1000-1100 (s)

937 (m)

750-850


Assignment

v (CH=CH2) of Si-CH=CH2

v,, (C-H) of CH3

v, (C-H) of CH3

v (Si-H)

v (C=O)

v (C=C) of Si-CH=CH2

8 (Si-CH=CH2)

(8 (CH3) from Si-CH3

o (CH2) from Si CH2- Si,v (Si-O-Si)

5 (Si-H)

v., (Si-C)


v = stretching ; 8 = bending ; (o = bending ; p = rocking; vs = very strong; s = strong;
m =medium; w = weak











4000


w
z
O




Z

I- ,


3000 2000 100 1200 800 400
. 1 I I I 1


4000 3000 2000 1800 1200 800 400

WAVENUMBER (cm-')



Figure 2.16. IR spectra of VPS polymer; (a) room temperature (b) 250C (c) 400*C (d)
6500C (e) 10000C [Sch91].








asymmetric stretching of CH2 band (3048 cm-" (ii) decrease in intensity and broadening

of Si-CH=CH2 deformation band (1397 cm-1), (iii) slight decrease in both the intensity

and area, and broadening of the Si-H stretching band (2078 cm'1), and (iv)

appearance of bending vibration at 1640 cm-', due to C-H bending vibration of Si-

CH=CH2. The decrease in intensity and broadening of Si-CH=CH2 band is attributed to

loss of vinyl groups due to cross-linking reactions. The increase in Si-H absorption band

at 4000C could be attributed to methylene insertion reactions, similar to the reactions

occurring in the conversion of polydimethylsilane to polycarbosilane [Yaj78B]. The

absorption band at 1642 cm-' due to the C-H bending vibration of Si-CH=CH2

disappears beyond 250C due to the loss of vinylic groups.

Abu-Eid et al. [Abu92] have also studied the pyrolysis behavior of polysilane

polymers prepared by Wurtz-coupling of monoorganosilanes ( R'R2SiCI where R' =

CH3 and R2=H, C2H, C3H7, C4H9, CH,,, C8H17 or C6H5 ) with sodium in an inert solvent.

Table 2.10 shows information regarding the polymer characteristics and the pyrolysis

behavior. According to Abu-Eid et al., the high ceramic yield for polymethylsilane (

(CH3SiH), ) is due to an early onset of intermediate carbosilane formation and cross-

linking of Si-H functionalities (e.g., reaction with moisture to form Si-OH, and

subsequent condensation to form Si-O-Si networks). The relatively high ceramic yield

for polydimethylsilane (-25%) is not consistent with values (-1%) reported by Wood

[Woo84] and Carlsson et al. [Car90]. For other dialkyl or alkylaryl polysilanes listed in

the table, the low ceramic yields are consistent with previously reported values.


















Table 2.10. Ceramic yield characteristics and decomposition temperatures for polysilane
polymers synthesized by Abu-Eid et al. [Abu92].

Polymer Type Theor. SiC Actual % of Onset of End of
yield,% ceramic Theor. decomp. decomp.
yield,% yield temp, *C temp, C
[(CH3)2Si], 69.0 25.0 36.0 240 610
[(C2Hs)2Si], 46.5 7.0 15.0 170 600
[(CH3SiC3H7)]n 46.5 7.8 17.0 330 650
[(CH3Si-n- 40.0 2.5 6.3 280 500
C4H,)],
[(CH3Si-n- 25.6 11.2 43.8 260 540
C.H17)]n
[(CH3SiH)], 91.0 60.0 66.0 240 750
[(CH3SiC6H5)], 33.3 21.5 64.6 270 520








2.4. Cross-linking of Polysilane Polymers

Polysilane polymers exhibit a wide range of properties based on the pendant

substituent groups in the polymer chain and the degree of cross-linking. The physical

appearance of the polymer could range from that of a viscous liquid (e.g.,

polymethylsilane) to a solid (e.g., polymethylphenylsilane) depending on the molecular

architecture of the polymer (cross-linking, molecular weight, side groups etc.). The

polymers can be cross-linked by oxidation, room temperature vulcanization, and

photolysis.

2.4.1 Oxidative cross-linking

Oxidative cross-linking of polysilane polymers can be accomplished by

converting Si-H groups in the polymer to Si-O-C or Si-O-Si groups by reacting with air or

moisture. These oxidatively cross-linked polymers are insoluble in organic solvents and

do not melt (i.e., infusible) during pyrolysis to silicon carbide. The degree and rate of

cross-linking depends on the amount of Si-H groups present in the polymer. Figure 2.17

shows an FTIR spectrum of a polymethylsilane polymer which clearly demonstrates the

air sensitivity of these polymers as indicated by the broad absorption band around 3450

cm1. (This absorption is due to Si-OH stretching which arises from conversion of Si-H.)

The oxygen sensitivity of the polysilane polymers is attractive for some applications

(e.g., multilayer lithography), but the incorporation of oxygen is sometimes not desirable

if the polymer is used as a SiC precursor.

2.4.2 Room temperature vulcanization

The Si-H groups present in the polysilane polymers have been exploited in the

preparation of highly cross-linked polymers by catalytic dehydrogenation (see section

2.3).







61




















0.6873



0.6145



0.5417



s 0.4689



0.3961



0.3233



0.2505 I I I
4000 3600 3200 2800 2400 2000 1600 1200 800 400

Wavenumber (cmn')










Figure 2.17. FTIR spectrum of polymethylsilane polymer prepared by Abu-Eid et al.
[Abu92]








West et al. [Wes86B] have cross-linked Si-H containing polyphenylsilane polymers by

using a vinylic silane monomer (e.g., trivinylphenylsilane, trivinylmethylsilane) as the

cross-linking agent in the presence of traces of chloroplatinic acid as a catalyst. During

the reaction, the initially viscous reaction mixture transforms to a solid polymer, which is

insoluble and infusible (a process analogous to room temperature vulcanization of

silicone elastomers). The cross-linking reaction can be represented as:


Ph Ph Ph

-Sii _Si

H H H


- n


-Si -

Vi -- Si-Ph
I H2PtCI6 I I
+ Vi-Si-Ph ------ -Si--Si-Ph + C2H
I I
V, Ph -Si-Ph

_Si-
1


(2.10)


Vi CH=CH2

Ph C6Hs





2.4.3 Photo-cross linking

Qiu and Du [Qiu89B] have shown that when polysilane polymers such as

polymethylsilane and polyphenylsilane were irradiated with UV light of wavelength 254








nm in nitrogen or vacuum, cross-linking of the polymer occurred with the formation of

insoluble material. One of the disadvantages of photo-cross linking is that some

degradation of polymer molecular weight (due to photo-scission) always accompanies

photo-cross linking (as shown by equations (2.11), (2.12), and (2.13)). However, West et

al. [Wes86B] observed that when a cross-linking agent containing C=C double bonds

(e.g., tetravinylsilane) was mixed with the polymer and then irradiated with UV light, no

degradation in molecular weight occurred and all of the polymer converted to an

insoluble material. The photo cross-linking takes place by cleavage of polysilane chains

to form radicals and addition of these radicals to C=C double bonds of vinylic silanes

(polyunsaturated additives), causing formation of cross-links and generation of new

carbon radicals. These new carbon radicals sustain further cross-linking reactions

(equation (2.14)). The reactions can be represented as given in Figure 2.18.



2.5. Applications of Polysilane Polymers

There are three main technological applications of polysilane polymers: (i)

precursors for P-SiC, (ii) photoinitiators for radical polymerization reactions, and (iii)

photoresists in microelectronics.

2.5.1 Precursor for B-SiC

Yajima and Hasegawa [Yaj78A; Yaj78B; Has83A; Has83B; Has86; Ich86;

Has89] pioneered research in the preparation of 3-SiC from polysilane-based

preceramic polymers. They first synthesized polydimethylsilane (PDMS) by Wurtz-

coupling of dimethyldichlorosilane with sodium in xylene at 135C and then converted

the insoluble PDMS to a soluble polycarbosilane by pressure pyrolysis at ~450C. The










fR Rf hv
------- -Si -Si------- 2

RI I
R1 R1


R2

-Si

R


I I I
R1 R1R




-------Si -Si -Si-------

SRI I
R1 R1R


hv
---


Si: + 2

R1


R2 RI
hv R2
S--Si: + -------Si
R/ RI
"1 R,


R2

- Si.

RI


Rf
Si -------

Ri


where R1= n-C4H11, n-C6H13, or c-C6H,;
R2= C-C4H11 or CH3


R2

------- Si. +

RI
R1


R2
hv I
t rated v p--- Nei C o a
Polyunsaturated vhyl corrpound I New Carbon radical
RI


Figure 2.18. Scheme for photo cross-linking reactions of polysilane polymers


(2.11)


(2.12)


(2.13)


(2.14)








conversion of PDMS to PCS takes place by Kumada rearrangement [Shi58], in which

insertion of CH2 groups into the main chain Si-Si takes place, leaving a hydrogen bound

to silicon, as shown below:




H3 H3 Argon CH3 H
I I Argon I I
--Si-Si --Si-C-- (2.15)
0I I 450 I I
CH3CH3 H H
n-


PDMS PCS



Yajima et al. melt spun the polycarbosilane polymers (Me,3,000) into fibers and

subsequently converted them to SiC by pyrolysis. The fibers required an air-curing step

(~200*C, 2-4 h) to render them infusible during pyrolysis to silicon carbide. These fibers,

commercially produced as NicalonTM fibers (by Nippon carbon company, Tokyo, Japan),

degrade rapidly at temperatures in excess of 1400C due to carbothermal reduction

reactions between siliceous material and carbon. This leads to evolution of volatile

species (primarily CO and SiO) which results in large weight losses, formation of

porosity, and growth of SiC grains and other strength degrading flaws in the fiber

structure. In recent years, a lot of attention has been directed toward improving the

thermomechanical stability of fibers derived via organosilicon polymer route. A method

developed at University of Florida involves preparation of fibers ("UF Fibers") by dry

spinning of high-molecular-weight polycarbosilanes. SiC fibers were produced with low

oxygen content and either carbon-rich (non-stoichiometric) or near-stoichiometric

composition [Tor92A; Tor92B; Tor94; Sac95A; Sac95B]. Non-stoichiometric UF fibers








have room temperature mechanical properties similar to that of NicalonM fibers, with

average tensile strengths ~3 GPa. In addition, UF fibers showed significantly improved

thermomechanical stability compared to Nicalon, as indicated by lower weight losses,

lower specific surface areas, and improved strength retention after heat treatment to

1700C. Near-stoichiometric UF fibers ("UF-HM Fibers") have high tensile strengths

(2.1-3.4 GPa), fine grain sizes (mostly -0.1-0.2 pm), high bulk densities (-3.1-3.2 g/cm3)

and small residual pore sizes (mostly 0.1 pm). These fibers retained -93% of their

initial strength after heat treatment in argon at 18000C.

It is also possible to convert polysilane polymers to silicon carbide fibers directly

without resorting to the preparation of intermediate polycarbosilane polymers. As

discussed in section 2.1.6, West et al. [Wes81; Wes86A] have prepared

phenylmethylsilane-dimethylsilane copolymers, (Polysilastyrene (PSS)), which afford

improved processability over PDMS. However, the fibers prepared from these polymers

require a cross-linking (curing) step to make them infusible in order to survive pyrolysis.

Since the polymers lack Si-H groups (eliminating the possibility of air-curing), the only

operative cross-linking mechanism is by UV irradiation. Thermomechanical data on the

fibers prepared by this method have not been reported.

Lipowitz et al. [Lip89] have prepared SiC fibers from methylpolysilane (MPS)

polymers, synthesized based on Baney et al.'s redistribution/substitution reactions of

methylchlorodisilanes (as discussed in section 2.2.6). Fibers were melt spun, cross-

linked (cured) and converted to SiC by pyrolysis. By varying the ratio of alkyl to phenyl

Grignard reagents (used to react the intermediate methylchloropolysilane polymer),

fibers with composition ranging from silicon-rich through stoichiometric to carbon-rich

were produced. The method of cross-linking was not specified but the relatively low








oxygen content in the fibers (0.6-6.0 wt%) compared to Nicalon TM suggests that air-

curing step was not used. The low oxygen content in the fibers contributed to improved

thermomechanical stability of these fibers over that of NicalonTM fibers.

More recently, Lipowitz et al. [Lip91A; Lip91B; Lip94A; Lip94B; Lip95] developed

near-stoichiometric, polycrystalline SiC fibers using polycarbosilane and

methylpolydisilylazane polymers. Fibers were melt spun, oxidatively cross-linked, and

heat treated at temperatures above 16000C in argon in order to react excess carbon

and oxygen in the fibers. As noted earlier, PC-derived fibers normally become very

weak and develop a porous, large-grained microstructure during this type of heat

treatment. However, Lipowitz et al. incorporated a boron-based sintering additive in the

polymer which allowed fibers to be densified after the carbothermal reduction reactions

discussed earlier. The resulting fibers had fine diameter (8-10 pm), high relative density,

small average grain sizes (in the range -0.03-0.5 pm, depending on the Si:C ratio), low

oxygen content (<0.1%), high tensile strength (2.6 GPa), high elastic modulus (up to

420 GPa), and good strength retention after high temperature (18000C) heat treatment

in argon. The key limitation in this process was apparently a difficulty in producing

continuous fibers.

Takeda et al. [Tak94] have reported the development of low-oxygen-content (0.4

wt%), fine-diameter (-15 pm) SiC fibers. These fibers ('Hi-Nicalon') were prepared in a

similar manner as Nicalon (i..e., by melt spinning of polycarbosilane) except that cross-

linking was accomplished by electron beam irradiation instead of oxidation. The high

temperature stability of the fibers increased dramatically as the oxygen content of the

fibers decreased. Fibers with 0.5 wt% oxygen retained high strength (-2.4 GPa) and

high modulus (-250 GPa) after heat treatment at 1500C in argon. These fibers had a

chemical composition of 62% Si, 37.5% C, and 0.5 wt% O. The main drawback of this









method is that cross-linking of the polymer by electron beam irradiation is a slower and

expensive processing step. More recently, Takeda et al. [Tak95] produced near-

stoichiometric SiC fibers ('Hi-Nicalon Type S') by a modified Hi-Nicalon process. These

fibers had a chemical composition of 69% Si and 31% C, and exhibited better

thermomechanical than Hi-Nicalon fibers.

Zhang et al. [Zha91; Zha94A; Zha94B] have solution-spun fibers from

polymethylsilane polymers (see section 3) and converted them to SiC fibers by

pyrolysis. Since the precursor polymer was low in molecular weight, it required addition

of a cross-linking agent (unspecified chemistry) to render the fibers infusible. The

additive also acted as a spinning aid for the polymer, in addition to providing extra

carbon to adjust the stoichiometry of the ceramic produced to that of pure SiC. The SiC

fibers produced by Zhang et al. had near-stoichiometric composition. Dense fibers were

produced by adding a boron-based sintering additive. DRIFT spectra of the 1000C

pyrolyzed fibers showed the presence of a small amount of oxygen (exact amount not

determined). This was attributed to contamination during to handling, as PMS polymers

are very sensitive towards air. Thermomechanical stability data on these fibers indicate

that they are superior to commercially available NicalonTM fibers, although no directly

comparable data was reported.

Seyferth et al. [Sey92] have demonstrated the potential for production of near-

stoichiometric SiC fibers from polymethylsilane polymers which are catalytically cross-

linked (see section 2.2.2). However, the fibers need an additional curing step, which can

be brought about by UV irradiation. Information on thermomechanical properties on

these fibers is not available.








2.5.2 Photoinitiators for Radical Polymerization

The ability of polysilane polymers to form silyl radicals on photo-irradiation has

been exploited in the free radical polymerization of styrene, methyl methacrylate etc.

Table 2.11 lists a variety of monomers that can be polymerized by using polysilanes as

photoinitiators. One disadvantage with the use of polysilanes as photoinitiators is that

rate of polymerization is low when compared with conventional photoinitiators such as

benzoin methylether.



Table 2.11. List of polysilanes that can be used in radical polymerization [Wes88].

Polysilanes used Monomers polymerized
(PhC2H4SiMe), Styrene
[(PhC2H4SiMe)o8(Me2Si),.01n Ethyl acrylate
[(PhC2H4SiMe),. (PhMeSi)o.6]n Methyl methacrylate
(PhMeSi)n Isooctyl acrylate
[(PhMeSi)(Me2Si)l] Acrylic acid
[(CyHexSiMe)n] Phenoxyethyl acrylate
[(CyHexSiMe)o.7(Me2Si) ]ln 1,6-hexanediol diacrylate


However, this disadvantage is more than compensated by the fact that the silyl radicals

are insensitive to termination of polymerization by oxygen. This is beneficial because

less rigorous control over atmosphere is needed. Although, speculative in nature, this

oxygen insensitivity is attributed to scavenging of oxygen by secondary species formed

during photolysis [Wol88].

2.5.3 Photoresists in Microelectronics

The current technology in microelectronics is geared towards use of sub-micron

features in the integrated circuit chips, leading to an increase in aspect ratio








(height/width) of features in IC chips [Mil88; Mil90A; Mil90B]. The classical single layer

resist process used in microlithography has been found to be inadequate when dealing

with current trends and lithographers have resorted to multilayer resist processes to

meet the current requirements. Figure 2.19 shows a comparison of single layer

process vs multilayer process [Mil88]. The classical single layer resist process (wet

development) involves exposure of the resist and development of a pattern using a

suitable solvent. There is a loss in line width control for small features since wet

development processes are isotropic. In the case of multilayer photoresist process, the

wafer is covered with a thick, inert planarizing polymer layer followed by a thin layer of

photoresist. High resolution in line width can be achieved since the resist layer can be

thinner than what is acceptable in single layer resist process (0.05- 0.2 pm compared to

-1 pm for single layer resists). Subsequently, the pattern can be wet developed (without

loss in resolution) or dry developed during imaging ablativee exposure) down to the

planarizing layer and the image can be transferred through the planarizing layer by 02-

RIE (oxygen resistant ion etching). A necessary requirement for the multilayer resist

process is that the photoresist remaining after developing must be resistant to Oz-RIE, in

order to mask the underlying polymer effectively. Polysilanes have been found to be

ideally suited for use as photoresists since they are stable to 02-RIE by forming a thin

layer of inert SiO2. In addition, polysilanes possess excellent processing properties such

as good thermal stability, solubility for coatings, and imageability to light and ionizing

radiation.











Wet Development (single layer)


r*-- Resist
-ili Substrate


Coat


- Mask


Expose




Develop




Etch





Strip


Dry Development (multilayer)


,- Resist
/// Planarizing Layer
-- Substrate


-- Mask

Expose


Develop



Dry Etch
02-Plasma


Etch


Strip


Figure 2.19: Comparison of single layer photoresist process vs. multilayer photoresist
process [Mil88].


r- -


--M r'-1 '-













CHAPTER 3
EXPERIMENTAL PROCEDURES


3.1 Role of Polyvinylsilazane as a Spinning Aid for Polycarbosilane

3.1.1 Polymer synthesis

PSZ was synthesized according to the procedures developed by Toreki et al.

[Tor90]. This involved polymerization of a cyclic vinylsilazane (1,3,5-trimethyl-1,3,5-

trivinylcyclotrisilazanet) (see Figure 3.1) in the presence of a radical initiator, dicumyl

peroxide (DCP). The reaction assembly used for PSZ synthesis is shown in Figure 3.2.

In a typical PSZ synthesis, 20 g of cyclic vinylsilazane monomer was mixed with 0.090 g

of DCP and 7.5 g of toluene in a 50 ml double-necked flask. Polymerization was typically

carried out under nitrogen at a temperature of 125C for 18 h.

H
I
N
CH3\ /\ /CH3
CH2=CH Si Si- CH=CH2


H--N N --H

\Si/
CH2=CH CH3



Figure 3.1. Structure of 1,3,5-trimethyl-1,3,5-trivinylcyclotrisilazane


*Petrarch Systems, Bristol, PA.



















WATER OUTLET*--













TOLUENE+ MONOMER+ DCP


TO FUME
HOOD

BUBBLER



, 4--- WATER INLET


BATH


MANTLE


Figure 3.2. Schematic of reaction assembly for PSZ synthesis








The molecular weight of PSZ was controlled by selectively removing low molecular

weight fractions ('oils') by fractional distillation using an oil bath at temperatures ranging

from 125 to 150C.

Polycarbosilane (PCS) was synthesized according to the methods reported by

Toreki et al. [Tor92] and procedures developed at University of Florida. PCS was

synthesized by pressure pyrolysis of polydimethylsilanet in a stainless steel autoclave*

under a nitrogen atmosphere at ~4500C. PCS polymers were prepared and supplied for

this study by coworkers at University of Florida. PCS lots 268, 269, and 262 (combined

in 3:2:1 proportion) were used in this study. The average molecular weight was

~11,000. (The GPC molecular weight distribution for the combined PCS polymer is

discussed in section 4.1.1.) This relatively high molecular weight PCS not only enabled

preparation of highly concentrated solutions (e.g., typically ~70 wt%), but also allowed

fibers to be pyrolyzed without melting.

3.1.2 Spin dope preparation, fiber spinning, and fiber heat treatment

The Influence of polyvinylsilazane (PSZ) as a spinning aid and a cross-linking

agent in the low temperature heat treatment of PCS fibers was investigated in this study.

Two types of polymer solutions were prepared for fiber spinning: one containing 14.5

wt% PSZ and the other without any PSZ. The PCS polymers used in this study were

dried in a vacuum furnace for 12 h to remove any adsorbed moisture, traces of solvent,

etc. prior to solution preparation. The dried PCS polymers were then dissolved in

toluene at 33 wt% solids loading. For use in fiber spin batches, PSZ was dissolved in

toluene at 25 wt% solids loading, filtered through a 0.1 pm filter, and mixed with the PCS

solution.


tNisso Company, Tokyo, Japan
* Model 4651, Parr Instrument Company, Moline, IL.








The polymer solutions were filtered through 0.1 pm filter and concentrated in a

rotary evaporator at -50C until ~25-30 wt% solvent remained. A 'flow test' was

used as a rough indication that an appropriate viscosity for fiber spinning was attained.

The flow test was carried out by tilting the glass vial containing the concentrated

polymer solution at a 450 angle and measuring the time taken for the solution to travel

2.5 cm. (A fixed size of glass vial was used for concentrating the polymer solution and

carrying out the flow test.) Use of the flow test minimized the number of iterations

needed to reach the optimum viscosity for fiber spinning and enabled conservation of

spin dope material (i.e., by not making any theological measurements until just before

the concentrated polymer solution was ready for fiber spinning). The theological

characteristics of the final polymer solution were determined by using a cone-plate

viscometer'. Approximately 0.5 ml of the concentrated polymer solution was used for

the measurement. The measurements were made first by increasing the shear rate

from 1 to 40 s1' and then decreasing the shear rate back to 1 s'1. A toluene-soaked

paper tissue was wrapped around the inside periphery of the cylinder containing the

concentrated polymer solution in order saturate the local atmosphere with toluene and

thereby to minimize evaporation of toluene from the polymer solution during the

measurement. Care was taken to make sure that toluene-soaked paper tissue did not

come in contact with polymer solution or interfere in the measurement in any other way.

Fiber spinning was carried out inside a glove box5 The glove box was purged

with nitrogen three times prior to each spinning experiment. The spin dope was

transferred to a spinneret assembly inside the glove box. Four-hole spinnerets of -70

pm hole sizes were used for fiber spinning. Care was taken to clean the spinnerets


Model HBT, Brookfield Engineering Laboratories,Inc., Stoughton, MA.
Model 50001, Labconco Corporation, Kansas City, MO.








thoroughly before spinning to ensure that there were no particulates blocking the

spinneret holes. The face of spinneret was wiped clean with a toluene-soaked paper

tissue prior to commencement of spinning. Continuous 'green' fibers were formed by

winding on a wheel which was placed approximately 30 cm from the spinneret face.

The spinning conditions (winding speed, nitrogen pressure, and solution viscosity) were

kept constant to enable comparison of fibers produced with and without PSZ. The

solution viscosity was -35-40 Pa-s, the applied gas pressure during spinning was 400

psi, and the speed of the fiber collection wheel was -210 rpm (-440 linear ft/min). The

spinning behavior was documented by noting the number of fiber breaks occurring at

regular intervals of time. After fiber spinning, batches (typically < 0.5-1 g) were cut from

the wheel. These bundles were wrapped in aluminum foil as an ~ 24 cm bundle, then

cut into four ~ 12 cm long bundles, labeled, and stored in a vacuum desiccator for at

least 12 h (to remove some of the residual solvent from fibers) prior to pyrolysis. Some

fibers were pyrolyzed by heating in a tube furnace in nitrogen at 13C/min to 1150C (1

h hold at temperature). The flow rate of nitrogen used for pyrolysis was 30 std. atm

cc/min.

In order to study the effect of oxidative cross-linking on fiber mechanical

properties, several batches of PCS and PCS+PSZ fibers were heat-treated in flowing air

to temperatures of 180 10C in a tube furnace. The flow rate of air was 50 std. atm

cc/min. The heating schedule used was: 1C/min to 500C, 18 min hold at 50*C, 1C/min

to 650C, 18 min hold at 650C, 1C/min to 80C, 12 min hold at 80*C, 1C/min to 95C,

18 min hold at 950C, 1C/min to final temperature (180 100C), 1 h hold at temperature.

PCS and PCS+PSZ (green and air-heat treated) fibers were also heat-treated in flowing

nitrogen (30 std.atm cc/min) in a tube furnace for 1 h at temperatures in the range of








200-1000C. The heat treatment rate was 1lC/min to 1500C and 40C/min from 150C to

the final temperature.

3.1.3 Characterization of PCS polymer solutions

The molecular weight distributions of PCS polymers were determined by Gel

Permeation Chromatography (GPC)' using polystyrene columns and standards and

THF (tetrahydrofuran) as the solvent. PCS solutions for GPC were prepared by mixing

0.5 wt% of polymer in THF and filtering the solution through a 0.1 pm filter. Polymer

solutions were passed through 1000 A and 500 A columns connected in series. The

mobile phase for the columns was THF. GPC for PSZ polymers were analyzed using

10,000 A and 1,000 A columns connected in series. THF could not be used as the

mobile phase for PSZ since the chromatogram showed no clear elution peaks

corresponding to the different molecular weight species in the polymer (i.e., the

chromatogram showed a broad peak and a valley). For this reason, toluene was used

as the mobile phase and the PSZ polymers were dissolved in toluene (0.5 wt%) instead

of THF. The columns were conditioned by purging toluene through them for 24 h prior to

analysis.

The intrinsic viscosities of polymer solutions were determined according to

ASTM D-446 procedure by employing a Ubellohde Viscometer (type OC)1 The

measurements were carried out in a water bath maintained at 300C and the

concentrations of polymer solutions used ranged from 2 to 6 wt%. The efflux time t

required for the solution to pass through the capillary of the viscometer between marked





Waters600E Systems Controller, Waters410 Differential Refractometer and Waters707 Autosampler,
Millipore Corporation, Waters Chromatography Division, Milford, MA.
t Phenomenex Corporation, Torrance, CA.
11 Industrial Research Glasswares Ltd, Union, NJ.








lines was measured. The corresponding efflux time to for the pure solvent (toluene) was

also measured. The specific viscosity lsp was determined according to formula:

lsp = (t-to)/to (3.1)

The intrinsic viscosity [ri] was calculated according Huggins equation:

lsp/c = [1] + k' [1]2 c (3.2)

where c is the concentration of the polymer solution used in the measurement, in g/dl.

[re] was determined by plotting "rs/c vs. c, and extrapolating the straight line to c=0.

Contact angle measurements of polymer solutions were carried out using the

sessile drop method and a Contact Angle Goniometer5. In the sessile drop method, a

liquid droplet is deposited on a solid substrate, as illustrated in Figure 3.3.

Measurements were made of the angle formed by the intersection of a line along the

solid-liquid interface and a line tangent to the droplet surface, both of which pass

through the three-phase (solid-liquid-vapor) intersection point. The substrates used for

measurement were stainless steel, teflon, and stainless steel which were first coated

with PCS or PCS+PSZ. The concentrations of polymer solutions (PCS and PCS+PSZ)

were 33 wt%. The stainless steel (2 cm x 2 cm) and teflon substrates (3 cm x 3 cm)

were cleaned in an ultrasonicator bath followed by rinsing in acetone and drying in an

oven at 700C for 30 min. (The teflon substrate was polished on 1 pm diamond wheel for

20 min to obtain a smooth surface prior to measurement.)

Initially, contact angles of water and toluene were measured on teflon and

stainless steel substrates to enable comparison with reported values in literature. Both

advancing and receding contact angles were measured using the drop-buildup and

drop-withdrawal methods. A Hamilton syringe, calibrated up to 0.5 ml was used for


Rame-Hart, Inc., Mountain Lakes, NJ.
tt Model FS 28, Fisher Scientific, Pittsburgh, PA.




Full Text
378
Table G-1. Weight loss data for air-heat treated and non-air heat treated PCS and
PCS+PSZ fibers after pyrolysis at 1150C in nitrogen.
Batch
Number of batches
Weiqht loss (%)
Standard deviation
PCS
18
22.7
2.3
PCS+PSZ
15
22.5
2.8
PCS (air-heat
treated)
2
12.2
0.5
PCS+PSZ (air-heat
treated)
3
15.3
0.2


353

re
CL
(A
O
O
(A
>
60
50
40
30
20
10
0
O Increasing Shear Rate
Decreasing Shear Rate
o§ §
o
-Q
T
(B)
0 5 10 15 20 25 30
Shear Rate (s'1)
Figure A-3. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for batch 69s spin dope (PCS) (solids concentration
~66 wt%).


Intensity (Kubelka-Munk units)
176
A
-v(Si-H) [2100 cm'1]
-vas(C-H) ofCH3 [2950 cm'1]
- vs(C-H) of CH3 [2894 cm'1]
-5as(CH3) ofSi-OHj [1407 cm'1]
100 200 300 400
Temperature (C)
500
600
700
Figure 4.43. Intensity vs. temperature from FTIR spectra of PCS+PSZ
fibers (batch 70s).


210
Tables 4.13 and 4.14 show the average tensile strengths and diameters for
various batches of PCS and PCS+PSZ fibers, respectively, which were pyrolyzed at
1150C in nitrogen. (The tensile strength data for individual fiber batches are shown in
Appendix H.) Histogram plots of the tensile strength and diameter distributions for the
combined batches of the PCS and PCS+PSZ fibers are shown in Figures 4.62 and 4.63,
respectively. As expected from the data shown for batches 69s and 70s (Table 4.11,
Figure 4.61a and Table 4.12, Figure 4.61b, respectively), the tensile strengths are
higher for batches prepared with PSZ. (As noted above, this is attributed to improved
spinning behavior which in turn, should result in fewer large defects in the bundles.)
Figure 4.61 shows that the average diameters for the two types of fibers were almost
the same. The distribution is somewhat broader for the PCS fibers. This might be due to
the increased frequency of breaks during spinning of the PCS fibers.
Figures 4.64a and 4.64b show plots of average tensile strength vs. temperature
of heat treatment (in nitrogen) for the PCS fibers (batch 65s) and PCS+PSZ fibers
(batch 70s) which were oxidized in air (180 10C) prior to the heat treatments. These
plots show the same data as in Tables 4.11 and 4.12. As noted earlier, fibers given the
initial air-heat treatment have higher strengths in the green state and after heat
treatment in nitrogen at 400C compared to the corresponding fibers without the initial
air heat treatment. Table 4.11 and 4.12 also show that this trend is observed after heat
treatments in nitrogen at other temperatures up to 500C. The PSZ has relatively little
effect on the tensile strengths of the air-heat treated fibers during the early stages of
heat treatment in nitrogen. Although Tables 4.11 and 4.12 show that the strengths of the
PCS+PSZ fibers are slightly higher than the PCS fibers up through the 500C heat
treatments, the differences are within experimental error of the measurements. Hence,
the strengths that develop as a result of these relatively low temperature heat


172
4.1.3.1.5 FTIR spectra of PCS+PSZ fibers during heat treatment in N,
Figure 4.41 shows FTIR spectra of PCS fibers containing 14.5 wt% PSZ
(PCS+PSZ) at 40C. Table 4.8 shows FTIR peak assignments for PCS+PSZ fibers. The
spectra shows all the major characteristic absorption bands due to PCS as well as a few
major absorption peaks due to PSZ, viz., the absorption peak at 1180 cm'1 (due to 5 (N-
H)), 3040 cm'1 (due to v (CH=CH2) from Si-CH=CH2), 1592 cm'1 (due to 5as (CH=CH2) of
Si-CH=CH2), 1180 cm'1 (due to 5 (N-H)), and 930 cm'1 (due to 8 (Si-N-Si)).
Figure 4.42 shows the FTIR spectra of PCS+PSZ during heat treatment to 600C
in nitrogen. Figure 4.43 shows plots of the intensities of various absorption peaks vs.
temperature for PCS+PSZ fibers. The absorption intensity of the Si-H groups increased
only slightly up to ~275C, remained constant until 440C and then started to decrease.
The intensity of the absorption band 5 (CH2) of Si-CH2-Si decreased slightly beyond
275C. The absorption intensity at 1020 cm'1 (due to co (CH2) of Si-CH2-Si) also
decreased at around ~300C. The intensity of absorption band at 1407 cm'1 (due to 5as
(CH3) of Si-CH3) decreased rapidly starting at 300C.
Figure 4.44 shows a direct comparison of PCS+PSZ spectra before and after
heat treatment in nitrogen at 600C. Figure 4.45 shows the subtraction spectra for the
same. It can be seen that the absorption intensity of 8as (CH3) of Si-CH3 at 1407 cm'1
decreased significantly after the heat treatment. In addition, the absorption intensities of
all bands due to PSZ disappeared after heat treatment at 600C. This observation is
also supported by the subtraction of the spectra for PCS fibers (69s) from the spectra
for the PCS+PSZ fibers (70s) at 40C (Figure 4.46) and 600C (Figure 4.47). At 40C,
the subtraction spectra clearly shows the presence of absorption bands due to PSZ.
After 600C heat treatment in nitrogen, the absorption bands due to PSZ were absent.


CONTACT ANGLE (Degrees) CONTACT ANGLE (Degrees)
119
40
35
30
25
20
15
10
5
0
0.00 0.02 0.04 0.06 0.08 0.10 0.12
DROP VOLUME (ml)
O Advancing Contact Angle
Trial #1
Receding Contact Angle
O
O
8
0

40
35
30
25
20
15
10
5
0
0.00 0.02 0.04 0.06 0.08 0.10 0.12
DROP VOLUME (ml)
Figure 4.10. Advancing and receding contact angles for PCS (33 wt%)/toluene
solution on stainless steel substrate as a function of cumulative drop
volume.
O Advancing Contact Angle
Receding Contact Angle
Trial #2
O

O

o

o

0


Intensity (Kubelka-Munk Units)
250
0 100 200 300 400 500 600 700
Temperature (C)
Figure 4.82. Intensity vs. temperature from FTIR spectra of PMS polymer F
(MDCS, MTCS (70:30 wt%); toluene, dioxane (50:50 vol%)).


11
Figure 2.2.
Effect of reactant addition rate on (PhMeSi)n molecular weight
distribution [Zei86],


103
thixotropy under the measuring conditions. The PCS and PCS+PSZ solutions showed a
slight decrease in viscosity at low shear rates. This is presumably because stress
measurement is inaccurate at low shear rates* Also, viscosity values were slightly
higher for down curves (i.e., decreasing shear rates) than for up curves (i.e.,
increasing shear rates) at low shear rates. This is probably due to some slight solvent
evaporation from spin dope during rheology measurements. (Solvent evaporation would
increase the polymer concentration and result in higher solution viscosity.)
The increase in solids loading for the PCS+PSZ solution in comparison with PCS
solution at similar viscosities may be explained as follows: The PSZ polymer (pure, not
containing any solvent) is a liquid and has a viscosity of ~18 Pa s. Figure 4.1 shows that
a PCS solution with 68 wt% polymer has a viscosity of ~39 Pa s. If some PSZ (with no
solvent) were added to the latter PCS solution, the overall viscosity of the new solution
would be lower. In order to raise the viscosity back to ~39 Pa s, it would be necessary
to remove some solvent. Hence, it is obvious that the mixed PSZ/PCS solution will have
a higher polymer concentration, compared to a pure PCS solution, at a fixed viscosity.
Table 4 1 shows the results obtained from spinning the PCS and PCS+PSZ spin
dopes. The detailed fiber spinning characteristics (i.e., number of breaks vs. time) for
individual fiber batches is presented in Appendix B. It is evident from the table that
addition of PSZ to PCS greatly improved the spinning of fibers. For example, PCS spin
dopes showed spin line breakage rates (i.e., number of breaks per minute per spinneret
hole) of ~ 0.4-3.1. In contrast, the rates were only ~0.1-0.3 for the PCS+PSZ spin
dopes. With less breaks (and, therefore, less interruptions of the fiber collection
* The shear stress vs. shear rate data is usually curve-fitted through the origin (linear fit) and the viscosity
vs. shear rate data is obtained from the curve-fitted data.


126
angles and (2) surface roughness of the substrates [Wu84; Her70], Wu et al. [Wu84]
have observed that hysteresis increases with increase in surface roughness. In the
present study, larger hysteresis was observed for measurements of water and toluene
on teflon compared to that observed for measurements on stainless steel (Figures 4.7a
and 4.8). This may be due to the greater roughness of the teflon substrates. (The teflon
substrates were polished on a 1 pm diamond wheel, but they still had rougher surfaces
than stainless steel.) It was also observed that PCS and PCS+PSZ solutions showed
greater contact angle hysteresis on teflon (Figures 4.12 and 4.13, respectively)
compared to the same solutions on stainless steel (Figures 4.10 and 4.11, respectively).
A large contact angle hysteresis was observed for the PCS solution on PCS-
coated stainless steel (Figure 4.14), i.e., compared to the hysteresis observed for the
PCS solution on uncoated stainless steel (Figure 4.10). The reason for this difference is
unclear. There was also a tendency for contact angle hysteresis to be greater with PCS
solutions compared to PCS+PSZ solutions. (This was most pronounced when coated
stainless steel substrates were used (Figures 4.14 and 4.15). In contrast, there was no
significant difference in contact angle hysteresis for the experiments with uncoated
stainless steel (Figures 4.10 and 4.11).) This effect may be related to the differences in
solvent evaporation rates from the solutions. As indicated in Figures 4.6a and 4.6b,
toluene evaporated at a higher rate in the early stages from a PCS solution (compared
to a PCS+PSZ solution).
4.1.2.4 Surface tension measurements
Experiments were carried out to determine if there were changes in surface
tension characteristics of the PCS polymer solution as a result of addition of PSZ to
PCS. In order to establish measurement protocols, surface tension experiments were
carried out for water, acetone, and toluene, and compared with published results


233
carried out using 30 wt% MTCS/70 wt% MDCS in toluene and 100% MDCS in toluene,
respectively).
4.2.3 Characterization of PMS polymers and ceramic residues resulting from pyrolysis
4.2.3.1 Weight loss behavior
The weight loss behavior of PMS polymers A-F were studied by Thermal
Gravimetric Analysis (TGA). The data on ceramic yield are presented in Table 4.15.
Figure 4.74 shows TGA plots for polymers prepared by polymerization of MDCS in
toluene (polymer A), toluene-THF (95:5 vol%) (polymer B), and toluene-1,4 dioxane
(50:50 vol%) (polymer C). The use of cosolvents (THF and dioxane) resulted in
polymers with slightly higher ceramic yields. Wood [W0086] also reported a beneficial
effect on ceramic yield when using a polar solvent in Wurtz-coupling polymerization.
When polymerization was carried out in a mixture of hexane and THF (7:1 by volume),
the ceramic yield was only ~25 wt%. However, when polymerization was carried out
entirely in THF, the resultant polymer had a ceramic yield of 55 wt%. The increase in
ceramic yield for polymers synthesized in polar solvents can be linked to the increase in
molecular weight (and presumably an increased degree of polymer cross-linking).
Figure 4.75 shows TGA plots for polymers prepared by polymerization of
MDCS/MTCS (70:30 wt%) in the presence of toluene (polymer D), toluene-THF (95:5
vol%) (polymer E), and toluene-1,4 dioxane (50:50 vol%) (polymer F). It can be seen
from the figure that ceramic yields for all the three polymers are approximately the same
and that the addition of polar solvents such as THF and 1,4-dioxane did not produce an
increase in ceramic yield even though it resulted in an increase in molecular weight. This
is contrary to what was observed in the case of polymerization of MDCS. It is presumed
that the ceramic yield is primarily determined by degree of cross-linking brought about
by addition of MTCS rather than the increase in molecular weight resulting from the use


Intensity (Kubelka-Munk Units)
178
A
8(N-H) [1180 cm'1]
v(CH=CH2)ofSi-CH=CH2 [3040 cm'1]
v(N-H) [3390 cm'1]
5as(CH=CH2) of Si-CH=CH2 [1592 cm'1]
700
Figure 4.43. (Cont'd.)


89
3.2.3 Determination of polymer yield
The actual polymer yield was determined by carrying out a solids loading test.
This was done as follows: two clean aluminum weighing pans were weighed before and
after adding 10 drops of polymer solution. The weighing pans were then quickly
transferred to a vacuum oven maintained at 65C and dried under vacuum for 2 h. The
weighing dishes were weighed after drying. Knowing the differences in weights of the
aluminum pans before and after drying, the solids loadings were calculated. The
polymer yield was calculated from the knowledge of total polymer solution in hand (after
rotary evaporation and dissolution in toluene). (Since this method doesnt take into
consideration the polymer trapped in the void space between Na/NaCI precipitates, the
actual yield is an underestimate.)
For polymers prepared from methyldichlorosilane (MDCS), the reaction is:
CH3SiHCI2 + 2Na -> [CH3SiH]x- + 2NaCI
The molecular weight of MDCS is 115 g/gmol and the molecular weight of the repeating
unit (R.U), [CH3SiH]x, is 44.08. Therefore, starting with 0.3204 gmoles of MDCS
(corresponding to 36.85 g) produces 0.3204 gmole of R.U or 14.10 g (theoretical yield).
The polymer yield is calculated as a percentage by dividing the actual polymer yield by
the theoretical yield determined above (and then multiplying by 100).
For polymers prepared from a mixture of methyldichlorosilane (MDCS) and
methyltrichlorosilane (MTCS) (70:30 proportion by weight), the reaction is:
CH3SiHCI2 + CH3SiCI3 + 5Na [CH3SiH]x[CH3Si]y~ + 5NaCI
The molecular weight of MTCS is 149.50 g/gmol and that of the R.U --[CH3Si]y-- is
43.08. Therefore, 0.3204 gmole of MDCS (corresponding to 36.85 g) produces 0.3204
gmole of R.U [CH3SiH]x-- or 14.10 g and 0.107 gmole of MTCS (corresponding to
15.94 g) produces 0.107 gmole of R.U --[CH3Si]y- or 4.58 g. Thus, the total yield is


359
UF-67S (PCS+PSZ)
t, min
Number of holes spun
Number of fiber breaks
0
-
-
1
0
0
2
3
1
3-5
2
0
6-8
3
3
9-10
3
4
11
3
0
12-13
3
2
14-18
3
0
19
3
1
20-21
3
0
22
3
4
23-24
3
5
Total number of breaks = 20
Number of breaks per minute per hole = 0.29
UF-68s (PCS+PSZ1
t, min
Number of holes spun
Number of fiber breaks
0
-
-
1
4
0
2
4
1
3-4
4
0
5-6
4
2
7-8
4
0
9
4
1
10-11
4
0
12
4
1
13
2
1
14
3
0
"otal number of breaks = 6
Number of breaks per minute per spinneret hole = 0.11


127
[CRC92], The detailed results are presented in Appendix E. The measured values were
within 5% of published surface tension values for each liquid.
Table 4.3 shows surface tension values for PCS and PCS+PSZ solutions at
three different solids loading (33 wt%, 50 wt%, and 66 wt%). The rheological behavior of
the polymer solutions at these concentrations are shown in Figures 4.16-4.21. The
solutions exhibited essentially near-Newtonian rheological behavior. (However, the most
concentrated PCS solution (66 wt%) in Figure 4.18 showed slight shear thinning
behavior.)
Figures 4.22 and 4.23 show plots of surface tension vs. concentration and
surface tension vs. viscosity for these solutions. At the lowest concentration (33 wt%
polymer), the surface tension of the PCS solution was only slightly higher than
PCS+PSZ solution. The differences in surface tension values increased slightly with
increasing polymer concentrations. It should be noted that the error involved in surface
tension measurement probably becomes larger at higher concentrations (and higher
viscosities) and the absolute values reported may not be reliable. For example, the
margin of error involved in measurement of surface tension for glycerol (which has a
viscosity of ~0.6 Pa s) was -9% (measured value: 0.068 N/m (Appendix E), reported
value: 0.063 N/m [CRC92]). Similarly, the margin of error involved in the measurement
of surface tension for polydimethylsiloxane (which had a viscosity of 12.1 Pa s) was
-11% (measured value: 0.024 N/m (Appendix E), reported value: 0.022 N/m [And91]§§.
In the case of polymer solutions, possible sources of error also may result from: (i)
evaporation of solvent, and (ii) residual polymer remaining on the platinum blade used
The polydimethylsiloxane used in the present study (PDMS 12500) was manufactured by GE Silicones,
Cincinnati, OH. The surface tension values published by Anderson et al. [And91] was obtained on an
identical polymer. Anderson et al. did not report the technique used for surface tension measurement.


257
Table 4.18. d-spacings and 20 Bragg angles.
Si (structure: diamond cubic)3
d-spacing, A
20, degrees
Intensity
h k I index
3.138
28.42
100
1 1 1
1.920
47.31
60
2 2 0
1.638
56.10
35
3 1 1
1.357
69.17
8
4 0 0
1.246
76.37
13
3 3 1
1.108
88.06
17
4 2 2
p-SiC (structure: simple cubic)6
d-spacing, A
20, degrees
Intensity
h k I index
2.51
35.74
100
1 1 1
2.17
41.58
20
2 0 0
1.54
60.03
63
2 2 0
1.31
72.03
50
3 1 1
1.26
75.37
5
2 2 2
1.09
89.93
6
4 0 0
a JCPDS Card # 5-565, International Diffraction Committee, Swarthmore, PA (1988)
bJCPDS Card # 5-565, International Diffraction Committee, Swarthmore, PA (1988)


APPENDIX J
GPC MOLECULAR WEIGHT DISTRIBUTIONS FOR PMS POLYMERS
FRACTIONALLY-PRECIPITATED BY ADDITION OF ACETONE


187
Figure 4.49 shows FTIR spectra of air-heat treated PCS+PSZ fibers during heat
treatment to 600C in nitrogen. Figure 4.50 shows plots of the intensities of various
absorption peaks for these fibers. Figure 4.51 shows a direct comparison between
spectra of air-heat treated PCS+PSZ fibers before and after heat treatment in nitrogen
at 600C. Figure 4.52 shows the subtraction spectra for the same. It can be seen that
intensities of absorption bands due to Si-OH (at 3650 cm'1) and C=0 (at 1722 cm'1)
gradually decreased starting above 120C and completely disappeared by 600C. The
v(Si-H), pas(CH3), and 8as (CH3) absorption peaks show small decreases in intensity upon
heating to 600C. The decrease in Si-OH and Si-H bonds would be expected to be
accompanied by an increase in siloxane bonds (Si-O-Si), i.e., according to equations
(4.2) and (4.3). The slight increase in intensity of the absorption band in the range of
-960-1100 cm'1 (Figure 4.50) is consistent with the formation of Si-O-Si bonds. The rest
of the absorption peaks associated with PCS showed little change during the heat
treatment. This could mean that methylene insertion reactions are inhibited during heat
treatment, as suggested previously for the case of green PCS+PSZ fibers (with no air
heat treatment) undergoing the same heat treatment in nitrogen.
Figures 4.53 and 4.54 show comparison plots of FTIR spectra of air-heat treated
PCS+PSZ and PCS fibers at 40C, and after heat treatment in N2 at 600C,
respectively. It is evident that Si-H peak intensity decreased considerably for PCS fibers
than PCS+PSZ fibers. Also, the intensity of absorption band at 960-1100 cm'1, due to co
(CH2) from Si-CH2-Si + v (Si-O-Si or Si-O-Si) is greater for air-heat treated PCS than
PCS+PSZ fibers. Thus, these observations also suggest that methylene insertion
reactions are inhibited for air-heat treated PCS+PSZ fibers relative to air-heat treated
PCS fibers.


338
wt% C. (The composition of the fiber after 1480C/1 h determined by EMA is 64.5 wt%
Si and 35.5 wt% C.)
Based on reaction (4.8), we have 1 mole of Si02 reacting with 1/2 mole of SiC to
produce 3/2 moles of SiO and 1/2 mole of CO. This means that 0.0936 mole (or 4.1 g)
of Si02 reacts with 0.046 mole (or 1.8 g) of SiC to form 0.139 mole (or 5.0 g) of SiO and
0.046 mole (or 0.9 g) of CO. The total amount of volatile species (SiO, CO) is 5.9 g.
Thus, the expected weight loss is 5.9%. The calculated stoichiometry for the fiber after
heat treatment is 62.6 wt% Si and 31.4 wt% C.
Based on reaction (4.9), we have 1 mole of Si02 reacting with 1 mole of C
forming 1 mole of SiO and 1 mole of CO or 0.09363 gmole of Si02 (4.1 g) reacting with
0.09363 gmole of C (or 1.1 g) forming 5.2 g of volatile species SiO and CO. Thus, the
expected weight loss is -5.2% (as opposed to the observed weight loss of 8%). The
calculated stoichiometry (based on loss of 1.1 g of C) is 67.3 wt% Si and 32.7 wt% C.
Thus, reaction (4.8) predicts the weight loss closest to the observed weight loss
for UF-75s fibers after 1480C/1 h heat treatment. However, the large weight losses
occurring after 1480C/10 h and 1845C/1 h cannot be adequately explained by this
reaction. More investigations on thermal stability of these fibers would be needed.
The large weight loss in UF-78s fibers after heat treatment at 1480C/1 h is likely
due to the carbothermal reduction reaction shown by equation (4.8). The weight loss
based on this reaction and stoichiometry change can be determined as follows: The
initial composition of the 1150C-pyrolyzed fiber is: 69.0 wt% Si, 25.1 wt% C, and 5.9
wt% O. Assuming that all 02 is tied to Si as Si02, we have 83.7 wt% SiC, and 16.3 wt%
Si02. Based on reaction (4.8), we have 1 mole of Si02 reacting with 1/2 mole of SiC,
forming 3/2 moles of Si and 1/2 mole of CO. This means that, for 16.3 g of Si02 in the
fiber (or 0.3704 gmole), the total amount of volatile species formed (SiO, CO) would be


Intensity (Kubelka-Munk units)
189
0 100 200 300 400 500 600 700
Temperature (C)
Figure 4.50. Intensity vs. temperature from FTIR spectra of air-heat treated
(177C) PCS+PSZ fibers (batch 70s).


NUMBER PERCENT NUMBER PERCENT
212
4 Batches (324 fibers)
Mean = 2.39 GPa (347 ksi)
Std. Dev. = 0.88 GPa (128 ksi)
(A)
2 3 4
TENSILE STRENGTH (GPa)
25
20
15 -
PCS + PSZ
3 Batches (283 fibers)
Mean = 2.98 GPa (432 ksi)
Std. Dev. = 0.82 GPa (119 ksi)
(B)
2 3 4
TENSILE STRENGTH (GPa)
Figure 4.62. Distribution of tensile strengths of fibers after pyrolysis at 1150C
in nitrogen: (A) PCS (B) PCS+PSZ.


Table 4.12. Tensile properties of as-spun and air-heat treated (177C) PCS+PSZ fibers
heat treated to various temperatures between 200-1150C in nitrogen.
204
Temperature of heat
# of fibers
Diameter
Rupture
Tensile strength
treatment (C)
tested
(pm)
strain (%)
(MPa)
PCS+PSZ fibers (70s)
None
23
17.5 1.02
0.63 0.23
16 5
200
22
17.5 1.17
0.57 0.20
155
300
20
17.4 0.99
1.43 0.58
29 10
400
21
17.9 2.01
5.99 1.19
58 7
500
21
18.1 1.76
5.63 1.00
77 14
600
24
16.6 1.11
2.19 0.69
288 107
700
23
15.7 1.43
1.81 0.47
900 462
800
22
13.5 0.66
1.60 0.26
2292 335
1000
22
13.1 0.58
1.88 0.28
3466 543
1150
72
12.7 0.98 b
1.61 0.47 b
3250 970b
PCS+PSZ fibers heat treated in air at 177C (70s)
None
26
17.2 1.51
4.33 1.27
58 13
200
25
17.5 1.38
4.75 1.47
63 10
300
23
16.4 1.22
5.57 1.12
76 12
400
22
19.6 1.89
7.38 1.49
105 14
500
22
18.1 0.77
4.40 1.23
117 31
600
23
18.4 3.50
3.39 0.66
184 48
700
22
16.0 0.58
1.62 0.51
621 202
800
20
14.5 0.76
1.76 0.38
1475 368
1000
20
15.0 1.36
1.49 0.38
1656 404
1150
18
13.3 1.11
1.37 0.40
2469 674
b Average for four separate heat treatments (Individual results are provided in Appendix H).


MOLECULAR WEIGHT (MJ
274
40000
35000
30000
25000
20000
15000
10000
5000
0
0 2 4 6 8 10 12 14
POLYDISPERSITY INDEX (PDI)
Figure 4.89. Polydispersty index vs. molecular weight for PMS polymers
containing 5-14.5 wt% PSZ (and 0.5-1.5 wt% DCP) as additives.
Initial PDI vs Initial MW
Final PDI vs Final MW
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/


81
Bunsen burner) prior to each measurement. When PCS solutions were used, the
platinum blade was first soaked in toluene for 5 min and then rinsed in acetone before
flame cleaning. Initially, surface tensions of standard liquids such as water and acetone
were measured to test the accuracy of the instrument. The measured surface tension
values were compared with the values reported in a technical handbook [CRC92],
Two toluene-based 33 wt% polymer solutions, one with PCS and the other with
PCS+14.5 wt% PSZ, were prepared and the solutions were filtered through 0.1 pm filter
prior to measurement. Viscosities of the solutions were measured using a cone-plate
viscometer by the method described in Section 3.1.2. After completing the
measurement, the 33 wt% polymer solutions were concentrated successively to 50 and
66 wt% polymer. Surface tension and viscosity measurements were made for each
concentrated solution. Surface tension measurements could not be made with more
concentrated solutions. (An attempt was made to measure the surface tension of a PCS
solution with 68 wt% solids loading (which had a viscosity of 32-35 Pa s). In this case,
the platinum blade did not penetrate the polymer solution and the thread attached to the
blade began to coil up.) Glycerol (viscosity: 0.6-0.57 Pa s) and polydimethylsiloxane
(viscosity: 12 Pa s) (which have viscosities in a similar range as the PCS and
PCS+PSZ solutions concentrated to 50 wt% and 66 wt% solids, respectively) were used
to assess the validity of surface tension measuring technique when applied to more
viscous liquids. (The surface tensions of these liquids are reported in technical
handbooks [CRC92].) The rate of solvent evaporation was minimized during the
measurements by covering the container used to hold the liquids with aluminum foil and
by placing two small beakers filled with toluene next to the container. Care was taken to
ensure that the aluminum foil did not interfere with the thread used to pull out the
platinum blade from the solution.


dwt/d(logM) dwt/d(logM)
293
Figure 4.101. GPC molecular weight distributions for PMS-240 polymer
(A) before and (B) after fractional precipitation with alcohol
mixture.


dwt/d(logM) dwt/d(logM)
109
(A)
(B)
Figure 4.4. GPC molecular weight distributions for: (A) PCS and (B) PSZ.


INTENSITY (arbitrary units)
1 I 1 I 1 I 1 I 1 I 1 I T I 1 I
4000 3600 3200 2800 2400 2000 1600 1200 800
WAVENUMBER (cm1)
Figure 4.45. Subtraction spectra for PCS+PSZ fibers (batch 70s), 600-40C
400
180


Intensity (Kubelka-Munk Units)
Wavenumber (cm'1)
Figure 4.54. Comparison of spectra of air-heat treated PCS fibers (batch 65s) and PCS+PSZ fibers (batch 70s) after
heat treatment in N2.
194


34
spectroscopically 'silent (i.e., absent in NMR because of paramagnetic nature). At
present, a mechanism for chain termination is not elucidated, although catalyst-induced
chain scission has been observed in the polymerization of cyclohexasilanes.
Since early transition metal complexes are not effective for dehydrocoupling of
secondary silanes, other catalysts have been investigated. Corey et al. [Cor91]
synthesized disilanes through pentasilanes by using a Cp2ZrCI2-nBuLi mixture as a
catalyst for dehydrocoupling of phenylmethylsilanes in toluene at 90C. (This
temperature is higher than that used for dehydrocoupling of primary silanes.) This
condensation reaction of secondary silanes is sensitive to steric effects (i.e., steric
hindrance) of the substituents, as observed by the sluggish reaction of Ph2SiH2
compared to PhMeSiH2 [Cor91],
Sakakura et al., [Sak91; Sak93] have developed a method for producing
polysilanes by dehydrocoupling of primary organosilanes using a lanthanoid complex
(1.5 wt%) as a catalyst. They reported that lanthanoid complexes have higher activity
and selectivity than early transition metal complexes used by Harrod et al. In this case,
the dehydrogenative reactions of phenylsilanes were performed at temperatures
ranging from 20C to 160C and in the presence of a solvent such as toluene or
benzene, with reaction times extending from several hours to several days. The authors
reported that higher polymerization temperatures and longer reaction times lead to
higher polymer molecular weight. The effect of the above variables in the polymerization
of phenylsilane in the presence of hydrobis(pentamethylcyclopentadienyl)-neodymium
catalysts (lanthanoid complex) is illustrated in Table 2.5.


35
Table 2.5: Effect of time and temperature on polymerization of phenylsilane in the
presence of a lanthanoid complex [Sak93],
Temperature, C
Time, days
Product
Appearance
Mw
Mn
25
15
oil
520
1.26
80
2
gum
780
1.37
100
2
gum
990
1.54
130
2
solid
1600
1.91
130, 160 a
2, 7 3
solid
4380
3.09
a 2 days at 130C followed by 7 days at 160C.


dwt/d(logM) dwt/d(logM)
408


334
solvent removal prior to winding of the fibers. (The fractionated PMS polymers appeared
to be solids at room temperature, so sticking in the green state did not result because of
flow of the polymer. In addition, no melting was observed for a sample of PMS-243-F in
a 1000C-melt test.)
Some changes in processing conditions were made in order to avoid sticking of
the as-spun fibers. First, a spinneret with smaller diameter holes (40 pm diameter, 3-
holes) was used in subsequent batches. (This was done so that a greater proportion of
the solvent would be evaporated by the time the fibers reached the winding drum.)
Second, some of the batches were prepared with a higher viscosity. (This was done so
that less liquid removal would be needed before the fibers would solidify.)
Spin batch UF-74s was prepared from a mixture of polymer solutions PMS-245-
F-1 (1^6200), PMS-246-F (M**16400), and PMS-247-F (M^16700) (in a 38:47:15
wt% proportion). It was not spinnable because the spinneret holes became clogged at
the start of fiber spinning. This may have been an indication that the polymer solution
was close to the point of gelation. This is suggested because it was difficult to filter the
solution prior to concentration (see Table 4.32). Two of the polymers used in this batch
(PMS-246-F and PMS-247-F) had very high molecular weights and may have contained
gel-like fractions.
UF-75s fibers was prepared from polymer batches PMS-250-F (Mw^6200), PMS-
251-F (1^1^5500), and PMS-248-F (Mw^=8700) in a 46:27:27 wt% proportion. These
fibers spun well and were highly separable both in the green state and after pyrolysis.
UF-76s spin batch was prepared from polymer batches PMS-250-F (Mw6200),
PMS-251-F (1^1^5500), and PMS-248-F (Mw8700) in a 29:28:43 wt% proportion. The
spin dope also contained 2 wt% DB. Previous work [Cho93] has shown that DB and


104
Table 4.1. Fiber spinning characteristics for PCS and PCS+PSZ spin dopes spun under
identical conditions.
(1) PCS Fiber batches:
Batch
Amount of
spin dope3
(g)
Amount
of
polymer
(g)
Amount of
fibers
collected
(g)
% of
fibers
yielded15
Duration of
spinning
(min)
Total
number
of breaks
Number
of
breaks'5
63s
4.41
2.99
0.30
10
17
46
3.07
64s
4.62
3.06
0.26
8.5
23
62
1.51
65s
3.78
2.49
0.45
18.1
17
22
0.81
69s
4.48
2.97
0.53
17.8
17
14
0.44
(2) PCS+PSZ fiber batches
Batch
Amount of
spin dope
(g)
Amount
of
polymer
(g)
Amount of
fibers
collected
(g)
%of
fibers
yielded3
Duration of
spinning
(min)
Total
number
of breaks
Number
of
breaks15
67s
4.58
3.16
1.07
33.9
24
20
0.29
68s
4.51
3.16
1.05
33.3
14
6
0.11
70s
4.56
3.19
1.03
32.3
12
5
0.11
3 Amount of spin dope = amount of polymer + amount of solvent
b Percentage yield = 100 x (Amount of fibers collected/Amount of polymer in the spin dope)
c Number of breaks during spinning per minute per spinneret hole. Fibers were spun using a four-hole, 70-
pm hole diameter spinneret


8
Initiation
R
R
Cl-Si-Cl
I 2
R
+ 2Na
ClSi Na
1 2
R
+ NaCI
Propagation
R
R
I
-Si-Na+ + Cl-Sr Cl
R
R2
_ 1 1
R R
I I
Si-Si-Cl + NaCI
I 2 I 2
R R
(Rate determining)
1 1
R R
I I
Si-Si-Cl + 2Na
I 2 I 2
R R
1 1
R R
I I
- Sr Si" Na+ + NaCI
R
(Fast)
(2.2)
(2.3)
(2.4)
Figure 2.1. Reaction scheme for Wurtz-coupling polymerization reaction


77
200-1000C. The heat treatment rate was 1C/min to 150C and 4C/min from 150C to
the final temperature.
3.1.3 Characterization of PCS polymer solutions
The molecular weight distributions of PCS polymers were determined by Gel
Permeation Chromatography (GPC)11 using polystyrene columns and standards1, and
THF (tetrahydrofuran) as the solvent. PCS solutions for GPC were prepared by mixing
0.5 wt% of polymer in THF and filtering the solution through a 0.1 pm filter. Polymer
solutions were passed through 1000 A and 500 A columns connected in series. The
mobile phase for the columns was THF. GPC for PSZ polymers were analyzed using
10,000 A and 1,000 A columns connected in series. THF could not be used as the
mobile phase for PSZ since the chromatogram showed no clear elution peaks
corresponding to the different molecular weight species in the polymer (i.e., the
chromatogram showed a broad peak and a valley). For this reason, toluene was used
as the mobile phase and the PSZ polymers were dissolved in toluene (0.5 wt%) instead
of THF. The columns were conditioned by purging toluene through them for 24 h prior to
analysis.
The intrinsic viscosities of polymer solutions were determined according to
ASTM D-446 procedure by employing a Ubellohde Viscometer (type 0C)n The
measurements were carried out in a water bath maintained at 30C and the
concentrations of polymer solutions used ranged from 2 to 6 wt%. The efflux time t
required for the solution to pass through the capillary of the viscometer between marked
11 Waters600E Systems Controller, Waters410 Differential Refractometer and Waters707 Autosampler,
Millipore Corporation, Waters Chromatography Division, Milford, MA.
1 Phenomenex Corporation, Torrance, CA.
HI Industrial Research Glasswares Ltd, Union, NJ.


ABSORBANCE (Kubelka-Munk Units)
188
4000 3500 3000 2500 2000 1500 1000 500
WAVENUMBER (cm1)
Figure 4.49. FTIR spectra of air-heat treated (177C) PCS+PSZ fibers (batch 70s) during
heat treatment to 600C in nitrogen.


ABSORBANCE (Kubelka-Munk Units)
261
4000 3500 3000 2500 2000 1500 1000 500
WAVENUMBER (cm'1)
Figure 4.86. FTIR spectra of polymer PMS-C (100% MDCS; toluene/dioxane
(50:50 vol%)) exposed to air, shown as a function of time.


413
1. Excess Si Calculations
Consider the composition of a 1150C-pyrolyzed PMS-245 polymer. The
elemental composition determined by Electron Microprobe Analysis (EMA) is 69.4 wt%
Si, 26.0 wt% C, and 2.2 wt% 02. Assuming that all 02 is tied to Si as Si02, we have 2.2
wt% O tied to 3.9 wt% Si (total of 7.1 wt% Si02). We, then, have 69.4 3.9 = 65.5 wt%
Si for combination with C. Now, the stoichiometric composition of SiC is 70 wt% Si and
30 wt% C (i.e., 30 wt% C requires 70 wt% Si to form SiC). Therefore, 26 wt% C requires
61 wt% Si to form SiC. The excess Si in the pyrolyzed PMS polymer is 65.5 -61.0 = 4.5
wt%.
2. Excess C calculations in PCS-based fibers
Consider the elemental composition of Nicalon SiC fiber: 55 wt% Si, 29 wt% C,
and 15 wt% O [Tor92B], Assuming that all 02 is tied to Si as Si02, we have 15 wt% 02
tied to 27 wt% Si as Si02 (total of 42 wt% Si02). We, then, have 55 27= 28 wt% Si
available for combination with C. 28 wt% of Si requires 12 wt% of C to form
stoichiometric SiC. The excess C in the Nicalon SiC fiber is then 29 -12 = 17 wt%.


Intensity (Kubelka-Munk Units)
245
A
Pas(CH3> of S¡-CH3 [830 cm'1]
Ps(CH3) of Si-CH3 [770 cm'1]
6s(CH3)ofSi-CH3 [1253 cm'1]
A v (Si-O-Si) + v (Si-O-C) [1020-1100 cm'1]
# 5(CH2) of Si-CH2-Si [1358 cm'1]
0 100 200 300 400 500 600
Temperature (C)
700
Figure 4.79. (Cont'd.).


160
v (cm-1)
Figure 4.35. FTIR spectra of air-heat treated Nippon PCS fibers during heat treatment in
nitrogen to 500C (from Ichikawa et al. [Ich90]).


INTENSITY (arbitrary units)
WAVENUMBER (cm1)
Figure 4.46. Subtraction spectra for PCS+PSZ (batch 70s) and PCS (batch 69s) fibers at 40C.


Ic (dl/g)
227
c (g/dl)
Figure 4.70. Plot of r|sp/c vs. c for polymer F (batch PMS-256) (MDCS/MTCS
(70/30); toluene/1,4-dioxane (50/50)) in a mixture of toluene and
1,4-dioxane (50:50 vol%).


18
yield and average molecular weight. At higher concentration of diglyme (-25 vol%),
polymer molecular weight distribution became monomodal and overall molecular weight
of the polymer decreased drastically. The polymer yield remained relatively high (32%).
The effect on polymer yield of diglyme additions was particularly significant in the case
of polysilane polymers derived from symmetric dialkylsilane monomers (e.g., dicholoro-
di-n-hexylsilane, dichloro-di-n-dodecylsilane) (see Table 2.1). In the case of poly(di-n-
hexylsilane), a typical dialkyldichlorosilane derived polymer, the yield of the polymer was
only 5.9% when synthesized in toluene alone as a solvent. The polymer yield increased
approximately six fold (-34-37%) when diglyme was added in amounts of 5, 10, and
30% by volume of toluene. The addition of diglyme also resulted in lower average
molecular weight of the polymer. In the case of dichloro-di-n-dodecylsilane, the addition
of 30% diglyme resulted in large increase in the polymer yield (from 3 to 34%), while the
average molecular weight increased slightly for each mode in the distribution. Also, the
high molecular weight proportion of the polymer decreased significantly.
Table 2.1 also shows the effect of addition of a non-polar solvent (i.e., heptane)
on polymerization of diakyldichlorosilane monomers (dicholoro-di-n-hexylsilane) and
arylakyldichlorosilane monomers (phenylmethyldichlorosilane). Addition of heptane
caused an increase in polymer yield for the case of polymerization of dicholoro-di-n-
hexylsilane and a decrease in polymer yield for the case of polymerization of
phenylmethyldichlorosilane. The heptane addition resulted in lower average molecular
weight in the former case and higher average molecular weight in the latter case. Miller
et al. explain that polymerization of arylalkyldichlorosilanes is highly exothermic and
takes place rapidly because arylalkyldichlorosilanes are not sterically hindered unlike
dialkyldichlorosilanes. Solvent effects on polymerization of arylalkyldichlorosilanes are


Intensity (Kubelka-Munk Units)
Wavenumber (cm'1)
Figure 4.36. Comparison of spectra of air-heat treated (187C) PCS fibers (batch 65s) before and after heat treatment
at 600C in N2
163


Viscosity (Pa s) Shear Stress (Pa)
133
2.0
1.5
1.0
0.5
0.0
o
Increasing Shear Rate
PCS+PSZ (50 wt%)

Decreasing Shear Rate
O
A
D CJ
(B)
0 50 100 150 200 250 300
Shear Rate (s'1)
Figure 4.20. Plots of: (A) shear stress vs. shear rate and (B) viscosity vs. shear rate
for a 50 wt% PCS+PSZ solution used in surface tension measurement.


dwt/d(logM) dwt/d(logM)
401
6 5 4 3 2
(A)
(B)
log MW
Figure I-2. GPC distributions for PMS-243 polymer: (A) before and
(B) after fractional precipitation with acohols.


79
adding and withdrawing drops. Efforts were made to use larger drop sizes in order to
minimize liquid evaporation effects. (For toluene/stainless steel combination, the total
drop size possible was 0.05 ml before the drop boundary exceeded the boundary of the
substrate.) In experiments with pure toluene and toluene-based polymer solutions, the
immediate environment was saturated with toluene-soaked paper tissues to minimize
the effects of liquid evaporation. The duration of measurement for advancing and
receding contact angles was ~3 min each. The measurements were carried out in a
room where air drafts were minimal.
sv
substrate
7 sv = 7sl + Ylv COS 0
(Young's equation)
where
Ysv = solid-vapor specific interfacial energy
Ysl = solid-liquid specific interfacial energy
¡¡_v = liquid-vapor specific interfacial energy
0 = contact angle
0 = 180 for a completely non-wetting liquid
0=0 for a completely wetting liquid
Figure 3.3. Definition of terms in Youngs equation and schematic illustration of the
geometry for determination of the contact angle by the sessile drop
method.


Table 4.31. Elemental analysis by Electron Microprobe for SiC fibers prepared from heat-treated PMS/PCS polymer blends3.
Fiber batch
PMSiPCS
Additives used
Composition
ratio
As-measured
Si % C % 0% Total %
Normalized (to 100%)b
Si % C % O %
UF-35S-1700
40:60
5 wt% PSZ
58.93 0.49
38.99 0.27
97.92 0.63
60.18 0.21
39.82 0.21
UF-39S-1000
60:40
14.5 wt% PSZ
58.99 0.66
35.37 0.31
2.50 0.32
96.86 0.95
60.90 0.29
36.51 0.35
2.58 0.32
UF-42S-1000
70:30
14.5 wt% PSZ
61.59 0.58
36.13 0.30
1.68 0.61
99.40 0.91
61.96 0.53
36.35 0.37
1.69 0.61
UF-52S-1000
100:0
0.25 wt% PSZ,
6 wt% DB
70.04 0.93
27.78 0.28
3.36 0.67
101.19 0.75
69.22 0.54
27.46 0.31
3.32 0.67
3 Nitrogen and B were below the detection limit of the Electron Microprobe Analyzer used.
b Normalized Si, C, and 0 to 100% total.
c Added to polymer solution prior to heat treatment.


WAVENUMBER (cm'1)
ABSORBANCE (Kubelka-Munk Units)
(Q
C
i
(D
bo
O
o
3
249


27
spectroscopy) and was produced in high yields (i.e., 60 to 70%). Average molecular
weights for these polymers were reported to be low (620-690). When the polymerization
was carried out in THF instead of a mixture of THF and hexane, the resulting polymer
apparently had higher molecular weight (absolute numbers were not reported) and more
cross-linked structure. The latter conclusions were based on NMR sudies (showing a
lower concentration of Si-H bonds) and thermogravimetric analysis (TGA) (showing
higher ceramic yield). When the reaction was carried out in xylene (under refluxing
conditions), the yellow-colored polymer was produced with a yield of 40%, molecular
weight in the range of 520-600 (Mw), and structure of ((CH3SiH)04(CH3Si)0 36)n
(determined from NMR).
Qiu and Du [Qiu89A; Qiu89B] prepared polymethylsilane polymers by
condensation of methyldichlorosilane with sodium (normal addition mode) in a blend of
toluene and dioxane (33:67 vol% ratio). It is expected that dioxane, a dipolar solvent, will
promote polymerization of MeHSiCI2 (i.e., higher reaction rate). (The effect of polar
solvents on Wuitz-coupling reaction of dichlorosilanes with sodium was discussed in
section 2.2.1.4) The polymerization was carried out at the reflux temperatures of the
toluene-dioxane solvent mixture. The end point of polymerization was determined by
testing for the acidic nature of the reaction contents. The reaction was stopped when the
reactions contents did not test acidic (pFI=6-7). The reaction contents were separated
from the NaCI precipitates by filtering and the polymer was isolated by evaporation of
the polymer solution under vacuum. The polymer was fractionated by adding, drop by
drop, a mixture of methanol and 2-propanol with vigorous stirring. The precipitate was
collected and dried in a vacuum oven at room temperature for 2 h. The polymers
synthesized by this method were used in studies involving oxidative cross-linking, photo


44
polydimethylsilane with methyl groups as substituents gives high theoretical yield
(69%) but low pyrolysis yield (~1%). (Experiments by Wood [Woo84] and West et al.
[Wes81] also confirm this observation.) Replacement of a methyl substituent by a bulky
phenyl group (as in polyphenylmethylsilane) results in improved pyrolysis yield, ~25%
(presumably due to the retention of some phenyl groups during pyrolysis). (It is also
possible that high yield depends on the ability to develop a Si-C-Si-C backbone with
sufficient cross-linking.)
Figure 2.11 shows the FTIR spectra of a polysilane terpolymer (polymer Vllb
shown in Table 2.6) during pyrolysis to 1200C. The polymer was cast as a thin film on a
silicon wafer and heated under argon atmosphere and spectra were collected at
different temperatures. The typical absorptions for the as-prepared polysilane occurred
at 3050 cm'1 (due to the C-H stretching vibration of Si-CH=CH2), 1428 cm'1 (due to the
CH2 bending vibration of Si-C6H5), 1468 cm'1 ( due to the CH bending vibration of Si-
C6H13) and 2100 cm'1 (due to stretching vibration of Si-H), and 1247 cm'1 (due to the
rocking vibration of Si-CH3). Figure 2.12 shows the changes in concentrations in residual
pendant organic groups calculated based on the IR spectra, allowing for reduction in
thickness of the film which occurred during pyrolysis. The slight increase in the Si-H
group intensity is attributed to methylene insertion reactions taking place between 200C
and 450C. (This observation was also confirmed by Schilling [Sch84; Sch88] and
Schmidt [Sch91] by NMR studies and resembled reactions occuring during the
conversion of polydimethylsilane to polycarbosilane [Has83].) Carlsson et al. indicated
that no significant changes occurred during the pyrolysis up to 300C but rapid
elimination of -CH3, -C6H5 and -C6H13 groups occurred between 300C and 450C. The
increase in the absorption intensity at 1030 cm'1 corresponded to formation of Si-(CH2)n-
Si linkages and network.


J-4. GPC molecular weight distributions for PMS-248 (A) before and (B) after
fractional precipitation with acetone 406
J-5. GPC molecular weight distributions for PMS-249 (A) before and (B) after
fractional precipitation with acetone 407
J-6. GPC molecular weight distributions for PMS-251 (A) before and (B) after
fractional precipitation with acetone 408
J-7. GPC molecular weight distributions for PMS-252 (A) before and (B) after
fractional precipitation with acetone 409
J-8. GPC molecular weight distributions for PMS-253 (A) before and (B) after
fractional precipitation with acetone 410
J-9. GPC molecular weight distributions for PMS-254 (A) before and (B) after
fractional precipitation with acetone 411
xx


Table 4.29. (cont'd.)
Batch
PMS used
PCS added
Before heat- After heat-
treatment treatment
PMS:
PCS ratio
Wt%
PSZ
added3
Wt% DB added
Before heat After heat
treatment treatment
Filtration
behavior6
Filter (pm)/
time(min)
Flow
test
time(s)
Solids
loading
(%)
Viscosity
(Pas)
Spin
speed
(rpm)
Spin
pressure
(psi)
UF-53S
PMS-225-
APD-H
PCS 213
*
90:10
0.25
0
6
0.1/35
(2 sets)
43
63.6
50-30
*
350
Spun poorly; no fibers collected.
UF-56S
PMS-225-
AD2-H
*
PCS 213
90:10
0.25
3
3
0.45/90
38
62.2
41-16
119
200-250
Spun poorly; as-spun
fibers separable but pyro
yzed fibers brittle.
UF-57S
PMS-226-
AD-H
*
PCS 213
90:10
0.25
3
3
0.45/90
48
57.5
48-10
*
150-175
Not spinna
ble
UF-29S
PMS-214-
A-H
*
*
100:0
5
0
0
0.45/10
46
87.1
25-18.6
28
450
Spun poorly; as-spun
fibers stuck together.
UF-30S
PMS-216-
A-H
*
*
100:0
5
0
0
0.45/10
41
82.0
23
54
450
Spun poorly; as-spun
fibers stuck together
UF-38S
PMS-219-
A-H
*
*
100:0
14.5
0
0
Centri
fuged3
18
69.1

54
300
Spun well; as-spun fibers stuck together.
UF-49S
PMS-223-
AD-H
*
*
100:0
0.25
6
0
0.45/45
(3 sets)
*
*
*
*
*
Spin dope gelled during processing.
309


231
polymerization reactions*. In this study, the purple color appeared in ~5, ~15, and -40
minutes for polymerization of MDCS/MTCS (70/30 wt. ratio) in toluene/dioxane (50/50
vol. ratio), toluene/THF (95/5 vol. ratio), and toluene, respectively. (Note that this
correlates with decreasing yields of -46, -37, and -15%, respectively.) It was also
observed that the reaction was essentially complete (i.e., as indicated by the acidity test
described earlier) in 14 h for the polymerization carried out in toluene/dioxane (50/50
vol. ratio), while 40 h was required for the polymerization carried out in toluene alone.
In contrast to the results discussed above, there was a negligible effect of the
solvent on the polymer yield when the polymerization reactions were carried out using
MDCS alone (see Figure 4.73 and Table 4.15). This apparently reflects the high reaction
rate for polymerizations carried out with MDCS (i.e., regardless of the solvent). The
purple color appeared in ~5 min with each type of solvent used in the polymerization.
The relatively high reaction rates are again consistent with the relatively high polymer
yields (i.e., -41-48% for polymers A, B, and C prepared with MDCS alone).
To further confirm the above trends, a polymerization reaction was carried out
using a mixture of 70 wt% MTCS and 30 wt% MDCS in toluene. As expected, the
reaction occurred more slowly and the polymer yield decreased with the higher
proportion of MTCS. The purple color change did not occur until 2 h after the start of the
reaction (i.e., compared to 40 and 5 minutes for the polymerizations carried out using 30
wt% MTCS/70 wt% MDCS in toluene and 100% MDCS in toluene, respectively). The
polymer yield was only -10% (i.e., compared to 15% and 41% for the polymerizations
* It is well-known in Wurtz-coupling polymerization that a color change to purple indicates significant
polymerization ([Ben92]; [Zei86A]; [MI89]; [MI93]). Miller et al. [MI93] reported that in the case of Wurtz-
coupling polymerization of aryldichlorosilanes, the purple color appeared within ~10 min of monomer
addition to Na, at which point, 80% of monomer was consumed.


dwt/d(log M) dwt/d(log M) dwt/d(log M)
273
(C)
Figure 4.88. Gel permeation chromatograms for PMS-231 polymer: (A) after 3 days of
storage, (B) after 260 days of storage, and (C) after heat treatment
(PMS-231-H).


Figure 4.112. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for UF-54s spin dope.


74
The molecular weight of PSZ was controlled by selectively removing low molecular
weight fractions (oils) by fractional distillation using an oil bath at temperatures ranging
from 125 to 150C.
Polycarbosilane (PCS) was synthesized according to the methods reported by
Toreki et al. [Tor92] and procedures developed at University of Florida. PCS was
synthesized by pressure pyrolysis of polydimethylsilane* in a stainless steel autoclave*
under a nitrogen atmosphere at ~450C. PCS polymers were prepared and supplied for
this study by coworkers at University of Florida. PCS lots 268, 269, and 262 (combined
in 3:2:1 proportion) were used in this study. The average molecular weight was
-11,000. (The GPC molecular weight distribution for the combined PCS polymer is
discussed in section 4.1.1.) This relatively high molecular weight PCS not only enabled
preparation of highly concentrated solutions (e.g., typically -70 wt%), but also allowed
fibers to be pyrolyzed without melting.
3.1.2 Spin dope preparation, fiber spinning, and fiber heat treatment
The Influence of polyvinylsilazane (PSZ) as a spinning aid and a cross-linking
agent in the low temperature heat treatment of PCS fibers was investigated in this study.
Two types of polymer solutions were prepared for fiber spinning: one containing 14.5
wt% PSZ and the other without any PSZ. The PCS polymers used in this study were
dried in a vacuum furnace for 12 h to remove any adsorbed moisture, traces of solvent,
etc. prior to solution preparation. The dried PCS polymers were then dissolved in
toluene at 33 wt% solids loading. For use in fiber spin batches, PSZ was dissolved in
toluene at 25 wt% solids loading, filtered through a 0.1 pm filter, and mixed with the PCS
solution.
T Nisso Company, Tokyo, Japan
* Model 4651, Parr Instrument Company, Moline, IL.


TABLE OF CONTENTS
ACKNOWLEDGMENTS ii
LIST OF TABLES vii
LIST OF FIGURES xi
ABSTRACT xxi
1. INTRODUCTION 1
2. LITERATURE REVIEW 5
2.1. Background 5
2.2. Polysilane synthesis 7
2.2.1. Wurtz-coupling of dichlorosilanes with alkali metal 7
2.2.1.1. Mechanism 7
2.2.1.2. Mode of addition of reagents 10
2.2.1.3. Effect of alkali metal 12
2.2.1.4. Solvent effects 14
2.2.1.5. Temperature effects 23
2.2.2. Ultrasonically activated Wurtz-coupling reactions 25
2.2.3. Polymerization of monoalkylchlorosilanes 25
2.2.4. Polysilane copolymers 28
2.2.5. Dehydrocoupling 28
2.2.6. Redistribution/substitution reactions 37
2.3. Pyrolysis behavior 42
2.4. Cross-linking of polysilane polymers 60
2.4.1. Oxidative cross-linking 60
2.4.2. Room temperature vulcanization 60
2.4.3. Photo-cross linking 62
2.5. Applications of Polysilane Polymers 63
2.5.1. Precursor for (3-SiC 63
2.5.2. Photoinitiators for radical polymerization 68
2.5.3. Photoresists in microelectronics 69
3. EXPERIMENTAL PROCEDURE 72
3.1. Role of polyvinylsilazane as a spinning aid for polycarbosilane 72
3.1.1. Polymer synthesis 72
3.1.2. Spin dope preparation, fiber spinning, and fiber heat treatment 74
3.1.3. Characterization of PCS polymer solutions 77
3.1.4. Characterization of fibers 82
3.2. Synthesis and characterization of polymethylsilane (PMS) polymers 84
iii


28
cross-linking, and room temperature vulcanization. The polymer was produced in -45%
yield and had an appearance of pale yellow waxy solid with Mw -1,800.
2.2.4 Polysilane copolymers
As discussed in section 2.1, when dialkyldichlorosilane is reacted with sodium in
a refluxing solvent, polydimethylsilane polymer is formed which is infusible and insoluble
in common organic solvents (e.g., toluene, benzene, xylene, etc.). West et al. [Wes81;
Wes86A] discovered that when phenylmethyldichlorosilane was added to
dialkyldichlorosilane in a 1:1 proportion by volume, and the reaction was carried out
under same conditions, the resultant polysilane copolymer was highly soluble in
common organic solvents (e.g., toluene, xylene, etc.). West et al. referred to this
copolymer as poly(silastyrene) (PSS). The copolymerization reaction can be
represented as:
CH3 C6Hs
>100C
(CH3)2SiCI2 + C6H5CH3SiCI2 -(-Si ^¡-f Si ^¡- (2.5)
ch3 ch3
The PSS copolymer had a bimodal molecular weight distribution with modal values of
-15,000 and -300,000.
2.2.5 Dehydrocouplinq
Harrod et al. [Har88; Mu91A; Mu91B; Ait89; Ait87; Ait85] were the first to report
a catalyst-based synthetic route for polysilanes prepared from primary organosilanes


292
Fractional precipitation was accomplished by using alcohols (for polymers PMS-
240-F through PMS-243-F) and acetone (for polymers PMS-245-F-1 through PMS-255-
F) as non-solvents. The alcohols used were 2-propanol and methanol in a 50:50 volume
ratio. Fractional precipitation was carried out by adding the propanol/methanol mixture
dropwise to the PMS polymer/THF solutions (which were vigorously stirred during the
alcohol additions). Table 4.25 shows the proportions of PMS, non-solvent, and THF
used in the fractionation experiments. Also shown are the initial and final PMS molecular
weights (i.e., before and after fractionation), the polymer yield (i.e., the percentage of
initial polymer which was recovered after fractionation), and the results of the melt test
(see section 3.2.4).
Figures 4.101a and 4.101b show the GPC molecular weight distribution of PMS-
240 before and after fractional precipitation using alcohols. The GPC molecular weight
distributions for other alcohol-fractionated polymers are shown in Appendix I. It is
evident from the figures that chromatogram of the fractionally-precipitated polymer is
less skewed towards lower molecular weight end compared to the as-prepared polymer.
The as-prepared PMS polymers are viscous liquids. As noted earlier, it is
necessary in SiC fiber preparation to use polymers which are solids at room
temperature and which do not melt upon pyrolysis (i.e., so that the fiber retains its shape
throughout the various processing steps). Table 4.25 shows that three of the four
samples fractionated with the alcohol mixture did not melt upon pyrolysis, while one of
the sample underwent partial melting.11
11 A melt test was carried out by pyrolyzing chunks of dried polymer to 1000C in a nitrogen atmosphere at
5C/min. The polymer was considered to have undergone no melting if the pyrolyzed polymer retained
sharp corners and edges. It was considered partially melted if some rounding of edges and corners
occurred and if the pyrolyzed chunks were stuck to the alumina boat used for pyrolysis.


Intensity (Kubelka-Munk Units)
170
A
700
Figure 4.40. (Cont'd.)


123
It is possible that spinneret holes become coated with a thin film of the polymer
solution during the process of fiber spinning. For this reason, contact angles of PCS
(~33 wt%)/toluene solution and PCS/PSZ (~33 wt%)/toluene solution were measured on
stainless steel substrates which had been previously coated with thin films of PCS and
PCS/PSZ, respectively. (As described in Chapter 3.1.3, thin films were prepared by
spin coating the same solutions that were used to form the sessile drops for the contact
angle measurements.) Figure 4.14 shows the contact angles for PCS solution on PCS-
coated stainless steel. The contact angles are considerably higher (especially the
advancing angles) compared to the contact angles for PCS solution on uncoated
stainless steel (Figure 4.10). (The advancing contact angles in Figure 4.14 range from
38.0 to 41.5, while the advancing angles in Figure 4.10 range from 16.0 to 18.5.) In
contrast to these results, the contact angles of PCS+PSZ solution on (PCS+PSZ)-
coated stainless steel (Figure 4.15) remain low and have similar values to the contact
angles for PCS+PSZ solution on uncoated stainless steel (Figure 4.11). (The advancing
angles range from 15.0 to 22.0 and 9.0 to 12.5 in Figures 4.15 and 4.11,
respectively.) The poorer wetting behavior (i.e., higher contact angles) for PCS solutions
on PCS-coated stainless steel may be a factor related to the problems (e.g., globule
formation) in spinning fibers from PCS solutions (with no PSZ).
Contact angle hysteresis (i.e., differences in advancing and receding angles for
a fixed drop size) was observed in all the measurements made in this study. Contact
angle hysteresis has been observed in many other studies also. For example, Herzberg
and Marian [Her70] have reported contact angle hysteresis for water on
polymethylmethacrylate and polyethylene substrates. Reasons for contact angle
hysteresis include (1) differences in evaporation of solvent from the substrate surface
encountered during measurement of advancing contact angles and receding contact


25
acceptors used in the polymerization were naphthalene, anthracene and tetraphenyl
ethene, and were used in stoichiometric excess to disperse sodium. The disadvantages
of typical Wurtz-type polymerization (e.g., low polymer yields, poor reproducibility)
persisted, but polydispersities of the polymer produced were much lower (1.5-3) than
that of typical Wurtz-type polymerization (> 5).
2.2.2 Ultrasonically-activated Wurtz-couplinq reactions
Matyjaszewski et al. [Mat88; Mat91; Kim88] pioneered the use of ultrasonic
energy in the Wurtz-coupling synthesis of polysilanes (derived from aryl-substituted
monomers) having high molecular weight and monomodal distributions. Use of
ultrasonic energy enabled reactions to be performed at low or ambient temperatures.
The principle of ultrasonic polymerization is based on the implosive collapse of cavities
with very high pressures and temperatures existing locally for short duration of times
[Pri94], The ultrasonic energy is generated using an immersion-type probe or ultrasonic
bath. The reasons for obtaining monomodal and high-molecular-weight distributions for
the polymers synthesized by ultrasonic method is attributed to the formation of high
quality sodium dispersions which are continuously regenerated during the coupling
process with continuous removal of sodium chloride byproduct from the sodium
surfaces.
Matyjaszewski et al. report that polymer molecular weight distribution becomes
broader and the average molecular weight decreases as the reaction temperature
increases. It was also observed that prolonged sonication (both during and after the
addition of monomer) results in degradation of high-molecular-weight components, as
shown in Table 2.3. (This results in polymers with lower average molecular weight and
lower polydispersity.)


APPENDIX L
CHARACTERISTICS OF PMS POLYMERS SYNTHESIZED FROM MDCS MONOMER


xml version 1.0 encoding UTF-8
REPORT xmlns http:www.fcla.edudlsmddaitss xmlns:xsi http:www.w3.org2001XMLSchema-instance xsi:schemaLocation http:www.fcla.edudlsmddaitssdaitssReport.xsd
INGEST IEID EWYZUI8GD_NRGK75 INGEST_TIME 2013-10-24T18:43:45Z PACKAGE AA00017705_00001
AGREEMENT_INFO ACCOUNT UF PROJECT UFDC
FILES


Intensity (Kubelka-Munk Units)
262
TIME (h)
Figure 4.87. Intensity vs. time of exposure to air from FTIR spectra for PMS
polymer PMS-C (100% MDCS; toluene, dioxane (50:50 vol%)).


33
[Cam89] have shown by gas chromatography that they are the main products in the
polymerization of alkylsilanes (e.g., n-butylsilanes) catalyzed by DMZ. This is attributed
to the ability of DMZ to promote reversible reactions for both primary and secondary
silanes. In the case of polymerization of methylsilane, Campbell et al. reported the
presence of a small amount of cyclic oligomers (n=5 to 10), in agreement with the
results of Mu and Harrod. Thus, it can be concluded that formation of cyclic oligomers is
inevitable in the polymerization of alkylsilanes by dehydrocoupling.
In general, DMZ and DMT catalysts are effective for polymerization of primary
organosilanes. However, as shown by Mu and Harrod [Mu91A], polymerization rates for
primary silanes are about ten times faster using DMZ compared to using DMT.
Nevertheless, molecular weight characteristics of the polymers synthesized with the
two catalysts are essentially identical. The DMT-catalyzed polymerization exhibited a
pronounced induction period and a complete reduction of titanium to Ti (III). In contrast,
an induction period was absent for DMZ catalyzed reactions and a slight auto
acceleration in the reaction rates was observed in the reactions at low catalyst or
monomer concentrations.
The mechanism of catalytically activated dehydrocoupling of organosilanes is
complex. Harrod [Har88] suggested (based on NMR studies) that the mechanism
involved formation of titanium (IV) silylhydride ( Cp2Ti(H)(SiH2R)) which decomposed by
elimination of a-hydride from the SiH2R group, followed by release of H2 from the
complex to give Cp2Ti=SiHR (silylene) complex. A number of metallocene (catalyst)
derivatives are formed during polymerization that can be isolated and these compounds
are presumed inactive in the polymerization cycle. Propagation then occurred by
repetitive insertion of the silylene into a Ti-Si bond (a rapid addition mechanism) in which
the intermediates are not observable because they are short-lived or because they are


301
Flow test times were measured for spin batches as an indicator of the viscosity
of the spin dopes. (See section 3.2.1 for the details of the flow test measurement.) The
flow test was used instead of viscosity measurements for two reasons. First, the test
does not consume material. (Rheological tests result in less material being available for
spinning.) Second, rheological measurements result in additional exposure of the air-
sensitive spin dope to the ambient atmosphere. The initial basis for choosing the flow
test time was the prior experience with PCS polymer solutions. As discussed in section
4.1, flow times on the order of 10 s (with corresponding viscosities of ~35-40 Pa s) were
typically used for spinning. It was subsequently discovered (see below), however, that
higher flow times (and viscosities) were required for spin dopes prepared with PMS/PCS
in order to obtain both good spinning behavior and green fibers which were not stuck
together after spinning.
Table 4.27 shows that three batches with 25:75 PMS:PCS composition were
spun, i.e., UF-11s, UF-21s, and UF-25s. Only UF-21s spun well* UF-11s was the
earliest spin batch prepared and spinning techniques were not yet perfected. (For
example, winding of fibers was difficult due to air draft effects in the laboratory. Thus,
subsequent experiments were carried out in a glove box.) UF-25s also spun poorly, but
this was probably due to microgel particles in the spin dope. (The solution was only
filterable through 1 pm (but not 0.45 pm) filters.)
Six batches of fibers were spun with the 40:60 PMS:PCS composition. Batches
with high flow test times (i.e., -48-60 s) did not spin well (e.g., UF-22s, UF-27s, and UF-
28s). The remaining three fiber batches with relatively lower viscosity (i.e., flow test
times of -20-44 s) spun well. UF-24s, which had a flow test time of only 20 s, spun well,
* Fiber spinning behavior was considered good when there were: (i) fewer fiber breaks during spinning, (ii)
the polymer easily fiberized and stretched, and (in) a larger amount of fibers was collected.


4.77. Room temperature FTIR spectra of PMS polymer F (batch PMS-256)
(prepared from 70:30 wt% MDCS:MTCS in toluene/dioxane solvent) 238
4.78. FTIR spectra of PMS polymer C (100% MDCS; toluene, dioxane (50:50
vol%)), 40 to 600C at 5C/min in nitrogen 242
4.79. Intensity vs. temperature from FTIR spectra for PMS polymer C 244
4.80. FTIR spectra of PMS polymer C, 750 to 1150C at 5C/min in nitrogen .... 247
4.81. FTIR spectra of PMS polymer F (MDCS, MTCS (70:30 wt%)), toluene,
dioxane (50:50 vol%)), 40 to 600C at 5C/min in nitrogen 248
4.82. Intensity vs. temperature from FTIR spectra for PMS polymer F 250
4.83. FTIR spectra of PMS polymer F, 750 to 1150C at 5C/min in nitrogen ... 253
4.84. XRD patterns for PMS polymers prepared from monomer MDCS: (A) 100%
toluene, (B) toluene:THF (95:5 Vol%), and (C) toluene:dioxane (50:50
vol%) 254
4.85. XRD patterns for PMS polymers prepared from monomers MDCS:MTCS
(70:30 wt%): (A) 100% toluene, (B) toluene:THF (95:5 Vol%), and (C)
toluene:dioxane (50:50 vol%) 255
4.86. FTIR spectra of PMS polymer C (100% MDCS; toluene/dioxane
(50:50 vol%)) exposed to air, shown as a function of time 261
4.87. Intensity vs. time of exposure to air from FTIR spectra for PMS polymer C. 262
4.88. Gel permeation chromatograms for PMS-231 polymer: (A) after 3 days
of storage, (B) after 260 days of storage, and (C) after heat treatment
(PMS-231-H) 273
4.89. Polydispersity index vs. molecular weight for PMS polymers containing
5-14.5 wt% PSZ (and 0.5-1.5 wt% DCP) as additives 274
4.90. GPC molecular weight distributions for: (A) PMS-214-A (B) PMS-214-A-H 275
4.91. GPC molecular weight distributions for: (A) PMS-216-A (B) PMS-216-A-FI...277
4.92. GPC molecular weight distribution for PMS-216-A2-H 278
4.93. GPC molecular weight distributions for: (A) PMS-219-A (B) PMS-219-A-H.. 280
4.94. GPC molecular weight distributions for: (A) PMS-223-AD2-A
(B) PMS-223-AD2-H 281
4.95. GPC molecular weight distribution for PMS-216-AP-H 285
xvii


240
Table 4.17. FTIR peak assignments for polymethylsilane (PMS) polymer PMS-F (batch
PMS-256).
Peak (cm'1)
Assiqnment
References
2962
vas (C-H) from Si-CH3
1,2
2886
vs (C-H) from Si-CH3
1,2
2798
vs (CH2) from Si-CH3
1,2,5
2096
vs (Si-H)
1,4
1410
Sas (CH3) from Si-CH3
2,3
1248
8S (CH3) from Si-CH3
2,3
1057
v (Si-O-Si) + v (Si-O-C)
1,3,5
930
6 (SiH3)
7
841
Pas (CH3) from Si CH3
1,2,3
771
Ps (CH3) from Si CH3
6
676
vs (Si-C)
1,2,3
v = stretching ; 8 = bending ; p = rocking
(1) W. Kriner, J. Org. Chem., 29, 1601 (1964)
(2) A.L. Smith, J. Chem. Phys., 21, 1997 (1953)
(3) A.L. Smith, Spectrochimica Acta, 16, 87 (1960)
(4) A.L. Smith, Spectrochimica Acta, 15, 412 (1959)
(5) R.M. Silverstein, G.C. Bassler, and T.C. Morrill, Spectroscopic Identification of Organic
Compounds, John Wiley, New York (1981)
(6) J.R. Durig, and C.W. Hawley, J. Chem. Phys., 59(1),1(1973)
(7) N.B. Colthup, L.H. Daly, and S.E. Wberley, Introduction to Infrared and Raman Spectroscopy,
Academic Press, New York, 1964


APPENDIX C
FIBER EXTENSION DISTANCES FOR PCS AND PCS+PSZ SPIN DOPES


Table 4.32. Conditions and qualitative results of fiber spinning experiments for fractionally-precipitated PMS polymers.
Batch
Amount of PMS
Mn
Mw
Spin, additive
(wt%)
Filtration
condition
Filter/press/time
Flow
test
time (s)
Solids
loading
(%)
Viscosity
(Pa s)
Spin
speed
(rpm)
Pressure
(psi)
UF-73s
2.60g PMS-243-F
2821
8443
10% PSZ
0.1pm/30psi/5
min
27
84.7
39-38
84
425
Spun well; green fibers were partially stuck together especially in the middle portion of the bundle.
UF-74S
1.23g PMS-245-F1 (37%),
1,56g PMS-246-F (48%),
0.50g PMS-247-F (15%)
4872a
12672a
10% PSZ
0.1pm/30psi/
90min (4sets)
40.5
73.2
37-35
Not spinnable as the spinneret got clogged as soon as the spinning started. Used 40pm, 3hole spinneret.
UF-75S
1.50g PMS-250-F (46%),
0.87g PMS-251-F (27%),
0.87g PMS-248-F (27%)
2810a
6686a
10% PSZ
0.1pm/30ps¡/
3-10min
30.1
79.5
47-43
54
500-600
Spun well. Used 40pm, 3-hole spinneret. Fibers separable in green state and after pyrolysis.
UF-76S
0.78g PMS-250-F (29%),
0.74g PMS-251-F (28%),
1.15g PMS-248-F (43%)
2739a
7089a
10% PSZ
2% DB
0.1pm/30psi/
3-10min
Polymer solution gelled during processing.
UF-77s
0.81 g PMS-252-F (30%),
0.41 g PMS-253-F (15%),
0.58g PMS-254-F (22%),
0.86g PMS-255-F (33%)
2450a
5620a
6% PSO
2% DB
0.5% PSZ
0.1pm/30ps¡/
5min
25
78.0
37-31
134
500
Spun well but two holes clogged and only one spun. Green fibers were separable but not as separable as UF-75s. Used 40pm,3-hole spinneret.
UF-78S
0.81 g PMS-252-F (30%),
0.41 g PMS-253-F (15%),
0.58g PMS-254-F (22%),
0.86g PMS-255-F (33%)
2450a
5620a
6% PSO
2% DB
0.5% PSZ
0.1pm/30psi/
5min
34
77.1
47-41
84
500
Spun well; repeat of UF-77s. Fibers highly separable both in green and pyrolyzed state. Used 40pm, 3hole spinneret.
a Calculated based on rule of mixtures using individual component molecular weight information.
333


271
Table 4.22. Nomenclature of PMS polymers used in the heat treatment experiments.
Polymer designation3
Description
PMS-XXX
As-synthesized polymer (no additives)
PMS-XXX-H
Heat-treated PMS-XXX polymer
PMS-XXX-A
As-prepared PMS-XXX with PSZ and DCP additives
PMS-XXX-A-H
Heat-treated PMS-XXX-A
PMS-XXX-A2
A second portion of as-prepared PMS-XXX-A with PSZ and
DCP additives
PMS-XXX-A2-H
Heat-treated PMS-XXX-A2
PMS-XXX-AP
As-prepared PMS-XXX which contains PCS and PSZ as
polymer additives. It also contains DCP
PMS-XXX-AP-H
Heat-treated PMS-XXX-AP
PMS-XXX-AP2b
A second portion of as-prepared PMS-XXX which contains
PCS and PSZ additives. It also contains DCP
PMS-XXX-AP2-H
Heat-treated PMS-XXX-AP2
PMS-XXX-AD
As-prepared PMS-XXX which contains DB and PSZ polymer
as additives. It may also contain DCP as an additive
PMS-XXX-AD-H
Heat-treated PMS-XXX-AD
PMS-XXX-AD2
A second portion of PMS-XXX-AD which contains DB and
PSZ polymer as additives. It may also contain DCP as an
additive
PMS-XXX-AD2-H
Heat-treated PMS-XXX-AD2
PMS-XXX-APD
As-prepared PMS-XXX which contains DB, PCS polymer,
and PSZ polymer as additives. It may also contain DCP as
an additive
PMS-XXX-APD-H
Heat-treated PMS-XXX-APD
PMS-XXX-APD-a
As-prepared PMS-XXX with the same additives as PMS-
XXX-APD but with different concentrations of the additives
PMS-XXX-APD-a-H
Heat-treated PMS-XXX-APD-a
3 XXX refers to the batch number (e g., 216, 217, etc.)
b PMS-217-AP2 and PMS-219-AP2 were prepared from the original stock solutions PMS-217-AP and PMS-
219-AP, respectively; PMS-218-AP2 was prepared by increasing the amount of PSZ in the solution to 14.5
wt% and DCP to 1 wt%; PMS-220-AP2 and PMS-221-AP2 contained type C PCS whereas PMS-220-AP
and PMS-221-AP contained type B PCS;


430
[Moc93], D. Mocaer, R. Pailler, R. Naslain, C. Richard, J.P. Pillot, J. Dunogues, C.
Gerardin, and F. Taulelle, Si-C-N Ceramics with a High Microstructural
Elaborated from the Pyrolysis of New Polycarbosilazane Precursors: Part I.
The Organic/Inorganic Transition," J. Mater. Sci., 28 2615-2631 (1993).
[Mu91A], Y. Mu and J.F. Harrod, Synthesis of Poly(methylsilylene) by Catalytic
Dehydrocoupling with Cp2MMe2 (M=Ti, Zr) Catalysts, in Inorganic and
Organometallic Oligomers and Polymers, pp 23-36, Eds., J.F. Harrod and
R.M. Laine, Kluwer Academic Publishers, Dordrecht (The Netherlands)
(1991).
[Mu91B], Y. Mu, C. Aitken, B. Cote, and J.F. Harrod, Reactions of Silanes with
bis(cyclopentadienyl) Dialkylzirconium Complexes," Can. J. Chem., 69 264-
276 (1991).
[Oka87], K. Okamura, Ceramic Fibers from Polymer Precursors, Composites, 18 [2]
107-120 (1987).
[Pri94], G.J. Price, A M. Patel, and P.J. West, Polymer Synthesis Using High
Intensity Ultrasound, Macromol. Reports, A31 (Suppls. 6 & 7) 1037-1044
(1994).
[Qiu89A], H.Qiu and Z. Du, Organosilane Polymers: Formable Polymers Containing
Methyl Silylene Units, J. Polym. Sci., Part A: Polym. Chem., 27 2849-2860
(1989).
[Qiu89B], H. Qiu and Z. Du, Organosilane Polymers: Formable Polymers Containing
Reactive Side Groups, J. Polym. Sci., Part A: Polym. Chem., 27 2861-2869
(1989).
[Ree58], T. Ree and H. Eyring, Relaxation Theory of Transport Phenomena, in
Rheology: Theory and Applications, Ed., Eirich, Vol. II, Academic Press, New
York (1958).
[Rei90], E. Reichmanis, A.E. Novembre, R.C. Tarascn, A. Shugard, and L.F.
Thompson, Organosilicon Polymers for Microlithographic Applications," in
Silicon-Based Polymer Science A Comprehensive Resource, pp 265-284,
Eds., J.M. Zeigler and F.W.G. Fearon, American Chemical Society,
Washington, DC (1990).
[Sac86]. M.D. Sacks, Rheology of Suspensions, in Science of Ceramic Processing,
pp 337-344, Eds., L.L. Hench and D.R. Ulrich, John Wiley & Sons, New York
(1986).
[Sac95A], M.D. Sacks, G.W. Scheiffele, M.Saleem. G.A. Staab, A.A. Morrone, and T.J.
Williams, Polymer-Derived Fibers with Near-Stoichiometric Composition and
Low Oxygen Content, in Mat. Res. Soc. Symp. Proc., Ceramic Matrix
Composites, Materials Research Society, Pittsburgh, PA (1995).


351
60
50
w 40
re
a
3* 30
(f
o
o
S2 20
10
O Increasing Shear Rate
Decreasing Shear Rate
08 &
(B)
0
0
1 1 I 1 I 1 I 1 I 1
5 10 15 20 25 30
Shear Rate (s'1)
Figure A-1. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for batch 64s spin dope (PCS) (solids concentration
~67 wt%).


143
4.1.3.1.1 FTIR spectra of PCS fibers during heat treatment in N,
The changes in the structure of PCS fibers during pyrolysis to 600C in nitrogen
are shown in Figure 4.26. The relative changes in intensities of various peaks as a
function of temperature are shown in Figure 4.27. No significant changes were observed
in the absorption bands for PCS up to ~300C. The intensity of the absorption band for
Si-H increased steadily, reached a maximum at ~500C and then started to decrease.
The initial increase in intensity is possibly due to the formation of additional Si-H groups
as a result of methylene insertion reactions (also known as Kumada rearrangement
reactions [Shi58]). Methylene insertion reaction (equation (4.1)) is the mechanism by
which conversion of polydimethylsilane (PDMS) to polycarbosilane (PCS) takes place.
I 9H3 II
-Si-Si -Si-CHp-Si- (4.1)
II I I
Schmidt et al. [Sch91] have also observed similar increases in intensities of the Si-H
absorption band between the temperatures of 200-400C during the pyrolytic conversion
of vinylic polysilane to silicon carbide and have suggested that the mechanism
responsible for this observation is the methylene insertion reaction. (This conclusion was
based on 1H CRAMPS (Combined Rotation and Multiple Pulse Spectroscopy), 13 C MAS
NMR (Magic Angle Spinning Nuclear Magnetic Resonance), and 29 Si MAS NMR
spectra.) Figure 4.27 also shows that the absorption band at 1020 cm'1 (due to co (CH2)
of Si-CH2-Si) started to increase relative to the absorption band at 1407 cm'1 (due to 5as
(CH3) of Si-CH3) in the temperature regime of 300-500C. In addition, Figure 4.27 shows
that the intensity of absorption band due to co(CH2) of Si-CH2-Si increases relative to


MOLECULAR WEIGHT
223
4000 -r
3500 -
3000 -
2500 -
2000 -
1500 -
1000 -
500 -
0 -
Mw
M
A: Toluene
B: Toluene:THF (95:5 Vol %)
C: Toluene:1,4-Dioxane (50:50 Vol %)
Figure 4.67. Effect of cosolvents on molecular weight of PMS polymers A,B, and C
(prepared using 100% MDCS).


4.27. Intensity vs. temperature from FTIR spectra for PCS (green) fibers 145
4.28. Subtraction spectra for PCS fibers (69s) heat-treated in nitrogen,
600-40C 149
4.29. Comparison of FTIR spectra of PCS fibers before and after heat treatment
at 600C in nitrogen 150
4.30. Room temperature FTIR spectra for PCS fibers heat-treated in air at
187C 152
4.31. Subtraction spectra for PCS fibers heat-treated in air at 187C (65s)
and PCS green fibers (69s) 154
4.32. Comparison of FTIR spectra of PCS fibers at 40C before and after heat
treatment in air 156
4.33. FTIR spectra for air-heat treated (187C) PCS fibers during heat
treatment to 600C at 1C/min in nitrogen 157
4.34. Intensity vs. temperature from FTIR spectra for PCS (air-heat treated
at 187C) fibers during heat treatment in nitrogen to 600C 158
4.35. FTIR spectra of air-heat treated Nippon PCS fibers during heat treatment
in nitrogen to 500C (from Ichikawa et al.) 160
4.36. Comparison of FTIR spectra of air-heat treated (187C) PCS fibers
before and after heat treatment at 600C in nitrogen 163
4.37. Subtraction spectra for air-heat treated (187C) PCS fibers heat treated
in nitrogen (600-40C) 164
4.38. Room temperature FTIR spectra for PSZ polymer (batch 0831A) 165
4.39. FTIR spectra for PSZ polymer during heat treatment to 600C at 1C/min
in nitrogen 167
4.40. Intensity vs. temperature from FTIR spectra of PSZ 169
4.41. Room temperature FTIR spectra of PCS+PSZ green fibers (batch 70s).. 173
4.42. FTIR spectra of PCS+PSZ green fibers during heat treatment to 600C in
nitrogen 175
4.43. Intensity vs. temperature from FTIR spectra of PCS+PSZ fibers 176
4.44. Comparison of FTIR spectra of PCS+PSZ fibers (70s) before and after
heat treatment at 600C in nitrogen 179
XIV


ABSORBANCE (Kubeika-Munk Units)
168
WAVENUMBER (cm'1)
Figure 4.39. (Cont'd.)


372
Table E-1. (Contd.)
Polydimethylsiloxane (viscosity: 12.12 Pa s (molecular weight-67,700) at 22C;
published surface tension: 0.0215 N/m)
Force (mq)
Surface tension ( N/m)
122.0
0.02391
122.6
0.02384
121.8
0.02387
122.4
0.02399
122.4
0.02395
Average surface tension : 0.02391 0.00006 [Deviation from published value: 11.2%]
Toluene (viscosity: 0.587 mPa-s at 20C; Published value of surface tension: 0.02828
N/m at 22C) [Dea85]
Force (mq)
Surface tension ( N/m)
152.40
0.02987
151.80
0.02975
152.00
0.02979
151.60
0.02971
151.00
0.02960
Average surface tension 0 02974 0.00010 [Deviation from publsihed value: 5.2%]
PCS Solution (33 wt%)
Force (mq)
Surface tension ( N/m)
144.60
0.02834
145.20
0.02846
145.80
0.02858
144.80
0.02838
145.20
0.02846
Average surface tension : 0.02844 0.00009


344
AMOUNT OF PSZ (Wt%)
Figure 4.118. Average extension for fibers drawn from PMS-based polymers
as a function of amount of PSZ 0908A added.


4.11. Advancing and receding contact angles for PCS+PSZ (33 wt%)/toluene
solution on stainless steel substrate as a function of cumulative drop
volume 120
4.12. Advancing and receding contact angles of PCS (33 wt%)/toluene solution
on teflon substrate as a function of cumulative drop volume 121
4.13. Advancing and receding contact angles of PCS+PSZ (33 wt%)/toluene
solution on teflon substrate as a function of cumulative drop volume 122
4.14. Advancing and receding contact angles for PCS (33 wt%)/toluene solution
on a stainless steel substrate coated with PCS as a function of cumulative
drop volume 124
4.15. Advancing and receding contact angles for PCS+PSZ (33 wt%)/toluene
solution on a stainless steel substrate coated with PCS+PSZ as a function
of cumulative drop volume 125
4.16. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
33 wt% PCS solution used in surface tension measurement 129
4.17. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
50 wt% PCS solution used in surface tension measurement 130
4.18 Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
66 wt% PCS solution used in surface tension measurement 131
4.19. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
33 wt% PCS+PSZ solution used in surface tension measurement 132
4.20. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
50 wt% PCS+PSZ solution used in surface tension measurement 133
4.21. Plots of: (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
66 wt% PCS+PSZ solution used in surface tension measurement 134
4.22. Surface tension as a function of concentration for PCS and PCS+PSZ
solutions 135
4.23. Surface tension as a function of viscosity for PCS and PCS+PSZ
solutions 136
4.24. Room temperature FTIR spectra of green PCS fibers 138
4.25. Room temperature FTIR spectra of polydimethylsilane (PDMS) 140
4.26. FTIR spectra of PCS fibers during heat treatment to 600C at 1C/min in
nitrogen atmosphere 144
xiii


153
Table 4.6. FTIR peak assignments for PCS fibers (batch 65s) heat-treated in air at 187C.
Peak (cm'1)
Assiqnment
References
3650
v (OH)
1,2
2950
vas (C-H)
1,2
2894
vs (C-H)
1,2
2098
v (Si-H)
1,4
1720
v (C=0)
2,3
1407
Sas (CH3) from Si-CH3
2,3
1358
5 (CH2) from Si CH2- Si
1,3
1253
5S (CH3) from Si-CH3
2,3
1000-1100
5 (Si-O-Si or Si-O-C)
1,3
1020
co (CH2) from Si CH2- Si
1,3
830
Pas (CH3) from Si CH3
1,2,3
735
vas (Si-C)
1,2,3
v = stretching ; 8 = bending ; co = bending ; p = rocking
(1) W. Kriner, J. Org. Chem., 29, 1601 (1964)
(2) A.L. Smith, J. Chem. Phys., 21, 1997 (1953)
(3) A.L. Smith, Spectrochimica Acta, 16, 87 (1960)
(4) A.L. Smith, Spectrochimica Acta, 15, 412 (1959)


ABSORBANCE (Kubelka-Munk Units)
i | i | | i | 1 | T I 1 | 1 | r_
4000 3600 3200 2800 2400 2000 1600 1200 800
Wavenumber (cm'1)
Figure 4.48. Room temperature FTIR spectra of PCS+PSZ fibers (batch 70s) heat-treated in air at 177C.
400
185


dwt/d(logM) dwt/d(logM)
275
6 5 4 3 2
log MW
Figure 4.90. GPC molecular weight distributions for: (A) PMS-214-A and
(B) PMS-214-A-H.


INTENSITY (cps) INTENSITY (cps) INTENSITY (cps)
255
20 (Degrees)
Figure 4.85. XRD Patterns for PMS polymers prepared from monomers MDCS/MTCS
(70:30 wt%) (A) 100% toluene (B) toluene:THF (95:5 Vol%) (C) toluene:
dioxane (50:50 Vol%).


22
Figure 2.7. Rate of disappearance of monomer n-hexylmethyldichlorosilane as a
function of time and weight percent of 15-crown-5 ether [Gau89].


236
of the more polar solvents. This is also suggested by the fact that the ceramic yields are
all higher for the polymers prepared from the MDCS/MTCS mixtures (i.e., compared to
the polymers prepared with MDCS alone).
Figure 4.74 shows that polymer C has an abrupt weight loss of ~10 wt% starting
at 860C. Polymer B shows a weight loss of about 3% starting at 977C. A similar (~10
wt%) high temperature weight loss was observed by Zhang et al. [Zha91] during TGA
analysis of PMS polymers. It is suggested that these high temperature weight losses are
attributed to the evolution of hydrogen arising from the decomposition of (Si-H)-
containing structures. It is noted that this type of high temperature weight loss was not
observed during the heat treatment of polymers prepared from MDCS/MTCS mixtures
(Figure 4.75). This is consistent with the expectation that less Si-H groups are retained
in these polymers since these groups are likely to be consumed during cross-linking
reactions promoted by the use of the trifunctional monomer, MTCS.
4.2.3.2 FTIR spectroscopy studies on PMS polymers
FTIR spectra on PMS polymers C (batch PMS-263) and F (batch PMS-256)
(polymers synthesized from MDCS and MDCS/MTCS in (70:30 wt. ratio), respectively in
toluene/dioxane solvent) were collected in the diffuse reflectance mode at room
temperature and during heat treatment from 40-600C in nitrogen atmosphere. Figure
4.76 and 4.77 show the room temperature spectra of polymers PMS-C and PMS-F,
respectively. The peak assignments for these polymers are shown in Table 4.16 and
Table 4.17. Polymer C (prepared from MDCS) may be richer in Si-H groups compared
to polymer PMS-F (prepared from mixture of MDCS/MTCS). This is suggested from the
splitting of the Si-H absorption into the asymmetric stretching peak (at 2133 cm'1) and
symmetric stretching peak (at 2053 cm'1). (As noted earlier, it is believed that the high
temperature (above 800C) weight losses in the polymers B and C prepared from


256
treatment at 10C/min to 1350C (no hold time) in argon. The d-spacings, 20 Bragg
angles, and the corresponding intensities of diffraction planes are shown in Table 4.18.
The XRD patterns were essentially the same for all samples. The major phase in these
samples is (3-SiC. Silicon is present as a minor phase. The pyrolytic decomposition of
PMS polymers to a SiC/Si mixture was reported by several previous workers [Sey92;
Zha94A],
The crystallite sizes for the Si and SiC phases were determined by the line
broadening method using Schemers formula (described in section 3.2.6) and the results
are tabulated in Table 4.19. The SiC crystallite sizes are virtually the same (in the range
of 8.1-9.3 nm) for all samples. The Si crystallite sizes are slightly smaller for the samples
prepared from the MDCS/MTCS polymers (i.e., compared to the samples prepared from
MDCS alone). However, the differences are not particularly significant given the range
of experimental variability observed when multiple samples were analyzed.
4.2.3.4 EMA analysis
Table 4.20 shows results of Electron Microprobe Analysis (EMA) for samples
obtained after pyrolysis of PMS polymers at 1000C in nitrogen. Results are shown for
samples prepared from polymer PMS-245-A (an as-synthesized batch of polymer F) and
polymer PMS-245-F-1 (a higher molecular weight portion of PMS-245-A prepared by
fractional precipitation; see section 4.3.1.2). The former sample showed a Si-rich
composition compared to that of stoichiometric SiC. (Stoichiometric SiC has a
composition of 70 wt% Si/30 wt% C.) PMS polymers with Si-rich composition have
been reported previously by other researchers [Sey92; Zha94A; Zha94B], The result in
this study is also consistent with the observation of free Si in the XRD pattern for a
similar PMS sample (polymer F, batch PMS-256) which was pyrolyzed at 1350C (in
argon), as shown in Figure 4.85.


252
Unlike polymer PMS-C, where no significant changes were observed for most of the
absorption bands up to 200C, polymer PMS-F showed changes early on in the heat
treatment. The intensity due to the stretching vibration of Si-H (at 2096 cm'1) increased
from 40C, reached a maximum at around 300C and then started to decrease. This
increase is again attributed to methylene insertion reaction shown in equation (4.6). This
was also suggested by the onset of the absorption band due to §s (CH2) of Si-CH2-Si at
~360C, which corresponds to the insertion of -CH2 groups in the main Si-Si chain.
However, some results are inconsistent with the hypothesis that methylene insertion
reaction occurs. First, the increase in the v (Si-H) vibration is considerably greater than
the increase in the 8S (CH2) vibration and the increase occurs at much lower
temperature. Second, the intensities due to symmetric ps (CH3) vibration of Si-CH3 at
770 cm'1, asymmetric pas (CH3) vibration of Si-CH3 at 830 cm'1 and symmetric stretch of
C-H of Si-CH3 at 2894 cnr1 increase, starting at relatively low temperatures and
increasing up to ~350C.
The FTIR spectra after heat treatment of PMS-F at temperatures in the range of
750-1150C are similar to those observed in PMS-C (see Figure 4.83). Above 750C,
the intensity of absorption band due to stretching vibration of (3-SiC (at 750-1000 cm'1) is
broader compared to that of polymer PMS-C. This may be due to a lesser degree of
crystallization for the SiC formed from polymer PMS-F. (This is suggested by XRD
results for heat-treated PMS-F and PMS-C samples, as discussed below in section
4.2.3.3.)
4.2.3.3. XRD characteristics
Figures 4.84 and 4.85 show representative XRD patterns of the residues
obtained from various MDCS-derived and MDCS/MTCS-derived polymers after heat


134

r
CL
5
(n
o
o

>
40
30
20
10
0
O Increasing Shear Rate PCS+PSZ (66 wt%)
Decreasing Shear Rate
0 S 0
(B)
0 50 100 150 200 250 300
Shear Rate (s'1)
Figure 4.21. Plots of: (A) shear stress vs. shear rate and (B) viscosity vs.shear rate
for a 66 wt% PCS+PSZ solution used in surface tension measurement.


62
West et al. [Wes86B] have cross-linked Si-H containing polyphenylsilane polymers by
using a vinylic silane monomer (e.g., trivinylphenylsilane, trivinylmethylsilane) as the
cross-linking agent in the presence of traces of chloroplatinic acid as a catalyst. During
the reaction, the initially viscous reaction mixture transforms to a solid polymer, which is
insoluble and infusible (a process analogous to room temperature vulcanization of
silicone elastomers). The cross-linking reaction can be represented as:
Ph Ph Ph
I II
.Si Si Si .
I I I
H H H
Vi
I H2PtCI6
+ ViSi_Ph
I
Vi
-Si-
Si Ph
_Si SiPh + C2H6 (2.10)
I I
Ph -Si-ph
I
_Si_
Vi- CH=CH2
Ph - C6H5
2.4.3 Photo-cross linking
Qiu and Du [Qiu89B] have shown that when polysilane polymers such as
polymethylsilane and polyphenylsilane were irradiated with UV light of wavelength 254


151
in the FTIR spectra. At ~800C, a well-defined absorption band due to vas (Si-C) at 735
cm'1 formed.
4.1.3.1.2 FTIR spectra of PCS fibers heat-treated in air
Figure 4.30 shows FTIR spectra at 40C of PCS fibers after heat treatment in air
at 187C for 1 h. (The fibers had a weight gain of 8.5 wt% after this treatment.) Table
4.6 shows peak assignments for PCS fibers heat-treated in air. In addition to the
characteristic absorption bands for normal PCS as described above (section 4.1.3.1.1),
the spectra also shows absorption bands at 3650 cm-1 and 3600-3400 cm'1 (due to free -
OH and bonded -OH, respectively), 1720 cm'1 (due to C=0), and a broad absorption
band at 1000-1100 cm'1 (due to Si-O-Si or Si-C-O)1-. The absorption band at 3220 cm'1
could not be identified. (It is suspected that this peak may have been due to some
contamination of the sample during vacuum drying prior to loading the sample in the
FTIR hot stage.) During heat treatment of PCS fibers in air, Si-H, Si-CH3 and Si-CH2-Si
groups get oxidized, resulting in the formation of Si-OH, Si-O-Si, Si-C-O, Si-O-C, and
C=0 linkages.
In the case of PCS fibers before heat treatment in air, the intensity of the
absorption band 5 (CH3) from Si-CH3 at 1407 cm'1 was less than that due to S(CH2) from
Si-CH2-Si at 1358 cm'1. After the air-heat treatment, it can be clearly seen that the
absorption band due to 5 (CH3) from Si-CH3 became higher in intensity than the
absorption band 8(CH2) from Si-CH2-Si. This is attributed to the conversion of Si-CH2-Si
bonds to Si-C-O bonds during heat treatment in air. (Hasegawa et al. argue that Si-
CH2* radicals form when the Si-CH2-Si chain is severed and that these radicals are
oxidized easily and form Si-C-O networks [Has89].) Figure 4.31 shows a subtraction
1 There would still be contributions from to (CH2) of Si-CHrSi vibrations at -1020 cm'1.


180
150
120
90
60
30
0
Green, no PSZ
400C (Nj), no PSZ
180C 10'C (Air), no PSZ
lUl 180*C 10*C (Air), 400*C (N2), no PSZ
| | Green, PSZ
mu 400C (Nj), PSZ
| | 180"C 10'C (Air), PSZ
[ ] 180C 10'C (Air), 400C (N2), PSZ

CO
CO
z
O
V)
CO
to
p
o
o
U)
5
CO

to
CO
O
w
lO
CO
O
0
O
o
Tf
U)
CT)
CO
(0
(7)
CO
63s, 64s, 65s, 69s: PCS fibers
67s, 68s, 70s: PCS + PSZ fibers
N
z
o
o
o
o
<
O
+1
o
BATCH DESIGNATION
Figure 4,55. Average tensile strengths for PCS, PCS+PSZ fibers, as-spun and after heat treatment in (i)nitrogen at 400C,
(ii) air at 180 10C, and (in) air at 180 10C, followed by N2 at 400C.
CD


23
by equation (2.2) in Figure 2.1) are involved in the polymerization of n-
hexylmethyldichlorosilane and claimed that 15-crown-5 ether accelerated the
occurrence of initiation reactions. Although data is limited, it is evident that the rate of
monomer consumption is increased with small additions of 15-crown-5 ether.
2.2.1.5 Temperature effects
Miller et al. [MI93] investigated the effect of temperature on the molecular weight
distribution and yield for polymers produced from diaryl and dialkyl substituted
chlorosilanes. They found in the case of polymerization of methylphenyldichlorosilane in
toluene that lowering the reaction temperature to 65C (from the refluxing temperature
of 110C) decreased the total yield from 25% to 10%, while causing an increase in
molecular weight of the polymer. In addition, the molecular weight distribution changed
from bimodal to monomodal (Table 2.2). However, in the presence of a polar solvent
(i.e., 15% diglyme), lowering the reaction temperature to 65C (instead of the reflux
temperature) resulted in the opposite trends from what is noted above, i.e., the
polymer yield increased slightly and the polymer molecular weight decreased. (The latter
changes may have been within the limits of experimental error.)
When polymerization was carried out in a blend of toluene/15% heptane,
lowering the reaction temperature to 65C had no effect on polymer yield or overall
polymer molecular weight. Miller et al. also reported that low temperature (65C)
polymerization of alkyl substituted chlorosilanes (such as dichloro-di-n-hexylsilane) took
place sluggishly. The typical change in color to purple or dark blue was conspicuously
absent. In addition, the yield for such a polymerization was less than a percent (i.e.,
essentially no polymerization occurred).
Jones et al. [Jon94] investigated polymerization of methylphenylsilane in THF at
low temperatures (-79C) using a sodium/electron acceptor complex. The electron


142
spectra are due to various modes of vibrations of Si-CH3 groups. In the case of PCS, it
is possible that some residual Si-Si bonds may be remaining in the polymer structure
depending on synthesis conditions. A comparison of FTIR spectra of PDMS and PCS
will enable determination of whether the PDMS to PCS conversion is essentially
complete. A mostly converted PCS shows an intense absorption band at 2100 cm'1 due
to Si-H bond. This absorption band is absent in PDMS due to the lack of Si-H bonds in
the structure of PDMS. A comparison of absorption bands at 1407 cm'1 and 1355 cm'1
for PDMS and PCS will also enable determination of the extent of conversion to PCS. In
the case of PDMS, there is an absorption band at 1407 cm'1 and none at 1355 cm'1.
This is consistent with the structure of PDMS, which shows CH3 groups attached as side
groups to the main Si-Si backbone. After conversion to PCS, one of the side groups
(CH3) is replaced by CH2, which attaches in the main chain as a Si-CH2-Si linkage, and
H which is attached to Si as side group. Hence, the contribution from Si-CH2-Si also
shows up in the FTIR spectra for PCS as an absorption band at 1355 cm'1. Since the
CH2 group is attached to the Si atom in the backbone, its absorption intensity is higher
than that of the Si-CH3 in which the CH3 is attached to a Si atom as a side group. Thus,
in a mostly converted PCS, the absorption intensity at 1355 cm'1 is greater than the
absorption intensity at 1407 cm'1. It was expected that the absorption intensities at 2950
cm'1 and 2850 cm'1 would be higher for PDMS because two CH3 groups are attached to
each Si atom in the backbone of the repeating unit (R.U) compared to PCS, where only
one CH3 group is attached to each Si atom in the backbone of the R.U. However, this
was not observed from Figures 4.24 and 4.25. (It is not clear if this is related to the fact
that the PCS fibers were analyzed in the diffuse reflectance mode, while the PDMS
sample was analyzed in the transmission mode.)


APPENDIX B
FIBER SPINNING CHARACTERISTICS FOR PCS AND PCS+PSZ SPIN DOPES


3
up to 1150C. Fourier transform infrared spectroscopy (FTIR) was used to study the
chemical changes occurring in these fibers during pyrolysis. In an effort to understand
the effect of PSZ on spinnability of PCS solutions, polymer solutions were characterized
using several methods, including measurements of surface tension, contact angles,
rheological characteristics (e.g., intrinsic viscosity), and the rate of evaporation of
solvent from the solutions.
The second major area of investigation was the synthesis and processing of
PMS (polymethylsilane) polymers for the fabrication of SiC-based fibers. There has
been limited work on the preparation of SiC fibers from organosilicon polymer blends.
SiC fibers may be fabricated by using PMS polymers and PMS/PCS polymer blends.
PMS polymers generally produce an excess of elemental Si (in addition to SiC) upon
pyrolysis. As indicated earlier, PCS polymers form an excess of elemental C upon
pyrolysis. Therefore, a combination of these two polymers might potentially be used to
form SiC fibers with controlled stoichiometry.
PMS polymers were synthesized in this study by Wurtz-coupling polymerization
of methyldichlorosilanes (MDCS) and methyltrichlorosilanes (MTCS) with sodium (Na) in
refluxing solvent/solvent mixtures. One of the major disadvantage of this method is poor
polymer yields. Polymer yields and molecular weight distributions are quite sensitive to
substituents (pendant groups) in the monomers, order of reagent addition, solvent
additives, reaction temperatures, etc. It has been reported that addition of polar solvents
promote anionic polymerization (such as Wurtz-coupling polymerization) and increase
polymer yields [MN93; Gau89], In this study, effects of addition of polar solvents THF
and 1,4-Dioxane on polymer yield and molecular weight were investigated.
One of the main drawbacks of PMS polymers for use in fiber fabrication is that
they are liquids at room temperature and generally have low molecular weight (Mn <


428
[Her70],
W.J. Herzberg, and J.E. Marian, Relationship Between Contact Angle and
Drop Size," J. of Colloid and Interface Sci., 33 [1] 161-163 (1970).
[Ich86],
H. Ichikawa, F. Machino, S. Mitsuno, T. Ishikawa, K. Okamura, and Y.
Hasegawa, Synthesis of Continuous Silicon Carbide Fibre- Part 5, Factors
Affecting Stability of Polycarbosilane to Oxidation, J. Mater. Sci., 21 4352-
4358 (1986).
[Ich90],
H. Ichikawa, F. Machino, H. Teranishi, and T. Ishikawa, Oxidation Reaction
of Polycarbosilane, in Silicon-Based Polymer Science-A comprehensive
Resource, pp 619-637, Eds., J. M. Zeigler, and F.W.G. Fearon, American
Chemical Society, Washington, DC (1990).
[Ish94],
T. Ishikawa, Recent Developments of the SiC Fiber Nicalon and its
Composites, Including Properties of the SiC Fiber Hi-Nicalon for Ultra-High
Temperature, Composites Sci. Technol., 51 135-144 (1994).
[Jon94],
R.G. Jones, R.E. Benfield, R.H. Cragg, P.J. Evans, and A.C. Swain, The
Formation of Polysilanes from Homogeneous Reagents in Tetrahydrofuran
Solution at Low Temperatures, Polymer, 35 [22] 4924-4925 (1994).
[Kim88],
H.K Kim and K. Matyjaszewski, Preparation of Polysilanes in the Presence
of Ultrasound, J. Am. Chem. Soc., 110 3321-3323 (1988).
[Kip21 ].
F.S. Kipping and J.E. Sands, Organic Derivatives of Silicon, Part XXV,
Saturated and Unsaturated Silicohydrocarbons Si4 Ph8, J. Chem. Soc., 119
830-835 (1921).
[Lip89],
J. Lipowitz, G. LeGrow, T. Lim, and N. Langley, Silicon Carbide Fibers from
Methylpolysilane Polymers, in Ceramic Transactions-Volume 2, Silicon
Carbide 87, Eds., J.D. Cawley and C.E. Semler, The American Ceramic
Society, Westerville, OH (1989).
[Lip91A],
J. Lipowitz, J.A. Rabe, and G.A. Zank, Polycrystalline SiC Fibers from
Organosilicon Polymers, Ceram. Eng. Sci. Proc., 12 [9-10] 1819-1831
(1991).
[Lip91 B],
J. Lipowitz, Structure and Properties of Ceramic Fibers Prepared from
Organosilicon Polymers, J. Inorg. Organomet. Polym., 1 [3] 277-297 (1991).
[Lip94A],
J. Lipowitz, T. Barnard, D. Bujalski, J.A. Rabe, G.A. Zank, Y. Xu, and A.
Zangvil, Fine-Diameter Polycrystalline SiC Fibers," Composites Sci.
Technol., 51 167-171 (1994).
[Lip94B],
J. Lipowitz, and J.A. Rabe, Polycrystalline Silicon Carbide Fibers," U.S. Pat.
No. 05 366 943 (1994).


Table H-3. (Cont'd.)
Batch 5:
dt(tim)
dum)
d.(avg,)
Load(a)
Strain
TSfGPal
EMiGPal
11.50
11.50
11.50
25.35
0.0102
2.39
233.90
12.50
13.50
13.00
42.48
0.0157
3.14
199.55
11.50
11.50
11.50
20.31
0.0084
1.92
228.61
12.50
12.50
12.50
17.77
0.0064
1.42
222.75
13.00
13.50
13.25
30.20
0.0096
2.15
223.57
13.50
13.50
13.50
23.86
0.0074
1.63
220.07
11.50
11.50
11.50
19.50
0.0082
1.84
225.08
13.50
13.50
13.50
21.13
0.0077
1.45
188.21
12.00
12.00
12.00
22.76
0.0086
1.97
228.23
11.50
11.50
11.50
28.80
0.0118
2.72
230.52
11.50
11.50
11.50
30.20
0.0119
2.85
239.18
11.50
11.50
11.50
36.43
0.0155
3.44
225.74
11.50
11.50
11.50
26.69
0.0105
2.52
239.26
11.50
11.50
11.50
39.26
0.0152
3.71
243.81
13.00
13.50
13.25
23.38
0.0075
1.66
221.10
11.00
11.50
11.25
32.98
0.0134
3.25
242.11
11.00
11.50
11.25
25.73
0.0109
2.54
232.29
11.50
11.50
11.50
19.40
0.0084
1.83
217.02
Average
11.97
12.14
12.06
27.01
0.01
2.36
225.61
Std. Dev
0.81
0.90
0.85
7.12
0.00
0.71
14.02


328
Figure 4.116. SEM micrographs of fracture surfaces of UF-35s fibers after heat
treatment at 1700C in argon.


424
5. Hexylmethyldichlorosilane
6. Hexyl-d¡-n-d¡chloros¡lane
7. Dodecylmethyldichlorosilane
C6H13
Cl Si Cl
ch3
<|6h13
Cl Si Cl
I
c6h13
Cl Si -Cl
ch3
(|12H25
Cl Si -Cl
I
c12h25
8. Dodecyl-di-n-dichlorosilane


Intensity (Kubelka-Munk Units)
177
A
pas(CH3) of Si-CH3 [830 cm'1]
co(CH2) of Si-CH2-Si [1020 cm'1]
5s(CH3) of Si-CH3 [1253 cm'1]
5(CH2) of Si-CH2-Si [1358 cm'1]
| i | i | i | i | i [
0 100 200 300 400 500 600
Temperature (C)
700
Figure 4.43. (Cont'd.)


306
GPa, whereas fiber batches prepared with 40:60 PMS:PCS ratio (and also pyrolyzed at
1000C) had an average tensile strength of 1.26 GPa. (Some of the fiber batches with
40:60 PMS:PCS ratio, such as UF-27s and UF-28s, were too weak to be tested.) Table
4.28 also shows that fibers heat-treated at 1500C had lower strengths than the
corresponding fibers heat-treated to 1000C.
In summary, it was not possible to prepare high strength SiC fibers from as-
prepared PMS/PCS polymer blends. A higher molecular weight (more cross-linked),
infusible PMS polymer was needed to avoid adhesion problems between as-spun fibers
and melting of fibers during pyrolysis.
4.3.2.2 Spinning of heat-treated PMS polymers and PMS/PCS polymer blends
Table 4.29 shows conditions and some qualitative results for fiber spinning
experiments carried out using heat-treated polymers. PMS:PCS blends of 40:60, 60:40,
70:30, 90:10, and 100:0 were used in making spin dopes. The blends were prepared by
two methods: (1) PMS polymers were heat-treated separately and mixed with as-
prepared PCS in the desired ratio and (2) As-prepared PMS and PCS were mixed
initially in the desired proportions and then the mixture was heat-treated.
Three spin dopes (UF-33s, UF-35s, and UF-36s) were prepared by method 1
using a 40:60 PMS:PCS mixture. The rheological flow behavior of these spin dopes is
shown in Figures 4.106, 4.107, and 4.108. All three batches spun well. However, the
UF-33s spin dope, which had a significantly lower viscosity (19-25 Pa s) compared to
the UF-35s (110-118 Pa s) and UF-36s (55-71 Pa s) spin dopes, produced as-spun
fibers which were stuck together. In contrast, fibers from the other two spin dopes were
easily separated. It is interesting to note UF-33s had much higher solids loading (87.1
wt%) despite the lower viscosity compared to the other two batches (which had solids
loadings of 69.7 and 73.0 wt%, respectively). This is attributed to a lower molecular


dwt/d(logM) dwt/d(logM)
409
(A)
Figure J-7. GPC distribution of PMS-252 polymer: (A) before and
(B) after fractional precipitation with acetone.


dwt/d(logM) dwt/d(logM)
277
(B)
Figure 4.91. GPC molecular weight distributions for: (A) PMS-216-A and
(B) PMS-216-A-H.


215
treatments in nitrogen appear to be controlled largely by the effects of the initial
oxidative cross-linking.
With further heat treatment (> 600C) in nitrogen, the air-heat treated PCS+PSZ
fibers have somewhat higher strengths than the air-heat treated PCS fibers. As in the
case of the corresponding fibers which were not given the initial air-heat treatment, this
difference is attributed to the improved spinning behavior which results in fewer large
defects in the pyrolyzed bundles. It is also noted that the air-heat treated fibers (both
PCS and PCS+PSZ) have lower strengths than the corresponding fibers without the air
heat treatment for samples pyrolyzed in nitrogen in the range of 600-1150C. The
reason for this behavior is not clear, but may reflect differences in phase composition.
(The 1150C-pyrolyzed fibers prepared without air heat treatment consist mostly of very
weakly crystalline (3-SiC and amorphous carbon. The corresponding air-heat treated
fibers contain these phases, but also contains an amorphous silica-like and/or silicon
oxycarbide material.)


INTENSITY (arbitrary units)
WAVENUMBER (cm'1)
Figure 4.31. Subtraction spectra for PCS fibers heat-treated in air at 187C (batch 65s) and PCS green fibers (batch 69s).
154


195
4.1.3.2 Mechanical properties of fibers
Tensile stress-strain measurements were carried out on green and heat-treated
fibers from different PCS and PCS+PSZ spin batches. Fibers were tested as-spun and
after various heat treatments (air at 180 10C/1 h and/or nitrogen at 400C/1 h).
Appendix F shows weight gains after heat treatment in air at 180 10C for PCS and
PCS+PSZ fibers.
Table 4.10 shows average tensile strengths and rupture strains for different
batches of PCS and PCS+PSZ fibers. Figures 4.55 and 4.56 show bar charts of average
tensile strengths and average rupture strains for the same. PCS and PCS+PSZ green
fibers had similar strengths and rupture strains (-14-22 MPa and 0.6-1%, respectively).
However, after heat treatment at 400C in nitrogen, PCS+PSZ fibers showed much
larger increases in tensile strength (-55-61 MPa) and rupture strain (~5.6-6.5%)
compared to PCS fibers. Two 400C heat treated PCS fiber batches (63s and 64s)
showed similar tensile strength and rupture strain as the green fibers, while two other
400C batches (65s and 69s) showed relatively small increases in tensile strengths
(-31 and -43 MPa, respectively) and rupture strain (-1.45 and -2.1%, respectively).
PCS and PCS+PSZ fibers heat-treated in air at 180 10C showed much higher
strengths (-50-51 and -58 MPa, respectively) and rupture strains (-2.9-3.2% and
-4.3%, respectively) compared to green fibers. PCS and PCS+PSZ fibers heat-treated
in air at 180 10C and subsequently heat-treated in nitrogen at 400C showed even
higher tensile strengths (-110 and -105 MPa, respectively) and rupture strains (-5.0
and -7.4%, respectively) compared to fibers given just one of the heat treatments.
Other studies [Has80] have also shown that the tensile strength and rupture
strain both increase after cured (oxidized) green fibers are heat-treated. Hasegawa et al.
reported a rupture strain of -4.5% and a tensile strength of -4 kgf/mm2 (-36 MPa) for


Table M-1. (Contd.)
Batch
Designation
Solvent(s)
Polymer
Yield (%)
GPC MW distribution
Mn Mw PDI
Ceramic Yield (%)
by pyrolysis by TGA b
XRD Results
(1350C/Ar)
P MS-2 54
Toluene, 1,4
Dioxane
(50:50)
42.0
887
1857
2.09
PMS-255
Toluene, 1,4
Dioxane
(50:50)
48.8
971
2017
2.08
PMS-256
Toluene, 1,4
Dioxane
(50:50)
45.3
953
1932
2.03
52.1
Strong Si; 15
nm
PMS-259
Toluene
15.2
815
1167
1.43
55.0
Strong Si; 15
nm
a Smaller batch size, prepared in 250 ml three necked flask.
b TGA analysis carried out at 1200C/Ar/10C per min/0 h hold.


Intensity (Kubelka-Munk Units)
169
v(C-H) [2950 cm'1]
v(N-H) [3390 cm'1]
v(CH=CH2) [3040 cm'1]
vs(C-H) [2894 cm'1]
5as (CH=CH2) [1592 cm'1]
A
Temperature (C)
700
Figure 4.40. Intensity vs. temperature from FTIR spectra of PSZ.


382
Table H-2. (Cont'cU
Batch 3:
cM|jml d,^m1 d(ava.) Loadial Strain TSfGPai EMtGPal
Average
Std. Dev
Batch 4:
Average
Std. Dev
10.50
11.50
11.00
18.70
0.0112
1.93
172.41
9.50
11.00
10.25
12.30
0.0093
1.47
157.84
10.50
11.00
10.75
29.20
0.0165
3.15
191.16
9.50
10.00
9.75
16.25
0.0114
2.13
187.57
6.00
8.50
7.25
7.68
0.0079
1.88
236.91
8.00
11.50
9.75
12.06
0.0111
1.64
147.95
9.00
10.50
9.75
19.47
0.0124
2.57
207.70
8.00
14.50
11.25
11.10
0.0086
1.19
138.16
9.50
10.00
9.75
19.52
0.0129
2.56
199.08
10.00
10.00
10.00
18.99
0.0122
2.37
193.78
8.50
12.00
10.25
13.26
0.0098
1.62
165.18
9.50
10.50
10.00
20.53
0.0121
2.57
212.05
9.00
11.00
10.00
6.47
0.0052
0.82
157.27
9.00
11.00
10.00
18.56
0.0117
2.34
200.61
9.50
10.00
9.75
24.96
0.0155
3.28
210.90
9.50
10.50
10.00
16.78
0.0111
2.10
189.81
8.50
11.00
9.75
1.66
0.0016
0.22
138.34
9.06
10.85
9.96
15.73
0.01
1.99
182.75
1.07
1.23
0.83
6.84
0.00
0.79
28.41
di(pm)
aHm)
d(avg.)
Loadfal
Strain
TSfGPal
EMfGPal
10.00
10.50
10.25
18.78
0.0102
2.23
218.65
6.50
13.50
10.00
7.23
0.0074
1.03
139.51
6.50
13.50
10.00
12.72
0.0094
1.81
191.39
650
13.50
10.00
9.21
0.0085
1.31
153.97
6.50
12.50
9.50
3.58
0.0032
0 55
171.69
9.50
11.00
10.25
5.74
0.0036
0.69
189.20
7.00
11.00
9.00
5.02
0.0037
0.81
222.77
9.50
10.50
10.00
20.27
0.0115
2.54
221.39
9.50
9.50
9.50
31.09
0.0189
4.30
227.73
8.00
11.00
9.50
6.85
0.0052
0.97
186.13
8.50
11.00
9.75
14.50
0.0095
1.94
202.66
6.00
13.50
9.75
4.49
0.0045
0.69
154.76
9.50
10.00
9.75
19.11
0.0120
2.51
209.76
9.50
10.00
9.75
28.69
0.0160
3.77
235.12
10.00
10.00
10.00
19.55
0.0109
2.44
223.49
6.50
12.50
9.50
8.53
0.0068
1.31
192.08
10.50
10.50
10.50
14.16
0.0083
1.60
191.97
8.24
11.41
9.82
13.50
0.0088
1.79
196.02
1.60
1.43
0.36
8.38
0.0043
1.08
28.34


41
(Information on oxygen incorporation into the polymer due to the addition of water and
NaOH was not reported.)
The main disadvantage of Baney et al. MPS polymers from the point of view of
subsequent processing for ceramic articles (e.g., fibers) is their poor oxidative stability
(MPS polymers are pyrophoric). Burns [Bur90] attributed this tendency for spontaneous
oxidation to a large number of Si-H groups in the polymer structure. The polymer
develops a cross-linked structure upon oxidation due to the formation of Si-O-Si
networks. Burns developed a remedy to the problem of oxidative instability in these
MPS polymers by inserting multiple unsaturated bonds (such as acetylene or phenyl
acetylene or diene compounds). According to Burns, by selectively inserting multiple
unsaturated bonds in the Si-Si backbone, the final Si:C stoichiometry can also be
controlled (unmodified MPS polymers typically yield silicon-rich ceramic residue). The
insertion reaction can be carried out by reacting MPS polymers with ~8 wt%
unsaturated compounds (e.g., phenyl acetylene) in the presence of a transition metal
catalyst (e.g., tetrakis (triphenylphosphine) palladium or tris(tri-phenylphosphine)
rhodium chloride) in an inert solvent such as toluene at reflux temperatures for ~20
hours. In addition to better oxidative stability and control of stoichiometry, Burns method
presents opportunities to synthesize polycarbosilanes by introducing unsaturated
moieties between Si-Si bonds. An example of such a synthesis is reported as the
reaction between 1,3-butadiene with a linear polysilane polymer [Bur90].
Bujalski et al. [Buj90] developed an alternate method of synthesis of chlorine-
containing polysilanes. These polymers were prepared by reacting a mixture of 70-99
wt% of one or more of chlorine-containing disilanes (e.g., ((CH3)2CISi)2,
(CH3Si)2CISiSiCI2CH3, (CH3CI2Si)2 etc.) with one or more of monoorganosilanes (e.g.,
C6H5SiCI3). The reaction required 0.1 to 2 wt% rearrangement catalyst (e.g., quaternary


260
The sample prepared from PMS-245-F-1 polymer showed a composition close
to that of stoichiometric SiC. This suggests that the higher molecular weight (and
presumably more cross-linked) portions of the PMS polymers either are compositionally
different (i.e., have lower Si/C ratio) or have different pyrolysis behavior (i.e., which
leads to the lower Si/C ratio) compared to the lower molecular weight portions in the as-
synthesized PMS polymers.
The oxygen present in the sample prepared from the PMS-245-A polymer is
presumably due to contamination by exposure to air during handling. This may have
occurred when the as-prepared polymer was initially concentrated and recovered after
the Wurtz-coupling polymerization reaction (i.e., prior to storage as a dilute solution in
toluene). However, this seems unlikely since PMS-245-F-1 was prepared from PMS-
245-A and yet the pyrolyzed sample from PMS-245-F-1 showed very little oxygen
contamination. Another possibility is that the oxygen contamination resulted from
exposure to air when the PMS-245-A sample was removed (from the dilute storage
solution), dried, and transferred to the pyrolysis furnace.
4.2.4. Sensitivity of PMS polymers to oxygen contamination
It is well known that PMS polymers are sensitive to contamination from exposure
to oxygen and water vapor [Zha91B; Woo84; Qiu89A; Abu92], This was observed for
PMS polymers prepared in this study. Figure 4.86 shows FTIR spectra as a function of
time for polymer PMS-C (prepared from MDCS in toluene/dioxane) which was exposed
to air at room temperature. Figure 4.87 shows plots of intensity vs. time for various
absorption peaks. It is evident that substantial oxygen contamination occurred within the
first hour of air exposure. A substantial increase in intensity is observed for the Si-OH
stretching vibration (~3198-3735 cm'1). This correlates with the disappearance of
asymmetric Si-H stretching vibration at 2131 cm'1. (The symmetric Si-H stretching


INTENSITY (cps) INTENSITY (cps) INTENSITY (cps)
254
Figure 4.84. XRD Patterns for PMS polymers prepared from monomer MDCS.
(A) 100% toluene (B) toluene:THF (95:5 Vol%) (C) toluene:dioxane
(50:50 Vol%).


174
Table 4.8. FTIR peak assignments for PCS+PSZ fibers.
Peak (cm-1)
Assiqnment
References
3390
v (N-H)
1,2
3040
v (CH=CH2) from Si-CH=CH2
5,6
2950
vas (C-H)
1,2
2894
vs (C-H)
1,2
2098
v (Si-H)
1,4
1592
5 (CH=CH2) from Si CH=CH2
6
1407
Sas (CH3) from Si-CH3
2,3
1358
8 (CH2) from Si-CH2-Si
1,3
1253
8S (CH3) from Si-CH3
2,3
1180
5 (N-H)
5,7
1020
co (CH2) from Si CH2- Si
1,3
930
5 (Si-N-Si)
5
830
Pas (CH3) from Si CH3
1,2,3
776
Ps (CH3) from Si CH3
1,2,3
735
vas (Si-C)
1,2,3
v = stretching ; 8 = bending ; co = bending ; p = rocking
(1) W. Kriner, J. Org. Chem., 29, 1601 (1964).
(2) A.L. Smith, J. Chem. Phys., 21, 1997 (1953).
(3) A.L. Smith, Spectrochimica Acta, 16, 87 (1960).
(4) A.L. Smith, Spectrochimica Acta, 15, 412 (1959).
(5) D. Seyferth, G.H. Wiseman, and C. Prudhomme, J. Am.Ceram. Soc., 1, C13-C14 (1983)
(6) W. Toreki, N.A. Creed, and C.D. Batich, Polymer Preprints, Am. Chem. Soc., 31 [2], 611-612
(1990).
(7) R.M. Silverstein, G.C. Bassler, and T.C. Morrill, Spectrometric Identification of Organic
Compounds, John Wley, New York (1981).


348
2. SiC fibers were prepared from polymethylsilane (PMS) polymers and PMS/PCS
polymer blends. PMS polymers were synthesized by Wurtz-coupling polymerization of
methyldichlorosilane (MDCS) and methyltrichlorosilane (MTCS) (in 70:30 wt%
proportion) with sodium in refluxing solvent mixtures. In order to address problems with
low polymer yields (associated with Wurtz polymerization reactions), polar solvents THF
and 1,4-dioxane were added to toluene. It was found that both THF and 1,4-dioxane
caused an increase in polymer yield and molecular weight of the polymers. One of the
major drawbacks of PMS polymers are that they are liquids at room temperature, and
have low molecular weights. In order to form fibers from these polymers, an increased
molecular weight and an increased extent of cross-linking are needed so that the
polymers are solids at room temperature (and remain solids during pyrolysis). Two
approaches were used to raise the molecular weight/cross-linking of the polymers: (1)
polymerization and cross-linking by heat treatment of solutions with and without
additives and (2) fractional precipitation of higher molecular weight fractions by addition
of non-solvents. The additives for heat treatment consisted of polyvinylsilazane (PSZ),
dicumyl peroxide (DCP), and decaborane (DB). It was found that heat treatment
approach was effective in increasing the molecular weight but it was not possible to
achieve these increases reproducibly. Furthermore, the heat-treated polymers tended to
have bimodal molecular weight distributions which is undesirable. (The low molecular
weight portion remains as a liquid.) Hence, these polymers are not particularly suitable
for fiber formation.
Fractional precipitation of higher molecular weight fractions was an effective
method of producing solid polymers. Use of alcohols as nonsolvents for fractional
precipitation was undesirable since it incorporated a large amount of oxygen in the
polymer. (This was indicated by analyses carried out on pyrolyzed samples which


20
Figure 2.6. Schematic illustration of the influence of solvent on the polymer/sodium
particle interaction during Wurtz polymerization [Zei87].


SURFACE TENSION (N/m)
136
0.040
0.038 -
0.036 -
0.034 -
0.032 -
0.030 -
0.028 -
0.026
-2
O PCS
PCS+PSZ

0 2 4 6 8 10
VISCOSITY (Pa-s)
Figure 4.23. Surface tension as a function of viscosity for PCS and
PCS+PSZ solutions.
12


4.4. FTIR peak assignments for polycarbosilane (PCS) fibers 139
4.5. FTIR peak assignments for polydimethylsilane (PDMS) polymer 141
4.6. FTIR peak assignments for PCS fibers (batch 65s) heat-treated in air
at 187C 153
4.7. FTIR peak assignments for polyvinylsilazane (PSZ) polymer 166
4.8. FTIR peak assignments for PCS+PSZ fibers (batch 70s) 174
4.9. FTIR peak assignments for PCS+PSZ fibers (batch 70s) heat-treated in air
at 177C 186
4.10. Average tensile strengths and rupture strains for PCS and PCS+PSZ fibers
(green, heat treatment in air at 180 10C, heat treatment in nitrogen at
400C, and heat treatment in air at 180 10C followed by heat
treatment in nitrogen at 400C) 196
4.11. Tensile properties of as-spun and air-heat treated (187C) PCS fibers,
heat-treated to various temperatures between 200 and 1150C in nitrogen 203
4.12. Tensile properties of as-spun and air-heat treated (177C) PCS+PSZ
fibers, heat-treated to various temperatures between 200 and 1150C
in nitrogen 204
4.13. Properties of SiC fibers spun from PCS 211
4.14. Properties of SiC fibers spun from PCS+PSZ 211
4.15. Synthesis conditions and characteristics for PMS polymers 219
4.16. FTIR peak assignments for polymethylsilane polymer PMS-F (batch
PMS-256) 239
4.17. FTIR peak assignments for polymethylsilane polymer PMS-C (batch
PMS-263) 240
4.18. d-spacings and 20 Bragg angles for Si and fPSiC 257
4.19. Crystallite sizes for Si and SiC calculated by Schemers formula for various
polymers pyrolyzed at 1350C in nitrogen at 10C/min with no hold 258
4.20. Results of Electron Microprobe Analysis (EMA) on pyrolyzed ceramic fibers
from PMS polymers 259
4.21. Conditions for heat treatment for PMS polymers containing PSZ, DCP,
and DB
viii
270


12
(Zeigler et al. did not provide plots of the molecular weight distributions obtained by
using different monomer addition rates (normal mode)).
2.2.1.3 Effect of alkali metal
As indicated earlier, sodium, potassium or lithium could be chosen as the alkali
metal for the polymerization reaction. Based on ease of handling (for example, sodium
is available as 3-5 mm pellets where as potassium and lithium are available as blocks of
materials and need to be cut into smaller sizes for accurately weighing) and flammability
considerations, sodium is normally preferred over the other two. Alternatively, alloys of
sodium and potassium of varying composition could be used but these alloys often
cause degradation of polymer molecular weight and form cyclic oligomers at elevated
temperatures (~100C) (Na/K alloy promotes hydrogen abstraction from solvent and
causes chain transfer) [MN93].
The polymerization reactions take place very close to the alkali metal surface
and, hence, the surface area of the alkali metal plays a very important role in
determining the molecular weight distribution of the polymer formed. Worsfold [Wor88]
studied the effect of sodium surface area on the molecular weight of polymers formed
during the polymerization of hexylymethyldichlorosilane and found that rate of
consumption of monomers increased as the sodium surface area increased (Figure 2.3)
(The monomer consumption was monitored by removing small amounts of the reaction
contents periodically during the course of reaction and analyzing the samples by gas
chromatography (GC).) Therefore, to obtain good polymer yield in a reasonable time, it
is important to use a fine dispersion of sodium in the reaction solvent.
The plots in Figure 2.3 show a sigmoidal behavior. The incubation period is
interpreted as the time during which initiation occurs, i.e., according to equation (2.2) in


65
conversion of PDMS to PCS takes place by Kumada rearrangement [Shi58], in which
insertion of CH2 groups into the main chain Si-Si takes place, leaving a hydrogen bound
to silicon, as shown below:
CHq CHo
l 31 3
Si Si
CH3CH3
Argon
450C
Si C
I I
H H
n
(2.15)
PDMS
PCS
Yajima et al. melt spun the polycarbosilane polymers (M^S.OOO) into fibers and
subsequently converted them to SiC by pyrolysis. The fibers required an air-curing step
(~200C, 2-4 h) to render them infusible during pyrolysis to silicon carbide. These fibers,
commercially produced as Nicalon fibers (by Nippon carbon company, Tokyo, Japan),
degrade rapidly at temperatures in excess of 1400C due to carbothermal reduction
reactions between siliceous material and carbon. This leads to evolution of volatile
species (primarily CO and SiO) which results in large weight losses, formation of
porosity, and growth of SiC grains and other strength degrading flaws in the fiber
structure. In recent years, a lot of attention has been directed toward improving the
thermomechanical stability of fibers derived via organosilicon polymer route. A method
developed at University of Florida involves preparation of fibers (UF Fibers) by dry
spinning of high-molecular-weight polycarbosilanes. SiC fibers were produced with low
oxygen content and either carbon-rich (non-stoichiometric) or near-stoichiometric
composition [Tor92A; Tor92B; Tor94; Sac95A; Sac95B], Non-stoichiometric UF fibers


78
lines was measured. The corresponding efflux time t0 for the pure solvent (toluene) was
also measured. The specific viscosity r|sp was determined according to formula:
hsP = (t-to)/to (3.1)
The intrinsic viscosity [r|] was calculated according Huggins equation:
We = [r,] + k [r,]2 c (3.2)
where c is the concentration of the polymer solution used in the measurement, in g/dl.
[r|] was determined by plotting r|sp/c vs. c, and extrapolating the straight line to c=0.
Contact angle measurements of polymer solutions were carried out using the
sessile drop method and a Contact Angle Goniometer5. In the sessile drop method, a
liquid droplet is deposited on a solid substrate, as illustrated in Figure 3.3.
Measurements were made of the angle formed by the intersection of a line along the
solid-liquid interface and a line tangent to the droplet surface, both of which pass
through the three-phase (solid-liquid-vapor) intersection point. The substrates used for
measurement were stainless steel, teflon, and stainless steel which were first coated
with PCS or PCS+PSZ. The concentrations of polymer solutions (PCS and PCS+PSZ)
were 33 wt%. The stainless steel (2 cm x 2 cm) and teflon substrates (3 cm x 3 cm)
were cleaned in an ultrasonicator bath**, followed by rinsing in acetone and drying in an
oven at 70C for 30 min. (The teflon substrate was polished on 1 pm diamond wheel for
20 min to obtain a smooth surface prior to measurement.)
Initially, contact angles of water and toluene were measured on teflon and
stainless steel substrates to enable comparison with reported values in literature. Both
advancing and receding contact angles were measured using the drop-buildup and
drop-withdrawal methods. A Hamilton syringe, calibrated up to 0.5 ml was used for
5 Rame-Hart, Inc., Mountain Lakes, NJ.
** Model FS 28, Fisher Scientific, Pittsburgh, PA.


304
Figure 4.105. SEM micrographs of pyrolyzed fibers (batch UF-26s) prepared
from PMS/PCS blends (non-heat treated) showing necking.


392
Table H-5. (Cont'd.)
Batch 5:
dt(pm)
d;(nm)
diava.1
11.00
11.50
11.25
10.00
10.50
10.25
11.00
11.50
11.25
11.00
11.50
11.25
11.00
11.00
11.00
10.00
10.50
10.25
11.00
11.50
11.25
11.00
11.00
11.00
7.50
11.00
9.25
11.00
11.50
11.25
10.50
11.50
11.00
10.00
10.50
10.25
10.00
10.00
10.00
10.00
10.50
10.25
11.00
12.00
11.50
10.00
10.50
10.25
10.00
10.00
10.00
11.00
11.50
11.25
Average
10.39
11.00
10.69
Std. Dev
0.87
0.59
0.63
Batch 6:
d.i(U!lQ
djium)
diava.l
11.00
11.50
11.25
10.50
10.50
10.50
10.50
10.50
10.50
10.50
10 50
10.50
10.00
10.00
10.00
10.50
10.50
10.50
10.00
11.00
10.50
10.00
10.50
10.25
11.00
11.00
11.00
10.00
10.00
10.00
9.50
10.50
10.00
10.50
11.50
11.00
11.00
11.50
11.25
10.00
10.00
10.00
11.00
11.00
11.00
10.50
11.50
11.00
10.00
10.50
10.25
Average
10.38
10.74
10.56
Std. Dev
0.45
0.53
0.45
Load(q)
Strain
TSfGPal
EMiGPal
35.76
0.0162
3.53
217.71
29.46
0.0164
3.50
212.90
25.57
0.0109
2.52
230.38
29.03
0.0132
2.86
221.33
33.93
0.0163
3.50
214.18
23.03
0.0119
2.74
229.24
27.06
0.0120
2.67
221.92
34.12
0.0155
3.52
227.17
12.46
0.0073
1.89
259.54
19.67
0.0091
1.94
213.33
34.46
0.0164
3.56
216.59
31.05
0.0166
3.69
222.34
32.11
0.0173
4.01
232.19
23.60
0.0129
2.81
216.88
32.73
0.0146
3.09
212.49
24.42
0.0130
2.90
224.00
28.89
0.0163
3.61
220.48
12 41
0.0064
1.22
192.44
27.21
0.0135
2.98
221.40
7.00
0.0033
0.74
13.11
Load(g)
Strain
TSiGPal
EMiGPal
29.08
0.0153
2.87
187.10
28.89
0.0163
3.27
201.16
34.50
0.0173
3.91
225.51
23.99
0.0127
2.72
213.71
31.43
0.0180
3.92
217.71
21.11
0.0135
2.39
177.55
31.19
0.0149
3.54
237.18
28.84
0.0165
3.43
207.40
34.26
0.0169
3.53
208.66
29.80
0.0170
3.72
218.14
15.39
0.0094
1.93
204.37
30.04
0.0151
3.10
205.13
30.66
0.0173
3.02
175.07
28.36
0.0166
3.54
212.55
28.65
0.0140
2.95
211.47
30.76
0.0148
3.18
214.95
27.73
0.0155
3.30
212.63
28.51
0.0154
3.19
207.66
4.66
0.0021
0.53
15.82


393
Table H-5. (Cont'dT
Batch 7:
di(Mm)
d2iy.ni)
d.(avg.)
Load(g)
Strain
TStGPal
EM(GPa)
11.00
11.00
11.00
29.49
0.0148
3.04
205.50
10.50
11.50
11.00
36.31
0.0176
3.75
213.35
11.50
11.50
11.50
24.59
0.0124
2.32
186.66
10.50
11.00
10.75
35.45
0.0171
3.83
224.50
10.50
12.00
11.25
22.38
0.0115
2.22
192.85
10.50
11.50
11.00
23.53
0.0115
2.43
211.08
10.50
11.00
10.75
30.93
0.0149
3.34
224.42
11.00
11.00
11.00
37.08
0.0177
3.82
216.43
9.00
10.00
9.50
15.50
0.0104
2.15
206.45
6.00
11.00
8.50
8.82
0.0072
1.67
231.24
10.00
10.00
10.00
30.55
0.0149
3.81
254.97
10.00
13.50
11.75
27.33
0.0139
2.53
182.26
11.00
11.00
11.00
36.51
0.0180
3.77
208.99
9.50
10.50
10.00
26.03
0.0149
3.26
218.84
10.00
11.00
10.50
23.48
0.0114
2.66
234.02
10.50
10.50
10.50
31.89
0.0182
3.61
197.88
10.00
10.00
10.00
5.17
0.0038
0.65
170.97
Average
10.12
11.06
10.59
26.18
0.0135
2.87
210.61
Std. Dev
1.22
0.85
0.80
9.32
0.0040
0.91
20.78


148
functionality appears to be the radical source for the pyrolytic conversion to silicon
carbide, since it has the lowest bond energy in the PCS skeleton.
Subtraction spectra of PCS fibers before and after heat treatment in nitrogen at
600C (i.e., 600 40C) is shown in Figure 4.28. A direct comparison of the spectra at
these temperatures is shown in Figure 4.29. The absorbance of band due to 5S(CH3)
from Si-CH3 at 1250 cm'1 increased only slightly up to 600C whereas the absorbance of
bands due to vs(C-H) at 2894 cm'1, 8as(CH3) from Si-CH3 at 1407 cm'1 and 5(CH2) from
Si-CH2-Si at 1358 cm'1 decreased slightly. The absorbance of v(Si-H) at 2100 cm'1,
co(CH2) from Si-CH2-Si at 1020 cm'1, and pas(CH3) of Si-CH3 at 830 cm'1 increased
significantly, and these changes may be attributed to the methylene insertion reactions
as explained previously.
Hasegawa et al. and Buoillon et al. [Buo91] studied the changes in the FTIR
absorption spectra of PCS upon pyrolysis to 1000C. They reported that intensities of
most absorption bands changed only slightly during heat treatment to 400C, similar to
observations made in the present study. No significant gas evolution was detected (by
gas chromatography) in this temperature range. Methylene insertion reactions took
place between 400C and 550C, resulting in increases in intensities of absorption
bands due to v(Si-H) at 2100 cm'1 and v (CH2) of Si-CH2-Si at 1358 cm'1. There was no
significant change in the intensities of other absorption bands in the FTIR spectra until
550C. This is indicative of the fact that polymer degrades slowly up to 550C (i.e., few
organosilicon bonds are broken). After 550C, decomposition of the side chains of the
polymer started to take place, leading to the formation of an amorphous inorganic
material. This was manifested by a rapid decrease in intensities of all absorption bands


Intensity (absolute units)
158
0 100 200 300 400 500 600 700
Temperature (C)
Figure 4.34. Intensity vs. temperature from FTIR spectra for PCS
(air-heat treated at 187C) fibers (batch 65s) during heat
treatment in N^o 600C.


37
cross-linking of chains and increased molecular weights. A wide range of homopolymers
with different structures were prepared by modifying the reaction conditions to vary the
degree of branching (cross-linking) or chain extension. For example, when 1,3-
disilylbenzene(1,3-(H3Si)2C6H4) or 1,3-dimethylsilyl benzene (1,3-(CH3H2Si)2C6H4) was
reacted in the presence of cyclopentadienyl zirconium hydride catalyst (Cp2(ZrH2)2), the
resulting polymer was highly cross-linked and high in molecular weight. The disilyl
monomers (1,3-disilyl benzene or 1,3-dimethylsilylbenezene) developed by Tilley were
prepared by reacting tetraethoxysilanes (Si(OEt)4) or methyl triethoxysilanes
(CH3Si(OEt)3) with dibromobenzene and magnesium in an inert solvent, followed by
reduction of the intermediate compound (1,3-di(triethoxylsilyl)-benzene or di-
(trimethoxysiloxy)-benzene) with lithium aluminum hydride. The dehydrogenative
polymerization was then carried out by adding organosilanes (containing multiple Si-H
groups per silicon center) drop by drop to a benzene solution containing the catalyst and
stirring for 24 hours at 20-65C under nitrogen. Many of the polymers prepared by
Tilleys method were highly cross-linked and were insoluble in common solvents (e.g.,
toluene), indicating difficulty in controlling cross-linking reactions. The soluble polymers
exhibited Mw ranging from 5,500 to 90,000 and Mn ranging from 1,300 to 2,200.
2.2.6 Redistribution/substitution reactions:-
Baney et al. [Ban82; Ban83; Ban85] prepared another class of polysilane
polymers, methylpolysilanes (MPS polymers) by catalytic redistribution reactions
involving Si-Si/Si-CI bonds of methylchlorodisilane mixtures11 The methylchlorodisilane
mixtures, comprising 55 wt% [MeCI2Si]2, 35 wt% Me2CISiSiMeCI2, and 10 wt%
11 Methylpolysilane (MPS) polymers, as described by Baney et al. have a structure of [((CH3)2Si)x(CH3Si)y]n.
They are different from polymethylsilane (PMS) polymers discussed earlier, which have a structure of
[(CH3SiH)x(CH3Si)y]n.


Table H-3. L)F65s-1150 (1150C/1 h/N2) (PCS)
Batch 1:
di(pm)
d2(ym)
diava.l
10.00
10.00
10.00
10.00
10.00
10.00
11.00
11.00
11.00
11.00
11.50
11.25
11.00
11.00
11.00
12.00
12.00
12.00
10.50
11.00
10.75
11.00
11.00
11.00
10.00
11.00
10.50
10.00
10.00
10.00
9.00
9.50
9.25
10.00
10.00
10.00
11.00
11.00
11.00
9.50
10.00
9.75
10.00
11.00
10.50
9.00
9.00
9.00
10.00
10.00
10.00
10.00
10.00
10.00
11.00
12.00
11.50
14.00
14.00
14.00
Average
10.50
10.75
10.63
Std. Dev
1.11
1.11
1.09
Batch 2:
djym)
datum)
djayg)
11.50
11.50
11.50
11.50
12.00
11.75
12.00
12.00
12.00
13.00
13.00
13.00
12.50
13.50
13.00
12.50
13 00
12.75
12.50
12.50
12.50
13.00
13.50
13.25
12.00
12.50
12.25
12.00
12.00
12.00
11.00
11.00
11.00
12.00
12.50
12.25
11.00
11.50
11.25
13.00
13.50
13.25
12.50
12.50
12.50
11.50
12.00
11.75
13.00
13.00
13.00
11.50
12.50
12.00
Average
12.11
12.44
12.28
Std. Dev
0.68
0.73
0.68
Loadial
Strain
TSiGPai
EMfGPal
18.38
0.0102
2.29
223.99
22.61
0.0121
2.82
238.57
30.86
0.0146
3.18
218.36
30.42
0.0134
3.00
223.65
41.24
0.0184
4.25
231.41
27.31
0.0122
2.37
194.29
25.52
0.0134
2.76
205.23
30.37
0.0148
3.13
211.38
31.58
0.0156
3.58
229.62
25.95
0.0147
3.24
220.94
24.35
0.0156
3.55
227.16
12.32
0.0075
1.54
206.02
25.27
0.0135
2.61
193.37
20.81
0.0126
2.73
213.95
31.24
0.0151
3.54
234.93
13.43
0.0096
2.07
214.56
20.71
0.0122
2.58
211.22
26.83
0.0148
3.35
226.49
16.83
0.0072
1.59
220.20
32.60
0.0098
2.08
212.53
25.43
0.01
2.81
217.89
7.07
0.00
0.70
12.32
Load(q)
Strain
TStGPal
EMfGPa)
14.03
0.0073
1.32
182.51
11.86
0.0055
1.07
208.10
27.65
0.0134
2.40
178.52
8.86
0.0035
0.65
185.09
15.48
0.0063
1.14
182.01
23.40
0.0099
1.80
180.60
12.97
0.0059
1.04
175.97
26.00
0.0101
1.85
183.25
36.43
0.0164
3.03
184.83
20.40
0.0102
1.77
173.81
22.48
0.0131
2.32
176.38
18.91
0.0087
1.57
181.15
17.22
0.0088
1.70
199.17
31.22
0.0128
2.22
173.56
19.68
0.0091
1.57
172.21
30.83
0.0156
2.79
178.36
42.71
0.0171
3.15
184.48
26.15
0.0116
2.27
194.86
22.57
0.01
1.87
183.05
8.96
0.00
0.71
9.32


Table 4.29. (Contd.)
Batch
PMS used
PCS added
Before heat- After heat-
treatment treatment
PMS:
PCS ratio
Wt%
PSZ
added3
Wt% DB added
Before heat After heat
treatment treatment
Filtration
behavior5
Filter (pm)/
time(min)
Flow
test
time(s)
Solids
loading
(%)
Viscosity
(Pas)
Spin
speed
(rpm)
Spin
pressure
(psi)
UF-52S
PMS-223-
AD2-H
*

100:0
0.25
6
0
0.45/45
(3 sets)
27
69.6
29-21
164-
179
225-250
Spun well; as-spun fibers separable but pyrolyzed fibers brittle.
UF-54S
PMS-225-
AD-H
*
*
100:0
0.25
6
0
0.1/35
(2 sets)
42
67.9
60-21
*
200-500
Not spinna
ble.
a PSZ added before heat-treatment.
b Time taken for filtration through specified filter at 20 psi nitrogen pressure.
c To conserve material, this particular heat-treated polymer solution was centrifuged at 20,000 rpm for 20 min to remove microgels.
310


431
[Sac95B], M.D. Sacks, A.A. Morrone, G.W. Scheiffele, and M.Saleem,
Characterization of Polymer-Derived SiC Fibers with Low Oxygen Content,
Near-Stoichiometric Composition, and Improved Thermomechanical
Stability," Ceram. Eng. Sci. Proc., 16 [4] 25-37 (1995).
[Sak91] T. Sakakura, H-J. Lautenschlager, M. Nakajima, and M. Tanaka,
Dehydrogenative Condensation of Hydrosilanes Catalyzed by an
Organoneodymium Complex, Chem. Lett., 913-916 (1991).
[Sak93], T. Sakakura, M. Tanaka, and T. Kobayashi, Method for Producing
Polysilanes, U.S. Pat. No. 5 252 766 (1993).
[Sal93], M. Saleem, unpublished work.
[Sal96], M. Saleem and M.D. Sacks, unpublished work.
[Sch84], C.L. Schilling, Jr, and T.C. Williams, Polymeric Routes to Silicon Carbide:
Polycarbosilanes, Polysilahydrocarbons and Vinylic Polysilanes," Polym.
Prepr.,25 1 (1984).
[Sch88], C.L. Schilling, Jr, and B. Kanner, Polysilane Precursors Containing Olefinic
Groups for Silicon Carbide, U.S. Pat. No. 4 783 516 (1988).
[Sch91], W.R. Schmidt, L.V. Internante, R.H. Doremus, T K. Trout, P.S. Marchetti, and
G.E. Maciel, Pyrolysis Chemistry of an Organometallic Precursor to Silicon
Carbide," Chem. Mater., 3 257-267 (1991).
[Sey88], D. Seyferth, G.H. Wiseman, Y-F. Yu, T.S. Targos, C.A.Sobon, T.G. Wood,
and G.E. Koppetsch, Applications of Methyldichlorosilane in the Preparation
of Silicon-Containing Ceramics, in Silicon Chemistry, pp 415-424, Eds., J.Y.
Corey, E.R. Corey, and P.P. Gaspar, Ellis Horwood Ltd., Chichester, U.K
(1988).
[Sey90], D. Seyferth, Synthesis of Some Organosilicon Polymers and Their Pyrolytic
Conversion to Ceramics, in Silicon-Based Polymer Science A
Comprehensive Resource, pp 565-591, Eds., J.M. Zeigler and F.W.G.
Fearon, American Chemical Society, Washington, DC (1990).
[Sey92]. D. Seyferth, T.G. Wood, H.J. Tracy, and J.L. Robison, Near-Stoichiometric
Silicon Carbide from an Economical Polysilane Precursor," J. Am. Ceram.
Soc., 75 [5] 1300-1302 (1992).
[Sey93], D. Seyferth, H.J. Tracy, and J.L. Robison, Preparation of Silicon Carbide
Ceramics from the Modification of an Si-H Containing Polysilane," U.S. Pat.
No. 5 204 380 (1993).
[Shi58], K. Shina and M. Kumada, Thermal Rearrangement of Hexamethyldisilane to
Trimethyl(dimethylsilylmethyl) Silane, J. Org. Chem., 23 139 (1958).


Intensity (absolute units)
159
A
-T- Pas(CH3) of Si-CH3 [830 cm'1]
-A- co(CH2) of Si-CH2-Si + v (Si-O-Si or Si-O-C) [1000-1100 cm'1]
53(^3)0151-0^ [1253 cm'1]
8(CH2) of Si-CH2-Si [1358 cm'1]
v(C=0) [1722 cm'1]

Temperature (C)
700
Figure 4.34. (Cont'd.)


36
Berris [Ber92] has also developed a process for synthesizing polysilane
polymers with a Mw of ~1000-1500 by dehydrogenative coupling of primary
organosilanes in the presence of (1-1.7 wt%) dimethyldialkylphosphine nickelhalide
(e.g., 1,2-bis(dimethylphosphine) ethanenickel(ll)chloride, dmpe NiCI2) at temperatures
of 20C to 50C in the presence of an inert solvent. The reaction time varied from 1 h to
10 days, depending on the temperature used (i.e., lower reaction times were used at
higher temperatures). The dmpe NiCI2 catalyst was reported to have a much higher
activity than the early transition metal complexes used by Harrod et al.[Har88],
Seyferth et al. [Sey88; Sey90; Sey92; Sey93] have used dehydrogenative
coupling to cross-link low molecular weight polymethylsilanes (containing multiple
secondary or tertiary Si-H bonds) which had been synthesized by the Wurtz-coupling
reaction of methyldichlorosilane with sodium in hexane/THF. This resulted in polymers
that could be pyrolyzed to produce near-stoichiometric SiC with high yield (in the range
of 95-98%). The low molecular weight polymethylsilanes were reacted with ~3 wt%
cyclopentadienyl zirconium hydride catalyst in an inert solvent (such as hexane) at reflux
temperatures. (Hexane was chosen because it readily dissolves the catalyst and it has a
low reflux temperature.) Seyferth et al. [Sey93] observed that the products of the
dehydrogenative coupling reaction of low-molecular-weight polysilanes with
cyclopentadienyl zirconium hydride catalyst ranged from oil to solid (both orange
in color) depending upon time-temperature conditions of the reaction. In order to impart
infusibility to articles prepared from these cross-linked polymers (e.g., fibers), photolysis
is required which can be accomplished by UV irradiation in hexane for 2 hours.
Tilley [TI91; TN93] developed a method of producing cross-linked, high-
molecular-weight, silicon-rich polymers by dehydrogenative coupling reactions of
organosilanes. The reaction of more than one Si-H group per silicon center caused


6
polymer to be cross-linked at some stage in processing, and (7) solubility in common
organic solvents. As indicated in (1) above, pyrolysis conditions (temperature,
atmosphere, and heating rate) play a very important role in determining the
characteristics (yield, elemental composition, and crystal structure) of the ceramic
produced. The ceramic yield (i.e., weight percentage retained after polymer-to-ceramic
conversion) is an important consideration when discussing the suitability of a polysilane
polymer as a precursor for silicon carbide. As indicated in (3) above, molecular
architecture also has great impact on the ceramic yield of the polymer synthesized.
Cross-linked or branched polymers give much higher ceramic yield than their linear
counterparts. However, excessive cross-linking is generally not desirable, as it would
make the processing of the polymer difficult (i.e., the polymer will be less likely to melt or
to be soluble in common solvents). It is sometimes desirable that the final composition
of the ceramic produced be that of near-stoichiometric silicon carbide. A convenient
method of achieving this is to start with a polymer which has a 1:1 Si:C ratio, such as
polymethylsilanes. This can be contrasted to polyphenylsilanes, for example, which
have Si:C ratios of 1:6, and, therefore, result in SiC/C mixtures upon pyrolysis.
Polysilane polymers were first synthesized by Kipping [Kip21] in the early 1920s
by condensation reaction of diphenyldichlorosilane with sodium. This polymer was not
useful in practical applications since it was intractable (i.e., not processable into useful
articles because of poor solubility and infusibility). Subsequently, in 1949, Burkhard
[Bur49] reacted dimethyldichlorosilane with sodium to produce poly(dimethylsilane),
which also was insoluble in common organic solvents and infusible. In 1975, Yajima and
coworkers [Yaj75; Yaj78A; Yaj78B] were able to convert poly(dimethylsilane) to a
tractable form of polycarbosilane (PCS) by pressure pyrolysis in an autoclave at 450C.
The polycarbosilanes were then melt spun into fibers which were subsequently heat


355
60
50 -
<£> 40
re
& 30 -
V)
o
o
- 20 -J
10 -
O Increasing Shear Rate
Decreasing Shear Rate
@8 §
-Q
(B)
T
5
T
10
T
15
20
25
30
Shear Rate (s'1)
Figure A-5. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for batch 68s spin dope (PCS+PSZ) (solids concentration
~70 wt%).


dwt/d(logM) dwt/d(logM)
298
Figure 4.103. GPC molecular weight distributions for PMS-250 polymer
(A) before and (B) after fractional precipitation with acetone.


297
fractional precipitation vs. the acetone/polymer ratio used in the process. The molecular
weight generally increased as the acetone/PMS ratio decreased. (This is consistent
with observations made for other fractional precipitation processes [BN83].) Figure 4.103
shows an example of the change in the GPC molecular weight distribution after
fractionation. (The GPC results for the other polymers fractionated with acetone are
shown in Appendix J.)
The fractionated polymers prepared using acetone were not contaminated with
oxygen5. This was illustrated by EMA measurements which were carried out on a
pyrolyzed (1150C in nitrogen) sample. Table 4.26 shows that the oxygen content of a
sample pyrolyzed from PMS-245-F-1 was only 0.2 wt%. (Table 4.26 indicates that this is
less than the oxygen content of a pyrolyzed sample prepared from the as-synthesized
PMS-245 polymer. It is inconceivable that low-molecular-weight (e.g., oligomeric)
portions of the PMS polymers (which are removed during fractionation) are the most
susceptible to oxygen incorporation during exposure to oxygen and water vapor in the
atmosphere. However, the difference in oxygen content observed between PMS-245
and PMS-245-F-1 is probably within experimental error. First, variations of at least 1-2%
in the oxygen content have been observed in SiC fibers (prepared by pyrolysis of
organosilicon polymers) when the same sample was re-analyzed by EMA at different
times [Sal95], Second, oxygen variations may occur due to differences in sample
preparation. For example, different amounts of oxygen contamination may have
occurred during pyrolysis of the polymers. More samples would need to be analyzed to
5 There was some concern that the THF used in the precipitation process could adsorb some atmospheric
moisture. In turn, this could lead to some hydrolysis reactions which incorporate hydroxyl groups in the
PMS polymers. However, this apparently did not occur to any significant extent in the present study. This
conclusion is based on the low oxygen content that was obtained for the pyrolyzed PMS-245-F-1 sample
prepared by fractional precipitation using acetone.


3200
__ 2400 -
ro
CL
O Increasing Shear Rate
Decreasing Shear Rate
(A
CO
CL
i*
V)
o
o
V)
>
60
50
40
30
20
10
0
O Increasing Shear Rate
Decreasing Shear Rate
O 0 Q
(B)
0 10 20 30 40 50 60
Shear Rate (s'1)
Figure 4.2. Plots of (A) shear stress vs. shear rate (B) viscosity vs. shear
rate for a PCS+PSZ spin dope (solids concentration ~70 wt%,
batch 70s).


229
4.2.2 Effect of synthesis conditions on polymer yield
As discussed earlier, the purpose of adding a trifunctional monomer (MTCS) to a
difunctional monomer (MDCS) was to increase the degree of cross-linking in the
polymer. (A higher degree of cross-linking will result in increased ceramic yield, which is
desirable.) However, the addition of MTCS to MDCS also results in a significant
decrease in the polymer yield in the absence of cosolvents. For example, Table 4.15
shows that yield for polymerization of MDCS in toluene was 41% (of theoretical yield)
whereas the yield decreased to 15% when 30 wt% MTCS was added to MDCS. It is,
therefore, necessary to add a polar solvent such as THF or 1,4-dioxane to toluene to
increase yield for the polymerization reaction. (It is well-known in literature that polar and
dipolar solvents (such as THF and dioxane) promote anionic polymerization, aiding the
transfer of electrons from Na to the monomers and favoring the formation of silyl anion
radicals ([MN91]; [Gau89]).) As shown in Figure 4.72 and Table 4.15, when a 5 vol% of
THF/95 vol% toluene mixture was used in the polymerization of MDCS:MTCS, the
polymer yield increased ~2.5 times (from 15% to 37%) compared to polymerization in
toluene alone. The polymer yield increased ~3 times (from 15% to 46%) when a 50 vol%
dioxane/50 vol% toluene mixture was used for polymerization (Figure 4.72 and Table
4.15).
The higher yields for polymerization of MDCS/MTCS mixtures with the addition
of polar solvents are apparently associated with a higher reaction rate. (As noted earlier,
prolonged reaction times can result in lower yields due to the loss of Si-containing
volatiles.) The correlation between the polymer yield and the reaction rate is suggested
from observations of color changes that occurred during the reactions. As discussed in
section 2.2.1.3, there is a change in color (to purple) during Wurtz-coupling


17
Table 2.1: Effect of diglyme and heptane additions on polymerization of some
dichlorosilane monomers [Mil91],
Polymer
toluene:diglyme
(vol%)
Yield, %
Mw x 10'3
R c
(c-HexSiMe)n
100:0
20
804, 4.5b
8.7
(c-HexSiMe)n
90:10
35
1477, 24.8 b
0.12
(c-HexSiMe)n
75:25
32
23.1 a
(c-HexSiMe)n
25:75
33
16.5 a
(n-dodecylSiMe)n
100:0
8
1345, 8.4 b
2.73
(n-dodecylSiMe)n
70:30
33
476, 40.7 b
0.74
(n-Hex2Si)n
100:0
5.9
1982, 1.2 b
3.12
(n-Hex2Si)n
95:5
34
1008, 22.3 b
3.4
(n-Hex2Si)n
90:10
36
1358, 26.6b
2.6
(n-Hex2Si)n
70:30
37
1073, 31.7
1.42
(n-dodecyl2Si)n
100:0
3
521, 14.1 b
5.2
(n-dodecyl2Si)n
70:30
34
570, 27.4 b
2.3
(PhMeSi)n
100:0
25
383, 16 b
Polymer
toluene:heptane
(vol%)
Yield, %
Mw x 10'3
R c
(n-Hex2Si)n
84:16
27
1386, 1.1 b
(PhMeSi)n
85:15
9
1390, 10.5
a monomodal; b bimodal; c ratio of amounts of high molecular weight to low molecular weight fractions


131
40
CL
(0
o
o

30 -
^ 20 -
10
O Increasing Shear Rate
PCS (66 wt%)
Decreasing Shear Rate
Q Q
l
50 100 150 200
Shear Rate (s'1)
(B)
250
300
Figure 4.18. Plots of: (A) shear stress vs. shear rate and (B) viscosity vs. shear rate
for a 66 wt% PCS solution used in surface tension measurement.


ACKNOWLEDGMENTS
I am grateful to Dr. M.D. Sacks for his invaluable guidance and support. I am
thankful to Drs. C.D. Batich, J.H. Simmons, E.D. Whitney, R. Drago, and D. Talham for
serving on my committee. I would like to thank Dr. S. Bates, Dr. A. Morrone, R.
Crockett, W. Aeree, and E. Lambers for their help in use of various analytical
instruments.
I would also like to thank G.W. Schieffele, J.H. Dow, Y.J. Lin, K. Wang, R.
Raghunathan, T.J. Williams, and G. Staab for their assistance in carrying out various
experiments in this study. I am grateful to Drs. Rajiv Bendale and Priya Bendale for
many useful technical discussions throughout the course of this study. Thanks are also
due to U. Mahajan, S. Lathi, M. Lakshmipathy, and J. DePuy for their help in compiling
this dissertation. I would also like to thank P. Raghunathan, R. Raghunathan, J.
Sethuraman, J.H. Dow, V. Shenoy, U. Shenoy, N. Srinivasa, A. Srinivasa, H. Kannan,
D. Kuruvilla, E. Naveen, R. Parikh, C. Parikh, and V. Srinivas for their friendship
throughout the course of my stay in Gainesville.
Finally, my special gratitude goes to Anuradha and Prakash Krishnans, for their
friendship, support, and encouragement, and for providing an atmosphere of home
away from home.
ii


Table 4,25. Conditions of fractional precipitation of PMS polymers.
Fractionated
polymer
designation
Polymer, non
solvents proportion
Non-solvent/
polymer
ratio (ml/g)
THF/
polymer
ratio (ml/g)
Non-solvent/
THF ratio
(ml/g)
Initial
Mn
Initial
Mw
Initial
PDI
Final
Mn
Final
Mw
Final
PDI
Yield
%
Melted
Yes /
No
PMS-240-F
PMS-240 (6.73g)
2-propanol (150ml)
methanol (150ml)
44.5
7.4
6.0
960
2395
2.49
2821
8443
2.99
44.5
No
PMS-241-F
PMS-241 (9.00g)
2-propanol (300ml)
methanol (300ml)
66.7
5.5
12.0
899
1865
2.07
2119
4512
2.13
22.0
No
PMS-242-F
PMS-242 (8.33g)
2-propanol (150ml)
methanol (150ml)
36.0
6.0
6.0
1653
3631
2.20
2200
5018
2.28
35.0
Yes
(partial)
PMS-243-F
PMS-243 (10.5g)
2-propanol (150ml)
methanol (150ml)
28.6
6.0
4.8
1004
2438
2.43
2555
5830
2.28
33.2
NO
PMS-245-F-1
PMS-245 (4g)
Acetone (100ml)
25.0
8.2
3.1
1055
2028
1.92
3153
6235
1.98
21.5
Yes
(partial)
PMS-245-F-2
PMS-245 (5.45g)
Acetone (110ml)
20.1
8.3
2.4
1126
2419
2.15
4493
11287
2.51
22.6
No
PMS-246-F
PMS-246 (8.15)
Acetone (164.5ml)
20.1
7.7
2.6
1069
2469
2.31
5317
16370
3.08
19.2
No
PMS-247-F
PMS-247 (7.47g)
Acetone (152ml)
20.3
8.8
2.3
1097
2276
2.07
7721
16719
2.17
7.0
No
PMS-248-F
PMS-248 (9.05g)
Acetone (208ml)
23.0
4.5
5.1
1027
2287
2.33
2572
8734
3.40
26.1
No
290


dwt/d(logM) dwt/d(logM)
405
6 5 4 3 2
log MW
Figure J-3. GPC distributions for PMS-247 polymer: (A) before and
(B) after fractional precipitation with acetone.


99
sided tape. Prior to examination by SEM, fibers were coated with a layer of Au-Pd for 20
sec using a sputter coatei4.
Elemental analyses of pyrolyzed fibers were carried out using an Electron
Microprobe Analyzer according to the methods described in section 3.2.4, with the
exception that fibers were cast upright in the sub-micrometer alumina suspension so
that fibers could be cross-sectioned perpendicular to the long dimension of the fibers.
Fractography was carried out on selected batches of fibers. The fibers were
mounted onto paper tabs. Each paper tab was given a number and labeled at the top
and the bottom, so that fiber fragments could be identified after tensile testing. The
diameters of fibers were determined using an optical microscope, as per the methods
described earlier in the section. The fibers were then coated with glycerin. Tensile
strength data on 21 fibers were collected. Except in a few cases, only one fragment (i.e.,
the top or the bottom portion) of the fractured fiber remained attached to the paper tab
after testing. The fiber fragments were taped to stiff aluminum foil pieces (cut from
aluminum weighing dishes). The fragments were subsequently sonicated for 5 sec in 1N
HN03 solution, then 5 sec in 1N NH4OH, and finally 2 min in methanol. This process
enabled removal of debris and dust adhered to the fracture surfaces. The fibers were
then mounted on an aluminum stub as described earlier in the section for observing the
cross-sectional features by SEM.
* Denton Vacuum Division, Moorestown, NJ.


19
not well understood because of the difficulty in obtaining controlled kinetic data (due to
the rapid polymerization rates).
Miller et al. attempted to explain the observation of increased polymer yield for
dialkyldichlorosilanes in the presence of polar cosolvents such as diglyme, crown ethers
etc., by suggesting the presence of silyl anion radical intermediates (such as shown in
equation (2.2) in Figure 2.1) as the main propagating species in the polymerization. It is
well known that polar solvents aid in the transfer of electrons from metal to monomer,
promoting formation of silyl anion radicals [Gau90; MI93; BN83]. A large number of
radicals formed would mean a large number of initiation sites and this would favor an
increased polymer yield. However, Miller et al. [MI91] reported the same beneficial
effect (i.e., improved yield) when 16 vol% of non-polar solvent (i.e., heptane) was added
to toluene in the polymerization of dialkyldichlorosilane (such as dichloro-di-n-
hexylsilane).
Zeigler et al. [Zei87] have developed a model concerning the bulk solvent effects
in the polymerization of dialkyldichlorosilanes when monomer is present in excess
compared to sodium (inverse mode of addition). According to their model, yield and
molecular weight are determined by effective monomer concentration at the sodium
surface. This depends on the rate of diffusion of monomer to the sodium surface, which,
in turn, depends on degree of coverage of the sodium by growing polymer chains (see
Figure 2.6). In a good solvent (i.e., in which the difference in polymer and solvent
solubility parameters, AS = 5P-8S, approaches zero), polymer-solvent contacts are highly
favored and the polymer coils are relatively extended in the solvent. Thus, polymers
tend to remain in the solvent phase and tend not to adsorb on the sodium particle
surfaces. The monomer continues to have easy access to sodium surface and


67
oxygen content in the fibers (0.6-6.0 wt%) compared to Nicalon suggests that air
curing step was not used. The low oxygen content in the fibers contributed to improved
thermomechanical stability of these fibers over that of Nicalon fibers.
More recently, Lipowitz et al. [Lip91A; Lip91B; Lip94A; Lip94B; Lip95] developed
near-stoichiometric, polycrystalline SiC fibers using polycarbosilane and
methylpolydisilylazane polymers. Fibers were melt spun, oxidatively cross-linked, and
heat treated at temperatures above 1600C in argon in order to react excess carbon
and oxygen in the fibers. As noted earlier, PC-derived fibers normally become very
weak and develop a porous, large-grained microstructure during this type of heat
treatment. However, Lipowitz et al. incorporated a boron-based sintering additive in the
polymer which allowed fibers to be densified after the carbothermal reduction reactions
discussed earlier. The resulting fibers had fine diameter (8-10 pm), high relative density,
small average grain sizes (in the range -0.03-0.5 pm, depending on the Si:C ratio), low
oxygen content (<0.1%), high tensile strength (2.6 GPa), high elastic modulus (up to
420 GPa), and good strength retention after high temperature (1800C) heat treatment
in argon. The key limitation in this process was apparently a difficulty in producing
continuous fibers.
Takeda et al. [Tak94] have reported the development of low-oxygen-content (0.4
wt%), fine-diameter (-15 pm) SiC fibers. These fibers ('Hi-Nicalon) were prepared in a
similar manner as Nicalon (i..e., by melt spinning of polycarbosilane) except that cross-
linking was accomplished by electron beam irradiation instead of oxidation. The high
temperature stability of the fibers increased dramatically as the oxygen content of the
fibers decreased. Fibers with 0.5 wt% oxygen retained high strength (-2.4 GPa) and
high modulus (-250 GPa) after heat treatment at 1500C in argon. These fibers had a
chemical composition of 62% Si, 37.5% C, and 0.5 wt% O. The main drawback of this


Table 4.33. Tensile strengths of SIC fibers spun from fractionally-precipitated PMS polymers.
Fiber batch
Heat treatment
temperature (C)
Heat treatment
atmosphere
# of fibers tested
Fiber diameter
(pm)
Tensile strength,
(GPa)
UF-75s
1150
n2
18
11.0 1.8
2.72 0.36
UF-78s
1150
n2
18
11.0 1.2
2.35 0.69
Table 4,34. Elemental analysis by Electron Microprobe for SiC fibers prepared from fractionally-precipitated PMS
polymers3.
Fiber batch
Composition
As-measured
Si % C % 0% Total %
Normalized (to 100%)b
Si % C % O %
UF-75s-1150
67.93 0.35
32.66 1.00
1.60 0.70
102.19 1.59
66.49 0.94
32.00 0.62
1.5 0.67
UF-75S-1150-
1480
65.70 1.51
36.20 1.39
0.00
101.90 1.68
64.48 1.16
35.52 1.16
0.00
UF-78s-1150
67.64 0.49
24.64 0.69
5.84 1.67
98.12 0.98
68.95 1.04
25.12 0.85
5.94 1.63
a Nitrogen and B were below the detection limit of the Electron Microprobe Analyzer used.
b Normalized Si, C, and O to 100% total.


82
Experiments with PCS and PCS+PSZ solutions were carried out to assess the
differences in solvent evaporation rates from the two solutions. Identical amounts of
PCS and PCS+PSZ solutions with identical solids loading (68 wt%) were prepared. Vials
containing the polymer solutions were placed in an analytical balance (with an accuracy
up to 5 decimals) and the change in weight was monitored as a function of time (up to
30 min). The change in weight was noted every 10 sec up to 5 min, every 30 sec for the
next 5 min, and every 60 sec for the remaining 20 min. The percentage weight change
for the polymer solutions was plotted as a function of time.
Fiber extension experiments were carried out inside a glove box. Polymer
solutions (PCS and PCS+PSZ(14.5 wt%)) were concentrated to the same viscosities
used in fiber spinning experiments. Fiber extension distances were determined by
dipping a glass rod (~0.5 cm diameter) in ~4 g of bulk polymer solution (in a glass vial)
and drawing fibers by hand until they became separated from the bulk solution. The
drawing process was carried out in approximately 1-2 seconds or less for each fiber.
Approximately 25 filaments were drawn and average fiber extension distances and
standard deviations were calculated.
3.1.4 Characterization of fibers
Fiber tensile strengths were measured at room temperature according to ASTM
procedure D3379-75 [AST88], Fibers were tested in the green state as well as after
heat treatments to various temperatures in the range of 200-1150C. Fibers were also
tested after oxidation at temperatures of 180 10C. For mechanical testing, individual
fibers were attached to paper tabs using wood glue5 and loaded in tension (0.5 mm/min
5 Titebond II, Franklin International, Columbus, OH.


ABSORBANCE (Kubelka-Munk Units)
247
4000 3500 3000 2500 2000 1500 1000 500
WAVENUMBER (cm'1)
Figure 4.80. FTIR spectra of PMS polymer C (100% MDCS; toluene, dioxane (50:50
vol%)),750C to 1150C at 5C/min in nitrogen.


331
that relatively large particulate defects were introduced into the UF-35s spin batch.
(Hard inorganic, or preceramic, particulates might interfere with fiber
shrinkage/densification during pyrolysis, thereby creating crack-like voids. Organic
particulates could partially or fully burnout during pyrolysis which would result in pores
with shapes and sizes somewhat comparable to the original particulates.)
Table 4.31 shows the results of elemental analyses (Si,C, and O) on 1150C-
pyrolyzed (in nitrogen) UF-35s, UF-42s, and UF-52s fibers, as determined by Electron
Microprobe Analysis (EMA). UF-52s fibers, spun using 100% heat-treated PMS, had a
Si-rich composition (2.2 wt% excess Si). (Details of calculation of excess Si are shown
in Appendix K.) Recall from section 4.2.4 that free Si was detected after pyrolysis of
PMS at 1350C in argon. XRD was used to show the presence of crystalline Si in the
pyrolysis product. UF-42s fibers, spun using a 70:30 PMS:PCS composition, had 10.4
wt% excess carbon11. (The details of calculation of excess C are shown in Appendix K.)
This is not surprising since it is well-known that PCS pyrolyzes to a highly carbon-rich
composition. The amount of excess carbon increased as the PMS:PCS ratio in the spin
dope decreased.
4.3.2.3 Spinning of fibers from fractionally-precipitated PMS polymers
Table 4.32 shows conditions for fiber spinning experiments and some qualitative
results using fractionally-precipitated PMS polymers. Fiber batch UF-73s was spun from
PMS-243-F (Mw8400) polymer (precipitated by adding alcohols) using a 70 pm hole
diameter, 4-hole spinneret. Although the fibers spun well (0.25 breaks per minute per
hole), the green fibers were slightly stuck together and this resulted in brittle fibers after
pyrolysis. The sticking between green fibers was most likely caused by inadequate
11 This is low compared with the excess carbon (i.e., -15-20 wt%) found in Nicalon fibers.


329
Figure 4.116. (Contd.)


CHAPTER 5
SUMMARY AND CONCLUSIONS
1. SiC fibers were prepared by dry spinning of polycarbosilane (PCS) solutions. The
effects of polyvinylsilazane (PSZ) on spinnability of PCS solutions and mechanical
properties of green and heat-treated fibers were investigated. It was found that the
addition of PSZ to PCS greatly improved fiber spinning by reducing the number of fiber
breaks occurring during spinning. (This also allowed a considerably greater amount of
fibers to be formed from the PCS solutions containing PSZ.) It was also observed
qualitatively that fibers could be stretched more easily in the case of PCS+PSZ solutions
than PCS solutions. Fiber extension experiments carried out separately confirmed this
observation. It was determined that PCS+PSZ solution had an average fiber extension
greater than PCS solution by ~20%.
Contact angle measurements for PCS and PCS+PSZ solutions (33 wt% solids
loading) on stainless steel and teflon substrates revealed differences in wetting
characteristics for these solutions. It was found that contact angles for PCS+PSZ
solutions were lower than for PCS solutions on both stainless steel and teflon
substrates. Contact angles for PCS solution on PCS-coated stainless steel and for
PCS+PSZ solution on PCS+PSZ-coated stainless steel were also measured. The
contact angles of the PCS solution on a PCS-coated stainless steel substrate were
larger than the contact angles of PCS+PSZ solution on PCS+PSZ-coated stainless steel
substrates.
346


MOLECULAR WEIGHT
224
4000 -r
3500 -
3000 -
2500 -
2000 -
1500 -
1000 -
500 -
0 -
I I Mw
Hi M
D: Toluene
E: Toluene:THF (95:5 Vol %)
F: Toluene:1,4-Dioxane (50:50 Vol %)
D E F
POLYMER BATCH
Figure 4.68. Effect of cosolvents on molecular weight of PMS polymers D,E, and F
(prepared using MDCS/MTCS (70/30 wt%)).


Table M-1. (Contd.)
Batch
Designation
Solvent(s)
Polymer
Yield (%)
GPC MW distribution
Mn Mw PDI
Ceramic Yield (%)
by pyrolysis by TGA b
XRD Results
(1350C/Ar)
PMS-246
Toluene, 1,4
Dioxane
(50:50)
42.0
1069
2469
2.31
PMS-247
Toluene, 1,4
Dioxane
(50:50)
38.3
1097
2276
2.07
PMS-248
Toluene, 1,4
Dioxane
(50:50)
46.4
1027
2287
2.33
PMS-249
Toluene, 1,4
Dioxane
(50:50)
45.7
977
2329
2.38
PMS-250
Toluene, 1,4
Dioxane
(50:50)
49.6
1207
1919
1.59
51.3
PMS-251
Toluene, 1,4
Dioxane
(50:50)
44.8
1174
1981
1.69
PMS-252
Toluene, 1,4
Dioxane
(50:50)
47.9
1133
2118
1.87
51.1
PMS-253
Toluene, 1,4
Dioxane
(50:50)
42.8
975
1725
1.77


70
60 -
_ 50 -
V)
r
9^ 40 -J
o
o
O Increasing Shear Rate
Decreasing Shear Rate
-6Q-
30 -
20 -
10 -
10
T
20
30
-a
T
40
T
50
(B)
60
Shear Rate (s'1)
Figure 4.106. Plots of (A) shear stess vs. shear rate and (B) viscosity vs.
shear rate for UF-33s spin dope.


390
Table H-5. UF67S-1150 (1150C/1 h/N2) (PCS+PSZ)
Batch 1:
d.i(tim)
daiym)
diava.l
10.50
11.00
10.75
10.50
11.00
10.75
10.50
10.50
10.50
11.00
11.00
11.00
10.00
10.00
10.00
11.00
11.50
11.25
10.50
10.50
10.50
10.50
11.00
10.75
10.00
10.00
10.00
11.00
11.00
11.00
10.50
10.50
10.50
11.00
11.00
11.00
10.50
10.50
10.50
10.00
10.50
10.25
10.00
10.50
10.25
10.50
10.50
10.50
10.00
10.00
10.00
10.50
12.00
11.25
Average
10.47
10.72
10.60
Std. Dev
0.36
0.52
0.40
Batch 2:
d^jm)
datm)
d(avg.)
10.50
10.50
10.50
11.50
11.50
11.50
10.50
10.50
10.50
11.00
11.50
11.25
10.50
10.50
10.50
11.50
12.00
11.75
10.50
11.00
10.75
10.50
10.50
10.50
10.00
11.00
10.50
11.00
11.50
11.25
10.50
10.50
10.50
10.50
10.50
10.50
10.50
10.50
10.50
11.00
11.50
11.25
11.50
12.00
11.75
10.50
10.50
10.50
10.50
10.50
10.50
10.50
10.50
10.50
Average
10.72
10.94
10.83
Std. Dev
0.43
0.57
0.48
Load(g)
Strain
TSiGPal
EMiGPal
34.44
0.0191
3.72
194.80
30.38
0.0177
3.28
185.87
30.29
0.0177
3.43
193.93
24.47
0.0141
2.52
179.35
24.27
0.0140
3.03
215.63
39.97
0.0208
3.94
189.32
24.91
0.0146
2.82
192.94
22.41
0.0145
2.42
167.43
29.01
0.0190
3.62
190.98
34.25
0.0178
3.53
197.95
29.89
0.0175
3.38
193.34
35.66
0.0183
3.68
200.91
30.58
0.0173
3.46
199.82
33.66
0.0199
4.00
201.23
22.36
0.0141
2.66
188.03
32.63
0.0189
3.69
195.11
30.68
0.0180
3.83
212.40
27.16
0.0148
2.69
182.22
29.83
0.0171
3.32
193.40
4.88
0.0022
0.50
11.23
Load(a)
Strain
TS(GPa)
EM(GPa)
25.64
0.0172
2.90
173.71
23.65
0.0140
2.23
159.38
25.30
0.0166
2.86
179.42
18.65
0.0106
1.84
182.60
25.30
0.0170
2.86
182.67
30.98
0.0175
2.80
160.43
27.29
0.0173
2.95
170.23
29.72
0.0195
3.36
172.58
28.17
0.0194
3.20
165.05
17.88
0.0106
1.76
166.66
23.07
0.0147
2.61
187.91
27.15
0.0175
3.07
180.47
21.81
0.0138
2.47
185.20
12.05
0.0066
1.19
180.76
36.61
0.0199
3.31
165.96
27.68
0.0180
3.13
176.98
26.76
0.0180
3.03
168.37
18.22
0.0113
2.06
191.90
24.77
0.0155
2.65
175.02
5.65
0.0037
0.60
9.52


60
2.4. Cross-linking of Polysilane Polymers
Polysilane polymers exhibit a wide range of properties based on the pendant
substituent groups in the polymer chain and the degree of cross-linking. The physical
appearance of the polymer could range from that of a viscous liquid (e.g.,
polymethylsilane) to a solid (e g., polymethylphenylsilane) depending on the molecular
architecture of the polymer (cross-linking, molecular weight, side groups etc.). The
polymers can be cross-linked by oxidation, room temperature vulcanization, and
photolysis.
2.4.1 Oxidative cross-linking
Oxidative cross-linking of polysilane polymers can be accomplished by
converting Si-H groups in the polymer to Si-O-C or Si-O-Si groups by reacting with air or
moisture. These oxidatively cross-linked polymers are insoluble in organic solvents and
do not melt (i.e., infusible) during pyrolysis to silicon carbide. The degree and rate of
cross-linking depends on the amount of Si-H groups present in the polymer. Figure 2.17
shows an FTIR spectrum of a polymethylsilane polymer which clearly demonstrates the
air sensitivity of these polymers as indicated by the broad absorption band around 3450
cm'1. (This absorption is due to Si-OH stretching which arises from conversion of Si-H.)
The oxygen sensitivity of the polysilane polymers is attractive for some applications
(e.g., multilayer lithography), but the incorporation of oxygen is sometimes not desirable
if the polymer is used as a SiC precursor.
2.4.2 Room temperature vulcanization
The Si-H groups present in the polysilane polymers have been exploited in the
preparation of highly cross-linked polymers by catalytic dehydrogenation (see section
2.3).


389
Table H-4. (Cont'c
Batch 5
dt(nm)
d?{pm)
dava.)
14.00
14.00
14.00
12.50
12.50
12.50
11.50
12.00
11.75
14.00
14.00
14.00
12.00
12.50
12.25
12.00
12.00
12.00
12.00
12.00
12.00
12.50
12.50
12.50
14.00
14.00
14.00
14.00
14.00
14.00
12.00
12.00
12.00
14.00
14.00
14.00
13.50
13.50
13.50
14.00
14.00
14.00
13.50
14.00
13.75
14.00
14.00
14.00
14.00
14.00
14.00
12.00
12.00
12.00
11.50
12.00
11.75
11.50
11.50
11.50
Average
12.93
13.03
12.98
Std. Dev
1.04
0.98
1.01
Batch 6
djium)
diJm)
d(avg.)
12.50
14.00
13.25
11.00
11.00
11.00
11.50
12.00
11.75
11.50
12.00
11.75
13.50
13.50
13.50
11.50
11.50
11.50
11.50
11.50
11.50
11.50
11.50
11.50
11.50
12.00
11.75
11.50
12.00
11.75
11.50
11.50
11.50
11.00
11.50
11.25
11.50
12.00
11.75
12.00
12.00
12.00
11.50
12.00
11.75
11.50
11.50
11.50
11.50
11.50
11.50
11.50
11.50
11.50
11.50
12.00
11.75
11.50
12.00
11.75
Average
11.63
11.93
11.78
Std. Dev
0.53
0.69
0.59
Load(g)
Strain
TS(GPa)
EMfGPal
37.77
0.0123
2.41
194.83
19.63
0.0081
1.57
193.74
26.95
0.0121
2.44
201.16
44.27
0.0137
2.82
205.56
30.06
0.0130
2.50
191.73
30.35
0.0133
2.63
198.36
41.31
0.0175
3.58
204.38
37.09
0.0157
2.96
188.12
52.86
0.0179
3.37
187.49
31.37
0.0101
2.00
198.43
24.91
0.0106
2.16
203.47
34.18
0.0112
2.18
193.77
27.34
0.0093
1.87
202.12
30.40
0.0100
1.94
193.88
53.78
0.0187
3.55
194.42
38.45
0.0135
2.45
180.77
53.97
0.0179
3.44
192.04
28.60
0.0127
2.48
195.44
26.27
0.0109
2.38
217.55
29.72
0.0132
2.80
211.76
34.96
0.0131
2.57
197.45
9.92
0.0031
0.58
8.53
Loadial
Strain
TSiGPal
EMfGPal
27.33
0.0096
1.95
203.12
20.23
0.0102
2.09
205.52
17.51
0.0081
1.58
195.20
41.62
0.0189
3.76
204.98
62.04
0.0224
4.25
198.00
29.86
0.0128
2.82
219.58
21.79
0.0092
2.06
223.67
47.90
0.0220
4.52
214.47
32.48
0.0162
2.94
183.45
33.02
0.0149
2.99
200.60
28.40
0.0138
2.68
194.84
30.83
0.0163
3.04
188.33
28.60
0.0149
2.59
173.35
25.09
0.0111
2.17
195.92
31.90
0.0144
2.88
200.12
35.40
0.0165
3.34
205.05
19.26
0.0085
1.82
214.69
33.21
0.0151
3.13
207.81
27.62
0.0118
2.50
211.88
49.01
0.0227
4.43
203.28
32.16
0.0145
2.88
202.19
10.97
0.0045
0.85
12.07


INTENSITY (Kubelka-Munk Units)
WAVENUMBER (cm'1)
Figure 4.76. Room temperature FTIR spectra of PMS polymer C (batch PMS-263) (prepared from 100% MDCS in
toluene/dioxane solvent).
237


203
Table 4.11. Tensile properties of as-spun and air-heat treated (187C) PCS fibers, heat
treated to various temperatures between 200-1150C in nitrogen.
Temperature of heat
treatment (C)
# of fibers
tested
Diameter
(pm)
Rupture
strain (%)
Tensile strength
(MPa)
PCS fibers (69s)
None
17
16.8 0.89
0.80 0.36
18 7
200
22
17.9 0.52
0.81 0.33
19 8
400
19
15.2 0.81
2.12 0.20
43 3
500
23
17.1 1.43
3.23 1.24
75 25
600
24
14.9 0.95
2.75 0.88
174 56
800
20
14.3 1.41
1.43 0.43
1771 544
1000
20
12.6 1.31
1.44 0.38
2554 726
1150
110
12.4 1.16 a
1.36 0.42 3
2700 800a
PCS fibers heat treated in air at
87C (65s)
None
19
17.7 1.17
3.23 1.31
51 9
300
19
18.4 1.15
5.45 1.43
78 11
500
16
17.9 1.03
2.81 0.89
97 27
600
18
17.5 0.80
2.07 0.36
147 28
800
20
14.8 0.82
1.29 0.26
1089 274
1150
18
11.5 0.24
1.37 0.45
2138 667
Average for four separate heat treatments (individual results are provided in Appendix H).


Intensity (Kubelka-Munk Units)
171
Figure 4.40. (Cont'd.)


ABSORBANCE (Kubelka-Munk Units)
248
WAVENUMBER (cm'1)
Figure 4.81. FTIR spectra of PMS polymer F (MDCS.MTCS (70:30 wt%)), toluene,
dioxane (50:50 vol%), 40C to 600C at 5C/min in nitrogen.


205
range 200-1150C in nitrogen. (Appendix G shows the weight losses that occur upon
pyrolysis of the fibers at 1150C in nitrogen.) The data for as-spun PCS fibers (as-spun)
is shown for the highest strength fiber batch, UF-69s. The data for PCS fibers which
were initially heat-treated in air is shown for batch UF-65s. (The selection of a particular
batch for air-heat treatment and/or heat treatment in nitrogen was, to some extent,
determined by the amount of fibers available.) Figures 4.59a and 4.59b show a
comparison of average rupture strains as a function of temperature for PCS and
PCS+PSZ fibers heat-treated in nitrogen. In both cases, the average rupture strains
reached maximum values after heat treatments in range of ~400-600C, and then
decreased rapidly after heat treatments at higher temperatures. The decrease in rupture
strain is due to the transition from an organosilicon polymer to an inorganic SiC-based
ceramic (i.e., the branched polymer chains lose methyl groups and hydrogen from the
Si-C backbone and form an amorphous Si-C network). Such a rapid decrease in rupture
strains beyond 400C was also reported by Hasegawa et al. [Has80] for low-molecular-
weight Nicalon-type fibers, where rupture strains decreased from 3.5% at 400C to
1.25% at 800C. Figures 4.60a and 4.60b show a comparison of average rupture strains
as a function of heat treatment temperature (in nitrogen) for PCS and PCS+PSZ fibers
which were initially heat-treated in air at ~180C. The trends were similar to the fibers
heat-treated only in nitrogen, except that the maximum rupture strains were higher and
were reached at lower temperatures for the air-heat treated fibers.
Figures 4.61a and 4.61b show plots of average tensile strength vs. the heat
treatment temperature (in nitrogen) for the PCS fibers (batch 69s) and PCS+PSZ fibers
(batch 70s). These plots show the same data as in Tables 4.11 and 4.12. It was noted
earlier that: (i) The addition of PSZ had essentially no effect on the green strength, (ii)
Batches with PSZ showed somewhat greater increases in strength during heat


PREPARATION OF SIC-BASED FIBERS FROM ORGANOSILICON POLYMERS
(I) EFFECTS OF POLYVINYLSILAZANE ON THE CHARACTERISTICS AND
PROCESSING BEHAVIOR OF POLYCARBOSILANE-BASED SOLUTIONS AND
(II) SYNTHESIS, CHARACTERIZATION, AND PROCESSING OF
POLYMETHYLSILANES
By
MOHAMED SALEEM
A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA


354
60
50 -
~
c/>
40 -
CL
-
£*
30 -
o
_
o
CO
20 -
>
10 -
O Increasing Shear Rate
Decreasing Shear Rate
^ § O
Q
(B)
10
20
30
40
50
60
Shear Rate (s'1)
Figure A-4. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for batch 67s spin dope (PCS+PSZ) (solids concentration
~69 wt%).


Table H-2. (Cont'd.)
Batch 5:
di(pm)
dilym)
d(avg.)
Load(g)
Strain
TSfGPal
EMfGPal
9.50
10.00
9.75
19.85
0.0122
2.61
219.83
9.00
9.00
9.00
18.74
0.0118
2.89
244.92
8.00
10.50
9.25
12.30
0.0086
1.83
211.55
9.00
9.00
9.00
21.94
0.0127
3.38
266.07
9.00
9.50
9.25
17.82
0.0124
2.60
208.92
8.50
9.00
8.75
9.49
0.0061
1.55
252.49
8.50
9.00
8.75
24.60
0.0167
4.01
240.52
8.50
9.00
8.75
18.40
0.0117
3.00
257.06
8.50
8.50
8.50
12.74
0.0087
2.20
253.91
8.50
9.00
8.75
23.92
0.0147
3.90
266.15
8.50
8.50
8.50
14.67
0.0103
2.53
246.37
7.50
12.00
9.75
14.04
0.0097
1.95
200.05
9.00
9.50
9.25
11.14
0.0067
1.63
240.93
8.00
10.50
9.25
10.94
0.0070
1.63
233.01
7.50
8.00
7.75
17.58
0.0122
3.66
300.07
8.00
10.50
9.25
20.29
0.0140
3.01
215.19
8.50
9.00
8.75
20.58
0.0131
3.36
257.16
Average
8.47
9.44
8.96
17.00
0.0111
2.69
242.01
Std. Dev
0.54
0.98
0.49
4.68
0.0030
0.81
25.43


I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and
quality, as a dissertation for the degree of Doctor of Philosophy.
J?
Daniel R. Talham /
Associate Professor of Chemistry
This dissertation was submitted to the Graduate Faculty of the College of
Engineering and to the Graduate School and was accepted as partial fulfillment of the
requirements for the degree of Doctor of Philosophy.
August 1998
Winfred M. Phillips
Dean, College of Engineering
Karen A. Holbrook
Dean, Graduate School


92
methanol dropwise and with vigorous stirring. The precipitated polymer solution was
transferred to teflon centrifuge tubes and centrifuged at 2000 rpm for 10 min. The clear
supernatant was decanted out. The wet cake collected at the end of centrifugation was
placed in a glass vial and dried in a vacuum oven at room temperature. To prevent
splashing of the polymer from vial during vacuum drying, the vial was covered with an
aluminum foil which had been perforated with tiny holes. After drying, the glass vial
containing the polymer was removed from the vacuum oven (by venting to N2) and
backfilled with N2. The dried polymer was dissolved in toluene (33 wt%) and stored in a
refrigerator for further processing (fiber spinning). Polymers PMS-245 through PMS-255
were fractionally precipitated by addition of acetone. The acetone to polymer ratios (ml
of acetone per g of polymer) used ranged from 20 to 27. The procedure for fractional
precipitation with acetone was identical to that of precipitation with alcohols.
3.2.6 Characterization of polymers and samples prepared by heat treatment of the
polymers
Molecular weight distributions of polymers were determined by GPC according to
the methods described in section 3.1.3. Polymer solutions were passed through 1000 A
and 500 A columns connected in series. The mobile phase for the columns was THF.
Weight loss behavior was monitored by Thermal Gravimetric Analysis (TGA)§.
Samples were heat-treated in argon at 10C/min to 1200C (no hold time). Sample
preparation for TGA involved using rotary evaporation to concentrate the original
polymer solutions (33 wt% in toluene) to 70-80 wt% and then drying the concentrated
polymers solution in a vacuum oven at 75C for 5 min to drive off any residual solvent
completely. (The vacuum oven was vented to nitrogen to prevent oxygen contamination
Model STA-409, Netzch Company, Exton, PA.


dwt/d(logM) dwt/d(logM)
342
Figure 4.117. Gel permeation chromatograms for PMS-242 polymer:
(A) before and (B) after fractional precipitation.


70
(height/width) of features in 1C chips [MI88; MI90A; MI90B], The classical single layer
resist process used in microlithography has been found to be inadequate when dealing
with current trends and lithographers have resorted to multilayer resist processes to
meet the current requirements. Figure 2.19 shows a comparison of single layer
process vs multilayer process [MI88], The classical single layer resist process (wet
development) involves exposure of the resist and development of a pattern using a
suitable solvent. There is a loss in line width control for small features since wet
development processes are isotropic. In the case of multilayer photoresist process, the
wafer is covered with a thick, inert planarizing polymer layer followed by a thin layer of
photoresist. High resolution in line width can be achieved since the resist layer can be
thinner than what is acceptable in single layer resist process (0.05- 0.2 pm compared to
~1 pm for single layer resists). Subsequently, the pattern can be wet developed (without
loss in resolution) or dry developed during imaging (ablative exposure) down to the
planarizing layer and the image can be transferred through the planarizing layer by 02-
RIE (oxygen resistant ion etching). A necessary requirement for the multilayer resist
process is that the photoresist remaining after developing must be resistant to 02-RIE, in
order to mask the underlying polymer effectively. Polysilanes have been found to be
ideally suited for use as photoresists since they are stable to 02-RIE by forming a thin
layer of inert Si02. In addition, polysilanes possess excellent processing properties such
as good thermal stability, solubility for coatings, and imageability to light and ionizing
radiation.


161
intensity of Si-H groups decreased after 300C, similar to the observation made in this
study, presumably due to reaction of Si-H groups with Si-OH groups (equation (4.3)).
Figure 4.34 shows that the band 8S (CH3) of Si-CH3 (at 1253 cm'1) increased
slightly around 300C and then started to decrease beyond 440C for the PCS. In
addition, the intensity of absorption band pas (CH3) of Si-CH3 (at 830 cm'1) showed an
increase at around 400C and decrease beyond 500C. These trends are similar to
those observed during heat treatment of the fibers prepared without air heat treatment,
although the magnitude of the increases in intensity are considerably smaller (see
Figure 4.27). In contrast to these results, Ichikawa et al. [Ich90] observed continuously
decreasing intensity for these absorption bands (5S (CH3) and pas (CH3) from Si-CH3) up
to 480C (Figure 4.35). Ichikawa et al. attributed the decrease in the intensities of the
absorption bands to reactions (4.4) and (4.5) shown below:
\ / \ / tA A\
S i O H + CH3Si Si-o Si +CH a (44)
/ \ / \ 4
\ / \ /
SiH + CHoSi SiCHoSi + Ho (4-5)
/ \ / 4 \ 2
Figure 4.34 also shows that (1) the absorption intensity at -1020 cm'1, which
represents a combination of the absorption intensities of (CH2) of Si-CH2-Si and v(Si-
O-Si/ Si-C-O), increased steadily up to 500C, (2) the absorption intensity at 1358 cm'1
(5 (CH2) of Si-CH2-Si) remained unchanged all the way to 500C, and (3) the absorption
due to v(C=0) group observed at 1722 cm'1 steadily decreased above ~200C until it
disappeared at ~520C. All of the results are reasonably consistent with the results in
Figure 4.35 from the study by Ichikawa et al.


427
[Fen94], Z.C. Feng, C.C. Tin, K.T. Yue, R. Hu, J. Williams, S.C. Liew, Y.G. Foo,
S.K.L. Choo, W.E. Ng, and S.H. Tang, Combined Structural and Optical
Assessment of CVD-grown 3C-SiC/Si, in Mat. Res. Soc. Symp. Proc.,
Diamond, SiC, and Nitride Wide Band Gap Semiconductors, Vol. 339,
Materials Research Society, Pittsburgh, PA (1994).
[Gau89], S. Gauthier and D.J. Worsfold, The Effect of Phase-Transfer Catalysts on
Polysilane Formation, Macromolecules, 22_ 2213-2218 (1989).
[Gau90], S. Gauthier and D.J. Worsfold, Mechanistic Studies of Polysilane
Polymerization, in Silicon-Based Polymer Science-A Comprehensive
Resource, pp 299-308, Eds., J.M. Zeigler and F.W.G. Fearon, American
Chemical Society, Washington, DC (1990).
[Gre72], N.N. Greenwood, E.J.F. Ross, and B.P. Straughan, in Index of Vibrational
Spectra of Inorganic and Organometallic Compounds, Vol. 1, CRC Press,
Cleveland, OH (1972).
[Han97], W. Han, S. Fan, Q. Li, W. Liang, B. Gu, and D. Yu, Continuous Synthesis
and Characterization of SiC Nanorods," Chem. Phys. Letters, 265 374-378
(1997).
[Har88]. J.F. Harrod, Polymerization of Group 14 Hydrides by Dehydrogenative
Coupling, in Inorganic and Organometallic Polymers, pp 89-100, Eds., M.
Zeldin, K.J. Wynne, and H.R. Allcock, American Chemical Society,
Washington, DC (1988).
[Has83A], Y. Hasegawa and K. Okamura, Synthesis of Continuous Silicon Carbide
Fibre-Part 3, Pyrolysis of Polycarbosilane and Structure of Products, J.
Mater. Sci., 18 3633-3648 (1983).
[Has83B], Y. Hasegawa, M. Ilmura, and S. Yajima, Synthesis of Continuous Silicon
Carbide Fibre-Part 2, Conversion of Polycarbosilane Fibre into Silicon
Carbide Fibres, J. Mater.Sci., 15 720-728 (1983).
[Has86], Y. Hasegawa and K Okamura, Synthesis of Continuous Silicon Carbide
Fibre-Part 4, The Structure of Polycarbosilane as the Precursor, J. Mater.
Sci., 21 321-328 (1986).
[Has89], Y. Hasegawa, Synthesis of Continuous Silicon Carbide Fibre- Part 6,
Pyrolysis Process of Cured Polycarbosilane Fibre and Structure of SiC
Fibre, J. Mater. Sci., 24 1177-1190 (1989).
[Has92], Y. Hasegawa, Si-C Fibre Prepared from Polycarbosilane Cured Without
Oxygen, J. Inorg. Organomet. Polym., 2 161-169 (1992).
[Has94], Y. Hasegawa, New Curing Method for Polycarbosilane with Unsaturated
Hydrocrabons and Application to Thermally Stable SiC Fibre, Composites
Sci. Technol., 51 161-166 (1994).


ABSORBANCE (Kubelka-Munk Units)
157
4000 3500 3000 2500 2000 1500 1000 500
WAVENUMBER (cm'1)
Figure 4.33. FTIR spectra for air-heat treated (187C) PCS fibers (batch 65s)
during heat treatment to 600C at 1C/min in nitrogen atmosphere.


68
method is that cross-linking of the polymer by electron beam irradiation is a slower and
expensive processing step. More recently, Takeda et al. [Tak95] produced near-
stoichiometric SiC fibers (Hi-Nicalon Type S) by a modified Hi-Nicalon process. These
fibers had a chemical composition of 69% Si and 31% C, and exhibited better
thermomechanical than Hi-Nicalon fibers.
Zhang et al. [Zha91; Zha94A; Zha94B] have solution-spun fibers from
polymethylsilane polymers (see section 3) and converted them to SiC fibers by
pyrolysis. Since the precursor polymer was low in molecular weight, it required addition
of a cross-linking agent (unspecified chemistry) to render the fibers infusible. The
additive also acted as a spinning aid for the polymer, in addition to providing extra
carbon to adjust the stoichiometry of the ceramic produced to that of pure SiC. The SiC
fibers produced by Zhang et al. had near-stoichiometric composition. Dense fibers were
produced by adding a boron-based sintering additive. DRIFT spectra of the 1000C
pyrolyzed fibers showed the presence of a small amount of oxygen (exact amount not
determined). This was attributed to contamination during to handling, as PMS polymers
are very sensitive towards air. Thermomechanical stability data on these fibers indicate
that they are superior to commercially available Nicalon fibers, although no directly
comparable data was reported.
Seyferth et al. [Sey92] have demonstrated the potential for production of near-
stoichiometric SiC fibers from polymethylsilane polymers which are catalytically cross-
linked (see section 2.2.2). However, the fibers need an additional curing step, which can
be brought about by UV irradiation. Information on thermomechanical properties on
these fibers is not available.


AVERAGE RUPTURE STRAIN (%) AVERAGE RUPTURE STRAIN (%)
207
Figure 4.60. Average rupture strain vs. temperature for fibers heat-treated in
air: (A) PCS (batch 65s/ 187C air heat treatment), and (B)
PCS+PSZ (batch 70s/ 177C air heat treatment).


Rotativo Wolght Percont
55
Figure 2.15. TGA and DTA plots for a VPS polymer heated in N2 at 20C/min to 1200C
[Sch91],
<0QN3 IV 0X3-:


360
UF-70S (PCS+PSZ)
t, min
Number of holes spun
Number of fiber breaks
0-1
-
-
2-5
4
0
6
4
1
7
4
0
8
4
1
9-10
4
0
11
4
1
12
4
2
Total number of breaks = 5
Number of breaks per minute per spinneret hole = 0.11


132
V)
ra
0.
E
5
V)
o
o
(/>
>
40
30
20
10
0
O Increasing Shear Rate PCS+PSZ (33 wt%)
Decreasing Shear Rate
(ji@ &
J
T
(B)
0 50 100 150 200 250 300
Shear Rate (s'1)
Figure 4.19. Plots of: (A) shear stress vs. shear rate and (B) viscosity vs. shear rate
for a 33 wt% PCS+PSZ solution used in surface tension measurement.


53
Figure 2.14. DRIFT Spectra of PMS polymer, prepared by Zhang et al. [Zha94].


265
4.3 Preparation of Silicon Carbide Fibers from Polvmethvlsilane Polymers
There are several requirements for successful conversion of PMS polymers to
SiC fibers. They are as follows:
(i) Fiber formation/lnfusibilitv. The polymer should be a solid at room temperature or
should solidify during the course of fiber spinning to prevent fibers from sticking to
the spinning wheel or to each other. In addition, even if the polymer is solid at room
temperature, it should not melt at higher temperatures (i.e., during conversion to
ceramic). Any melting could cause the fibers to stick to each other. Prior experience
with some PMS polymers has shown that if the molecular weight becomes too low
(e.g., <4,000), it will melt upon pyrolysis. Such polymers could be rendered infusible
by carrying out a cross-linking (or curing) treatment below the melting temperature of
the polymer. Alternatively, the molecular weight/degree of cross-linking of the
polymer could be increased prior to spinning. (However, this would reduce the
maximum concentration of polymer that could be dissolve in solvents used in
solution spinning.)
(ii) Solubility. If fibers are formed by dry or wet spinning, then the solid polymer must
have good solubility in an appropriate solvent. Good solubility is desired to achieve
high polymer concentration in the spin dope, so that less solvent needs to be
removed during spinning. Common solvents for organosilicon polymers include
toluene, xylene, THF, etc. (In dry or wet spinning, a viscous spin dope is prepared
and is extruded through a spinneret to form fibers.)
(iii) Molecular weight/ degree of cross-linking. If the polymer molecular weight is too high
(e.g., >10,000 for some organosilicon polymers) or if it is highly cross-linked, the
polymer will not be readily soluble in common organic solvents. This will lead to
difficulties in spin dope preparation and fiber spinning (e.g., difficulty in filtration of


dwt/d(logM) dwt/d(logM) dwt/d(logM)
403
2.4
2.0
1.6 -
1.2 -
0.8
0.4 -
0.0
2.4
2.0 -
1.6 -
1.2 -
0.8 -
0.4
0.0 4.
2.0 -
1.6 -
1.2 -
0.8 -
0.4 -
0.0
PMS-245
Mn=1126; Mw=2419; P.D.1=2.15
T
5
PMS-245-F1
Mn=3153; Mw=6235; P.D.I= 1.98
T
5
PMS-245-F2
Mn=4493; Mw=11287; P.D.I=2.51
(A)
(B)
(C)
Figure J-1.GPC distributions for PMS-245 polymer: (A) before and,
(B) and (C) after two fractional precipitations with acetone.


429
[Lip95]. J. Lipowitz, J A. Rabe, K.T. Nguyen, L.D. Orr, and R.R. Androl, "Structure
and Properties of Polymer-derived Stoichiometric SiC Fiber, Ceram. Eng.
Sci. Proc., 16 [4] 55-62 (1995).
[Mah84], T. Mah, N.L. Hecht, D.E. McCullum, J.R. Hoenignman, H.M. Kim, A.P. Katz,
and H.P. Lipsitt, Thermal Stability of Nicalon Fibers, J. Mater. Sci., 19 [4]
1191-1201 (1984).
[Mar92], J.E. Mark, H.R. Allcock, and R. West, Polysilanes and Related Polymers," in
Inorganic Polymers, pp186-236, Prentice Hall, Englewood Cliffs, New Jersey
(1992).
[Mat88], K. Matyjaszewski, Y.L. Chen, and H.K. Kim, New Synthetic Routes to
Polysilanes, in Inorganic and Organometallic Polymers, pp 78-88, Eds., M.
Zeldin, K.J. Wynne, and H.R. Allcock, American Chemical Society,
Washington, DC (1988).
[Mat91], K. Matyjaszewski, M. Cypryk, H. Frey, J. Hrkach, H.K. Kim, M. Moeller, K.
Ruehl, and M. White, Synthesis and Characterization Polysilanes, J.
Macromol. Sci., Chem., A28 [11 & 12] 1151-1176 (1991).
[Mat92], R.B. Mathur, O.P. Bahl, and J. Mittal, A New Approach to Thermal
Stabilization of PAN Fibers, Carbon, 30 [4] 657-663 (1992).
[M¡I88], R.D. Miller, J.F. Rabolt, R. Sooriyakumaran, W. Fleming, G.N. Fickes, B.L.
Farmer, and H. Kuzmany, Soluble Polysilane Derivatives: Chemistry and
Spectroscopy, in Inorganic and Organometallic Polymers, pp 43-60, Eds.,
M. Zeldin, K.J. Wynne, and H.R. Allcock, American Chemical Society,
Washington, DC (1988).
[MI89], R.D. Miller and J. Michl, Polysilane High Polymers, Chem. Rev., 89 1359-
1410 (1989).
[MI90], R.D. Miller, Radiation Sensitivity of Soluble Polysilane Derivatives, in
Silicon-Based Polymer Science A Comprehensive Resource, pp 413-458,
Eds., J.M. Zeigler and F.W.G. Fearon, American Chemical Society,
Washington, DC (1990).
[MI91], R.D. Miller, D. Thompson, R. Sooriyakumaran, and G.N. Fickes, Synthesis
of Soluble, Substituted Silane High Polymers by Wurtz Coupling
Techniques, J. Polym. Sci., Part A: Polym. Chem., 29 813-824 (1991).
[MI93], R.D. Miller, E.J. Ginsburg, and D. Thompson, Low Temperature Wurtz Type
Polymerization of Substituted Dichlorosilanes," Polym. J., 25 [8] 807-823
(1993).


86
assembly was thoroughly purged with nitrogen for 30 min prior to use. The reaction
assembly (see Figure 3.4) consisted of a 1000 ml three-necked flask equipped with a
reflux condenser, pressure-equalizing addition funnel, inert gas inlet port, a magnetic
stirrer, oil bath and a heating mantle. In a typical polymerization, 25.4 g of sodium (1.27
gmoles, 15 wt% excess)1 and 400 ml of toluene* were heated to reflux (~110C for
toluene-THF mixture at 760 mm Fig and ~105C for toluene-1,4 dioxane mixture at 760
mm Hg). When THF* and 1,4-Dioxane§ were used as additives, the total volume of the
solvent mixture was kept constant at 400 ml in the desired proportions. After the sodium
melted completely (~30 min; melting point: 98C) and formed a fine dispersion, 33.5 ml
methyldichlorosilane¥ and 12.5 ml of methyltrichlorosilane§§ monomers in 70:30 wt%
proportion was added drop by drop through the addition funnel. The total time for the
addition of monomer(s) was one hour, during which time the heating mantle was
turned off to prevent the reaction from becoming violently exothermic. The reaction
contents were tested for acidity periodically. This was done as follows: the reaction
contents were allowed to settle for 2-3 min (i.e., stirring of the reaction contents was
stopped) and about 0.5 cc of the clear polymer solution was pipetted out and added to a
water-soaked pH paper. If chlorosilane monomer remains in the solution, it will react
with water on the pH paper to form HCI. This will, in turn, cause the pH paper to change
color to pink. The polymerization was carried out at reflux until the solution no longer
tested acidic (i.e., pH of 6-7; wet pH paper remained colorless after the clear polymer
1 3 to 8 mm spheres, Aldrich Chemical Company, Milwaukee, Wl.
* Grade Optima, Fisher Scientific Company, Fair Lawn, NJ.
t Grade HPLC, Fisher Scientific Company, Fair Lawn, NJ.
§ Grade ACS, Fisher Scientific Company, Fair Lawn, NJ.
Â¥ 99% purity, Aldrich Chemical Company, Milwaukee, Wl.
§§ 97% purity, Aldrich Chemical Company, Milwaukee, Wl.


AVERAGE RUPTURE STRAIN (%) AVERAGE RUPTURE STRAIN (%)
206
(A)
Figure 4.59. Average rupture strain vs. temperature for: (A) PCS fibers (batch 69s),
and (B) PCS+PSZ fibers (batch 70s).


29
(e.g., RSiH3, where R is an alkyl or aryl group) with the evolution of hydrogen. The
reaction can be represented as
R
Catalyst
(2.6)
H
The catalysts used were early transition metal complexes of titanium and zirconium,
namely, bis(r|5-cyclopentadienyl) dimethyltitanium (Cp2TiMe2)(Dimethyl Titanocene,
DMT) and bis (n5-cyclopentadienyl) dimethylzirconium (Cp2ZrMe2) (Dimethyl
Zirconocene, DMZ). Mu and Harrod [Mu91A] have investigated polymerization of
methylsilane by dehydrocoupling in the presence of DMT catalyst and reported
significantly higher yield of polymer in the form of a glassy solid in comparison to that
produced by classic Wurtz-coupling reactions. Table 2.4 shows polymerization
conditions (temperature, catalysts, solvents, time, amount of monomer used) and
characteristics of the polymers produced (yield, molecular weight, etc.). Their method,
however, suffers from the following disadvantages: (i) the reaction must be performed at
9-10 atm at 50C because methylsilane is a gas at room temperatures; enhancing
reaction rate would require working at higher pressures, which in turn requires
sophisticated instrumentation in order to perform the experiments safely and (ii)
handling methylsilane is dangerous since it is spontaneously flammable in air.
The monomer, methylsilane, was synthesized from methyltrichlorosilane.
Methyltrichlorosilane was reacted with a suspension of lithium aluminum hydride in THF
at 50C for 3 h and then reaction products were cooled under liquid N2 temperature to


APPENDIX H
TENSILE STRENGTH DATA FOR PYROLYZED PCS AND PCS+PSZ FIBERS


54
The olefin groups in olefinic halosilanes do not react with sodium and, therefore, are
retained in large amounts in the polymer.
Schmidt et al. [Sch91] have studied the pyrolysis characteristics of vinylic
polysilane (VPS) (manufactured by Union Carbide Corporation, Tarrytown, NY based on
Schilling and Kanners patent [Sch88]). The polymer was prepared using Me3SiCI,
Me2SiCI2, CH2=CHSiMeCI2 monomers in 0.85 :0.3: 1 proportion under refluxing
conditions in a xylene/THF mixture (7:1 wt ratio). The TGA profile of the VPS polymer is
shown in Figure 2.15. The pyrolysis process can be divided into three distinct regions
based on the TGA of profile: (i) ~ 50-300C, where thermal cross-linking occurred
without much loss of weight, (ii) ~300-750C, where major weight loss occurred due to
polymer degradation, and (iii) above 750C, where small weight losses were observed.
The ceramic yield was -58%, which is slightly higher than that reported by Schilling and
Kanner. The DTA showed a strong exotherm at around 250C, corresponding to cross-
linking reactions, and a weaker exotherm (at about 450C) during regime of large
weight loss. Schmidt et al. suggested that the exotherm at about ~1100C may be
indicative of partial crystallization of silicon carbide. Elemental analysis of the ceramic
formed after pyrolysis at 1000C showed a composition of 55% Si, 40% C, 2.7% O, and
less than a percent each of H and N. The presence of excess carbon (-17 wt%) in the
ceramic is not surprising, considering the fact that vinylic groups are retained in the
polymer backbone due to early cross-linking reactions at temperatures less than 300C.
The transmission IR spectra of as-received VPS and VPS heat-treated at temperatures
of 250C, 400C, 650C and 1000C in nitrogen atmosphere are shown in Figure 2.16.
Table 2.9 [Qiu89B; Col64] lists the IR peak assignments for the VPS polymer. The VPS
polymer undergoes following changes upon heating to 250C: (i) decrease in


4
1,000 and Mw < 2,500). In order to form fibers from these polymers, an increased
molecular weight and an increased extent of cross-linking are needed so that the
polymers are solids at room temperature (and remain solids during pyrolysis).
Investigations were carried out to increase the molecular weight/cross-linking of these
polymers as well as produce a solid polymer with sufficiently high molecular weight to
permit fiber spinning. Two approaches were utilized to raise the molecular weight/cross
linking of the polymer: (1) polymerization and cross-linking by heat treatment with
additives and (2) fractional precipitation of higher molecular weight fractions by addition
of nonsolvents. The additives used consisted of polyvinylsilazane (PSZ), dicumyl
peroxide (DCP), and decaborane (DB). The nonsolvents used were a mixture of
methanol and 2-propanol, and acetone. Fibers were spun from heat-treated PMS,
PMS/PCS polymer blends, and fractionally-precipitated PMS polymers, and converted to
SiC fibers by pyrolysis at 1000-1150C in a nitrogen atmosphere.


Table 4.20. Results of Electron Microprobe Analysis (EMA) on pyrolyzed ceramic from PMS polymers.
Batch
Sample
description
# of points
analyzed
Elemental composition
As-measured Normalized
Si % C% 0% Total% Si% C% 0%
PMS-245-
A-1000
As prepared, then
pyrolyzed to
1000C in N2
10
69.41 1.6
26.00 3.7
2.15 1.8
97.57 3.4
71.18 1.47
26.57 2.85
2.25 1.88
PMS-245-
F-1000
Fractionated in
acetone, then
pyrolyzed to
1000C in N2
10
70.63 1.1
30.44 0.5
0.20 0.4
101.27 1.1
69.74 0.5
30.06 0.40
0.20 0.41
PMS-238-
A-1000
Oxidized in static
air, then pyrolyzed
to 1000C in N2
6
48.90 1.1
29.88 0.9
20.63 1.8
99.36 0.44
49.22 1.1
30.04 1.0
20.74 1.8
259


284
amount of PCS (30 wt%, type A) and PSZ (5 wt%). The molecular weight distributions
for the heat-treated polymers are shown in Figures 4.95, 4.96, and 4.97, respectively.
The molecular weights increase with increasing heat treatment temperature (i.e., the
maximum heat treatment temperatures were 85, 100, and 115C, respectively). It is also
observed from Figure 4.97 that the increase in molecular weight for the PMS-217-AP2
sample was large enough that the bimodality of the distribution became more
pronounced. (PMS-217-AP and PMS-217-AP2 also showed a similar effect as noted in
regard to PMS-216-A and PMS-216-A2, i.e., the solution which was aged longer before
heat treatment (PMS-217-AP2) had a higher initial viscosity.)
PMS-218-AP had higher molecular weight (see Figure 4.98) compared to the
PMS-216-AP, PMS-217-AP, and PMS-217-AP2. In addition, PMS-218-AP2 gelled upon
heat treatment. One factor responsible for these effects was presumably the higher heat
treatment temperatures (140-150C); however, there were many other variables that
were changed so it is not possible to draw any definitive conclusions. The initial
molecular weight of the PMS/PCS blend, the molecular weight of the PCS, the amount
of PSZ, and the amount of DCP were all higher for these two PMS-218 samples, i.e.,
compared to the corresponding PMS-216 and PMS-217 samples listed in Table 4.23. All
of these could be factors contributing to the higher molecular weight of the heat-treated
PMS-218-AP samples.
There is some evidence to indicate that using a PCS with higher molecular
weight results in a heat-treated polymer with higher molecular weight. PMS-220-A
solution was prepared from PMS-220 polymer with 14.5 wt% PSZ and 1.5 wt% DCP.
PMS-220-AP was prepared by adding 30 wt% type B PCS to some PMS-220-A solution.
PMS-220-AP2 was prepared by adding 30 wt% type C PCS to some PMS-220-A
solution. Type C PCS has a lower molecular weight than type B PCS. (Despite this, the


75
The polymer solutions were filtered through 0.1 pm filter and concentrated in a
rotary evaporator at ~50C until -25-30 wt% solvent remained. A flow test was
used as a rough indication that an appropriate viscosity for fiber spinning was attained.
The flow test was carried out by tilting the glass vial containing the concentrated
polymer solution at a 45 angle and measuring the time taken for the solution to travel
2.5 cm. (A fixed size of glass vial was used for concentrating the polymer solution and
carrying out the flow test.) Use of the flow test minimized the number of iterations
needed to reach the optimum viscosity for fiber spinning and enabled conservation of
spin dope material (i.e., by not making any rheological measurements until just before
the concentrated polymer solution was ready for fiber spinning). The rheological
characteristics of the final polymer solution were determined by using a cone-plate
viscometer11. Approximately 0.5 ml of the concentrated polymer solution was used for
the measurement. The measurements were made first by increasing the shear rate
from 1 to 40 s'1 and then decreasing the shear rate back to 1 s'1. A toluene-soaked
paper tissue was wrapped around the inside periphery of the cylinder containing the
concentrated polymer solution in order saturate the local atmosphere with toluene and
thereby to minimize evaporation of toluene from the polymer solution during the
measurement. Care was taken to make sure that toluene-soaked paper tissue did not
come in contact with polymer solution or interfere in the measurement in any other way.
Fiber spinning was carried out inside a glove box5 The glove box was purged
with nitrogen three times prior to each spinning experiment. The spin dope was
transferred to a spinneret assembly inside the glove box. Four-hole spinnerets of -70
pm hole sizes were used for fiber spinning. Care was taken to clean the spinnerets
11 Model HBT, Brookfield Engineering Laboratories,Inc., Stoughton, MA.
5 Model 50001, Labconco Corporation, Kansas City, MO.


APPENDIX N
CHEMICAL FORMULAS OF MONOMERS USED IN
WURTZ-COUPLING POLYMERIZATION


EXTENSION (cm) EXTENSION (cm)
363
10 15
TRIAL NUMBER
50
40
30
20
10
0
0 5 10 15 20 25
Experiment #2 (PCS+PSZ spin dope B) Average= 14.26 6.8 cm
TRIAL NUMBER
Figure C-2. Fiber extension distances for PCS+PSZ spin dopes.


137
in surface tension measurement by Wilhemy Plate technique. The first factor does not
appear to be significant. This is suggested by the observation that the surface tension
increased by -0.002-0.004 N/m when the polymer concentration increased from 50 to
66 wt%. The amount of solvent loss during the measurement would be far less than this
concentration change and, hence, solvent loss should have minimal effect on the
surface tension value. On the other hand, any polymer remaining on the platinum blade
during the surface tension measurement would cause the surface tension reading to be
higher than the true value [Wu84], It would be expected that more polymer would remain
on the blade during the measurement when more concentrated (i.e., more viscous)
polymer solutions are used. Hence, this may explain the increase in surface tension with
increasing polymer concentration that was shown in Figure 4.22.
4.1.3 Characterization of fibers
PCS and PCS+PSZ fibers were characterized in the green state and after
various heat treatments (in air at 180 10C and in nitrogen at temperatures in the
range of 200-1150C). Fibers were characterized using diffuse reflectance Fourier
transform infrared spectroscopy (DRIFT) and tensile testing.
4.1.3.1 Characterization of fibers by FTIR
FTIR spectra of PCS-based fibers (green and heat-treated in air at 187C) were
collected at room temperature (25C) and during heat treatment from 40-600C in
nitrogen. Figure 4.24 shows the room temperature FTIR spectra for green PCS
fibers (batch UF-69s)(not containing any additives). The peak assignments for these
fibers are shown in Table 4.4. The room temperature FTIR spectra (transmission mode)
for polydimethylsilane (PDMS), the precursor for PCS, is shown in Figure 4.25. Table
4.5 shows a list of characteristic absorption bands for PDMS. Since PDMS consists of a
Si-Si backbone with attached methyl groups, the major absorption bands in the FTIR


Table H-2. UF64s-1150 (1150C/1 h/N,) (PCS)
Batch 1:
djlym)
dun
djavgj
9.0
9.0
9.0
8.0
9.5
8.8
9.0
9.0
9.0
8.0
10.0
9.0
9.0
9.5
9.3
8.0
9.0
8.5
8.5
9.0
8.8
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
8.0
9.0
8.5
8.0
9.0
8.5
7.0
10.0
8.5
8.0
10.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
9.0
Average
8.53
9.22
8.88
Std. Dev
0.61
0.39
0.23
Batch 2:
di(nm)
dbum)
diava.)
9.00
10.00
9.50
9.50
9.50
9.50
8.50
11.50
10.00
7.00
12.50
9.75
9.50
10.00
9.75
9.50
10.00
9.75
10.00
10.00
10.00
9.50
9.50
9.50
10.00
10.00
10.00
9.50
10.50
10.00
8.50
12.00
10.25
9.50
9.50
9.50
9.50
9.50
9.50
9.50
9.50
9.50
9.50
9.50
9.50
9.50
10.00
9.75
9.50
10.00
9.75
Average
9.26
10.21
9.74
Std. Dev
0.71
0.92
0.24
Load(g)
Strain
TS(GPa)
EMfGPal
21.30
0.0153
3.28
215.07
14.93
0.0125
2.45
196.07
17.17
0.0132
2.65
199.96
18.63
0.0128
2.91
227.22
28.26
0.0171
4.12
241.16
10.22
0.0080
1.77
221.40
9.92
0.0080
1.62
202.40
23.98
0.0164
3.69
225.71
22.23
0.0149
3.42
229.99
27.24
0.0174
4.20
241.41
30.30
0.0191
4.67
244.45
26.85
0.0180
4.14
229.65
12.89
0.0091
1.99
219.29
31.18
0.0201
5.40
269.18
14.06
0.0106
2.44
230.84
2.05
0.0023
0.37
158.10
11.82
0.0095
1.84
193.89
20.62
0.0139
3.18
228.37
18.39
0.0134
2.83
211.52
22.37
0.0159
3.45
216.30
19.09
0.0132
3.01
220.79
8.10
0.0046
1.26
24.50
Load(g)
Strain
TS(GPa)
EMiGPal
10.17
0.0075
1.41
183.82
16.79
0.0137
2.91
212.05
14.07
0.0107
1.80
167.52
10.08
0.0088
1.44
163.28
21.32
0.0169
2.80
175.16
18.92
0.0129
2.49
192.91
19.97
0.0129
2.49
193.45
14.31
0.0106
1.98
186.78
23.19
0.0150
2.89
192.40
21.65
0.0141
2.71
192.20
9.65
0.0072
1.18
163.19
20.21
0.0135
2.80
206.51
17.48
0.0119
2.42
202.58
17.38
0.0114
2.40
211.05
12.24
0.0090
1.69
187.76
16.95
0.0121
2.23
184.71
16.95
0.0118
2.23
184.71
16.55
0.0118
2.23
188.24
4.22
0.0026
0.55
15.01


32
Figure 2.8. GPC of polymethylsilanes synthesized by Mu and Harrod [Mu91A], A: DMT
catalyst B: DMZ catalyst


APPENDIX L CHARACTERISTICS OF PMS POLYMERS SYNTHESIZED
FROM MDCS MONOMER 415
APPENDIX M CHARACTERISTICS OF PMS POLYMERS SYNTHESIZED
FROM MDCS AND MTCS MONOMER MIXTURE 417
APPENDIX N CHEMICAL FORMULAS FOR MONOMERS USED IN
WURTZ-COUPLING POLYMERIZATION 424
REFERENCES 426
VI


Average 13.19 13.67 13.43 38.55 0.02 2.68 164.91
Std. Dev 0.94 1.14 1.02 8.76 0.00 0.57 8.54
N)
CO
ro
£
KJ
CO
CO
K)
K>
-U
8
b
o
b
o
8
8
8
8
8
b
o
8
8
8
8
cn
o
ro
£
N)
ro
fO
ro
£
cn
8
8
cn
o
cn
o
8
8
cn
o
cn
o
b
o
8
cn
o
8
8
8
k
k
t
k
k
_k
k
k
k
ro
CO
ro
-u
-U
K)
CO
CO
ro
ro
A
8
'J
cn
M
cn
k)
cn
k)
cn
8
k)
cn
ro
cn
kj
cn
cn
o
io
cn
8
8
kj
cn
ro
£
CO
ro
cn
CO
fe
p
cn
cn
CO
CO
CO
CO
CO
ro
CJ)
o
cn
o
cn
00
CO
ro
b
o
Lk
CD
b
CD
b
CO
b
b
cn
bo
~o
ro
-fc.
CO
CD
CO
ro
o
CO
CO
CD
CD
o
o
O
o
o
o
o
o
o
o
o
o
o
o
b
b
b
o
b
b
b
b
b
b
b
b
o
o
ro
ro
ro
CD
cn
o
oo
-o
cn
'j
o
'si
00
cn
CO
CO
CD
cn
-fc.
'j
CD
o
cn
O)
'si
o
o
ro
ro
ro
-
CO
CO
ro
ro
CO
CO
ro
CO
ro
b
ro
CD
cn
'I
b
CO
8
b
ro
00
CO
o
kj
ro
oo
CO
b
CD
&
8
cn
OO
2
cn
'i
cn
cn
00
cn
cn
cn
-U
o
o
O)
ro
CD
ro
ro
*
o
cn
cn
ro
cn
&
CD
8
kj
00
cn
CD
3
kj
CO
b
CO
t*
8
k|
ro
8
b
CD
>
pf
o
3-
ro
d^nm) d^ml dfavq.) Load(q) Strain TSiGPal EMfGPal
12.00 12.00 12.00 35.97 0.0193 3.12 161.64
13.00 15.00 14.00 34.03 0.0139 2.18 156.23
14.00 14.50 14.25 49.07 0.0198 3.02 152.20
14.00 14.50 14.25 30.40 0.0118 1.87 158.83
2 >
O ai
(V (O
< CO
0)
oi 'cn cn 'cn cn cn b cn 'o b 'o 'cn 'o o 'o o 'o 'o o
wwoooooooooooooooooo
L* cnbbbb boo b b bobb o cn b o
*-*000000000000000000
- N) ^ ^
3
ro
-*
-*
ro
ro
ro
o
-*
-*
-*
-*
-*
-*

ro
ro
co
b
kl
b
ro
k|
b
kg
8
Kj
kj
'si
b
b
b
8
ro
ro
cn
ro
o
cn
o
cn
cn
o
cn
cn
cn
cn
o
o
o
cn
cn
o
CO
cn
t
CO
CO
CO
CO
cn
'si

ro
CD
CO
CO
ro
CD
CO
CO
ro
CD
ro
CD
6
ro
cn
CO
o
CO
A
CO
CD
o
)
u
CO
b
bo
bo
CO

b
b
CD
CO
ro
b
b
cn
fc.
b
b
Q.
Oi
^1
cn
ro
oo
CD
cn
cn
CD
cn
ro
CO
ro
ro
cn
Q
oooooooooooooooooo
Pbbbbobbbbbbbbbbbbo
NCOO)U10)tDCJ)^(£)faiU100)CnO)(DO)^
CO
CO
CO
CO
CO
CO
CO
CO
CO
ro
CO
ro
CO
ro
ro
co
CO
UJ
co
Lx
b
b
8
b
2
Kj
8
A
8
b
b
o
kj
kj
b
l
cn
t*
oo
CO
CD
CO
cn
00
cn
cn
CD
cn
-* * N)
CD CD -*
cd cn 'si
rc-ocncoocoopco
ro
_k
ro
_k
_k
_k
_k
ro
8
8
~vl
o
cn
00
CD
00
8
cn
00
CD
cn
CO
cn
70
b
_k
b
b
Lk
ro
b
b
b
Lk
ro
00
U
cn
CO
co
cn
CD
ro
CO
CD
Table H-6. UF-68s-1150: (1150C/1 h/N2) (PCS+PSZ)


Intensity (Kubelka-Munk Units)
4000 3600 3200 2800 2400 2000 1600 1200 800 400
Wavenumber (cm1)
Figure 4.44. Comparison of FTIR spectra of PCS+PSZ fibers (70s) before and after heat-treatment at 600C in nitrogen.
179


83
cross-head speed) until failure using a mechanical testing apparatus1. The gage length
was 25 mm and at least eight fibers (but usually 15-20) were tested for each batch. To
calculate tensile strengths, fiber diameters were determined using an optical microscope
equipped with a micrometer in the eyepiece. Two measurements of fiber diameter were
made per fiber, and an average fiber diameter was used for calculation of tensile
strengths.
FTIR spectra of fibers (as-spun and air-heat treated) were collected in the range
600-4000 cm-1 in diffuse reflectance mode11. FTIR spectra were obtained by mixing
ground fibers with diamond powder5 (0.01 g fibers in 0.3 g diamond powder). The fibers
were heat-treated from 30 to 600C in nitrogen at 1C/min and spectra were collected at
intervals of 80C. Background spectra for diamond were also collected separately, at
room temperature and during heat treatment from 30 to 600C at 1C/min in nitrogen.
Fibers were also separately heat-treated at 5C/min to temperatures of 750C, 900C,
and 1050C (1 h hold) in nitrogen. The pyrolyzed fibers were then ground and mixed
with diamond powder (0.01 g fibers in 0.3 g diamond powder) and spectra were
collected in the diffuse reflectance mode at room temperature. All intensities in the
spectra were converted to Kubelka-Munk units using the conversion:
f(R) = (1-R)2/2R (3.4)
where R = reflectance in absolute units
f(R) = reflectance in Kubelka-Munk units
* Model 1122, Instron Corporation, Canton, MA.
11 Nicolet 60SX Spectrometer, Nicolet Instruments Company, Madison, Wl.
5 Size 30 (22-36), Engis Corporation, Wheeling, IL.


3.2.1. Starting materials 84
3.2.2. Procedure for polymerization 84
3.2.3 Determination of polymer yield 89
3.2.4. General procedure for heat treatment of PMS-based polymer
solutions 90
3.2.5. Procedure for fractional precipitation of PMS polymers 91
3.2.6. Characterization of polymers and samples prepared by heat
treatment of the polymers 92
3.3.Spinning and characterization of fibers prepared from PMS-based
polymers 95
3.3.1. Spin dope preparation, fiber spinning, and fiber heat treatment 95
3.3.2. Fiber characterization 98
4. RESULTS AND DISCUSSION 100
4.1. Effect of PSZ as a cross-linking/processing aid for spinning of fibers
from PCS solution 100
4.1.1. Fiber spinning characteristics 100
4.1.2. Polymer solution characteristics 107
4.1.2.1. Molecular weight and intrinsic viscosity measurements 107
4.1.2.2. Studies on rate of evaporation of solvents from PCS
and PCS+PSZ solutions 111
4.1.2.3. Contact angle measurements 114
4.1.2.4. Surface tension measurements 126
4.1.3. Characterization of fibers 137
4.1.3.1. Characterization of fibers by FTIR 137
4.1.3.1.1.FTIR spectra of PCS fibers during heat
treatment in nitrogen 143
4.1 3.1.2. FTIR spectra of PCS fibers heat-treated in air 151
4.1.3.1.3. FTIR spectra of air-heat treated PCS fibers
during heat treatment in nitrogen 155
4.1.3.1.4. FTIR spectra of PSZ during heat treatment
in nitrogen 162
4.1.3.1.5. FTIR spectra of PCS+PSZ fibers during heat
treatment in nitrogen 172
4.1.3.1.6. FTIR spectra of air-heat treated PCS+PSZ
fibers during heat treatment in nitrogen 184
4.1.3.2. Mechanical properties of fibers 195
4.2. Synthesis and characterization of polymethylsilane polymers 216
4.2.1. Effect of synthesis conditions on molecular weight 220
4.2.2. Effect of synthesis conditions on polymer yield 229
4.2.3. Characterization of PMS polymers and ceramic residues resulting
from pyrolysis 225
4.2.3.1. Weight loss behavior 233
4.2.3.2. FTIR spectroscopy studies on PMS polymers 236
4.2.3.3. XRD characteristics 252
4.2.3.4. EMA analysis 256
4.2.4. Sensitivity of PMS polymers to oxygen contamination 260
4.3. Preparation of silicon carbide fibers from polymethylsilane polymers 265
4.3.1. Methods to increase molecular weight of PMS polymers 268
IV


96
solutions through the smallest-sized filter possible in order to eliminate strength-limiting
defects in fiber batches spun from these solutions.
The additives for fiber spinning, PSZ and DB, were filtered separately through
0.1 pm filters and added to the PMS solution. The amount of PSZ added ranged from
0.25 to 14.5 wt% and the amount of DB added ranged from 0.25 to 6 wt%. PSZ is a
highly viscous liquid at room temperature. For use in fiber spin batches, PSZ was
dissolved in toluene at 25 wt% solids loading and filtered through a 0.1 pm filter.
Decaborane (DB) (B10H14) was purchased commercially* DB was dissolved in toluene
at 25 wt% solids loading and filtered through a 0.1 pm filter prior to use in fiber spin
batches. '
The polymer solution containing additives was concentrated in a rotary
evaporator at ~50C until ~15-30 wt% solvent remained. A 'flow test was used as a
rough indication that an appropriate viscosity for fiber spinning was attained (see section
3.1.1). The rheological characteristics of the final polymer solution were determined by
using a cone-plate viscometer11 (described in section 3.1.1).
Fiber spinning was carried out inside a glove box. The glove box was purged
with nitrogen three times prior to each spinning experiment. The spin dope was
transferred to spinneret assembly inside the glove box. Three-hole spinnerets of ~40 pm
or four-hole spinnerets of ~70 pm hole sizes were used for fiber spinning. Care was
taken to clean the spinnerets thoroughly before spinning to ensure that there were no
particulates blocking the spinneret holes. The face of spinneret was wiped clean with a
toluene-soaked paper tissue prior to commencement of spinning. Fibers were formed at
room temperature by extruding the polymer solutions through the spinneret under
* Consumer Health Research, Los Angeles, CA.
11 Model HBT, Brookfield Engineering Laboratories,Inc., Stoughton, MA.


39
Cl Cl
1 1
Cl
1 1
zz Si Cl + Me Si- Si- Me
i 1
Cl Cl
~250C(
= Si-Si-Me + MeSiC^
Cl
Catalyst
Cl Me
Cl
1 1
Si-Cl + Me-Si-Si-Me
~250C,
EE Si- Si- Me + M^SiC^
Catalyst
Cl Cl
Cl
Cl Me
I I
Me
1
EE Si-Cl + Me- Si- Si- Me
| |
~250C (
= Si- Si- Me + MeSiClj
Catalyst
Cl Cl
Cl
(2.7)
(2.8)
(2.9)
Figure 2.9. Scheme for redistribution/substitution reactions of chlorodisilanes.


106
Figure 4.3.
(a)
Schematic illustration of globule formation during spinning of fibers from
PCS spin dope: (a) top view (b) front view of the spinneret assembly.


4.96. GPC molecular weight distribution for PMS-217-AP-H 285
4.97. GPC molecular weight distribution for PMS-217-AP2-H 286
4.98. GPC molecular weight distribution for PMS-218-AP-H 286
4.99. GPC molecular weight distribution for PMS-220-AP2-H 288
4.100. GPC molecular weight distribution for PMS-221-AP2-H 288
4.101. GPC molecular weight distribution for PMS-240 polymer (A) before and
(B) after fractional precipitation with alcohol mixture 293
4.102. Plot of non-solvent to polymer ratio vs. final Mw for polymers precipitated
using acetone as non-solvent 296
4.103. GPC molecular weight distribution for PMS-250 polymer (A) before and
(B) after fractional precipitation with acetone 298
4.104. SEM micrographs of as-spun fibers (batch 24s) prepared from PMS/PCS
blends (non-heat treated) showing necking 303
4.105. SEM micrographs of pyrolyzed fibers (batch 26s) prepared from
PMS/PCS blends (non-heat treated) showing necking 304
4.106 Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-33s spin dope 311
4.107. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-35s spin dope 312
4.108. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-36s spin dope 313
4.109. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-45s spin dope 316
4.110. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-42s spin dope 318
4.111. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-56s spin dope 319
4.112. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-54s spin dope 321
4.113. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
UF-52s spin dope 322
xviii


ABSORBANCE (Kubelka-Munk Units)
242
4000 3500 3000 2500 2000 1500 1000 500
WAVENUMBER (cm1)
Figure 4.78. FTIR spectra of PMS polymer C (100% MDCS; toluene, dioxane
(50:50 vol%)), 40C to 600C at 5C/min in nitrogen.


APPENDIX K
CALCULATIONS FOR EXCESS SILICON AND CARBON IN SIC FIBERS


CHAPTER 1
INTRODUCTION
There has been much interest in the preparation of ceramic materials from
organosilicon-based preceramic polymers. Polycarbosilane (PCS) polymers, in
particular, have been shown to be useful for producing SiC-based ceramic materials,
particularly fibers. Continuous SiC fibers with fine diameter and high strength are of
considerable interest for the development of ceramic-matrix composites for high
temperature applications. Commercially available fibers (e.g., Nicalon, Nippon Carbon
Company, Tokyo, Japan and Tyranno, Ube Industries, Tokyo, Japan) are not pure
stoichiometric SiC, i.e., the fibers contain relatively high concentrations of excess carbon
and oxygen. (In addition, Tyranno fibers are actually Si-Ti-C-0 fibers.) As a
consequence, these fibers degrade extensively at high temperatures. This degradation
is associated with the presence of oxygen (-8-15 wt%) and excess carbon (-15 wt%) in
the fibers. At high temperatures, carbothermal reduction reactions occur between
carbon and siliceous material in the fibers, leading to large weight losses and
degradation in mechanical properties. The fibers contain excess carbon as a result of
the high C:Si ratios in the starting materials. (PCS has a high C:Si ratio, as it is formed
by pressure pyrolysis of polydimethylsilane (PDMS) which has a C:Si ratio of-2. (PDMS
is produced from dimethyldichlorosilane, (CH3)2SiCI2, which, in turn, also has a C:Si
ratio of 2.) The high C:Si ratio in the preceramic polymer, PCS, leads to excess C in the
SiC-based fibers after pyrolysis.) The oxygen in SiC-based fibers, such as Nicalon and
1


4.114. SEM micrographs of pyrolyzed fibers (batch 42s) prepared from
heat-treated PMS/PCS polymer blends showing necking between fibers ... 324
4.115. SEM micrographs of UF-35s fibers after heat treatment at 1700C in argon:
(A) and (B) surfaces, (C) fiber cross section 326
4.116. SEM micrographs of fracture surfaces of UF-35s fibers after heat treatment
at 1700C in argon 328
4.117. GPC molecular weight distribution for PMS-242 polymer: (A) before and
(B) after fractional precipitation 342
4.118. Average extension for fibers drawn from PMS-based polymers as a
function of amount of PSZ 0908A added 344
A-1. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
64s spin dope (PCS) (solids concentration ~67 wt%) 351
A-2. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
65s spin dope (PCS) (solids concentration ~66 wt%) 352
A-3. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
69s spin dope (PCS) (solids concentration ~66 wt%) 353
A-4. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
67s spin dope (PCS+PSZ) (solids concentration ~69 wt%) 354
A-5. Plots of (A) shear stress vs. shear rate and (B) viscosity vs. shear rate for
68s spin dope (PCS+PSZ) (solids concentration ~70 wt%) 355
C-1. Fiber extension distances for PCS spin dope 362
C-2. Fiber extension distances for PCS+PSZ spin dope 363
1-1. GPC molecular weight distributions for PMS-241 (A) before and (B) after
fractional precipitation with alcohols 400
I-2. GPC molecular weight distributions for PMS-243 (A) before and (B) after
fractional precipitation with alcohols 401
J-1. GPC molecular weight distributions for PMS-245 (A) before (B) and (C)
after two fractional precipitations with acetone 403
J-2. GPC molecular weight distributions for PMS-246 (A) before and (B) after
fractional precipitation with acetone 404
J-3. GPC molecular weight distributions for PMS-247 (A) before and (B) after
fractional precipitation with acetone 405
XIX


dwt/d(log M) dwt/d(log M) dwt/d(log M)
221
(A)
(B)
Figure 4.66. (a) Gel permeation chromatograms for polymers prepared from MDCS.
(A)Toluene, (B) Toluene,THF(95:5 vol%), (C) Toluene, Dioxane
(50:50 vol%).


Table 4.30. Tensile strengths of SIC fibers spun from heat-treated PMS polymers and PMS/PCS polymer blends.
Desiqnation
PMS/PCS ratio
(wt%)
Heat treatment
temperature
(C)
Heat treatment
atmosphere
# of fibers tested
Fiber diameter
(Mm)
Tensile strenqth
(GPa)
UF-35s
40:60
1000
n2
11
13.9 1.5
2.22 0.83
UF-35s
40:60
1500
Ar
13
14.2 1.4
2.07 0.45
UF-35S
40:60
1700
Ar
12
14.0 1.0
1.28 0.40
UF-36s
40:60
1000
n2
12
16.1 1.4
1.22 0.31
UF-39S
60:40
1000
n2
17
27.7 6.1
0.84 0.39
UF-42s
70:30
1000
n2
17
18.4 1.7
1.22 0.46
323


433
[Tre85j.
P. Trefonas, III, R. West, and R.D. Miller, Polysilane High Polymers:
Mechanism of Photodegradation, J. Am. Chem. Soc., 107 2732-2742
(1985).
[Wes81],
R. West, L.D. David, P.l. Djurovich, K.L. Stearley, K.S.V. Srinivasan, and H.
Yu, Phenylmethylpolysilanes: Formable Silane Copolymers with Potential
Semiconducting Properties, J. Am. Chem. Soc., 103 7352-7354 (1981).
[Wes86A], R. West, The Polysilane High Polymers, J. Organomet. Chem., 300 327-
346 (1986).
[Wes86B], R. West, X-H. Zhang, P.l. Djurovich, and H. Stuger, Cross-linking of
Polysilanes as Silicon Carbide Precursors, in Science of Ceramic
Processing, pp 337-344, Eds., L.L. Hench and D.R. Ulrich, John Wiley &
Sons, New York (1986).
[Wes88],
R. West and J. Maxka, Polysilane High Polymers: An Overview, in
Inorganic and Organometallic Polymers, pp 6-20, Eds., M. Zeldin, K.J.
Wynne, and H.R. Allcock, American Chemical Society, Washington, DC
(1988).
[Wey69],
D.R. Weyenberg, L.G. Mahone, and W.H. Atwell, Redistribution Reactions in
the Chemistry of Silicon, Ann. N.Y. Acad. Sci., 159 [1] 38-55 (1969).
[W0I88].
A.R. Wolff, I. Nozue, J. Maxka, and R. West, 29SI NMR of Dimethyl and
Phenylmethyl Containing Polysilanes," J. Polym. Sci., Part A: Polym. Chem.,
26 [3] 701-712 (1988).
[Woo84],
T.G. Wood, I. Phosphido-Bridged Diiron Hexacarbonyl Complexes and II:
Polymeric Precursors to Silicon Carbide, Ph.D Dissertation, Massachusetts
Institute of Technology, Cambridge, MA (1984).
[Wor88],
D.J. Worsfold, Polysilylene Preparations, in Inorganic and Organometallic
Polymers, pp 101-111, Eds., M. Zeldin, K.J. Wynne, and H.R. Allcock,
American Chemical Society, Washington, DC (1988).
[Wu82],
S. Wu, Polymer Interface and Adhesion, Marcel Dekker, New York (1982)
[Wyn87],
K.J. Wynne and R.W. Rice, Ceramics via Polymer Pyrolysis, Ann. Rev.
Mater. Sci., 14 297-324 (1987).
[Xu93],
Y. Xu, A. Zangvil, J. Lipowitz, J.A. Rabe, and G.A. Zank, Microstructure and
Microchemistry of Polymer-Derived Crystalline SiC Fibers, J. Am. Ceram.
Soc., 76 [12] 3034-3040 (1993).
[Yaj75],
S. Yajima, J. Hayashi, and M. Omori, Continuous Silicon Carbide Fiber of
High Tensile Strength, Chem. Lett, 931-934 (1975).


BIOGRAPHICAL SKETCH
The author was born in Kerala, India, on May 30th, 1965. He graduated with a
Bachelor of Technology (B.Tech) degree in chemical engineering from Regional
Engineering College, Trichy, India, in 1986. After working for 1 year at Tamil Nadu
Petroproducts Ltd., Madras, India, as a deputy manager, he came to the U.S. in 1987 to
pursue the Master of Science degree in chemical engineering at Tufts University,
Medford, Massachusetts. After completing the M.S degree in the Fall of 1989, he moved
to the University of Florida in Spring 1990 to pursue the Ph.D degree in materials
science and engineering. He is presently employed as a technology development
engineer at Ultra Clean Technology, a semiconductor equipment manufacturing
company, in Menlo Park, California.
435


317
fibers from shear thinning and thixotropic solutions) have been reported previously
[Sac86],
Spin batch UF-42s also exhibited highly shear thinning rheological flow behavior
(Figure 4.110). However, unlike UF-45s, this batch spun well. The UF-42s batch was
prepared with no DB and the PMS polymer used in the batch had been prepared with
14.5 wt% PSZ during heat treatment. In contrast, the UF-45s batch was prepared with 3
wt% DB and the PMS polymer used in the batch had 0.5 wt% PSZ and 3 wt% DB during
heat treatment. The higher solids loading in batch UF-42s suggests that the polymers
develop a less cross-linked structure. However, it is not understood why the solution still
shows such highly shear thinning behavior.
Three spin batches (UF-53s, UF-56s, and UF-57s) were prepared with 90:10
PMS:PCS polymer blends. These spin batches either spun poorly or could not be spun
at all The spin batches had low solids loading and rheological flow behavior was highly
shear thinning (typical rheological flow behavior is shown in Figure 4.111 for UF-56s).
As discussed earlier in the case of the UF-45s spin batch, the poor spinning behavior
may have been caused by highly shear thinning behavior of the spin dopes.
Six spin batches were prepared with 100% heat-treated PMS polymer. Fiber
batches UF-29s and UF-30s spun poorly. The spin dopes used for these batches had
low viscosities (~25 Pa s) and the as-spun fibers stuck together. Fiber batch UF-38s
spun well, but the as-spun fibers also stuck together. Rheological measurements were
not made (due to limited amount of spin dope) for this spin batch but the low flow test
time indicated that the viscosity was probably too low. Spin batches UF-49s, UF-52s,
and UF-54S were prepared using PMS polymers which were heat-treated with 6 wt%
DB. As discussed in section 4.3.1.1, these polymers had a tendency towards gelation.
Hence, it was not surprising that it was difficult to prepare stable spin dopes with these



PAGE 1

35(3$5$7,21 2) 6,&%$6(' ),%(56 )520 25*$126,/,&21 32/<0(56 ,f ())(&76 2) 32/<9,1
PAGE 2

$&.12:/('*0(176 DP JUDWHIXO WR 'U 0' 6DFNV IRU KLV LQYDOXDEOH JXLGDQFH DQG VXSSRUW DP WKDQNIXO WR 'UV &' %DWLFK -+ 6LPPRQV (' :KLWQH\ 5 'UDJR DQG 7DOKDP IRU VHUYLQJ RQ P\ FRPPLWWHH ZRXOG OLNH WR WKDQN 'U 6 %DWHV 'U $ 0RUURQH 5 &URFNHWW : $HUHH DQG ( /DPEHUV IRU WKHLU KHOS LQ XVH RI YDULRXV DQDO\WLFDO LQVWUXPHQWV ZRXOG DOVR OLNH WR WKDQN *: 6FKLHIIHOH -+ 'RZ
PAGE 3

7$%/( 2) &217(176 $&.12:/('*0(176 LL /,67 2) 7$%/(6 YLL /,67 2) ),*85(6 [L $%675$&7 [[L ,1752'8&7,21 /,7(5$785( 5(9,(: %DFNJURXQG 3RO\VLODQH V\QWKHVLV f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f SRO\PHUV LLL

PAGE 4

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

PAGE 5

+HDW WUHDWPHQW RI 306 SRO\PHUV )UDFWLRQDO SUHFLSLWDWLRQ 6SLQQLQJ RI ILEHUV IURP 306EDVHG SRO\PHUV 6SLQQLQJ RI ILEHUV IURP DVSUHSDUHG EOHQGV RI 3063&6 SRO\PHUV 6SLQQLQJ RI KHDWWUHDWHG 306 SRO\PHUV DQG 3063&6 SRO\PHU EOHQGV 6SLQQLQJ RI ILEHUV IURP IUDFWLRQDOO\SUHFLSLWDWHG 306 SRO\PHUV )LEHU H[WHQVLRQ H[SHULPHQWV RQ 306 SRO\PHU VSLQ GRSHV FRQWDLQLQJ 36= 6800$5< $1' &21&/86,216 $33(1',; $ 5+(2/2*,&$/ &+$5$&7(5,=$7,21 2) 3&6 $1' 3&636= 32/<0(5 63,1 '23(6 $33(1',; % ),%(5 63,11,1* &+$5$&7(5,67,&6 )25 3&6 $1' 3&636= 63,1 %$7&+(6 $33(1',; & ),%(5 (;7(16,21 ',67$1&(6 )25 3&6 $1' 3&636= 63,1 '23(6 $33(1',; ,175,16,& 9,6&26,7< &$/&8/$7,216 )25 3&6 3&636= $1' 306 32/<0(56 $33(1',; ( 5(68/76 2) 685)$&( 7(16,21 0($685(0(176 $33(1',; ) 7(03(5$785( $1' :(,*+7 *$,16 )25 +($7 75($70(17 2) 3&6 3&636= ),%(56 ,1 $,5 $33(1',; :(,*+7 /266 '$7$ )25 3&6 3&636= ),%(56 $,5+($7 75($7(' $1' 121$,5 +($7 75($7('f $)7(5 3<52/<6,6 $7 r& ,1 1,752*(1 $33(1',; + 7(16,/( 675(1*7+ '$7$ )25 3<52/<=(' 3&6 $1' 3&636= ),%(56 $33(1',; *3& 02/(&8/$5 :(,*+7 ',675,%87,216 )25 306 32/<0(56 )5$&7,21$//<35(&,3,7$7(' %< $'',7,21 2) $/&2+2/6 $33(1',; *3& 02/(&8/$5 :(,*+7 ',675,%87,216 )25 306 32/<0(56 )5$&7,21$//<35(&,3,7$7(' %< $'',7,21 2) $&(721( $33(1',; &$/&8/$7,216 )25 (;&(66 6,/,&21 $1' &$5%21 ,1 6,& ),%(56 Y

PAGE 6

$33(1',; / &+$5$&7(5,67,&6 2) 306 32/<0(56 6<17+(6,=(' )520 0'&6 02120(5 $33(1',; 0 &+$5$&7(5,67,&6 2) 306 32/<0(56 6<17+(6,=(' )520 0'&6 $1' 07&6 02120(5 0,;785( $33(1',; 1 &+(0,&$/ )2508/$6 )25 02120(56 86(' ,1 :857=&283/,1* 32/<0(5,=$7,21 5()(5(1&(6 9,

PAGE 7

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

PAGE 8

)7,5 SHDN DVVLJQPHQWV IRU SRO\FDUERVLODQH 3&6f ILEHUV )7,5 SHDN DVVLJQPHQWV IRU SRO\GLPHWK\OVLODQH 3'06f SRO\PHU )7,5 SHDN DVVLJQPHQWV IRU 3&6 ILEHUV EDWFK Vf KHDWWUHDWHG LQ DLU DW r& )7,5 SHDN DVVLJQPHQWV IRU SRO\YLQ\OVLOD]DQH 36=f SRO\PHU )7,5 SHDN DVVLJQPHQWV IRU 3&636= ILEHUV EDWFK Vf )7,5 SHDN DVVLJQPHQWV IRU 3&636= ILEHUV EDWFK Vf KHDWWUHDWHG LQ DLU DW r& $YHUDJH WHQVLOH VWUHQJWKV DQG UXSWXUH VWUDLQV IRU 3&6 DQG 3&636= ILEHUV JUHHQ KHDW WUHDWPHQW LQ DLU DW sr& KHDW WUHDWPHQW LQ QLWURJHQ DW r& DQG KHDW WUHDWPHQW LQ DLU DW sr& IROORZHG E\ KHDW WUHDWPHQW LQ QLWURJHQ DW r&f 7HQVLOH SURSHUWLHV RI DVVSXQ DQG DLUKHDW WUHDWHG r&f 3&6 ILEHUV KHDWWUHDWHG WR YDULRXV WHPSHUDWXUHV EHWZHHQ DQG r& LQ QLWURJHQ 7HQVLOH SURSHUWLHV RI DVVSXQ DQG DLUKHDW WUHDWHG r&f 3&636= ILEHUV KHDWWUHDWHG WR YDULRXV WHPSHUDWXUHV EHWZHHQ DQG r& LQ QLWURJHQ 3URSHUWLHV RI 6L& ILEHUV VSXQ IURP 3&6 3URSHUWLHV RI 6L& ILEHUV VSXQ IURP 3&636= 6\QWKHVLV FRQGLWLRQV DQG FKDUDFWHULVWLFV IRU 306 SRO\PHUV )7,5 SHDN DVVLJQPHQWV IRU SRO\PHWK\OVLODQH SRO\PHU 306) EDWFK 306f )7,5 SHDN DVVLJQPHQWV IRU SRO\PHWK\OVLODQH SRO\PHU 306& EDWFK 306f GVSDFLQJV DQG %UDJJ DQJOHV IRU 6L DQG I36L& &U\VWDOOLWH VL]HV IRU 6L DQG 6L& FDOFXODWHG E\ 6FKHPHUfV IRUPXOD IRU YDULRXV SRO\PHUV S\URO\]HG DW r& LQ QLWURJHQ DW r&PLQ ZLWK QR KROG 5HVXOWV RI (OHFWURQ 0LFURSUREH $QDO\VLV (0$f RQ S\URO\]HG FHUDPLF ILEHUV IURP 306 SRO\PHUV &RQGLWLRQV IRU KHDW WUHDWPHQW IRU 306 SRO\PHUV FRQWDLQLQJ 36= '&3 DQG '% YLLL

PAGE 9

1RPHQFODWXUH RI 306 SRO\PHUV XVHG LQ WKH KHDW WUHDWPHQW H[SHULPHQWV &RQGLWLRQV DQG UHVXOWV RI KHDW WUHDWPHQW IRU 3063&6 SRO\PHU EOHQGV 0ROHFXODU ZHLJKW GLVWULEXWLRQV IRU 3&6 SRO\PHUV XVHG LQ WKH KHDW WUHDWPHQW RI 3063&6 EOHQGV &RQGLWLRQV IRU IUDFWLRQDO SUHFLSLWDWLRQ RI 306 SRO\PHUV 5HVXOWV RI (0$ DQDO\VLV RQ IUDFWLRQDOO\ SUHFLSLWDWHG r&S\URO\]HG QLWURJHQf SRO\PHUV &RQGLWLRQV IRU ILEHU VSLQQLQJ H[SHULPHQWV IURP DVSUHSDUHG 3063&6 SRO\PHU EOHQGV QRQKHDW WUHDWHGf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f ( 5HVXOWV RI VXUIDFH WHQVLRQ PHDVXUHPHQWV ) $LUKHDW WUHDWPHQW WHPSHUDWXUHV DQG ZHLJKW JDLQV IRU 3&6 DQG 3&636= ILEHUV ,;

PAGE 10

* :HLJKW ORVV GDWD IRU 3&6 3&636= ILEHUV DLUKHDW WUHDWHG DQG QRQDLU KHDW WUHDWHGf DIWHU S\URO\VLV DW r& LQ QLWURJHQ + 7HQVLOH VWUHQJWK GDWD IRU S\URO\]HG 3&6 ILEHUV EDWFK Vf + 7HQVLOH VWUHQJWK GDWD IRU S\URO\]HG 3&6 ILEHUV EDWFK Vf + 7HQVLOH VWUHQJWK GDWD IRU S\URO\]HG 3&6 ILEHUV EDWFK Vf + 7HQVLOH VWUHQJWK GDWD IRU S\URO\]HG 3&6 ILEHUV EDWFK Vf + 7HQVLOH VWUHQJWK GDWD IRU S\URO\]HG 3&636= ILEHUV EDWFK Vf + 7HQVLOH VWUHQJWK GDWD IRU S\URO\]HG 3&636= ILEHUV EDWFK Vf + 7HQVLOH VWUHQJWK GDWD IRU S\URO\]HG 3&636= ILEHUV EDWFK Vf / 5HVXOWV RI FKDUDFWHUL]DWLRQ RI 306 SRO\PHUV V\QWKHVL]HG IURP 0'&6 0 5HVXOWV RI FKDUDFWHUL]DWLRQ RI 306 SRO\PHUV V\QWKHVL]HG IURP 0'&6 DQG 07&6 ZWbf [

PAGE 11

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r&PLQ WR r& ,5 VSHFWUD RI 936 SRO\PHUDf r& Ef r& Ff r& Gf r& Hf r& ;,

PAGE 12

)7,5 VSHFWUXP RI SRO\PHWK\OVLODQH SRO\PHU SUHSDUHG E\ $EX(LG HW DO 6FKHPH IRU SKRWR FURVVOLQNLQJ UHDFWLRQV RI SRO\VLODQH SRO\PHUV &RPSDULVRQ RI VLQJOH OD\HU SKRWRUHVLVW SURFHVV YV PXOWLOD\HU SKRWRUHVLVW SURFHVV 6WUXFWXUH RI WULPHWK\OWULYLQ\OF\FORWULVLOD]DQH 6FKHPDWLF RI UHDFWLRQ DVVHPEO\ IRU 36= V\QWKHVLV 'HILQLWLRQ RI WHUPV LQ
PAGE 13

$GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU 3&636= ZWbfWROXHQH VROXWLRQ RQ VWDLQOHVV VWHHO VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV RI 3&6 ZWbfWROXHQH VROXWLRQ RQ WHIORQ VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV RI 3&636= ZWbfWROXHQH VROXWLRQ RQ WHIORQ VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU 3&6 ZWbfWROXHQH VROXWLRQ RQ D VWDLQOHVV VWHHO VXEVWUDWH FRDWHG ZLWK 3&6 DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU 3&636= ZWbfWROXHQH VROXWLRQ RQ D VWDLQOHVV VWHHO VXEVWUDWH FRDWHG ZLWK 3&636= DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&6 VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&6 VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&6 VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&636= VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&636= VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&636= VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW 6XUIDFH WHQVLRQ DV D IXQFWLRQ RI FRQFHQWUDWLRQ IRU 3&6 DQG 3&636= VROXWLRQV 6XUIDFH WHQVLRQ DV D IXQFWLRQ RI YLVFRVLW\ IRU 3&6 DQG 3&636= VROXWLRQV 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI JUHHQ 3&6 ILEHUV 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI SRO\GLPHWK\OVLODQH 3'06f )7,5 VSHFWUD RI 3&6 ILEHUV GXULQJ KHDW WUHDWPHQW WR r& DW r&PLQ LQ QLWURJHQ DWPRVSKHUH [LLL

PAGE 14

,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD IRU 3&6 JUHHQf ILEHUV 6XEWUDFWLRQ VSHFWUD IRU 3&6 ILEHUV Vf KHDWWUHDWHG LQ QLWURJHQ r& &RPSDULVRQ RI )7,5 VSHFWUD RI 3&6 ILEHUV EHIRUH DQG DIWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ 5RRP WHPSHUDWXUH )7,5 VSHFWUD IRU 3&6 ILEHUV KHDWWUHDWHG LQ DLU DW r& 6XEWUDFWLRQ VSHFWUD IRU 3&6 ILEHUV KHDWWUHDWHG LQ DLU DW r& Vf DQG 3&6 JUHHQ ILEHUV Vf &RPSDULVRQ RI )7,5 VSHFWUD RI 3&6 ILEHUV DW r& EHIRUH DQG DIWHU KHDW WUHDWPHQW LQ DLU )7,5 VSHFWUD IRU DLUKHDW WUHDWHG r&f 3&6 ILEHUV GXULQJ KHDW WUHDWPHQW WR r& DW r&PLQ LQ QLWURJHQ ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD IRU 3&6 DLUKHDW WUHDWHG DW r&f ILEHUV GXULQJ KHDW WUHDWPHQW LQ QLWURJHQ WR r& )7,5 VSHFWUD RI DLUKHDW WUHDWHG 1LSSRQ 3&6 ILEHUV GXULQJ KHDW WUHDWPHQW LQ QLWURJHQ WR r& IURP ,FKLNDZD HW DOf &RPSDULVRQ RI )7,5 VSHFWUD RI DLUKHDW WUHDWHG r&f 3&6 ILEHUV EHIRUH DQG DIWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ 6XEWUDFWLRQ VSHFWUD IRU DLUKHDW WUHDWHG r&f 3&6 ILEHUV KHDW WUHDWHG LQ QLWURJHQ r&f 5RRP WHPSHUDWXUH )7,5 VSHFWUD IRU 36= SRO\PHU EDWFK $f )7,5 VSHFWUD IRU 36= SRO\PHU GXULQJ KHDW WUHDWPHQW WR r& DW r&PLQ LQ QLWURJHQ ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD RI 36= 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI 3&636= JUHHQ ILEHUV EDWFK Vf )7,5 VSHFWUD RI 3&636= JUHHQ ILEHUV GXULQJ KHDW WUHDWPHQW WR r& LQ QLWURJHQ ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD RI 3&636= ILEHUV &RPSDULVRQ RI )7,5 VSHFWUD RI 3&636= ILEHUV Vf EHIRUH DQG DIWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ ;,9

PAGE 15

6XEWUDFWLRQ VSHFWUD IRU 3&636= ILEHUV Vf r& 6XEWUDFWLRQ VSHFWUD IRU 3&636= DQG 3&6 ILEHUV DW r& 6XEWUDFWLRQ VSHFWUD IRU 3&636= DQG 3&6 ILEHUV DW r& 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI 3&636= ILEHUV KHDWWUHDWHG LQ DLU DW r& )7,5 VSHFWUD RI DLUKHDW WUHDWHG 3&636= ILEHUV GXULQJ KHDW WUHDWPHQW WR r& LQ QLWURJHQ ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD RI DLUKHDW WUHDWHG 3&636= ILEHUV &RPSDULVRQ RI VSHFWUD IRU DLUKHDW WUHDWHG 3&636= ILEHUV EHIRUH DQG DIWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ 6XEWUDFWLRQ VSHFWUD IRU DLUKHDW WUHDWHG 3&636= ILEHUV r& &RPSDULVRQ RI VSHFWUD IRU DLUKHDW WUHDWHG 3&6 ILEHUV EDWFK Vf DQG 3&636= ILEHUV EDWFK Vf DW r& &RPSDULVRQ RI VSHFWUD IRU DLUKHDW WUHDWHG 3&6 ILEHUV EDWFK Vf DQG 3&636= ILEHUV EDWFK Vf DIWHU KHDW WUHDWPHQW LQ QLWURJHQ $YHUDJH WHQVLOH VWUHQJWK IRU 3&6 3&636= ILEHUV DVVSXQ DQG DIWHU KHDW WUHDWPHQW LQ Lf QLWURJHQ DW r& LLf DLU DW sr& LLLf DLU DW sr& IROORZHG E\ QLWURJHQ DW r& $YHUDJH UXSWXUH VWUDLQ IRU 3&6 3&636= ILEHUV DVVSXQ DQG DIWHU KHDW WUHDWPHQW LQ Lf QLWURJHQ DW r& LLf DLU DW sr& LLLf DLU DW sr& IROORZHG E\ QLWURJHQ DW r& 3ORWV RI Df WHQVLOH VWUHQJWK YV KHDW WUHDWPHQW WHPSHUDWXUH Ef b HORQJDWLRQ YV WHPSHUDWXUH IRU SRO\DFU\ORQLWULOH 3$1f ILEHUV 6FKHPDWLF RI VWUXFWXUDO FKDQJHV WDNLQJ SODFH LQ 3&6 GXULQJ KHDW WUHDWPHQW LQ DLU DW sr& $YHUDJH UXSWXUH VWUDLQ YV WHPSHUDWXUH IRU $f 3&6 EDWFK Vf DQG %f 3&636= ILEHUV EDWFK Vf $YHUDJH UXSWXUH VWUDLQ YV WHPSHUDWXUH IRU ILEHUV KHDWWUHDWHG LQ DLU $f 3&6 EDWFK V r& DLU KHDW WUHDWPHQWf DQG %f 3&636= EDWFK V r& DLU KHDW WUHDWPHQWf $YHUDJH WHQVLOH VWUHQJWK YV WHPSHUDWXUH IRU $f 3&6 EDWFK Vf DQG %f 3&636= ILEHUV EDWFK Vf [Y

PAGE 16

'LVWULEXWLRQ RI WHQVLOH VWUHQJWKV IRU ILEHUV DIWHU S\URO\VLV DW r& LQ QLWURJHQ $f 3&6 %f 3&636= 'LVWULEXWLRQ RI GLDPHWHUV IRU ILEHUV DIWHU S\URO\VLV DW r& LQ QLWURJHQ $f 3&6 %f 3&636= $YHUDJH WHQVLOH VWUHQJWK YV WHPSHUDWXUH IRU ILEHUV KHDWWUHDWHG LQ DLU $f 3&6 EDWFK V r& DLU KHDW WUHDWPHQWf DQG %f 3&636= EDWFK V r& DLU KHDW WUHDWPHQWf 6FKHPDWLF IRU :XUW] SRO\PHUL]DWLRQ RI Df 0'&6 Ef 0'&6 DQG 07&6 ZWbf Df *HO SHUPHDWLRQ FKURPDWRJUDPV IRU SRO\PHUV SUHSDUHG IURP 0'&6 $f WROXHQH %f 7ROXHQH7+) YRObf &f 7ROXHQH GLR[DQH YRObf Ef *HO SHUPHDWLRQ FKURPDWRJUDPV IRU SRO\PHUV SUHSDUHG IURP 0'&607&6 ZWbf $f WROXHQH %f 7ROXHQH7+) YRObf &f 7ROXHQH GLR[DQH YRObf (IIHFW RI FRVROYHQWV RQ PROHFXODU ZHLJKW RI 306 SRO\PHUV $% DQG & SUHSDUHG XVLQJ b 0'&6f (IIHFW RI FRVROYHQWV RQ PROHFXODU ZHLJKW RI 306 SRO\PHUV '( DQG ) SUHSDUHG XVLQJ 0'&607&6 ZWbff 3ORW RI [@VSF YV & IRU SRO\PHU ) EDWFK 306f 0'&607&6 ZWbf WROXHQHGLR[DQH ff LQ WROXHQH 3ORW RI U_VSF YV & IRU SRO\PHU ) EDWFK 306f 0'&607&6 ZWbf WROXHQHGLR[DQH ff LQ D PL[WXUH RI WROXHQH DQG GLR[DQH YRObf 6FKHPDWLF LOOXVWUDWLRQ IRU VROYHQW HIIHFWV LQ SRO\PHUL]DWLRQ RI 0'&6 Df LQ WROXHQH Ef LQ D PL[WXUH RI WROXHQH GLR[DQH (IIHFW RI FRVROYHQWV RQ \LHOG IRU 306 SRO\PHUV '( DQG ) SUHSDUHG IURP 0'&607&6 ZWbff (IIHFW RI FRVROYHQWV RQ \LHOG IRU 306 SRO\PHUV $% DQG & SUHSDUHG IURP b 0'&6f 7*$ SORWV b ZHLJKW YV WHPSHUDWXUHf IRU SRO\PHUV SUHSDUHG ZLWK b 0'&6 7*$ SORWV b ZHLJKW YV WHPSHUDWXUHf IRU SRO\PHUV SUHSDUHG ZLWK ZWb 0'&607&6 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI 306 SRO\PHU & EDWFK 306f SUHSDUHG IURP b 0'&6 LQ WROXHQHGLR[DQH VROYHQWf ;9,

PAGE 17

5RRP WHPSHUDWXUH )7,5 VSHFWUD RI 306 SRO\PHU ) EDWFK 306f SUHSDUHG IURP ZWb 0'&607&6 LQ WROXHQHGLR[DQH VROYHQWf )7,5 VSHFWUD RI 306 SRO\PHU & b 0'&6 WROXHQH GLR[DQH YRObff WR r& DW r&PLQ LQ QLWURJHQ ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD IRU 306 SRO\PHU & )7,5 VSHFWUD RI 306 SRO\PHU & WR r& DW r&PLQ LQ QLWURJHQ )7,5 VSHFWUD RI 306 SRO\PHU ) 0'&6 07&6 ZWbff WROXHQH GLR[DQH YRObff WR r& DW r&PLQ LQ QLWURJHQ ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD IRU 306 SRO\PHU ) )7,5 VSHFWUD RI 306 SRO\PHU ) WR r& DW r&PLQ LQ QLWURJHQ ;5' SDWWHUQV IRU 306 SRO\PHUV SUHSDUHG IURP PRQRPHU 0'&6 $f b WROXHQH %f WROXHQH7+) 9RObf DQG &f WROXHQHGLR[DQH YRObf ;5' SDWWHUQV IRU 306 SRO\PHUV SUHSDUHG IURP PRQRPHUV 0'&607&6 ZWbf $f b WROXHQH %f WROXHQH7+) 9RObf DQG &f WROXHQHGLR[DQH YRObf )7,5 VSHFWUD RI 306 SRO\PHU & b 0'&6 WROXHQHGLR[DQH YRObff H[SRVHG WR DLU VKRZQ DV D IXQFWLRQ RI WLPH ,QWHQVLW\ YV WLPH RI H[SRVXUH WR DLU IURP )7,5 VSHFWUD IRU 306 SRO\PHU & *HO SHUPHDWLRQ FKURPDWRJUDPV IRU 306 SRO\PHU $f DIWHU GD\V RI VWRUDJH %f DIWHU GD\V RI VWRUDJH DQG &f DIWHU KHDW WUHDWPHQW 306+f 3RO\GLVSHUVLW\ LQGH[ YV PROHFXODU ZHLJKW IRU 306 SRO\PHUV FRQWDLQLQJ ZWb 36= DQG ZWb '&3f DV DGGLWLYHV *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU $f 306$ %f 306$+ *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU $f 306$ %f 306$), *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$+ *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU $f 306$ %f 306$+ *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU $f 306$'$ %f 306$'+ *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+ [YLL

PAGE 18

*3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+ *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+ *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+ *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+ *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+ *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DOFRKRO PL[WXUH 3ORW RI QRQVROYHQW WR SRO\PHU UDWLR YV ILQDO 0Z IRU SRO\PHUV SUHFLSLWDWHG XVLQJ DFHWRQH DV QRQVROYHQW *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH 6(0 PLFURJUDSKV RI DVVSXQ ILEHUV EDWFK Vf SUHSDUHG IURP 3063&6 EOHQGV QRQKHDW WUHDWHGf VKRZLQJ QHFNLQJ 6(0 PLFURJUDSKV RI S\URO\]HG ILEHUV EDWFK Vf SUHSDUHG IURP 3063&6 EOHQGV QRQKHDW WUHDWHGf VKRZLQJ QHFNLQJ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH [YLLL

PAGE 19

6(0 PLFURJUDSKV RI S\URO\]HG ILEHUV EDWFK Vf SUHSDUHG IURP KHDWWUHDWHG 3063&6 SRO\PHU EOHQGV VKRZLQJ QHFNLQJ EHWZHHQ ILEHUV 6(0 PLFURJUDSKV RI 8)V ILEHUV DIWHU KHDW WUHDWPHQW DW r& LQ DUJRQ $f DQG %f VXUIDFHV &f ILEHU FURVV VHFWLRQ 6(0 PLFURJUDSKV RI IUDFWXUH VXUIDFHV RI 8)V ILEHUV DIWHU KHDW WUHDWPHQW DW r& LQ DUJRQ *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ $YHUDJH H[WHQVLRQ IRU ILEHUV GUDZQ IURP 306EDVHG SRO\PHUV DV D IXQFWLRQ RI DPRXQW RI 36= $ DGGHG $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU V VSLQ GRSH 3&6f VROLGV FRQFHQWUDWLRQ a ZWbf $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU V VSLQ GRSH 3&6f VROLGV FRQFHQWUDWLRQ a ZWbf $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU V VSLQ GRSH 3&6f VROLGV FRQFHQWUDWLRQ a ZWbf $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU V VSLQ GRSH 3&636=f VROLGV FRQFHQWUDWLRQ a ZWbf $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU V VSLQ GRSH 3&636=f VROLGV FRQFHQWUDWLRQ a ZWbf & )LEHU H[WHQVLRQ GLVWDQFHV IRU 3&6 VSLQ GRSH & )LEHU H[WHQVLRQ GLVWDQFHV IRU 3&636= VSLQ GRSH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DOFRKROV *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DOFRKROV *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH %f DQG &f DIWHU WZR IUDFWLRQDO SUHFLSLWDWLRQV ZLWK DFHWRQH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH ;,;

PAGE 20

*3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH [[

PAGE 21

$EVWUDFW RI 'LVVHUWDWLRQ 3UHVHQWHG WR WKH *UDGXDWH 6FKRRO RI WKH 8QLYHUVLW\ RI )ORULGD LQ 3DUWLDO )XOILOOPHQW RI WKH 5HTXLUHPHQWV IRU WKH 'HJUHH RI 'RFWRU RI 3KLORVRSK\ 35(3$5$7,21 2) 6,&%$6(' ),%(56 )520 25*$126,/,&21 32/<0(56 ,f ())(&76 2) 32/<9,1
PAGE 22

3&636= VROXWLRQV GHSRVLWHG RQ VWDLQOHVV VWHHO DQG WHIORQ VXEVWUDWHV DV ZHOO DV RQ 3&6FRDWHG DQG 3&636=FRDWHG VWDLQOHVV VWHHO VXEVWUDWHV 7KH UDWH RI HYDSRUDWLRQ RI VROYHQW ZDV KLJKHU IRU 3&6 VROXWLRQ WKDQ IRU 3&636= VROXWLRQ DW LGHQWLFDO SRO\PHU FRQFHQWUDWLRQV $VVSXQ 3&6 DQG 3&636= ILEHUV GHYHORSHG VLPLODU WHQVLOH VWUHQJWKV DQG UXSWXUH VWUDLQV $IWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ 3&636= ILEHUV VKRZHG KLJKHU WHQVLOH VWUHQJWK DQG UXSWXUH VWUDLQ FRPSDUHG WR 3&6 ILEHUV %DVHG RQ )7,5 VSHFWUD RI 3&6 DQG 3&636= ILEHUV GXULQJ KHDW WUHDWPHQW IURP r& LW LV VXJJHVWHG WKDW 36= DFWV DV D FURVVOLQNLQJ DLG IRU 3&6 3&636= ILEHUV GHYHORSHG KLJKHU WHQVLOH VWUHQJWKV WKDQ 3&6 ILEHUV DW DOO KHDW WUHDWPHQW WHPSHUDWXUHV EHWZHHQ r& 6L& ILEHUV ZHUH IDEULFDWHG IURP SRO\PHWK\OVLODQH 306f DQG 3063&6 SRO\PHU EOHQGV 306 SRO\PHUV ZHUH V\QWKHVL]HG E\ D :XUW]FRXSOLQJ SRO\PHUL]DWLRQ RI PHWK\OGLFKORURVLODQH 0'&6f DQG PHWK\OWULFKORURVLODQH 07&6f LQ ZWb SURSRUWLRQ ZLWK VRGLXP LQ UHIOX[LQJ WROXHQH 7KH DGGLWLRQ RI SRODU VROYHQWV LH 7+) DQG GLR[DQHf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

PAGE 23

&+$37(5 ,1752'8&7,21 7KHUH KDV EHHQ PXFK LQWHUHVW LQ WKH SUHSDUDWLRQ RI FHUDPLF PDWHULDOV IURP RUJDQRVLOLFRQEDVHG SUHFHUDPLF SRO\PHUV 3RO\FDUERVLODQH 3&6f SRO\PHUV LQ SDUWLFXODU KDYH EHHQ VKRZQ WR EH XVHIXO IRU SURGXFLQJ 6L&EDVHG FHUDPLF PDWHULDOV SDUWLFXODUO\ ILEHUV &RQWLQXRXV 6L& ILEHUV ZLWK ILQH GLDPHWHU DQG KLJK VWUHQJWK DUH RI FRQVLGHUDEOH LQWHUHVW IRU WKH GHYHORSPHQW RI FHUDPLFPDWUL[ FRPSRVLWHV IRU KLJK WHPSHUDWXUH DSSOLFDWLRQV &RPPHUFLDOO\ DYDLODEOH ILEHUV HJ 1LFDORQr1 1LSSRQ &DUERQ &RPSDQ\ 7RN\R -DSDQ DQG 7\UDQQRr1 8EH ,QGXVWULHV 7RN\R -DSDQf DUH QRW SXUH VWRLFKLRPHWULF 6L& LH WKH ILEHUV FRQWDLQ UHODWLYHO\ KLJK FRQFHQWUDWLRQV RI H[FHVV FDUERQ DQG R[\JHQ ,Q DGGLWLRQ 7\UDQQRr1 ILEHUV DUH DFWXDOO\ 6L7L& ILEHUVf $V D FRQVHTXHQFH WKHVH ILEHUV GHJUDGH H[WHQVLYHO\ DW KLJK WHPSHUDWXUHV 7KLV GHJUDGDWLRQ LV DVVRFLDWHG ZLWK WKH SUHVHQFH RI R[\JHQ ZWbf DQG H[FHVV FDUERQ ZWbf LQ WKH ILEHUV $W KLJK WHPSHUDWXUHV FDUERWKHUPDO UHGXFWLRQ UHDFWLRQV RFFXU EHWZHHQ FDUERQ DQG VLOLFHRXV PDWHULDO LQ WKH ILEHUV OHDGLQJ WR ODUJH ZHLJKW ORVVHV DQG GHJUDGDWLRQ LQ PHFKDQLFDO SURSHUWLHV 7KH ILEHUV FRQWDLQ H[FHVV FDUERQ DV D UHVXOW RI WKH KLJK &6L UDWLRV LQ WKH VWDUWLQJ PDWHULDOV 3&6 KDV D KLJK &6L UDWLR DV LW LV IRUPHG E\ SUHVVXUH S\URO\VLV RI SRO\GLPHWK\OVLODQH 3'06f ZKLFK KDV D &6L UDWLR RI 3'06 LV SURGXFHG IURP GLPHWK\OGLFKORURVLODQH &+f6L&, ZKLFK LQ WXUQ DOVR KDV D &6L UDWLR RI f 7KH KLJK &6L UDWLR LQ WKH SUHFHUDPLF SRO\PHU 3&6 OHDGV WR H[FHVV & LQ WKH 6L&EDVHG ILEHUV DIWHU S\URO\VLVf 7KH R[\JHQ LQ 6L&EDVHG ILEHUV VXFK DV 1LFDORQr1 DQG

PAGE 24

7\UDQQRr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r1 DQG +L1LFDORQr1 7\SH 6 ILEHUV >7DN 7DN@ 'RZ &RUQLQJ &R 6\OUDPLFr1 ILEHUVf >/LS@ DQG WKH 8QLYHUVLW\ RI )ORULGD 8) DQG 8)+0 ILEHUVf >7RU 6DF$ 6DF%@ $OO RI WKHVH ILEHUV VKRZ LPSURYHG WKHUPRFKHPLFDO VWDELOLW\ DQG WKHUPRPHFKDQLFDO SURSHUWLHV FRPSDUHG WR ILEHUV ZKLFK FRQWDLQ ODUJH DPRXQWV RI R[\JHQ VXFK DV 1LFDORQr1 DQG 7\UDQQRr1 ILEHUV 7KH DSSURDFK GHYHORSHG DW WKH 8QLYHUVLW\ RI )ORULGD LV EDVHG RQ XVLQJ D KLJK PROHFXODUZHLJKW 3&6 SRO\PHU ZKLFK LV LQIXVLEOH +HQFH DQ R[LGDWLYH FXULQJ VWHS LV XQQHFHVVDU\ GXULQJ S\URO\VLV ,Q SURGXFLQJ 6L&EDVHG ILEHUV IURP WKH KLJKPROHFXODU ZHLJKW 3&6 SRO\PHUV 7RUHNL HW DO >7RU@ UHSRUWHG WKDW WKH DGGLWLRQ RI D SRO\YLQ\OVLOD]DQH 36=f SRO\PHU WR D 3&6EDVHG VSLQQLQJ VROXWLRQ LQ DPRXQWV XS WR ZWbf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

PAGE 25

XS WR r& )RXULHU WUDQVIRUP LQIUDUHG VSHFWURVFRS\ )7,5f ZDV XVHG WR VWXG\ WKH FKHPLFDO FKDQJHV RFFXUULQJ LQ WKHVH ILEHUV GXULQJ S\URO\VLV ,Q DQ HIIRUW WR XQGHUVWDQG WKH HIIHFW RI 36= RQ VSLQQDELOLW\ RI 3&6 VROXWLRQV SRO\PHU VROXWLRQV ZHUH FKDUDFWHUL]HG XVLQJ VHYHUDO PHWKRGV LQFOXGLQJ PHDVXUHPHQWV RI VXUIDFH WHQVLRQ FRQWDFW DQJOHV UKHRORJLFDO FKDUDFWHULVWLFV HJ LQWULQVLF YLVFRVLW\f DQG WKH UDWH RI HYDSRUDWLRQ RI VROYHQW IURP WKH VROXWLRQV 7KH VHFRQG PDMRU DUHD RI LQYHVWLJDWLRQ ZDV WKH V\QWKHVLV DQG SURFHVVLQJ RI 306 SRO\PHWK\OVLODQHf SRO\PHUV IRU WKH IDEULFDWLRQ RI 6L&EDVHG ILEHUV 7KHUH KDV EHHQ OLPLWHG ZRUN RQ WKH SUHSDUDWLRQ RI 6L& ILEHUV IURP RUJDQRVLOLFRQ SRO\PHU EOHQGV 6L& ILEHUV PD\ EH IDEULFDWHG E\ XVLQJ 306 SRO\PHUV DQG 3063&6 SRO\PHU EOHQGV 306 SRO\PHUV JHQHUDOO\ SURGXFH DQ H[FHVV RI HOHPHQWDO 6L LQ DGGLWLRQ WR 6L&f XSRQ S\URO\VLV $V LQGLFDWHG HDUOLHU 3&6 SRO\PHUV IRUP DQ H[FHVV RI HOHPHQWDO & XSRQ S\URO\VLV 7KHUHIRUH D FRPELQDWLRQ RI WKHVH WZR SRO\PHUV PLJKW SRWHQWLDOO\ EH XVHG WR IRUP 6L& ILEHUV ZLWK FRQWUROOHG VWRLFKLRPHWU\ 306 SRO\PHUV ZHUH V\QWKHVL]HG LQ WKLV VWXG\ E\ :XUW]FRXSOLQJ SRO\PHUL]DWLRQ RI PHWK\OGLFKORURVLODQHV 0'&6f DQG PHWK\OWULFKORURVLODQHV 07&6f ZLWK VRGLXP 1Df LQ UHIOX[LQJ VROYHQWVROYHQW PL[WXUHV 2QH RI WKH PDMRU GLVDGYDQWDJH RI WKLV PHWKRG LV SRRU SRO\PHU \LHOGV 3RO\PHU \LHOGV DQG PROHFXODU ZHLJKW GLVWULEXWLRQV DUH TXLWH VHQVLWLYH WR VXEVWLWXHQWV SHQGDQW JURXSVf LQ WKH PRQRPHUV RUGHU RI UHDJHQW DGGLWLRQ VROYHQW DGGLWLYHV UHDFWLRQ WHPSHUDWXUHV HWF ,W KDV EHHQ UHSRUWHG WKDW DGGLWLRQ RI SRODU VROYHQWV SURPRWH DQLRQLF SRO\PHUL]DWLRQ VXFK DV :XUW]FRXSOLQJ SRO\PHUL]DWLRQf DQG LQFUHDVH SRO\PHU \LHOGV >01 *DX@ ,Q WKLV VWXG\ HIIHFWV RI DGGLWLRQ RI SRODU VROYHQWV 7+) DQG 'LR[DQH RQ SRO\PHU \LHOG DQG PROHFXODU ZHLJKW ZHUH LQYHVWLJDWHG 2QH RI WKH PDLQ GUDZEDFNV RI 306 SRO\PHUV IRU XVH LQ ILEHU IDEULFDWLRQ LV WKDW WKH\ DUH OLTXLGV DW URRP WHPSHUDWXUH DQG JHQHUDOO\ KDYH ORZ PROHFXODU ZHLJKW 0Q

PAGE 26

DQG 0Z f ,Q RUGHU WR IRUP ILEHUV IURP WKHVH SRO\PHUV DQ LQFUHDVHG PROHFXODU ZHLJKW DQG DQ LQFUHDVHG H[WHQW RI FURVVOLQNLQJ DUH QHHGHG VR WKDW WKH SRO\PHUV DUH VROLGV DW URRP WHPSHUDWXUH DQG UHPDLQ VROLGV GXULQJ S\URO\VLVf ,QYHVWLJDWLRQV ZHUH FDUULHG RXW WR LQFUHDVH WKH PROHFXODU ZHLJKWFURVVOLQNLQJ RI WKHVH SRO\PHUV DV ZHOO DV SURGXFH D VROLG SRO\PHU ZLWK VXIILFLHQWO\ KLJK PROHFXODU ZHLJKW WR SHUPLW ILEHU VSLQQLQJ 7ZR DSSURDFKHV ZHUH XWLOL]HG WR UDLVH WKH PROHFXODU ZHLJKWFURVVn OLQNLQJ RI WKH SRO\PHU f SRO\PHUL]DWLRQ DQG FURVVOLQNLQJ E\ KHDW WUHDWPHQW ZLWK DGGLWLYHV DQG f IUDFWLRQDO SUHFLSLWDWLRQ RI KLJKHU PROHFXODU ZHLJKW IUDFWLRQV E\ DGGLWLRQ RI QRQVROYHQWV 7KH DGGLWLYHV XVHG FRQVLVWHG RI SRO\YLQ\OVLOD]DQH 36=f GLFXP\O SHUR[LGH '&3f DQG GHFDERUDQH '%f 7KH QRQVROYHQWV XVHG ZHUH D PL[WXUH RI PHWKDQRO DQG SURSDQRO DQG DFHWRQH )LEHUV ZHUH VSXQ IURP KHDWWUHDWHG 306 3063&6 SRO\PHU EOHQGV DQG IUDFWLRQDOO\SUHFLSLWDWHG 306 SRO\PHUV DQG FRQYHUWHG WR 6L& ILEHUV E\ S\URO\VLV DW r& LQ D QLWURJHQ DWPRVSKHUH

PAGE 27

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f QDWXUH RI WKH FHUDPLF PDWHULDO FKHPLFDO FRPSRVLWLRQ DQG FU\VWDO VWUXFWXUHf SURGXFHG DIWHU IXUWKHU SURFHVVLQJ HJ KHDW WUHDWPHQWf f HOHPHQWDO FRPSRVLWLRQ RI WKH VWDUWLQJ SRO\PHU ZKLFK LQIOXHQFHV WKH ILQDO VWRLFKLRPHWU\ RI WKH FHUDPLF SURGXFHGf f PROHFXODU DUFKLWHFWXUH RI WKH SRO\PHU OLQHDU YV FURVVOLQNHG SRO\PHU ZKLFK VWURQJO\ LQIOXHQFHV WKH FHUDPLF \LHOGf f VHQVLWLYLW\ WR DLU LH R[\JHQ DQG ZDWHU YDSRUf RI WKH SRO\PHU f VWDUWLQJ PROHFXODU ZHLJKW f FDSDFLW\ RI WKH

PAGE 28

SRO\PHU WR EH FURVVOLQNHG DW VRPH VWDJH LQ SURFHVVLQJ DQG f VROXELOLW\ LQ FRPPRQ RUJDQLF VROYHQWV $V LQGLFDWHG LQ f DERYH S\URO\VLV FRQGLWLRQV WHPSHUDWXUH DWPRVSKHUH DQG KHDWLQJ UDWHf SOD\ D YHU\ LPSRUWDQW UROH LQ GHWHUPLQLQJ WKH FKDUDFWHULVWLFV \LHOG HOHPHQWDO FRPSRVLWLRQ DQG FU\VWDO VWUXFWXUHf RI WKH FHUDPLF SURGXFHG 7KH FHUDPLF \LHOG LH ZHLJKW SHUFHQWDJH UHWDLQHG DIWHU SRO\PHUWRFHUDPLF FRQYHUVLRQf LV DQ LPSRUWDQW FRQVLGHUDWLRQ ZKHQ GLVFXVVLQJ WKH VXLWDELOLW\ RI D SRO\VLODQH SRO\PHU DV D SUHFXUVRU IRU VLOLFRQ FDUELGH $V LQGLFDWHG LQ f DERYH PROHFXODU DUFKLWHFWXUH DOVR KDV JUHDW LPSDFW RQ WKH FHUDPLF \LHOG RI WKH SRO\PHU V\QWKHVL]HG &URVVOLQNHG RU EUDQFKHG SRO\PHUV JLYH PXFK KLJKHU FHUDPLF \LHOG WKDQ WKHLU OLQHDU FRXQWHUSDUWV +RZHYHU H[FHVVLYH FURVVOLQNLQJ LV JHQHUDOO\ QRW GHVLUDEOH DV LW ZRXOG PDNH WKH SURFHVVLQJ RI WKH SRO\PHU GLIILFXOW LH WKH SRO\PHU ZLOO EH OHVV OLNHO\ WR PHOW RU WR EH VROXEOH LQ FRPPRQ VROYHQWVf ,W LV VRPHWLPHV GHVLUDEOH WKDW WKH ILQDO FRPSRVLWLRQ RI WKH FHUDPLF SURGXFHG EH WKDW RI QHDUVWRLFKLRPHWULF VLOLFRQ FDUELGH $ FRQYHQLHQW PHWKRG RI DFKLHYLQJ WKLV LV WR VWDUW ZLWK D SRO\PHU ZKLFK KDV D 6L& UDWLR VXFK DV SRO\PHWK\OVLODQHV 7KLV FDQ EH FRQWUDVWHG WR SRO\SKHQ\OVLODQHV IRU H[DPSOH ZKLFK KDYH 6L& UDWLRV RI DQG WKHUHIRUH UHVXOW LQ 6L&& PL[WXUHV XSRQ S\URO\VLV 3RO\VLODQH SRO\PHUV ZHUH ILUVW V\QWKHVL]HG E\ .LSSLQJ >.LS@ LQ WKH HDUO\ fV E\ FRQGHQVDWLRQ UHDFWLRQ RI GLSKHQ\OGLFKORURVLODQH ZLWK VRGLXP 7KLV SRO\PHU ZDV QRW XVHIXO LQ SUDFWLFDO DSSOLFDWLRQV VLQFH LW ZDV LQWUDFWDEOH LH QRW SURFHVVDEOH LQWR XVHIXO DUWLFOHV EHFDXVH RI SRRU VROXELOLW\ DQG LQIXVLELOLW\f 6XEVHTXHQWO\ LQ %XUNKDUG >%XU@ UHDFWHG GLPHWK\OGLFKORURVLODQH ZLWK VRGLXP WR SURGXFH SRO\GLPHWK\OVLODQHf ZKLFK DOVR ZDV LQVROXEOH LQ FRPPRQ RUJDQLF VROYHQWV DQG LQIXVLEOH ,Q
PAGE 29

WUHDWHG WR IRUP 6L&EDVHG FHUDPLF ILEHUV 7KH FRQYHUVLRQ SURFHVV RI SRO\GLPHWK\OVLODQH WR SRO\FDUERVLODQH WDNHV SODFH E\ .XPDGD UHDUUDQJHPHQW UHDFWLRQV DQG LV GHVFULEHG LQ GHWDLO HOVHZKHUH >6KL@ 3RO\VLODQH 6\QWKHVLV 7KH SURPLQHQW PHWKRGV RI V\QWKHVLV RI SRO\VLODQHV DUH Lf :XUW]FRXSOLQJ GHKDORFRXSOLQJf UHDFWLRQV RI FKORURVLODQHV ZLWK DONDOL PHWDOV LLf 'HK\GURFRXSOLQJ RI SULPDU\ RUJDQRVLODQHV LQ WKH SUHVHQFH RI D FDWDO\VW LLLf 5HGLVWULEXWLRQVXEVWLWXWLRQ UHDFWLRQV RI FKORURVLODQHV :XUW]FRXSOLQJ RI GLFKORURVLODQHV ZLWK DONDOL PHWDO 0HFKDQLVP :XUW]FRXSOLQJ RI GLFKORURVLODQHV ZLWK DQ DONDOL PHWDO LV D VWURQJO\ H[RWKHUPLF DQG KHWHURJHQHRXV UHDFWLRQ 7KH UHDFWLRQ FDQ EH UHSUHVHQWHG DV IROORZV 5 5 6L&, 1D 6ROYHQWn5HQX[ 5 5 6LfQ 1D&, f ZKHUH 5 5 FDQ EH + &+ &+ &+ HWF 7KH GHWDLOHG UHDFWLRQ FKHPLVWU\ LV VKRZQ LQ )LJXUH >%HQ@ $OWKRXJK PDQ\ SRO\PHUV DUH SURGXFHG E\ WKLV URXWH LW VXIIHUV IURP WKH GLVDGYDQWDJHV RI SRRU UHSURGXFLELOLW\ SRO\PRGDO PROHFXODU ZHLJKW GLVWULEXWLRQV DQG ORZ SRO\PHU \LHOGV 3RRU UHSURGXFLELOLW\ DULVHV EHFDXVH LW LV GLIILFXOW WR FRQWURO WKH H[RWKHUPLF DQG KHWHURJHQHRXV UHDFWLRQ LH WKH UHDFWLRQ LV KHWHURJHQHRXV LQ WKDW LW LQYROYHV OLTXLG DQG VROLG UHDJHQWV >=HL$@f ,Q DGGLWLRQ VRPH UHDFWLRQ YDULDEOHV VXFK DV WKH SXULW\ RI WKH FKORURVLODQHV DQG WKH VWDWH RI GLVSHUVLRQ RI VRGLXP DUH GLIILFXOW WR FRQWURO >0DU@

PAGE 30

,QLWLDWLRQ 5 5 &O6L&O 5 1D &Of§6L 1D 5 1D&, 3URSDJDWLRQ 5 5 6L1D &O6U &O 5 5 B 5 5 , 6L6L&O 1D&, , 5 5 5DWH GHWHUPLQLQJf 5 5 , 6L6L&O 1D , 5 5 5 5 , 6U 6L 1D 1D&, 5 )DVWf f f f )LJXUH 5HDFWLRQ VFKHPH IRU :XUW]FRXSOLQJ SRO\PHUL]DWLRQ UHDFWLRQ

PAGE 31

3RO\PHU \LHOGV DQG PROHFXODU ZHLJKW GLVWULEXWLRQV DUH TXLWH VHQVLWLYH WR VXEVWLWXHQWV SHQGDQW JURXSVf LQ WKH PRQRPHUV RUGHU RI UHDJHQW DGGLWLRQ VROYHQW FRPSRVLWLRQ UHDFWLRQ WHPSHUDWXUHV HWF 7KH UHDFWLRQ LV XVXDOO\ FDUULHG RXW DW HOHYDWHG WHPSHUDWXUHV ar&f XVLQJ D VXLWDEOH DONDOL PHWDO GLVSHUVLRQ 6RGLXP SRWDVVLXP RU OLWKLXP FRXOG EH FKRVHQ DV DONDOL PHWDOV EXW VRGLXP LV XVXDOO\ SUHIHUUHG EHFDXVH SRWDVVLXP DQG OLWKLXP DUH UHODWLYHO\ PRUH IODPPDEOH DQG KD]DUGRXV ,Q WKH :XUW]FRXSOLQJ UHDFWLRQ VRGLXP LV QRUPDOO\ HPSOR\HG DV D GLVSHUVLRQ LQ DQ DSSURSULDWH VROYHQW VXFK DV WROXHQH [\OHQH 7+) HWF $V GLVFXVVHG LQ VHFWLRQ WKH FKRLFH RI VROYHQWV SOD\V DQ LPSRUWDQW UROH LQ GHWHUPLQLQJ WKH SRO\PHU PROHFXODU ZHLJKW GLVWULEXWLRQ DQG SRO\PHU \LHOGV (TXDWLRQ f LV LQGLFDWLYH RI WKH IDFW WKH SRO\PHUL]DWLRQ UHDFWLRQ SURFHHGV E\ FRQGHQVDWLRQ W\SH PHFKDQLVP +RZHYHU :RUVIROG >:RU@ DQG 0LOOHU HW DO >0,@ UHSRUWHG EDVHG RQ WKH FKDUDFWHULVWLFV RI WKH SRO\PHUV SURGXFHG GXULQJ WKH UHDFWLRQ WKDW LW SURFHHGV E\ DQ DGGLWLRQ W\SH PHFKDQLVP ,Q DQ DGGLWLRQ W\SH SRO\PHUL]DWLRQ UHDFWLRQ KLJK PROHFXODU ZHLJKW SRO\PHU IUDFWLRQV IRUP YHU\ HDUO\ LQ WKH UHDFWLRQ DQG WKH IRUPDWLRQ RI KLJK PROHFXODU ZHLJKW SRO\PHU LV QRW DIIHFWHG E\ WKH VWRLFKLRPHWU\ RI WKH UHDJHQWV LH KLJK PROHFXODU ZHLJKW SRO\PHU IRUPV HYHQ ZKHQ RQH RI WKH UHDJHQWV LV LQ H[FHVVf :RUVIROG GHPRQVWUDWHG WKHVH FKDUDFWHULVWLFV IRU :XUW]FRXSOLQJ SRO\PHUL]DWLRQ RI KH[\OPHWK\OGLFKORURVLODQH FDUULHG RXW LQ WKH fQRUPDO PRGHf VHH VHFWLRQ f LQ ZKLFK PRQRPHUV DUH DGGHG WR PROWHQ VRGLXPf E\ LVRODWLQJ KLJK PROHFXODU ZHLJKW SRO\PHU af LQ WKH HDUO\ VWDJHV RI UHDFWLRQ 7KH UDWH GHWHUPLQLQJ VWHS LQ :XUW] FRXSOLQJ SRO\PHUL]DWLRQ LV WKH UHDFWLRQ EHWZHHQ VLO\O UDGLFDO DQG PRQRPHU DV VKRZQ E\ HTXDWLRQ f LQ )LJXUH 7KH UHDFWLRQ EHWZHHQ FKORULQHHQGHG FKDLQ DQG VRGLXP WDNHV SODFH UDSLGO\ HTXDWLRQ f LQ )LJXUH f :H\HQEHUJ >:H\@ HW DO KDYH

PAGE 32

GHPRQVWUDWHG E\ JDV FKURPDWRJUDSK\ WKDW PROHFXOHV FRQWDLQLQJ VHTXHQFHV RI 6L DWRPV UHDFW IDVWHU WKDQ PROHFXOHV FRQWDLQLQJ VLQJOH DWRPV 0RGH RI DGGLWLRQ RI UHDJHQWV $W WKH EHJLQQLQJ RI WKH UHDFWLRQ PROWHQ VRGLXP PHOWLQJ SRLQW RI VRGLXP r&f FDQ EH DGGHG WR GLFKORURVLODQHV GLVVROYHG LQ D VXLWDEOH VROYHQW DW WKH UHIOX[ WHPSHUDWXUH RI WKH VROYHQW fLQYHUVHf PRGH RI DGGLWLRQf RU GLFKORURVLODQHV GLVVROYHG LQ D VPDOO DPRXQW RI VROYHQW FRXOG EH DGGHG WR WKH PROWHQ VRGLXP GLVSHUVHG LQ WKH LQHUW VROYHQW nQRUPDOn PRGH RI DGGLWLRQf 7KH LQYHUVH PRGH RI DGGLWLRQ XVXDOO\ OHDGV WR KLJKHU PROHFXODU ZHLJKW SRO\PHUV ZLWK ORZHU SRO\PHU \LHOGV FRPSDUHG WR WKH QRUPDO PRGH RI DGGLWLRQ 7KH IRUPHU PHWKRG LV DOVR PRUH KD]DUGRXV LH GXH WR KDQGOLQJ RI VRGLXPf DQG GLIILFXOW WR FRQWURO =HLJOHU >=HL$ =HL@ LQYHVWLJDWHG WKH HIIHFW RI UDWH RI PRQRPHU DGGLWLRQ LQ WKH QRUPDO PRGHf DQG VRGLXP DGGLWLRQ LQ WKH LQYHUVH PRGHf RQ WKH SRO\PRGDOLW\ RI WKH PROHFXODU ZHLJKW GLVWULEXWLRQ LQ WKH V\QWKHVLV RI SRO\PHWK\OSKHQ\OVLODQH =HLJOHU FRQFOXGHG WKDW WKH UDWH RI UHDJHQW DGGLWLRQ PRQRPHU RU VRGLXPf DQG WKH PRGH RI DGGLWLRQ KDG DQ LPSRUWDQW UROH LQ GHWHUPLQLQJ WKH PROHFXODU ZHLJKW GLVWULEXWLRQ EHFDXVH RI LWV LQIOXHQFH LQ FRQWUROOLQJ WKH UDWH RI GLIIXVLRQ RI UHDFWLYH VSHFLHV WR DQG IURP WKH VRGLXP VXUIDFH :KHQ WKH UDWHV RI DGGLWLRQ RI 1D RU PRQRPHU ZHUH NHSW FRQVWDQW IRU D UDQJH RI DGGLWLRQ UDWHV PHTPLQ LH PROHV HTXLYDOHQW SHU PLQff WKH PROHFXODU ZHLJKW GLVWULEXWLRQV ZHUH QHDUO\ PRQRPRGDO DQG WKH DYHUDJH PROHFXODU ZHLJKWV UHPDLQHG DSSUR[LPDWHO\ FRQVWDQW DW IRU LQYHUVH PRGH RI DGGLWLRQ DQG IRU QRUPDO PRGH RI DGGLWLRQ +RZHYHU ZKHQ WKH DGGLWLRQ UDWH ZDV YDULHG WKHUH ZDV D WHQGHQF\ WR IRUP D ELPRGDO PROHFXODU ZHLJKW GLVWULEXWLRQ )LJXUH VKRZV WKH HIIHFW RI WKH UDWH RI 1D DGGLWLRQ LQYHUVH PRGHf RQ WKH 3K0H6LfQ PROHFXODU ZHLJKW GLVWULEXWLRQ

PAGE 33

)LJXUH (IIHFW RI UHDFWDQW DGGLWLRQ UDWH RQ 3K0H6LfQ PROHFXODU ZHLJKW GLVWULEXWLRQ >=HL@

PAGE 34

=HLJOHU HW DO GLG QRW SURYLGH SORWV RI WKH PROHFXODU ZHLJKW GLVWULEXWLRQV REWDLQHG E\ XVLQJ GLIIHUHQW PRQRPHU DGGLWLRQ UDWHV QRUPDO PRGHff (IIHFW RI DONDOL PHWDO $V LQGLFDWHG HDUOLHU VRGLXP SRWDVVLXP RU OLWKLXP FRXOG EH FKRVHQ DV WKH DONDOL PHWDO IRU WKH SRO\PHUL]DWLRQ UHDFWLRQ %DVHG RQ HDVH RI KDQGOLQJ IRU H[DPSOH VRGLXP LV DYDLODEOH DV PP SHOOHWV ZKHUH DV SRWDVVLXP DQG OLWKLXP DUH DYDLODEOH DV EORFNV RI PDWHULDOV DQG QHHG WR EH FXW LQWR VPDOOHU VL]HV IRU DFFXUDWHO\ ZHLJKLQJf DQG IODPPDELOLW\ FRQVLGHUDWLRQV VRGLXP LV QRUPDOO\ SUHIHUUHG RYHU WKH RWKHU WZR $OWHUQDWLYHO\ DOOR\V RI VRGLXP DQG SRWDVVLXP RI YDU\LQJ FRPSRVLWLRQ FRXOG EH XVHG EXW WKHVH DOOR\V RIWHQ FDXVH GHJUDGDWLRQ RI SRO\PHU PROHFXODU ZHLJKW DQG IRUP F\FOLF ROLJRPHUV DW HOHYDWHG WHPSHUDWXUHV ar&f 1D. DOOR\ SURPRWHV K\GURJHQ DEVWUDFWLRQ IURP VROYHQW DQG FDXVHV FKDLQ WUDQVIHUf >01@ 7KH SRO\PHUL]DWLRQ UHDFWLRQV WDNH SODFH YHU\ FORVH WR WKH DONDOL PHWDO VXUIDFH DQG KHQFH WKH VXUIDFH DUHD RI WKH DONDOL PHWDO SOD\V D YHU\ LPSRUWDQW UROH LQ GHWHUPLQLQJ WKH PROHFXODU ZHLJKW GLVWULEXWLRQ RI WKH SRO\PHU IRUPHG :RUVIROG >:RU@ VWXGLHG WKH HIIHFW RI VRGLXP VXUIDFH DUHD RQ WKH PROHFXODU ZHLJKW RI SRO\PHUV IRUPHG GXULQJ WKH SRO\PHUL]DWLRQ RI KH[\O\PHWK\OGLFKORURVLODQH DQG IRXQG WKDW UDWH RI FRQVXPSWLRQ RI PRQRPHUV LQFUHDVHG DV WKH VRGLXP VXUIDFH DUHD LQFUHDVHG )LJXUH f 7KH PRQRPHU FRQVXPSWLRQ ZDV PRQLWRUHG E\ UHPRYLQJ VPDOO DPRXQWV RI WKH UHDFWLRQ FRQWHQWV SHULRGLFDOO\ GXULQJ WKH FRXUVH RI UHDFWLRQ DQG DQDO\]LQJ WKH VDPSOHV E\ JDV FKURPDWRJUDSK\ *&ff 7KHUHIRUH WR REWDLQ JRRG SRO\PHU \LHOG LQ D UHDVRQDEOH WLPH LW LV LPSRUWDQW WR XVH D ILQH GLVSHUVLRQ RI VRGLXP LQ WKH UHDFWLRQ VROYHQW 7KH SORWV LQ )LJXUH VKRZ D VLJPRLGDO EHKDYLRU 7KH LQFXEDWLRQ SHULRG LV LQWHUSUHWHG DV WKH WLPH GXULQJ ZKLFK LQLWLDWLRQ RFFXUV LH DFFRUGLQJ WR HTXDWLRQ f LQ

PAGE 35

7LPH PLQ )LJXUH (IIHFW RI VRGLXP VXUIDFH DUHD RQ WKH UDWH RI FRQVXPSWLRQ RI KH[\OPHWK\OGLFKORURVLODQH >:RU@ $ P Â’ P R P SHU PROH RI GLFKORURVLODQH

PAGE 36

)LJXUH ,W PLJKW EH H[SHFWHG EDVHG RQ HTXDWLRQ f WKDW WKH UDWH RI LQLWLDWLRQ ZRXOG EH GHSHQGHQW XSRQ WKH DYDLODEOH VRGLXP VXUIDFH DUHD 7KH UHVXOWV LQ )LJXUH DUH FRQVLVWHQW ZLWK WKLV LQWHUSUHWDWLRQ LQ WKDW WKH LQFXEDWLRQ SHULRG GHFUHDVHV ZLWK LQFUHDVLQJ VRGLXP VXUIDFH DUHD 7KH :XUW] SRO\PHUL]DWLRQ UHDFWLRQ LV VWURQJO\ H[RWKHUPLF DQG WKH LQLWLDOO\ FOHDU UHDFWLRQ PL[WXUH FKDQJHV WR SXUSOH RU GDUN EOXH FRORU TXLFNO\ 0LOOHU HW DO >01@ DWWULEXWHG WKLV EOXH FRORU WR fGHIHFWVf LQ VRGLXP FKORULGH LH FRORU FHQWHUV SURGXFHG E\ LQFRUSRUDWLRQ RI VRGLXP LRQV LQ WKH LQWHUVWLWLDOV RI SUHFLSLWDWLQJ VRGLXP FKORULGH %HQILHOG HW DO >%HQ@ VXJJHVWHG EDVHG RQ VSHFWURVFRSLF VWXGLHV WKDW WKH EOXH FRORU LV GXH WR FROORLGDO 1D SDUWLFOHV VXEPLFURQf IRUPHG GXULQJ WKH UHDFWLRQ 7KH\ FROOHFWHG GLIIXVH UHIOHFWDQFH XOWUDYLROHWYLVLEOH 89 9LVf VSHFWUD RI WKH SURGXFWV IRUPHG GXULQJ WKH UHDFWLRQ DQG IRXQG WKDW WKHUH ZHUH WZR DEVRUSWLRQ EDQGV IRU SRO\VLODQHV D VKDUSHU EDQG EHORZ QP DQG D EURDGHU EDQG FHQWHUHG DURXQG QP )LJXUH f &RPSDULQJ WKLV VSHFWUD ZLWK SXEOLVKHG UHVXOWV RI VRGLXP FROORLGV DQG GHIHFW FHQWHUV RI VRGLXP FKORULGH WKH DXWKRUV FRQFOXGHG WKDW WKH DEVRUSWLRQV LQ WKH 899LV VSHFWUD ZHUH GXH WR FROORLGDO VRGLXP IRUPHG GXULQJ WKH UHDFWLRQ 6ROYHQW HIIHFWV 7KH LQIOXHQFH RI W\SHV RI VROYHQWV RQ :XUW]FRXSOLQJ UHDFWLRQV RI GLFKORURVLODQHV ZLWK VRGLXP ZDV ILUVW QRWHG E\ 0LOOHU HW DO>0LO@ LQ WKH SUHSDUDWLRQ RI SRO\F\FORKH[\OPHWK\OVLODQH QRUPDO PRGHf 7KH\ UHSRUWHG WKDW ZKHQ GLJO\PH GLHWK\OHQHJO\FRO GLPHWK\OHWKHU VHH )LJXUH f ZDV DGGHG WR WKH UHDFWLRQ PL[WXUH RI VRGLXP DQG PRQRPHUV RYHUDOO SRO\PHU \LHOG DQG PROHFXODU ZHLJKW GLVWULEXWLRQ DUH DIIHFWHG VHH 7DEOH f :KHQ GLJO\PH ZDV DGGHG LQ ORZ FRQFHQWUDWLRQV a YRObf LQ WKH SRO\PHUL]DWLRQ RI F\FORKH[\OPHWK\OVLODQH WKHUH ZDV D VLJQLILFDQW LQFUHDVH LQ SRO\PHU

PAGE 37

)LJXUH 899LV 'LIIXVH 5HIOHFWDQFH VSHFWUXP RI SXUSOH VROLG LVRODWHG GXULQJ :XUW] SRO\PHUL]DWLRQ >%HQ@

PAGE 38

&URZQ (WKHU &+fLR 3HQWDR[DF\FORSHQWDGHFDQHf 'LR[DQH 7HWUDK\GURIXUDQ 7+)f &+2&+&+f 'LHWK\OHQHJO\FRO GLPHWK\OHWKHU 'LJO\PHf )LJXUH &KHPLFDO IRUPXODV RI SRODU VROYHQWV XVHG LQ :XUW]FRXSOLQJ SRO\PHUL]DWLRQ

PAGE 39

7DEOH (IIHFW RI GLJO\PH DQG KHSWDQH DGGLWLRQV RQ SRO\PHUL]DWLRQ RI VRPH GLFKORURVLODQH PRQRPHUV >0LO@ 3RO\PHU WROXHQHGLJO\PH YRObf
PAGE 40

\LHOG DQG DYHUDJH PROHFXODU ZHLJKW $W KLJKHU FRQFHQWUDWLRQ RI GLJO\PH YRObf SRO\PHU PROHFXODU ZHLJKW GLVWULEXWLRQ EHFDPH PRQRPRGDO DQG RYHUDOO PROHFXODU ZHLJKW RI WKH SRO\PHU GHFUHDVHG GUDVWLFDOO\ 7KH SRO\PHU \LHOG UHPDLQHG UHODWLYHO\ KLJK bf 7KH HIIHFW RQ SRO\PHU \LHOG RI GLJO\PH DGGLWLRQV ZDV SDUWLFXODUO\ VLJQLILFDQW LQ WKH FDVH RI SRO\VLODQH SRO\PHUV GHULYHG IURP V\PPHWULF GLDON\OVLODQH PRQRPHUV HJ GLFKRORUR GLQKH[\OVLODQH GLFKORURGLQGRGHF\OVLODQHf VHH 7DEOH f ,Q WKH FDVH RI SRO\GLQ KH[\OVLODQHf D W\SLFDO GLDON\OGLFKORURVLODQH GHULYHG SRO\PHU WKH \LHOG RI WKH SRO\PHU ZDV RQO\ b ZKHQ V\QWKHVL]HG LQ WROXHQH DORQH DV D VROYHQW 7KH SRO\PHU \LHOG LQFUHDVHG DSSUR[LPDWHO\ VL[ IROG bf ZKHQ GLJO\PH ZDV DGGHG LQ DPRXQWV RI DQG b E\ YROXPH RI WROXHQH 7KH DGGLWLRQ RI GLJO\PH DOVR UHVXOWHG LQ ORZHU DYHUDJH PROHFXODU ZHLJKW RI WKH SRO\PHU ,Q WKH FDVH RI GLFKORURGLQGRGHF\OVLODQH WKH DGGLWLRQ RI b GLJO\PH UHVXOWHG LQ ODUJH LQFUHDVH LQ WKH SRO\PHU \LHOG IURP WR bf ZKLOH WKH DYHUDJH PROHFXODU ZHLJKW LQFUHDVHG VOLJKWO\ IRU HDFK PRGH LQ WKH GLVWULEXWLRQ $OVR WKH KLJK PROHFXODU ZHLJKW SURSRUWLRQ RI WKH SRO\PHU GHFUHDVHG VLJQLILFDQWO\ 7DEOH DOVR VKRZV WKH HIIHFW RI DGGLWLRQ RI D QRQSRODU VROYHQW LH KHSWDQHf RQ SRO\PHUL]DWLRQ RI GLDN\OGLFKORURVLODQH PRQRPHUV GLFKRORURGLQKH[\OVLODQHf DQG DU\ODN\OGLFKORURVLODQH PRQRPHUV SKHQ\OPHWK\OGLFKORURVLODQHf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

PAGE 41

QRW ZHOO XQGHUVWRRG EHFDXVH RI WKH GLIILFXOW\ LQ REWDLQLQJ FRQWUROOHG NLQHWLF GDWD GXH WR WKH UDSLG SRO\PHUL]DWLRQ UDWHVf 0LOOHU HW DO DWWHPSWHG WR H[SODLQ WKH REVHUYDWLRQ RI LQFUHDVHG SRO\PHU \LHOG IRU GLDON\OGLFKORURVLODQHV LQ WKH SUHVHQFH RI SRODU FRVROYHQWV VXFK DV GLJO\PH FURZQ HWKHUV HWF E\ VXJJHVWLQJ WKH SUHVHQFH RI VLO\O DQLRQ UDGLFDO LQWHUPHGLDWHV VXFK DV VKRZQ LQ HTXDWLRQ f LQ )LJXUH f DV WKH PDLQ SURSDJDWLQJ VSHFLHV LQ WKH SRO\PHUL]DWLRQ ,W LV ZHOO NQRZQ WKDW SRODU VROYHQWV DLG LQ WKH WUDQVIHU RI HOHFWURQV IURP PHWDO WR PRQRPHU SURPRWLQJ IRUPDWLRQ RI VLO\O DQLRQ UDGLFDOV >*DX 0, %1@ $ ODUJH QXPEHU RI UDGLFDOV IRUPHG ZRXOG PHDQ D ODUJH QXPEHU RI LQLWLDWLRQ VLWHV DQG WKLV ZRXOG IDYRU DQ LQFUHDVHG SRO\PHU \LHOG +RZHYHU 0LOOHU HW DO >0,@ UHSRUWHG WKH VDPH EHQHILFLDO HIIHFW LH LPSURYHG \LHOGf ZKHQ YROb RI QRQSRODU VROYHQW LH KHSWDQHf ZDV DGGHG WR WROXHQH LQ WKH SRO\PHUL]DWLRQ RI GLDON\OGLFKORURVLODQH VXFK DV GLFKORURGLQ KH[\OVLODQHf =HLJOHU HW DO >=HL@ KDYH GHYHORSHG D PRGHO FRQFHUQLQJ WKH EXON VROYHQW HIIHFWV LQ WKH SRO\PHUL]DWLRQ RI GLDON\OGLFKORURVLODQHV ZKHQ PRQRPHU LV SUHVHQW LQ H[FHVV FRPSDUHG WR VRGLXP LQYHUVH PRGH RI DGGLWLRQf $FFRUGLQJ WR WKHLU PRGHO \LHOG DQG PROHFXODU ZHLJKW DUH GHWHUPLQHG E\ HIIHFWLYH PRQRPHU FRQFHQWUDWLRQ DW WKH VRGLXP VXUIDFH 7KLV GHSHQGV RQ WKH UDWH RI GLIIXVLRQ RI PRQRPHU WR WKH VRGLXP VXUIDFH ZKLFK LQ WXUQ GHSHQGV RQ GHJUHH RI FRYHUDJH RI WKH VRGLXP E\ JURZLQJ SRO\PHU FKDLQV VHH )LJXUH f ,Q D fJRRGf VROYHQW LH LQ ZKLFK WKH GLIIHUHQFH LQ SRO\PHU DQG VROYHQW VROXELOLW\ SDUDPHWHUV $6 36 DSSURDFKHV ]HURf SRO\PHUVROYHQW FRQWDFWV DUH KLJKO\ IDYRUHG DQG WKH SRO\PHU FRLOV DUH UHODWLYHO\ H[WHQGHG LQ WKH VROYHQW 7KXV SRO\PHUV WHQG WR UHPDLQ LQ WKH VROYHQW SKDVH DQG WHQG QRW WR DGVRUE RQ WKH VRGLXP SDUWLFOH VXUIDFHV 7KH PRQRPHU FRQWLQXHV WR KDYH HDV\ DFFHVV WR VRGLXP VXUIDFH DQG

PAGE 42

)LJXUH 6FKHPDWLF LOOXVWUDWLRQ RI WKH LQIOXHQFH RI VROYHQW RQ WKH SRO\PHUVRGLXP SDUWLFOH LQWHUDFWLRQ GXULQJ :XUW] SRO\PHUL]DWLRQ >=HL@

PAGE 43

QHZ LQLWLDWLRQ UHDFWLRQV FDQ RFFXU UHDGLO\ 7KLV WHQGV WR UHVXOW LQ KLJK SRO\PHU \LHOG EHFDXVH PRQRPHU LV fFRQVXPHGf UHDGLO\f DQG ORZ DYHUDJH PROHFXODU ZHLJKW %HFDXVH WKHUH DUH D ODUJH QXPEHU RI FKDLQV WKH DPRXQW RI FKDLQ H[WHQVLRQ LV OLPLWHG VLQFH WKH VXSSO\ RI PRQRPHU LV IL[HGf ,Q D SRRU VROYHQW RQ WKH RWKHU KDQG SRO\PHU FRLOV DUH FRQWUDFWHG DQG WKHUH LV D PXFK JUHDWHU WHQGHQF\ IRU WKH SRO\PHU FKDLQV WR DEVRUE RQ WKH VRGLXP SDUWLFOH VXUIDFHV 6LQFH WKH GLUHFW SDWK RI PRQRPHU WR WKH VRGLXP VXUIDFH WKURXJK WKH VROYHQWVf LV LPSHGHG QRZ WKH PRQRPHU LV IRUFHG WR GLIIXVH WKURXJK SRO\PHU FKDLQV 7KLV WHQGV WR SURPRWH SURSDJDWLRQ UHDFWLRQV DW WKH UHDFWLYH FKDLQ HQGVf LH FDXVHV IRUPDWLRQ RI ORQJHU FKDLQ SRO\PHUVf DQG OHDGV WR ORZHU SRO\PHU \LHOG DQG KLJKHU RYHUDOO SRO\PHU PROHFXODU ZHLJKW ,Q WKH H[WUHPH FDVH ZKHQ WKH VROYHQW LV nWRR SRRUf WKH SRO\PHU ZRXOG WHQG WR SUHFLSLWDWH RXW RI VROXWLRQ ZKLFK LV QRW GHVLUDEOH 7KXV =HLJOHU HW DO PRGHO VXJJHVWV WKDW WKHUH LV DQ RSWLPXP $ IRU D JLYHQ SRO\VLODQH SRO\PHUVROYHQW V\VWHP ZKLFK ZRXOG GLFWDWH WKH \LHOG DQG RYHUDOO PROHFXODU ZHLJKW RI WKH SRO\PHU *DXWKLHU DQG :RUVIROG >*DX@ LQYHVWLJDWHG WKH LQIOXHQFH RI FRVROYHQW FURZQ HWKHU fSKDVHWUDQVIHU FDWDO\VWff RQ WKH :XUW]FRXSOLQJ SRO\PHUL]DWLRQ RI Q KH[\OPHWK\OGLFKORURVLODQH )LJXUH VKRZV VWUXFWXUH RI FURZQ HWKHUf 7KH SULPDU\ VROYHQW XVHG ZDV WROXHQH DQG WKH DPRXQW RI FURZQ HWKHU XVHG ZDV LQ WKH UDQJH RI PROb RI KH[\OPHWK\OGLFKORURVLODQHf 7KH\ DOVR IRXQG WKDW LQ WKH SUHVHQFH RI WKH FRVROYHQW WKH SRO\PHU \LHOG EHFRPHV KLJK WKH RYHUDOO PROHFXODU ZHLJKW RI WKH SRO\PHU GHFUHDVHV DQG WKH PROHFXODU ZHLJKW GLVWULEXWLRQ FKDQJHV IURP ELPRGDO WR PRQRPRGDO )LJXUH VKRZV WKH DPRXQW RI PRQRPHU FRQVXPHG DV D IXQFWLRQ RI WLPH LQ WKH VWXG\ E\ *DXWKLHU DQG :RUVIROG 7KH\ VXJJHVWHG WKDW VLO\O DQLRQLF LQWHUPHGLDWHV VKRZQ

PAGE 44

)LJXUH 5DWH RI GLVDSSHDUDQFH RI PRQRPHU QKH[\OPHWK\OGLFKORURVLODQH DV D IXQFWLRQ RI WLPH DQG ZHLJKW SHUFHQW RI FURZQ HWKHU >*DX@

PAGE 45

E\ HTXDWLRQ f LQ )LJXUH f DUH LQYROYHG LQ WKH SRO\PHUL]DWLRQ RI Q KH[\OPHWK\OGLFKORURVLODQH DQG FODLPHG WKDW FURZQ HWKHU DFFHOHUDWHG WKH RFFXUUHQFH RI LQLWLDWLRQ UHDFWLRQV $OWKRXJK GDWD LV OLPLWHG LW LV HYLGHQW WKDW WKH UDWH RI PRQRPHU FRQVXPSWLRQ LV LQFUHDVHG ZLWK VPDOO DGGLWLRQV RI FURZQ HWKHU 7HPSHUDWXUH HIIHFWV 0LOOHU HW DO >0,@ LQYHVWLJDWHG WKH HIIHFW RI WHPSHUDWXUH RQ WKH PROHFXODU ZHLJKW GLVWULEXWLRQ DQG \LHOG IRU SRO\PHUV SURGXFHG IURP GLDU\O DQG GLDON\O VXEVWLWXWHG FKORURVLODQHV 7KH\ IRXQG LQ WKH FDVH RI SRO\PHUL]DWLRQ RI PHWK\OSKHQ\OGLFKORURVLODQH LQ WROXHQH WKDW ORZHULQJ WKH UHDFWLRQ WHPSHUDWXUH WR r& IURP WKH UHIOX[LQJ WHPSHUDWXUH RI r&f GHFUHDVHG WKH WRWDO \LHOG IURP b WR b ZKLOH FDXVLQJ DQ LQFUHDVH LQ PROHFXODU ZHLJKW RI WKH SRO\PHU ,Q DGGLWLRQ WKH PROHFXODU ZHLJKW GLVWULEXWLRQ FKDQJHG IURP ELPRGDO WR PRQRPRGDO 7DEOH f +RZHYHU LQ WKH SUHVHQFH RI D SRODU VROYHQW LH b GLJO\PHf ORZHULQJ WKH UHDFWLRQ WHPSHUDWXUH WR r& LQVWHDG RI WKH UHIOX[ WHPSHUDWXUHf UHVXOWHG LQ WKH RSSRVLWH WUHQGV IURP ZKDW LV QRWHG DERYH LH WKH SRO\PHU \LHOG LQFUHDVHG VOLJKWO\ DQG WKH SRO\PHU PROHFXODU ZHLJKW GHFUHDVHG 7KH ODWWHU FKDQJHV PD\ KDYH EHHQ ZLWKLQ WKH OLPLWV RI H[SHULPHQWDO HUURUf :KHQ SRO\PHUL]DWLRQ ZDV FDUULHG RXW LQ D EOHQG RI WROXHQHb KHSWDQH ORZHULQJ WKH UHDFWLRQ WHPSHUDWXUH WR r& KDG QR HIIHFW RQ SRO\PHU \LHOG RU RYHUDOO SRO\PHU PROHFXODU ZHLJKW 0LOOHU HW DO DOVR UHSRUWHG WKDW ORZ WHPSHUDWXUH r&f SRO\PHUL]DWLRQ RI DON\O VXEVWLWXWHG FKORURVLODQHV VXFK DV GLFKORURGLQKH[\OVLODQHf WRRN SODFH VOXJJLVKO\ 7KH W\SLFDO FKDQJH LQ FRORU WR SXUSOH RU GDUN EOXH ZDV FRQVSLFXRXVO\ DEVHQW ,Q DGGLWLRQ WKH \LHOG IRU VXFK D SRO\PHUL]DWLRQ ZDV OHVV WKDQ D SHUFHQW LH HVVHQWLDOO\ QR SRO\PHUL]DWLRQ RFFXUUHGf -RQHV HW DO >-RQ@ LQYHVWLJDWHG SRO\PHUL]DWLRQ RI PHWK\OSKHQ\OVLODQH LQ 7+) DW ORZ WHPSHUDWXUHV r&f XVLQJ D VRGLXPHOHFWURQ DFFHSWRU FRPSOH[ 7KH HOHFWURQ

PAGE 46

7DEOH (IIHFW RI WHPSHUDWXUH RQ SRO\PHUL]DWLRQ RI PHWK\OSKHQ\OGLFKORURVLODQH >0LO@ 3K0H6L&, 1D 3K0H6LfQf 6ROYHQW 7HPSHUDWXUHr& $GGLWLYH
PAGE 47

DFFHSWRUV XVHG LQ WKH SRO\PHUL]DWLRQ ZHUH QDSKWKDOHQH DQWKUDFHQH DQG WHWUDSKHQ\O HWKHQH DQG ZHUH XVHG LQ VWRLFKLRPHWULF H[FHVV WR GLVSHUVH VRGLXP 7KH GLVDGYDQWDJHV RI W\SLFDO :XUW]W\SH SRO\PHUL]DWLRQ HJ ORZ SRO\PHU \LHOGV SRRU UHSURGXFLELOLW\f SHUVLVWHG EXW SRO\GLVSHUVLWLHV RI WKH SRO\PHU SURGXFHG ZHUH PXFK ORZHU f WKDQ WKDW RI W\SLFDO :XUW]W\SH SRO\PHUL]DWLRQ f 8OWUDVRQLFDOO\DFWLYDWHG :XUW]FRXSOLQT UHDFWLRQV 0DW\MDV]HZVNL HW DO >0DW 0DW .LP@ SLRQHHUHG WKH XVH RI XOWUDVRQLF HQHUJ\ LQ WKH :XUW]FRXSOLQJ V\QWKHVLV RI SRO\VLODQHV GHULYHG IURP DU\OVXEVWLWXWHG PRQRPHUVf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f UHVXOWV LQ GHJUDGDWLRQ RI KLJKPROHFXODUZHLJKW FRPSRQHQWV DV VKRZQ LQ 7DEOH 7KLV UHVXOWV LQ SRO\PHUV ZLWK ORZHU DYHUDJH PROHFXODU ZHLJKW DQG ORZHU SRO\GLVSHUVLW\f

PAGE 48

7DEOH (IIHFW RI VRQLFDWLRQ WLPH RQ PROHFXODU ZHLJKWV DQG SRO\GLVSHUVLWLHV RI SRO\PHWK\OSKHQ\OVLODQH >.LP@ 0ROHFXODU :HLJKW 6RQLFDWLRQ WLPH PLQf 'XULQT DGGLWLRQ RI PRQRPHUV 6RQLFDWLRQ WLPH PLQf $IWHU DGGLWLRQ RI PRQRPHUV 0Q n 0Z n 0-0Q 0DW\MDV]HZVNL HW DO DOVR REVHUYHG WKDW XOWUDVRQLF SRO\PHUL]DWLRQ RI GLDON\O VXEVWLWXWHG FKORURVLODQHV RFFXU VOXJJLVKO\ ZKHQ FRPSDUHG ZLWK WKDW RI GLDU\OVXEVWLWXWHG GLFKORURVLODQHV DQG WKDW FRVROYHQW DGGLWLRQV HJ GLJO\PHf DQG KLJKHU WHPSHUDWXUHV ZHUH UHTXLUHG WR REWDLQ DQ\ PHDQLQJIXO \LHOG RI SRO\PHU ,Q JHQHUDO SRO\PHU \LHOGV IRU XOWUDVRQLF V\QWKHVLV RI SRO\VLODQHV DUH ORZ ZKHQ FRPSDUHG WR WKRVH RI FODVVLF :XUW] FRXSOLQJ UHDFWLRQV SHUIRUPHG DW KLJK WHPSHUDWXUHV LH WKH UHIOX[ WHPSHUDWXUHV RI WKH VROYHQWVf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f LQ D VROYHQW PL[WXUH RI KH[DQH DQG 7+) E\ YROXPHf DW UHIOX[ IRU K 7KH SRO\PHU ZDV D OLTXLG ZLWK D FRPSRVLWLRQ RI &+6L+f&+6LffQ HOXFLGDWHG E\ 105

PAGE 49

VSHFWURVFRS\f DQG ZDV SURGXFHG LQ KLJK \LHOGV LH WR bf $YHUDJH PROHFXODU ZHLJKWV IRU WKHVH SRO\PHUV ZHUH UHSRUWHG WR EH ORZ f :KHQ WKH SRO\PHUL]DWLRQ ZDV FDUULHG RXW LQ 7+) LQVWHDG RI D PL[WXUH RI 7+) DQG KH[DQH WKH UHVXOWLQJ SRO\PHU DSSDUHQWO\ KDG KLJKHU PROHFXODU ZHLJKW DEVROXWH QXPEHUV ZHUH QRW UHSRUWHGf DQG PRUH FURVVOLQNHG VWUXFWXUH 7KH ODWWHU FRQFOXVLRQV ZHUH EDVHG RQ 105 VXGLHV VKRZLQJ D ORZHU FRQFHQWUDWLRQ RI 6L+ ERQGVf DQG WKHUPRJUDYLPHWULF DQDO\VLV 7*$f VKRZLQJ KLJKHU FHUDPLF \LHOGf :KHQ WKH UHDFWLRQ ZDV FDUULHG RXW LQ [\OHQH XQGHU UHIOX[LQJ FRQGLWLRQVf WKH \HOORZFRORUHG SRO\PHU ZDV SURGXFHG ZLWK D \LHOG RI b PROHFXODU ZHLJKW LQ WKH UDQJH RI 0Zf DQG VWUXFWXUH RI &+6L+f&+6Lf fQ GHWHUPLQHG IURP 105f 4LX DQG 'X >4LX$ 4LX%@ SUHSDUHG SRO\PHWK\OVLODQH SRO\PHUV E\ FRQGHQVDWLRQ RI PHWK\OGLFKORURVLODQH ZLWK VRGLXP QRUPDO DGGLWLRQ PRGHf LQ D EOHQG RI WROXHQH DQG GLR[DQH YROb UDWLRf ,W LV H[SHFWHG WKDW GLR[DQH D GLSRODU VROYHQW ZLOO SURPRWH SRO\PHUL]DWLRQ RI 0H+6L&, LH KLJKHU UHDFWLRQ UDWHf 7KH HIIHFW RI SRODU VROYHQWV RQ :XLW]FRXSOLQJ UHDFWLRQ RI GLFKORURVLODQHV ZLWK VRGLXP ZDV GLVFXVVHG LQ VHFWLRQ f 7KH SRO\PHUL]DWLRQ ZDV FDUULHG RXW DW WKH UHIOX[ WHPSHUDWXUHV RI WKH WROXHQHGLR[DQH VROYHQW PL[WXUH 7KH HQG SRLQW RI SRO\PHUL]DWLRQ ZDV GHWHUPLQHG E\ WHVWLQJ IRU WKH DFLGLF QDWXUH RI WKH UHDFWLRQ FRQWHQWV 7KH UHDFWLRQ ZDV VWRSSHG ZKHQ WKH UHDFWLRQV FRQWHQWV GLG QRW WHVW DFLGLF S), f 7KH UHDFWLRQ FRQWHQWV ZHUH VHSDUDWHG IURP WKH 1D&, SUHFLSLWDWHV E\ ILOWHULQJ DQG WKH SRO\PHU ZDV LVRODWHG E\ HYDSRUDWLRQ RI WKH SRO\PHU VROXWLRQ XQGHU YDFXXP 7KH SRO\PHU ZDV IUDFWLRQDWHG E\ DGGLQJ GURS E\ GURS D PL[WXUH RI PHWKDQRO DQG SURSDQRO ZLWK YLJRURXV VWLUULQJ 7KH SUHFLSLWDWH ZDV FROOHFWHG DQG GULHG LQ D YDFXXP RYHQ DW URRP WHPSHUDWXUH IRU K 7KH SRO\PHUV V\QWKHVL]HG E\ WKLV PHWKRG ZHUH XVHG LQ VWXGLHV LQYROYLQJ R[LGDWLYH FURVVOLQNLQJ SKRWR

PAGE 50

FURVVOLQNLQJ DQG URRP WHPSHUDWXUH YXOFDQL]DWLRQ 7KH SRO\PHU ZDV SURGXFHG LQ b \LHOG DQG KDG DQ DSSHDUDQFH RI SDOH \HOORZ ZD[\ VROLG ZLWK 0Z 3RO\VLODQH FRSRO\PHUV $V GLVFXVVHG LQ VHFWLRQ ZKHQ GLDON\OGLFKORURVLODQH LV UHDFWHG ZLWK VRGLXP LQ D UHIOX[LQJ VROYHQW SRO\GLPHWK\OVLODQH SRO\PHU LV IRUPHG ZKLFK LV LQIXVLEOH DQG LQVROXEOH LQ FRPPRQ RUJDQLF VROYHQWV HJ WROXHQH EHQ]HQH [\OHQH HWFf :HVW HW DO >:HV :HV$@ GLVFRYHUHG WKDW ZKHQ SKHQ\OPHWK\OGLFKORURVLODQH ZDV DGGHG WR GLDON\OGLFKORURVLODQH LQ D SURSRUWLRQ E\ YROXPH DQG WKH UHDFWLRQ ZDV FDUULHG RXW XQGHU VDPH FRQGLWLRQV WKH UHVXOWDQW SRO\VLODQH FRSRO\PHU ZDV KLJKO\ VROXEOH LQ FRPPRQ RUJDQLF VROYHQWV HJ WROXHQH [\OHQH HWFf :HVW HW DO UHIHUUHG WR WKLV FRSRO\PHU DV fSRO\VLODVW\UHQHff 366f 7KH FRSRO\PHUL]DWLRQ UHDFWLRQ FDQ EH UHSUHVHQWHG DV &+ &+V !r& &+f6L&, &+&+6L&, f§f§ 6L AcI 6L Ac f FK FK 7KH 366 FRSRO\PHU KDG D ELPRGDO PROHFXODU ZHLJKW GLVWULEXWLRQ ZLWK PRGDO YDOXHV RI DQG 'HK\GURFRXSOLQT +DUURG HW DO >+DU 0X$ 0X% $LW $LW $LW@ ZHUH WKH ILUVW WR UHSRUW D FDWDO\VWEDVHG V\QWKHWLF URXWH IRU SRO\VLODQHV SUHSDUHG IURP SULPDU\ RUJDQRVLODQHV

PAGE 51

HJ 56L+ ZKHUH 5 LV DQ DON\O RU DU\O JURXSf ZLWK WKH HYROXWLRQ RI K\GURJHQ 7KH UHDFWLRQ FDQ EH UHSUHVHQWHG DV 5 &DWDO\VW f + 7KH FDWDO\VWV XVHG ZHUH HDUO\ WUDQVLWLRQ PHWDO FRPSOH[HV RI WLWDQLXP DQG ]LUFRQLXP QDPHO\ ELVU_F\FORSHQWDGLHQ\Of GLPHWK\OWLWDQLXP &S7L0Hf'LPHWK\O 7LWDQRFHQH '07f DQG ELV QF\FORSHQWDGLHQ\Of GLPHWK\O]LUFRQLXP &S=U0Hf 'LPHWK\O =LUFRQRFHQH '0=f 0X DQG +DUURG >0X$@ KDYH LQYHVWLJDWHG SRO\PHUL]DWLRQ RI PHWK\OVLODQH E\ GHK\GURFRXSOLQJ LQ WKH SUHVHQFH RI '07 FDWDO\VW DQG UHSRUWHG VLJQLILFDQWO\ KLJKHU \LHOG RI SRO\PHU LQ WKH IRUP RI D JODVV\ VROLG LQ FRPSDULVRQ WR WKDW SURGXFHG E\ FODVVLF :XUW]FRXSOLQJ UHDFWLRQV 7DEOH VKRZV SRO\PHUL]DWLRQ FRQGLWLRQV WHPSHUDWXUH FDWDO\VWV VROYHQWV WLPH DPRXQW RI PRQRPHU XVHGf DQG FKDUDFWHULVWLFV RI WKH SRO\PHUV SURGXFHG \LHOG PROHFXODU ZHLJKW HWFf 7KHLU PHWKRG KRZHYHU VXIIHUV IURP WKH IROORZLQJ GLVDGYDQWDJHV Lf WKH UHDFWLRQ PXVW EH SHUIRUPHG DW DWP DW r& EHFDXVH PHWK\OVLODQH LV D JDV DW URRP WHPSHUDWXUHV HQKDQFLQJ UHDFWLRQ UDWH ZRXOG UHTXLUH ZRUNLQJ DW KLJKHU SUHVVXUHV ZKLFK LQ WXUQ UHTXLUHV VRSKLVWLFDWHG LQVWUXPHQWDWLRQ LQ RUGHU WR SHUIRUP WKH H[SHULPHQWV VDIHO\ DQG LLf KDQGOLQJ PHWK\OVLODQH LV GDQJHURXV VLQFH LW LV VSRQWDQHRXVO\ IODPPDEOH LQ DLU 7KH PRQRPHU PHWK\OVLODQH ZDV V\QWKHVL]HG IURP PHWK\OWULFKORURVLODQH 0HWK\OWULFKORURVLODQH ZDV UHDFWHG ZLWK D VXVSHQVLRQ RI OLWKLXP DOXPLQXP K\GULGH LQ 7+) DW r& IRU K DQG WKHQ UHDFWLRQ SURGXFWV ZHUH FRROHG XQGHU OLTXLG 1 WHPSHUDWXUH WR

PAGE 52

7DEOH 6XPPDU\ RI PHWK\OVLODQH SRO\PHUL]DWLRQ E\ FDWDO\WLF GHK\GURJHQDWLRQ UHDFWLRQV >0X $@ 5XQ 6ROYHQW &DWDO\VW 0H6L+ SVL [ /Ef 2 R ,n 7LPH GD\V $PRXQW RI 306 J
PAGE 53

WUDS PHWK\OVLODQH 7KH VXEVHTXHQW SRO\PHUL]DWLRQ RI SRO\PHWK\OVLODQH ZDV FDUULHG RXW LQ F\FORKH[HQH VROYHQW ZKLFK KHOSV WR DYRLG EXLOG XS RI K\GURJHQ SURGXFHG GXULQJ UHDFWLRQ E\ SURPRWLQJ K\GURJHQDWLRQ RI F\FORKH[HQH WR F\FORKH[DQH 0ROHFXODU ZHLJKW FKDUDFWHULVWLFV RI VRPH RI WKH SRO\PHUV V\QWKHVL]HG E\ 0X DQG +DUURG DUH LOOXVWUDWHG E\ WKH *3& SURILOHV LQ )LJXUH 7KH FKURPDWRJUDPV DUH IRU VDPSOHV DVVRFLDWHG ZLWK WKH HQWULHV LQ 7DEOH 7KH f$f FKURPDWRJUDPV IURP WRSWR ERWWRP FRUUHVSRQG WR UXQ V DQG UHVSHFWLYHO\ DQG WKH f%f FKURPDWRJUDPV IURP WRSWRERWWRP FRUUHVSRQG WR UXQ V DQG UHVSHFWLYHO\f 7KH ELPRGDO GLVWULEXWLRQV WKDW GHYHORS ZLWK ORQJHU UHDFWLRQ WLPHV DUH UHSRUWHG WR EH W\SLFDO RI GHK\GURFRXSOLQJ RI SULPDU\ RUJDQRVLODQHV 7KH ORZHU PROHFXODU ZHLJKW SHDN DSSHDULQJ DV D VKRXOGHU LQ PRVW FKURPDWRJUDPV LQ )LJXUH f LV DWWULEXWHG GXH WR F\FOLF ROLJRPHUV 7KH KLJK SRO\GLVSHUVLW\ RI WKHVH SRO\PHUV FDQ EH DWWULEXWHG WR EUDQFKLQJFURVVOLQNLQJ WKDW RFFXUV DW UHVLGXDO 6L+ 6L+ DQG 6L+ JURXSV GXULQJ SURORQJHG UHDFWLRQ 0X DQG )ODUURG DOVR VWXGLHG SRO\PHUL]DWLRQ RI SKHQ\OVLODQH E\ GHK\GURFRXSOLQJ XVLQJ WKH DIRUHPHQWLRQHG FDWDO\VWV 7KH SRO\SKHQ\OVLODQH SRO\PHU V\QWKHVL]HG ZLWK '07 DQG '0= KDG DYHUDJH GHJUHHV RI SRO\PHUL]DWLRQ RI DQG UHVSHFWLYHO\ FRUUHVSRQGLQJ WR PROHFXODU ZHLJKWV RI DQG UHVSHFWLYHO\f ,Q ERWK FDVHV JHO SHUPHDWLRQ FKURPDWRJUDPV GLG QRW VXJJHVW WKH SUHVHQFH RI F\FOLF ROLJRPHUV LH ORZ PROHFXODU ZHLJKW ROLJRPHUV ZHUH QRW REVHUYHGf )ODUURG HW DO DOVR UHSRUW WKDW VHFRQGDU\ RUJDQRVLODQHV HJ SKHQ\OPHWK\OVLODQHf GR QRW SRO\PHUL]H HDVLO\ XQGHU VLPLODU UHDFWLRQ FRQGLWLRQV DQG IRUP RQO\ GLPHUV DQG WULPHUV %URZQ:HQVOH\ >%UR %UR@ KDV VKRZQ WKDW D JRRG FDWDO\VW IRU FRQYHUVLRQ RI VHFRQGDU\ VLODQHV 56L)+f WR GLPHULF VLODQHV )+56L6L5+f LV D 3K3f5K&, FRPSOH[ :KLOH )ODUURGfV ZRUN RQ WKH V\QWKHVLV RI SRO\DU\OVLODQHVf HJ SRO\SKHQ\OVLODQHff LQGLFDWHG WKDW F\FOLF ROLJRPHUV GR QRW IRUP &DPSEHOO DQG )+LOW\

PAGE 54

)LJXUH *3& RI SRO\PHWK\OVLODQHV V\QWKHVL]HG E\ 0X DQG +DUURG >0X$@ $ '07 FDWDO\VW % '0= FDWDO\VW

PAGE 55

>&DP@ KDYH VKRZQ E\ JDV FKURPDWRJUDSK\ WKDW WKH\ DUH WKH PDLQ SURGXFWV LQ WKH SRO\PHUL]DWLRQ RI DON\OVLODQHV HJ QEXW\OVLODQHVf FDWDO\]HG E\ '0= 7KLV LV DWWULEXWHG WR WKH DELOLW\ RI '0= WR SURPRWH UHYHUVLEOH UHDFWLRQV IRU ERWK SULPDU\ DQG VHFRQGDU\ VLODQHV ,Q WKH FDVH RI SRO\PHUL]DWLRQ RI PHWK\OVLODQH &DPSEHOO HW DO UHSRUWHG WKH SUHVHQFH RI D VPDOO DPRXQW RI F\FOLF ROLJRPHUV Q WR f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f ,Q FRQWUDVW DQ LQGXFWLRQ SHULRG ZDV DEVHQW IRU '0= FDWDO\]HG UHDFWLRQV DQG D VOLJKW DXWRn DFFHOHUDWLRQ LQ WKH UHDFWLRQ UDWHV ZDV REVHUYHG LQ WKH UHDFWLRQV DW ORZ FDWDO\VW RU PRQRPHU FRQFHQWUDWLRQV 7KH PHFKDQLVP RI FDWDO\WLFDOO\ DFWLYDWHG GHK\GURFRXSOLQJ RI RUJDQRVLODQHV LV FRPSOH[ +DUURG >+DU@ VXJJHVWHG EDVHG RQ 105 VWXGLHVf WKDW WKH PHFKDQLVP LQYROYHG IRUPDWLRQ RI WLWDQLXP ,9f VLO\OK\GULGH &S7L+f6L+5ff ZKLFK GHFRPSRVHG E\ HOLPLQDWLRQ RI DK\GULGH IURP WKH 6L+5 JURXS IROORZHG E\ UHOHDVH RI + IURP WKH FRPSOH[ WR JLYH &S7L 6L+5 VLO\OHQHf FRPSOH[ $ QXPEHU RI PHWDOORFHQH FDWDO\VWf GHULYDWLYHV DUH IRUPHG GXULQJ SRO\PHUL]DWLRQ WKDW FDQ EH LVRODWHG DQG WKHVH FRPSRXQGV DUH SUHVXPHG LQDFWLYH LQ WKH SRO\PHUL]DWLRQ F\FOH 3URSDJDWLRQ WKHQ RFFXUUHG E\ UHSHWLWLYH LQVHUWLRQ RI WKH VLO\OHQH LQWR D 7L6L ERQG D UDSLG DGGLWLRQ PHFKDQLVPf LQ ZKLFK WKH LQWHUPHGLDWHV DUH QRW REVHUYDEOH EHFDXVH WKH\ DUH VKRUWOLYHG RU EHFDXVH WKH\ DUH

PAGE 56

VSHFWURVFRSLFDOO\ nVLOHQWf LH DEVHQW LQ 105 EHFDXVH RI SDUDPDJQHWLF QDWXUHf $W SUHVHQW D PHFKDQLVP IRU FKDLQ WHUPLQDWLRQ LV QRW HOXFLGDWHG DOWKRXJK FDWDO\VWLQGXFHG FKDLQ VFLVVLRQ KDV EHHQ REVHUYHG LQ WKH SRO\PHUL]DWLRQ RI F\FORKH[DVLODQHV 6LQFH HDUO\ WUDQVLWLRQ PHWDO FRPSOH[HV DUH QRW HIIHFWLYH IRU GHK\GURFRXSOLQJ RI VHFRQGDU\ VLODQHV RWKHU FDWDO\VWV KDYH EHHQ LQYHVWLJDWHG &RUH\ HW DO >&RU@ V\QWKHVL]HG GLVLODQHV WKURXJK SHQWDVLODQHV E\ XVLQJ D &S=U&,Q%X/L PL[WXUH DV D FDWDO\VW IRU GHK\GURFRXSOLQJ RI SKHQ\OPHWK\OVLODQHV LQ WROXHQH DW r& 7KLV WHPSHUDWXUH LV KLJKHU WKDQ WKDW XVHG IRU GHK\GURFRXSOLQJ RI SULPDU\ VLODQHVf 7KLV FRQGHQVDWLRQ UHDFWLRQ RI VHFRQGDU\ VLODQHV LV VHQVLWLYH WR VWHULF HIIHFWV LH VWHULF KLQGUDQFHf RI WKH VXEVWLWXHQWV DV REVHUYHG E\ WKH VOXJJLVK UHDFWLRQ RI 3K6L+ FRPSDUHG WR 3K0H6L+ >&RU@ 6DNDNXUD HW DO >6DN 6DN@ KDYH GHYHORSHG D PHWKRG IRU SURGXFLQJ SRO\VLODQHV E\ GHK\GURFRXSOLQJ RI SULPDU\ RUJDQRVLODQHV XVLQJ D ODQWKDQRLG FRPSOH[ ZWbf DV D FDWDO\VW 7KH\ UHSRUWHG WKDW ODQWKDQRLG FRPSOH[HV KDYH KLJKHU DFWLYLW\ DQG VHOHFWLYLW\ WKDQ HDUO\ WUDQVLWLRQ PHWDO FRPSOH[HV XVHG E\ +DUURG HW DO ,Q WKLV FDVH WKH GHK\GURJHQDWLYH UHDFWLRQV RI SKHQ\OVLODQHV ZHUH SHUIRUPHG DW WHPSHUDWXUHV UDQJLQJ IURP r& WR r& DQG LQ WKH SUHVHQFH RI D VROYHQW VXFK DV WROXHQH RU EHQ]HQH ZLWK UHDFWLRQ WLPHV H[WHQGLQJ IURP VHYHUDO KRXUV WR VHYHUDO GD\V 7KH DXWKRUV UHSRUWHG WKDW KLJKHU SRO\PHUL]DWLRQ WHPSHUDWXUHV DQG ORQJHU UHDFWLRQ WLPHV OHDG WR KLJKHU SRO\PHU PROHFXODU ZHLJKW 7KH HIIHFW RI WKH DERYH YDULDEOHV LQ WKH SRO\PHUL]DWLRQ RI SKHQ\OVLODQH LQ WKH SUHVHQFH RI K\GURELVSHQWDPHWK\OF\FORSHQWDGLHQ\OfQHRG\PLXP FDWDO\VWV ODQWKDQRLG FRPSOH[f LV LOOXVWUDWHG LQ 7DEOH

PAGE 57

7DEOH (IIHFW RI WLPH DQG WHPSHUDWXUH RQ SRO\PHUL]DWLRQ RI SKHQ\OVLODQH LQ WKH SUHVHQFH RI D ODQWKDQRLG FRPSOH[ >6DN@ 7HPSHUDWXUH r& 7LPH GD\V 3URGXFW $SSHDUDQFH 0Z 0Q RLO JXP JXP VROLG D VROLG D GD\V DW r& IROORZHG E\ GD\V DW r&

PAGE 58

%HUULV >%HU@ KDV DOVR GHYHORSHG D SURFHVV IRU V\QWKHVL]LQJ SRO\VLODQH SRO\PHUV ZLWK D 0Z RI a E\ GHK\GURJHQDWLYH FRXSOLQJ RI SULPDU\ RUJDQRVLODQHV LQ WKH SUHVHQFH RI ZWbf GLPHWK\OGLDON\OSKRVSKLQH QLFNHOKDOLGH HJ ELVGLPHWK\OSKRVSKLQHf HWKDQHQLFNHOOOfFKORULGH GPSH 1L&,f DW WHPSHUDWXUHV RI r& WR r& LQ WKH SUHVHQFH RI DQ LQHUW VROYHQW 7KH UHDFWLRQ WLPH YDULHG IURP K WR GD\V GHSHQGLQJ RQ WKH WHPSHUDWXUH XVHG LH ORZHU UHDFWLRQ WLPHV ZHUH XVHG DW KLJKHU WHPSHUDWXUHVf 7KH GPSH 1L&, FDWDO\VW ZDV UHSRUWHG WR KDYH D PXFK KLJKHU DFWLYLW\ WKDQ WKH HDUO\ WUDQVLWLRQ PHWDO FRPSOH[HV XVHG E\ +DUURG HW DO>+DU@ 6H\IHUWK HW DO >6H\ 6H\ 6H\ 6H\@ KDYH XVHG GHK\GURJHQDWLYH FRXSOLQJ WR FURVVOLQN ORZ PROHFXODU ZHLJKW SRO\PHWK\OVLODQHV FRQWDLQLQJ PXOWLSOH VHFRQGDU\ RU WHUWLDU\ 6L+ ERQGVf ZKLFK KDG EHHQ V\QWKHVL]HG E\ WKH :XUW]FRXSOLQJ UHDFWLRQ RI PHWK\OGLFKORURVLODQH ZLWK VRGLXP LQ KH[DQH7+) 7KLV UHVXOWHG LQ SRO\PHUV WKDW FRXOG EH S\URO\]HG WR SURGXFH QHDUVWRLFKLRPHWULF 6L& ZLWK KLJK \LHOG LQ WKH UDQJH RI bf 7KH ORZ PROHFXODU ZHLJKW SRO\PHWK\OVLODQHV ZHUH UHDFWHG ZLWK a ZWb F\FORSHQWDGLHQ\O ]LUFRQLXP K\GULGH FDWDO\VW LQ DQ LQHUW VROYHQW VXFK DV KH[DQHf DW UHIOX[ WHPSHUDWXUHV +H[DQH ZDV FKRVHQ EHFDXVH LW UHDGLO\ GLVVROYHV WKH FDWDO\VW DQG LW KDV D ORZ UHIOX[ WHPSHUDWXUHf 6H\IHUWK HW DO >6H\@ REVHUYHG WKDW WKH SURGXFWV RI WKH GHK\GURJHQDWLYH FRXSOLQJ UHDFWLRQ RI ORZPROHFXODUZHLJKW SRO\VLODQHV ZLWK F\FORSHQWDGLHQ\O ]LUFRQLXP K\GULGH FDWDO\VW UDQJHG IURP RLO WR VROLG ERWK RUDQJH LQ FRORUf GHSHQGLQJ XSRQ WLPHWHPSHUDWXUH FRQGLWLRQV RI WKH UHDFWLRQ ,Q RUGHU WR LPSDUW LQIXVLELOLW\ WR DUWLFOHV SUHSDUHG IURP WKHVH FURVVOLQNHG SRO\PHUV HJ ILEHUVf SKRWRO\VLV LV UHTXLUHG ZKLFK FDQ EH DFFRPSOLVKHG E\ 89 LUUDGLDWLRQ LQ KH[DQH IRU KRXUV 7LOOH\ >7, 71@ GHYHORSHG D PHWKRG RI SURGXFLQJ FURVVOLQNHG KLJK PROHFXODUZHLJKW VLOLFRQULFK SRO\PHUV E\ GHK\GURJHQDWLYH FRXSOLQJ UHDFWLRQV RI RUJDQRVLODQHV 7KH UHDFWLRQ RI PRUH WKDQ RQH 6L+ JURXS SHU VLOLFRQ FHQWHU FDXVHG

PAGE 59

FURVVOLQNLQJ RI FKDLQV DQG LQFUHDVHG PROHFXODU ZHLJKWV $ ZLGH UDQJH RI KRPRSRO\PHUV ZLWK GLIIHUHQW VWUXFWXUHV ZHUH SUHSDUHG E\ PRGLI\LQJ WKH UHDFWLRQ FRQGLWLRQV WR YDU\ WKH GHJUHH RI EUDQFKLQJ FURVVOLQNLQJf RU FKDLQ H[WHQVLRQ )RU H[DPSOH ZKHQ GLVLO\OEHQ]HQH+6Lf&+f RU GLPHWK\OVLO\O EHQ]HQH &++6Lf&+f ZDV UHDFWHG LQ WKH SUHVHQFH RI F\FORSHQWDGLHQ\O ]LUFRQLXP K\GULGH FDWDO\VW &S=U+ff WKH UHVXOWLQJ SRO\PHU ZDV KLJKO\ FURVVOLQNHG DQG KLJK LQ PROHFXODU ZHLJKW 7KH GLVLO\O PRQRPHUV GLVLO\O EHQ]HQH RU GLPHWK\OVLO\OEHQH]HQHf GHYHORSHG E\ 7LOOH\ ZHUH SUHSDUHG E\ UHDFWLQJ WHWUDHWKR[\VLODQHV 6L2(Wff RU PHWK\O WULHWKR[\VLODQHV &+6L2(Wff ZLWK GLEURPREHQ]HQH DQG PDJQHVLXP LQ DQ LQHUW VROYHQW IROORZHG E\ UHGXFWLRQ RI WKH LQWHUPHGLDWH FRPSRXQG GLWULHWKR[\OVLO\OfEHQ]HQH RU GL WULPHWKR[\VLOR[\fEHQ]HQHf ZLWK OLWKLXP DOXPLQXP K\GULGH 7KH GHK\GURJHQDWLYH SRO\PHUL]DWLRQ ZDV WKHQ FDUULHG RXW E\ DGGLQJ RUJDQRVLODQHV FRQWDLQLQJ PXOWLSOH 6L+ JURXSV SHU VLOLFRQ FHQWHUf GURS E\ GURS WR D EHQ]HQH VROXWLRQ FRQWDLQLQJ WKH FDWDO\VW DQG VWLUULQJ IRU KRXUV DW r& XQGHU QLWURJHQ 0DQ\ RI WKH SRO\PHUV SUHSDUHG E\ 7LOOH\fV PHWKRG ZHUH KLJKO\ FURVVOLQNHG DQG ZHUH LQVROXEOH LQ FRPPRQ VROYHQWV HJ WROXHQHf LQGLFDWLQJ GLIILFXOW\ LQ FRQWUROOLQJ FURVVOLQNLQJ UHDFWLRQV 7KH VROXEOH SRO\PHUV H[KLELWHG 0Z UDQJLQJ IURP WR DQG 0Q UDQJLQJ IURP WR 5HGLVWULEXWLRQVXEVWLWXWLRQ UHDFWLRQV %DQH\ HW DO >%DQ %DQ %DQ@ SUHSDUHG DQRWKHU FODVV RI SRO\VLODQH SRO\PHUV PHWK\OSRO\VLODQHV 036 SRO\PHUVf E\ FDWDO\WLF UHGLVWULEXWLRQ UHDFWLRQV LQYROYLQJ 6L6L6L&, ERQGV RI PHWK\OFKORURGLVLODQH PL[WXUHV 7KH PHWK\OFKORURGLVLODQH PL[WXUHV FRPSULVLQJ ZWb >0H&,6L@ ZWb 0H&,6L6L0H&, DQG ZWb 0HWK\OSRO\VLODQH 036f SRO\PHUV DV GHVFULEHG E\ %DQH\ HW DO KDYH D VWUXFWXUH RI >&+f6Lf[&+6Lf\@Q 7KH\ DUH GLIIHUHQW IURP SRO\PHWK\OVLODQH 306f SRO\PHUV GLVFXVVHG HDUOLHU ZKLFK KDYH D VWUXFWXUH RI >&+6L+f[&+6Lf\@Q

PAGE 60

0H&,6Lf ZHUH REWDLQHG DV IUDFWLRQV IURP DQ LQGXVWULDO SURFHVV IRU PDQXIDFWXUH RI PHWK\OFKORURVLODQHV 7KH FDWDO\VW XVHG IRU WKH UHGLVWULEXWLRQVXEVWLWXWLRQ UHDFWLRQV RI PHWK\OFKORURGLVLODQH PL[WXUHV ZDV WHWUDEXW\OSKRVSKRQLXP FKORULGH 7KH SURSRVHG UHDFWLRQ VFKHPH IRU WKHVH UHDFWLRQV LV VKRZQ LQ )LJXUH 7KH UHDUUDQJHPHQW RI GLVLODQHV LQWR D PRQRPHUSRO\PHU PL[WXUH RFFXUUHG ZKHQ WKH GLVLODQH PL[WXUH ZDV KHDWHG WR r& $GGLWLRQDO PRQRPHULF PHWK\OFKORURVLODQHV IRUPHG HYHQ DIWHU WKH VWDUWLQJ GLVLODQHV UHDFWHG FRPSOHWHO\ 7KLV RFFXUUHG E\ WKH UHDFWLRQ RI DQ\ 6L&, ERQG ZLWK D WHUPLQDO 6L6L ERQG LQ WKH SRO\VLODQH EDFNERQH 7KH DPRXQW RI PRQRPHUV IRUPHG DQG WKH H[WHQW RI SRO\PHUL]DWLRQ ZHUH FRQWUROOHG E\ PDQLSXODWLQJ WKH KHDWLQJ VFKHGXOH DQG ILQDO UHDFWLRQ WHPSHUDWXUH 7KH UHVXOWLQJ \HOORZ FRORUHG PHWK\OFKORURSRO\VLODQH SRO\PHUV 0&36f ZHUH VROXEOH LQ WROXHQH DQG KDG SRO\F\FOLF VWUXFWXUHV ZLWK VHYHQ ULQJV SHU PROHFXOH 0H6Lf0H6Lf&,ff DV GHWHUPLQHG E\ JDV FKURPDWRJUDSK\ VHH )LJXUH f 7KH 6L&, ERQGV LQ WKH PHWK\OFKORURSRO\VLODQH SRO\PHUV ZHUH KLJKO\ UHDFWLYH DQG SHUPLWWHG HDV\ FKHPLFDO PRGLILFDWLRQ VXFK DV UHDFWLRQ ZLWK *ULJQDUG UHDJHQWV DON\OPDJQHVLXP KDOLGH RU SKHQ\OPDJQHVLXP KDOLGHf WR IRUP PHWK\OSRO\VLODQH SRO\PHU 036f $FFRUGLQJ WR %DQH\ HW DO 0&36 SRO\PHU UHDFWV UHDGLO\ ZLWK *ULJQDUG UHDJHQWV WR UHSODFH WKH UHDFWLYH 6L&, JURXSV ZLWK PRUH VWDEOH 6L5 JURXSV 7KH PRGLILHG SRO\PHUV FDQ EH PHOW VSXQ WR IRUP ILEHUV ZKLFK FDQ EH VXEVHTXHQWO\ S\URO\]HG WR 6L& DV GLVFXVVHG LQ VHFWLRQ 7KH FKHPLFDO PRGLILFDWLRQ RI PHWK\OFKORURSRO\VLODQHV 0&36f FDQ DOVR EH DFFRPSOLVKHG E\ UHGXFLQJ 0&36 RYHU D VOXUU\ RI OLWKLXP DOXPLQXP K\GULGH XQGHU DQ LQHUW EODQNHW LQ D UHIOX[LQJ VROYHQW VXFK DV WROXHQH >%DQ@ 7KH H[FHVV UHGXFLQJ DJHQW LV QHXWUDOL]HG E\ DGGLQJ ZDWHU DQG DTXHRXV 1D2+ DQG WKH VROXWLRQ LV VXEVHTXHQWO\ ILOWHUHG WR JLYH D \HOORZFRORUHG SRO\PHU RI FRPSRVLWLRQ &+f6Lf&+6LffQf

PAGE 61

&O &O &O ]] 6Lf§ &O 0Hf§ 6L 6L 0H L &O &O ar& 6L6L0H 0H6L&A &O &DWDO\VW &O 0H &O 6L&O 0H6L6L0H ar& (( 6L 6L 0H 0A6L&A &DWDO\VW &O &O &O &O 0H , 0H (( 6L&O 0H 6L 6L 0H _ ar& 6L 6L 0H 0H6L&OM &DWDO\VW &O &O &O f f f )LJXUH 6FKHPH IRU UHGLVWULEXWLRQVXEVWLWXWLRQ UHDFWLRQV RI FKORURGLVLODQHV

PAGE 62

0H 0H f 0H6L D D )LJXUH 6WUXFWXUH RI PHWK\OFKORURSRO\VLODQH SRO\PHU >%DQ@

PAGE 63

,QIRUPDWLRQ RQ R[\JHQ LQFRUSRUDWLRQ LQWR WKH SRO\PHU GXH WR WKH DGGLWLRQ RI ZDWHU DQG 1D2+ ZDV QRW UHSRUWHGf 7KH PDLQ GLVDGYDQWDJH RI %DQH\ HW DO 036 SRO\PHUV IURP WKH SRLQW RI YLHZ RI VXEVHTXHQW SURFHVVLQJ IRU FHUDPLF DUWLFOHV HJ ILEHUVf LV WKHLU SRRU R[LGDWLYH VWDELOLW\ 036 SRO\PHUV DUH S\URSKRULFf %XUQV >%XU@ DWWULEXWHG WKLV WHQGHQF\ IRU VSRQWDQHRXV R[LGDWLRQ WR D ODUJH QXPEHU RI 6L+ JURXSV LQ WKH SRO\PHU VWUXFWXUH 7KH SRO\PHU GHYHORSV D FURVVOLQNHG VWUXFWXUH XSRQ R[LGDWLRQ GXH WR WKH IRUPDWLRQ RI 6L26L QHWZRUNV %XUQV GHYHORSHG D UHPHG\ WR WKH SUREOHP RI R[LGDWLYH LQVWDELOLW\ LQ WKHVH 036 SRO\PHUV E\ LQVHUWLQJ PXOWLSOH XQVDWXUDWHG ERQGV VXFK DV DFHW\OHQH RU SKHQ\O DFHW\OHQH RU GLHQH FRPSRXQGVf $FFRUGLQJ WR %XUQV E\ VHOHFWLYHO\ LQVHUWLQJ PXOWLSOH XQVDWXUDWHG ERQGV LQ WKH 6L6L EDFNERQH WKH ILQDO 6L& VWRLFKLRPHWU\ FDQ DOVR EH FRQWUROOHG XQPRGLILHG 036 SRO\PHUV W\SLFDOO\ \LHOG VLOLFRQULFK FHUDPLF UHVLGXHf 7KH LQVHUWLRQ UHDFWLRQ FDQ EH FDUULHG RXW E\ UHDFWLQJ 036 SRO\PHUV ZLWK a ZWb XQVDWXUDWHG FRPSRXQGV HJ SKHQ\O DFHW\OHQHf LQ WKH SUHVHQFH RI D WUDQVLWLRQ PHWDO FDWDO\VW HJ WHWUDNLV WULSKHQ\OSKRVSKLQHf SDOODGLXP RU WULVWULSKHQ\OSKRVSKLQHf UKRGLXP FKORULGHf LQ DQ LQHUW VROYHQW VXFK DV WROXHQH DW UHIOX[ WHPSHUDWXUHV IRU a KRXUV ,Q DGGLWLRQ WR EHWWHU R[LGDWLYH VWDELOLW\ DQG FRQWURO RI VWRLFKLRPHWU\ %XUQVf PHWKRG SUHVHQWV RSSRUWXQLWLHV WR V\QWKHVL]H SRO\FDUERVLODQHV E\ LQWURGXFLQJ XQVDWXUDWHG PRLHWLHV EHWZHHQ 6L6L ERQGV $Q H[DPSOH RI VXFK D V\QWKHVLV LV UHSRUWHG DV WKH UHDFWLRQ EHWZHHQ EXWDGLHQH ZLWK D OLQHDU SRO\VLODQH SRO\PHU >%XU@ %XMDOVNL HW DO >%XM@ GHYHORSHG DQ DOWHUQDWH PHWKRG RI V\QWKHVLV RI FKORULQH FRQWDLQLQJ SRO\VLODQHV 7KHVH SRO\PHUV ZHUH SUHSDUHG E\ UHDFWLQJ D PL[WXUH RI ZWb RI RQH RU PRUH RI FKORULQHFRQWDLQLQJ GLVLODQHV HJ &+f&,6Lf &+6Lf&,6L6L&,&+ &+&,6Lf HWFf ZLWK RQH RU PRUH RI PRQRRUJDQRVLODQHV HJ &+6L&,f 7KH UHDFWLRQ UHTXLUHG WR ZWb UHDUUDQJHPHQW FDWDO\VW HJ TXDWHUQDU\

PAGE 64

DPPRQLXP KDLLGH TXDWHUQDU\ SKRVSKRQLXP KDOLGH HWFf DW WHPSHUDWXUHV UDQJLQJ IURP r& WR r& 7KH SRO\VLODQHV VROLG DW URRP WHPSHUDWXUHf ZHUH HDVLO\ FRQYHUWHG WR VLOLFRQ FDUELGH E\ S\URO\VLV DW HOHYDWHG WHPSHUDWXUHV DW !r&f $FFRUGLQJ WR %XMDOVNL HW DO WKH XVH RI D PRQRRUJDQRVLODQH RI VWUXFWXUH 5n6L; ZKHUH 5f LV PHWK\O SKHQ\O RU RFW\O JURXSV DQG ; LV FKORULQHf RU D PL[WXUH RI PRQRRUJDQRVLODQHVf SHUPLWV FRQWURO RI WKH JODVV WUDQVLWLRQ WHPSHUDWXUH 7J RI WKH SRO\VLODQHV DV ZHOO DV WKH VWRLFKLRPHWU\ RI WKH VLOLFRQ FDUELGH SURGXFHG 7KHLU ZRUN VXJJHVWV XVLQJ PRQRRUJDQRVLODQHV ZLWK VLO\O JURXSV 5f6L ZKHUH 5f QRFW\Of DOORZV D JUHDWHU UHGXFWLRQ LQ 7J RI WKH SRO\PHU FRPSDUHG WR XVLQJ PRQRRUJDQRVLODQHV 5f6L; ZKHUH 5f SKHQ\Of %XMDOVNL HW DO UHSRUWHG WKDW DOO WKH QRFW\O JURXSV DUH ORVW DV ROHILQV XSRQ S\URO\VLV DQG WKLV UHVXOWV LQ D FDUERQGHILFLHQW FHUDPLF ,Q FRQWUDVW SRO\PHUV ZLWK SKHQ\O JURXSV SURGXFH D FDUERQULFK FHUDPLF DIWHU S\URO\VLV +RZHYHU WKH ILQDO 6L& VWRLFKLRPHWU\ DOVR GHSHQGV VLJQLILFDQWO\ RQ WKH SUHVHQFH RI PHWK\O UDGLFDOV LQ WKH SRO\VLODQH &+6L RU &+6Lf6Lf ZKLFK DUH JHQHUDOO\ QRW ORVW XSRQ S\URO\VLV %XMDOVNL HW DO LQGLFDWHG WKDW SUHVHQFH RI WKH QRFW\O RU SKHQ\O6L XQLWV HQDEOHG fILQH WXQLQJf RI WKH VLOLFRQ DQG FDUERQ FRQWHQWV LQ WKH FHUDPLF 3\URO\VLV %HKDYLRU &DUOVVRQ HW DO >&DU@ KDYH VWXGLHG WKH S\URO\VLV EHKDYLRU RI YDULRXV VLOLFRQ EDFNERQH SRO\PHUV VXFK DV SRO\SKHQ\OVLODQHV SRO\QKH[\OVLODQHV DQG SRO\GLPHWK\OVLODQHV E\ PHDQV RI WKHUPRJUDYLPHWULF DQDO\VLV 7*$f DQG )RXULHU WUDQVIRUP LQIUDUHG VSHFWURVFRS\ )7,5f 3RO\PHUV IRU WKH 7*$ VWXG\ ZHUH KHDWHG DW r&PLQ ZLWK PLQ LVRWKHUPDO KROGV DW r& r& r& DQG r& 3RO\PHUV IRU )7,5 VWXG\ ZHUH KHDWHG DW r& r& r& DQG r& ZLWK D PLQ KROG DW HDFK WHPSHUDWXUH 7KHLU UHVXOWV DUH VXPPDUL]HG LQ 7DEOH 7KH HIIHFW RI SHQGDQW JURXSV VXFK DV SKHQ\Of RQ S\URO\VLV \LHOG LV SDUWLFXODUO\ QRWLFHDEOH )RU H[DPSOH

PAGE 65

7DEOH &HUDPLF \LHOGV DQG FKHPLFDO FRPSRVLWLRQV RI SRO\VLODQH KRPRSRO\PHUV FRSRO\PHUV DQG WHUSRO\PHUV >&DU@ %DWFK 3RO\PHU &DOFXODWHG 6L& \LHOGGWKHRUHWLFDO 6L& \LHOGE@[ ORZ 0: YLVFRXV RLO K KLJK 0: IUDFWLRQ

PAGE 66

SRO\GLPHWK\OVLODQH ZLWK PHWK\O JURXSV DV VXEVWLWXHQWV JLYHV KLJK WKHRUHWLFDO \LHOG bf EXW ORZ S\URO\VLV \LHOG abf ([SHULPHQWV E\ :RRG >:RR@ DQG :HVW HW DO >:HV@ DOVR FRQILUP WKLV REVHUYDWLRQf 5HSODFHPHQW RI D PHWK\O VXEVWLWXHQW E\ D EXON\ SKHQ\O JURXS DV LQ SRO\SKHQ\OPHWK\OVLODQHf UHVXOWV LQ LPSURYHG S\URO\VLV \LHOG ab SUHVXPDEO\ GXH WR WKH UHWHQWLRQ RI VRPH SKHQ\O JURXSV GXULQJ S\URO\VLVf ,W LV DOVR SRVVLEOH WKDW KLJK \LHOG GHSHQGV RQ WKH DELOLW\ WR GHYHORS D 6L&6L& EDFNERQH ZLWK VXIILFLHQW FURVVOLQNLQJf )LJXUH VKRZV WKH )7,5 VSHFWUD RI D SRO\VLODQH WHUSRO\PHU SRO\PHU 9OOE VKRZQ LQ 7DEOH f GXULQJ S\URO\VLV WR r& 7KH SRO\PHU ZDV FDVW DV D WKLQ ILOP RQ D VLOLFRQ ZDIHU DQG KHDWHG XQGHU DUJRQ DWPRVSKHUH DQG VSHFWUD ZHUH FROOHFWHG DW GLIIHUHQW WHPSHUDWXUHV 7KH W\SLFDO DEVRUSWLRQV IRU WKH DVSUHSDUHG SRO\VLODQH RFFXUUHG DW FPn GXH WR WKH &+ VWUHWFKLQJ YLEUDWLRQ RI 6L&+ &+f FPn GXH WR WKH &+ EHQGLQJ YLEUDWLRQ RI 6L&+f FPn GXH WR WKH &+ EHQGLQJ YLEUDWLRQ RI 6L &+f DQG FPn GXH WR VWUHWFKLQJ YLEUDWLRQ RI 6L+f DQG FPn GXH WR WKH URFNLQJ YLEUDWLRQ RI 6L&+f )LJXUH VKRZV WKH FKDQJHV LQ FRQFHQWUDWLRQV LQ UHVLGXDO SHQGDQW RUJDQLF JURXSV FDOFXODWHG EDVHG RQ WKH ,5 VSHFWUD DOORZLQJ IRU UHGXFWLRQ LQ WKLFNQHVV RI WKH ILOP ZKLFK RFFXUUHG GXULQJ S\URO\VLV 7KH VOLJKW LQFUHDVH LQ WKH 6L+ JURXS LQWHQVLW\ LV DWWULEXWHG WR PHWK\OHQH LQVHUWLRQ UHDFWLRQV WDNLQJ SODFH EHWZHHQ r& DQG r& 7KLV REVHUYDWLRQ ZDV DOVR FRQILUPHG E\ 6FKLOOLQJ >6FK 6FK@ DQG 6FKPLGW >6FK@ E\ 105 VWXGLHV DQG UHVHPEOHG UHDFWLRQV RFFXULQJ GXULQJ WKH FRQYHUVLRQ RI SRO\GLPHWK\OVLODQH WR SRO\FDUERVLODQH >+DV@f &DUOVVRQ HW DO LQGLFDWHG WKDW QR VLJQLILFDQW FKDQJHV RFFXUUHG GXULQJ WKH S\URO\VLV XS WR r& EXW UDSLG HOLPLQDWLRQ RI &+ &+ DQG &+ JURXSV RFFXUUHG EHWZHHQ r& DQG r& 7KH LQFUHDVH LQ WKH DEVRUSWLRQ LQWHQVLW\ DW FPn FRUUHVSRQGHG WR IRUPDWLRQ RI 6L&+fQ 6L OLQNDJHV DQG QHWZRUN

PAGE 67

)LJXUH ,5 VSHFWUDO FKDQJHV GXULQJ S\URO\VLV RI D SRO\VLODQH SRO\PHU 9OOE LQ 7DEOH f >&DU@ $ LQLWLDO ILOP % r& K KROGf & r& Kf r& Kf (r& Kf ) GLVSHUVLRQ RI VLQJOH FU\VWDO 6L& ZKLVNHUV LQ .%U IRU FRPSDULVRQ

PAGE 68

),5,1* 7(03(5$785( r&! 2 8! /8 + 8FF )LJXUH &KDQJH LQ LQWHQVLWLHV RI SHQGDQW JURXSV EDVHG RQ ,5 VSHFWUD IRU SRO\VLODQH SRO\PHU 9OOE LQ 7DEOH f >&DU@ R S&+f IURP 6L&+ &+f RI 6L&+ Â’ &+f RI 6L&+ &+f RI 6L&+fQ6L $Y 6L+f 9 Y 6L&f

PAGE 69

:RRG >:RR@ VWXGLHG WKH S\URO\VLV EHKDYLRU RI WKUHH GLIIHUHQW SRO\PHWK\OVLODQHV GHVLJQDWHG DV 306, 306,, DQG 306,,,f SUHSDUHG E\ :XUW]FRXSOLQJ UHDFWLRQV RI GLFKORURVLODQH ZLWK VRGLXP LQ WKH SUHVHQFH RI KH[DQH KH[DQH7+) YROXPHf PL[WXUH DQG 7+) UHVSHFWLYHO\ 7DEOH JLYHV D VXPPDU\ RI WKH V\QWKHVLV FRQGLWLRQV DQG FKDUDFWHULVWLFV IRU WKH WKUHH SRO\PHUV 306, VKRZHG YHU\ ORZ FHUDPLF \LHOG bf XSRQ S\URO\VLV WR r& 7KH ORZ FHUDPLF \LHOG ZDV DWWULEXWHG WR WKH ORVV RI 6L E\ YRODWLOL]DWLRQ RI ORZ PROHFXODU ZHLJKW FRPSRQHQWV ZKLFK ZDV FRQILUPHG E\ PDVV VSHFWUDO DQDO\VLV RI WKH S\URO\VLV VSHFLHVf ;UD\ 'LIIUDFWLRQ ;5'f DQDO\VLV RI WKH FHUDPLF UHVLGXH REWDLQHG IURP S\URO\VLV RI 306, VKRZHG SHDNV GXH WR H[FHVV 6L DV ZHOO DV 6L& SHDNV 7KH S\URO\]HG FHUDPLF KDG DQ RYHUDOO FRPSRVLWLRQ RI b 6L& DQG ZWb 6L FDOFXODWHG EDVHG RQ WKH 6L& UDWLR GHWHUPLQHG E\ HOHPHQWDO DQDO\VLVf 3RO\PHU 306,, VKRZHG D FHUDPLF \LHOG RI b 7KH ;5' DQDO\VLV RI WKH S\URO\]HG FHUDPLF UHVLGXH VKRZHG QR 6L SHDNV IRU XQNQRZQ UHDVRQVf DOWKRXJK HOHPHQWDO DQDO\VLV UHYHDOHG VLOLFRQULFK FRPSRVLWLRQ ZWb 6L& DQG ZWb 6Lf 306,,, VKRZHG D PXFK KLJKHU FHUDPLF \LHOG RI b FRPSDUHG WR WKH RWKHU WZR 306 SRO\PHUV DQG KDG DQ HOHPHQWDO FRPSRVLWLRQ RI ZWb 6L& DQG ZWb 6L ;5' DQDO\VLV VKRZHG ERWK 6L DQG 6L& SHDNVf 7KH GLIIHUHQFHV LQ WKH S\URO\VLV \LHOGV ZHUH DWWULEXWHG WR GLIIHUHQFHV LQ FURVVOLQNLQJ LQ WKH WKUHH SRO\PHUV %DVHG RQ 105 GDWD ERWK 306, DQG 306,, FRQWDLQHG KLJKHU QXPEHU RI 6L+ IXQFWLRQDOLWLHV ZKLFK DUH SRWHQWLDO FURVVOLQNLQJ VLWHVf FRPSDUHG WR 306,,, 7KLV VXJJHVWHG WKDW FURVVOLQNLQJ ZDV PRUH H[WHQVLYH LQ 306,,, GXH WR FRQVXPSWLRQ RI 6L+ PRLHWLHV E\ FRQGHQVDWLRQ UHDFWLRQV 5HFDOO WKDW D SRODU VROYHQW VXFK DV 7+) DLGV LQ WKH DQLRQLF SRO\PHUL]DWLRQ RI PHWK\OFKORURVLODQHV ZLWK VRGLXP DQG OHDGV WR IRUPDWLRQ RI SRO\PHUV ZKLFK DUH ULFK LQ 6L+ JURXSV WKHVH 6L+ JURXSV XQGHUJR FRQGHQVDWLRQ FDXVLQJ H[WHQVLYH FURVVOLQNLQJ LQ WKH SRO\PHUf

PAGE 70

7DEOH 6\QWKHVLV FRQGLWLRQV DQG FKDUDFWHULVWLFV IRU 306 SRO\PHUV SUHSDUHG E\ :RRG >:RR@ 3RO\PHU 'HVLJQDWLRQ 6\QWKHVLV &RQGLWLRQV 0ROHFXODU :HLJKW &HUDPLF
PAGE 71

6H\IHUWK DW DO >6H\@ KDYH VLJQLILFDQWO\ HQKDQFHG S\URO\VLV \LHOGV RI 306 SRO\PHUV SUHSDUHG E\ :RRGfV PHWKRG E\ GHK\GURJHQDWLYHO\ FURVVOLQNLQJ WKH SRO\PHUV LQ WKH SUHVHQFH RI HDUO\ WUDQVLWLRQ PHWDO FRPSOH[ FDWDO\VWV ]LUFRQRFHQH DQG WLWDQRFHQHf VHH VHFWLRQ f 7KH FHUDPLF \LHOG RI 306 SRO\PHUV LQFUHDVHG IURP b IRU XQPRGLILHG SRO\PHUf WR b IRU FURVVOLQNHG SRO\PHUf 7KH FHUDPLF UHVLGXH DIWHU S\URO\VLV IRU D W\SLFDO FURVVOLQNHG SRO\VLODQH SRO\PHU KDG DQ HOHPHQWDO FRPSRVLWLRQ RI b 6L& b =U& DQG WUDFHV RI HOHPHQWDO 6L DV RSSRVHG WR b 6L& DQG b 6L IRU DQ XQPRGLILHG SRO\PHUf 7DEOH VKRZV S\URO\VLV UHVXOWV IRU D QXPEHU RI FURVV OLQNHG SRO\PHWK\OVLODQH SRO\PHUV SUHSDUHG XQGHU GLIIHUHQW SURFHVVLQJ FRQGLWLRQV LH YDU\LQJ FDWDO\VW FRQFHQWUDWLRQ VROYHQW DQG UHIOX[ WLPHf ,W LV HYLGHQW IURP WKH WDEOH WKDW WKH W\SH RI VROYHQW XVHG IRU WKH FDWDO\WLF FURVVOLQNLQJ SOD\V DQ LPSRUWDQW UROH LQ GHWHUPLQLQJ WKH FHUDPLF \LHOG RI WKH SRO\PHU SURGXFHG )RU H[DPSOH LW DSSHDUV WKDW KH[DQH DQG EHQ]HQH DUH JRRG VROYHQWV IRU FURVVOLQNLQJ LQ FRPSDULVRQ ZLWK SRODU VROYHQWV HWKHU DQG 7+) 7KLV LV QRW WR EH FRQIXVHG ZLWK WKH HIIHFW RI SRODU VROYHQWV RQ :XUW]FRXSOLQJ RI GLFKORURVLODQHV )RU H[DPSOH :RRG UHSRUWHG KLJKHU FHUDPLF \LHOG XVLQJ 7+) DQG ORZHU \LHOG XVLQJ KH[DQH 6H\IHUWK HW DOfV UHVXOWV LQGLFDWHG WKDW QRQSRODU VROYHQWV DUH XVHIXO LQ GHK\GURJHQDWLYH FURVVOLQNLQJ RI ORZ PROHFXODU ZHLJKW SRO\VLODQHV SUHSDUHG E\ WKH :XUW]FRXSOLQJ PHWKRGf )XUWKHUPRUH WKHUH DSSHDUV WR EH D OHYHO RI FDWDO\VW FRQFHQWUDWLRQ DERYH ZKLFK WKH S\URO\VLV \LHOG GRHV QRW FKDQJH VLJQLILFDQWO\ EXW EHORZ ZKLFK WKH S\URO\VLV \LHOG GHFUHDVHV =KDQJ HW DO >=KD =KD$ =KD%@ VWXGLHG WKH S\URO\VLV EHKDYLRU RI SRO\PHWK\OVLODQH SRO\PHUV SUHSDUHG E\ GHK\GURFRXSOLQJ RI PHWK\OVLODQH LQ WKH SUHVHQFH RI D '0= 'LPHWK\O =LUFRQRFHQHf FDWDO\VW &HUDPLF \LHOGV ZHUH b ZKHQ WKH SRO\PHU GLG QRW FRQWDLQ DQ\ SURFHVVLQJ DGGLWLYHV DQG b ZKHQ b SURFHVVLQJ DGGLWLYHV ZHUH DGGHG )LJXUH f 7KH FKHPLVWU\ RI WKH SURFHVVLQJ DGGLWLYHV ZDV QRW VSHFLILHGf

PAGE 72

7DEOH 3\URO\VLV UHVXOWV IRU FDWDO\WLFDOO\ FURVVOLQNHG SRO\VLODQH SRO\PHUV >6H\@D b &DWDO\VW '0=f PROb 6ROYHQW 5HDFWLRQ FRQGLWLRQ 3RO\PHU DSSHDUDQFH 3\URO\VLV \LHOG b +H[DQHE PLQUHIOX[ 2UDQJH VROLG +H[DQHE PLQUHIOX[ 2UDQJH VROLG +H[DQHE PLQUHIOX[ 2UDQJH VROLG +H[DQHE PLQUHIOX[
PAGE 73

)LJXUH 7*$ SORWV IRU SRO\PHWK\OVLODQH SRO\PHU SUHSDUHG E\ =KDQJ HW DO >=KD@

PAGE 74

7KH S\URO\]HG FHUDPLF UHVLGXH KDG DQ HOHPHQWDO FRPSRVLWLRQ RI ZWb 6L ZWb & LH FORVH WR VWRLFKLRPHWULF FRPSRVLWLRQf 7KH EXON RI WKH ZHLJKW ORVV LV VKRZQ WR RFFXU EHWZHHQ r& DQG r& LQ D JUDGXDO PDQQHU 7KLV ZHLJKW ORVV EHKDYLRU LV GLIIHUHQW IURP WKDW RI :RRGnV SRO\PHWK\OVLODQH SRO\PHUV SUHSDUHG E\ :XUW] FRXSOLQJ UHDFWLRQf ZKHUH ZHLJKW ORVV LV UHSRUWHG WR RFFXU EHWZHHQ r& DQG r& 7KH KHDWLQJ UDWHV ZHUH FRPSDUDEOH LH r&PLQ WR r&f =KDQJ HW DO DOVR VWXGLHG WKH FKHPLFDO HYROXWLRQ RI WKH SRO\PHWK\VOLODQH SRO\PHU GXULQJ S\URO\VLV WR r& XVLQJ GLIIXVH UHIOHFWDQFH LQIUDUHG )RXULHU WUDQVIRUP VSHFWURVFRS\ '5,)76f )LJXUH VKRZV '5,)7 VSHFWUD RI SRO\PHWK\OVLODQH SRO\PHU KHDWHG WR VHOHFWHG WHPSHUDWXUHV DW r&PLQ LQ QLWURJHQ DQG KHOG DW WHPSHUDWXUH IRU K 7KH r& VSHFWUD VKRZV WKH DSSHDUDQFH RI D VWURQJ SHDN DW a FPn DWWULEXWHG WR WKH EHQGLQJ YLEUDWLRQ RI 6L&+6L JURXS 7KLV LV DQDORJRXV WR WKH WKHUPDO UHDUUDQJHPHQW WDNLQJ SODFH GXULQJ WKH FRQYHUVLRQ RI SRO\GLPHWK\OVLODQH WR SRO\FDUERVLODQHf 6FKPLGW HW DO >6FK@ KDYH UHSRUWHG VLPLODU REVHUYDWLRQV $W r& WKH SRO\PHU LV VKRZQ WR ORVH ZHOO GHILQHG PROHFXODU VWUXFWXUH ZLWK WKH RQO\ SHDNV UHPDLQLQJ DWWULEXWHG WR Y &+f RI &)f FPnf Y 6L+f a FPnf DQG &+f RI 6L&+6L DW FPnf 7KHVH SHDNV GLVDSSHDUHG DW WHPSHUDWXUHV !r& DQG WKH VSHFWUD VKRZHG DEVRUSWLRQV LQ WKH UHJLRQ RI FPn WR FPn FRUUHVSRQGLQJ WR 6L& 5HFDOO WKDW OLQHDU SRO\VLODQHV SUHSDUHG E\ WKH :XUW]FRXSOLQJ UHDFWLRQ RI GLDON\O RU PRQRDON\O FKORURVLODQHV KDYH FHUDPLF \LHOGV RI RQO\ XS WR b >%XU 4LX :RR@ 6FKLOOLQJ DQG .DQQHU >6FK@ UHSRUWHG WKDW ZKHQ ROHILQLF KDORVLODQHV DUH XVHG DV PRQRPHUV LQ WKH :XUW]FRXSOLQJ UHDFWLRQ ZLWK VRGLXP WKH UHVXOWDQW SRO\VLODQHV FRQWDLQ ROHILQLF JURXSV ZKLFK DFW DV EDFNERQH EUDQFKLQJ VLWHV DQG FDXVH LQVLWX FURVV OLQNLQJ 7KLV UHVXOWHG LQ UHODWLYHO\ KLJKHU FHUDPLF \LHOGV bf IRU WKHVH SRO\PHUV

PAGE 75

)LJXUH '5,)7 6SHFWUD RI 306 SRO\PHU SUHSDUHG E\ =KDQJ HW DO >=KD@

PAGE 76

7KH ROHILQ JURXSV LQ ROHILQLF KDORVLODQHV GR QRW UHDFW ZLWK VRGLXP DQG WKHUHIRUH DUH UHWDLQHG LQ ODUJH DPRXQWV LQ WKH SRO\PHU 6FKPLGW HW DO >6FK@ KDYH VWXGLHG WKH S\URO\VLV FKDUDFWHULVWLFV RI YLQ\OLF SRO\VLODQH 936f PDQXIDFWXUHG E\ 8QLRQ &DUELGH &RUSRUDWLRQ 7DUU\WRZQ 1< EDVHG RQ 6FKLOOLQJ DQG .DQQHUfV SDWHQW >6FK@f 7KH SRO\PHU ZDV SUHSDUHG XVLQJ 0H6L&, 0H6L&, &+ &+6L0H&, PRQRPHUV LQ SURSRUWLRQ XQGHU UHIOX[LQJ FRQGLWLRQV LQ D [\OHQH7+) PL[WXUH ZW UDWLRf 7KH 7*$ SURILOH RI WKH 936 SRO\PHU LV VKRZQ LQ )LJXUH 7KH S\URO\VLV SURFHVV FDQ EH GLYLGHG LQWR WKUHH GLVWLQFW UHJLRQV EDVHG RQ WKH 7*$ RI SURILOH Lf a r& ZKHUH WKHUPDO FURVVOLQNLQJ RFFXUUHG ZLWKRXW PXFK ORVV RI ZHLJKW LLf ar& ZKHUH PDMRU ZHLJKW ORVV RFFXUUHG GXH WR SRO\PHU GHJUDGDWLRQ DQG LLLf DERYH r& ZKHUH VPDOO ZHLJKW ORVVHV ZHUH REVHUYHG 7KH FHUDPLF \LHOG ZDV b ZKLFK LV VOLJKWO\ KLJKHU WKDQ WKDW UHSRUWHG E\ 6FKLOOLQJ DQG .DQQHU 7KH '7$ VKRZHG D VWURQJ H[RWKHUP DW DURXQG r& FRUUHVSRQGLQJ WR FURVV OLQNLQJ UHDFWLRQV DQG D ZHDNHU H[RWKHUP DW DERXW r&f GXULQJ UHJLPH RI ODUJH ZHLJKW ORVV 6FKPLGW HW DO VXJJHVWHG WKDW WKH H[RWKHUP DW DERXW ar& PD\ EH LQGLFDWLYH RI SDUWLDO FU\VWDOOL]DWLRQ RI VLOLFRQ FDUELGH (OHPHQWDO DQDO\VLV RI WKH FHUDPLF IRUPHG DIWHU S\URO\VLV DW r& VKRZHG D FRPSRVLWLRQ RI b 6L b & b 2 DQG OHVV WKDQ D SHUFHQW HDFK RI + DQG 1 7KH SUHVHQFH RI H[FHVV FDUERQ ZWbf LQ WKH FHUDPLF LV QRW VXUSULVLQJ FRQVLGHULQJ WKH IDFW WKDW YLQ\OLF JURXSV DUH UHWDLQHG LQ WKH SRO\PHU EDFNERQH GXH WR HDUO\ FURVVOLQNLQJ UHDFWLRQV DW WHPSHUDWXUHV OHVV WKDQ r& 7KH WUDQVPLVVLRQ ,5 VSHFWUD RI DVUHFHLYHG 936 DQG 936 KHDWWUHDWHG DW WHPSHUDWXUHV RI r& r& r& DQG r& LQ QLWURJHQ DWPRVSKHUH DUH VKRZQ LQ )LJXUH 7DEOH >4LX% &RO@ OLVWV WKH ,5 SHDN DVVLJQPHQWV IRU WKH 936 SRO\PHU 7KH 936 SRO\PHU XQGHUJRHV IROORZLQJ FKDQJHV XSRQ KHDWLQJ WR r& Lf GHFUHDVH LQ

PAGE 77

5RWDWLYR :ROJKW 3HUFRQW )LJXUH 7*$ DQG '7$ SORWV IRU D 936 SRO\PHU KHDWHG LQ 1 DW r&PLQ WR r& >6FK@ f§41 ,9 ;

PAGE 78

7DEOH 3HDN DVVLJQPHQWV IRU ,5 DEVRUSWLRQ VSHFWUD RI YLQ\OLF SRO\VLODQHV >4LX% &RO@ 3HDN FPnf $VVLTQPHQW Pf Y &+ &+f RI 6L&+ &+ Vf YDV &+f RI &+ Vf YV &+f RI &+ Vf Y 6L+f Zf Y & f Zf Y & &f RI 6L&+ &+ Vf 6L&+ &+f YVf 6 &+f IURP 6L&+ Vf FR &+f IURP 6L &+ 6LY 6L26Lf Pf 6L+f 9DV 6L&f Y VWUHWFKLQJ EHQGLQJ FR EHQGLQJ S URFNLQJ YV YHU\ VWURQJ V VWURQJ P PHGLXP Z ZHDN

PAGE 79

L r L L L n L L L L L n L L L L L r r :$9(180%(5 FPrf )LJXUH ,5 VSHFWUD RI 936 SRO\PHU Df URRP WHPSHUDWXUH Ef r& Ff r& Gf r& Hf r& >6FK@

PAGE 80

DV\PPHWULF VWUHWFKLQJ RI &+ EDQG FPn LLf GHFUHDVH LQ LQWHQVLW\ DQG EURDGHQLQJ RI 6L&+ &+ GHIRUPDWLRQ EDQG FPnf LLLf VOLJKW GHFUHDVH LQ ERWK WKH LQWHQVLW\ DQG DUHD DQG EURDGHQLQJ RI WKH 6L+ VWUHWFKLQJ EDQG FPnf DQG LYf DSSHDUDQFH RI EHQGLQJ YLEUDWLRQ DW FPn GXH WR &+ EHQGLQJ YLEUDWLRQ RI 6L &+ &+ 7KH GHFUHDVH LQ LQWHQVLW\ DQG EURDGHQLQJ RI 6L&+ &+ EDQG LV DWWULEXWHG WR ORVV RI YLQ\O JURXSV GXH WR FURVVOLQNLQJ UHDFWLRQV 7KH LQFUHDVH LQ 6L+ DEVRUSWLRQ EDQG DW r& FRXOG EH DWWULEXWHG WR PHWK\OHQH LQVHUWLRQ UHDFWLRQV VLPLODU WR WKH UHDFWLRQV RFFXUULQJ LQ WKH FRQYHUVLRQ RI SRO\GLPHWK\OVLODQH WR SRO\FDUERVLODQH >$EX@ KDYH DOVR VWXGLHG WKH S\URO\VLV EHKDYLRU RI SRO\VLODQH SRO\PHUV SUHSDUHG E\ :XUW]FRXSOLQJ RI PRQRRUJDQRVLODQHV 556L&, ZKHUH 5 &+ DQG 5 + &+ &+ &+ &+Q &+ RU &+f ZLWK VRGLXP LQ DQ LQHUW VROYHQW 7DEOH VKRZV LQIRUPDWLRQ UHJDUGLQJ WKH SRO\PHU FKDUDFWHULVWLFV DQG WKH S\URO\VLV EHKDYLRU $FFRUGLQJ WR $EX(LG HW DO WKH KLJK FHUDPLF \LHOG IRU SRO\PHWK\OVLODQH &+6L+fQ f LV GXH WR DQ HDUO\ RQVHW RI LQWHUPHGLDWH FDUERVLODQH IRUPDWLRQ DQG FURVV OLQNLQJ RI 6L+ IXQFWLRQDOLWLHV HJ UHDFWLRQ ZLWK PRLVWXUH WR IRUP 6L2+ DQG VXEVHTXHQW FRQGHQVDWLRQ WR IRUP 6L26L QHWZRUNVf 7KH UHODWLYHO\ KLJK FHUDPLF \LHOG IRU SRO\GLPHWK\OVLODQH bf LV QRW FRQVLVWHQW ZLWK YDOXHV abf UHSRUWHG E\ :RRG >:RR@ DQG &DUOVVRQ HW DO >&DU@ )RU RWKHU GLDON\O RU DON\ODU\O SRO\VLODQHV OLVWHG LQ WKH WDEOH WKH ORZ FHUDPLF \LHOGV DUH FRQVLVWHQW ZLWK SUHYLRXVO\ UHSRUWHG YDOXHV

PAGE 81

7DEOH &HUDPLF \LHOG FKDUDFWHULVWLFV DQG GHFRPSRVLWLRQ WHPSHUDWXUHV IRU SRO\VLODQH SRO\PHUV V\QWKHVL]HG E\ $EX(LG HW DO >$EX@ 3RO\PHU 7\SH 7KHRU 6L& \LHOGb $FWXDO FHUDPLF \LHOG b bRI 7KHRU \LHOG 2QVHW RI GHFRPS WHPS r& (QG RI GHFRPS WHPS r& >&+f6L@Q >&+f6L@Q >&+6L&+f@Q >&+6LQ &+f@Q &+6LQ &+f@Q >&+6L+f@Q >&+6L&+f@f

PAGE 82

&URVVOLQNLQJ RI 3RO\VLODQH 3RO\PHUV 3RO\VLODQH SRO\PHUV H[KLELW D ZLGH UDQJH RI SURSHUWLHV EDVHG RQ WKH SHQGDQW VXEVWLWXHQW JURXSV LQ WKH SRO\PHU FKDLQ DQG WKH GHJUHH RI FURVVOLQNLQJ 7KH SK\VLFDO DSSHDUDQFH RI WKH SRO\PHU FRXOG UDQJH IURP WKDW RI D YLVFRXV OLTXLG HJ SRO\PHWK\OVLODQHf WR D VROLG H J SRO\PHWK\OSKHQ\OVLODQHf GHSHQGLQJ RQ WKH PROHFXODU DUFKLWHFWXUH RI WKH SRO\PHU FURVVOLQNLQJ PROHFXODU ZHLJKW VLGH JURXSV HWFf 7KH SRO\PHUV FDQ EH FURVVOLQNHG E\ R[LGDWLRQ URRP WHPSHUDWXUH YXOFDQL]DWLRQ DQG SKRWRO\VLV 2[LGDWLYH FURVVOLQNLQJ 2[LGDWLYH FURVVOLQNLQJ RI SRO\VLODQH SRO\PHUV FDQ EH DFFRPSOLVKHG E\ FRQYHUWLQJ 6L+ JURXSV LQ WKH SRO\PHU WR 6L2& RU 6L26L JURXSV E\ UHDFWLQJ ZLWK DLU RU PRLVWXUH 7KHVH R[LGDWLYHO\ FURVVOLQNHG SRO\PHUV DUH LQVROXEOH LQ RUJDQLF VROYHQWV DQG GR QRW PHOW LH LQIXVLEOHf GXULQJ S\URO\VLV WR VLOLFRQ FDUELGH 7KH GHJUHH DQG UDWH RI FURVVOLQNLQJ GHSHQGV RQ WKH DPRXQW RI 6L+ JURXSV SUHVHQW LQ WKH SRO\PHU )LJXUH VKRZV DQ )7,5 VSHFWUXP RI D SRO\PHWK\OVLODQH SRO\PHU ZKLFK FOHDUO\ GHPRQVWUDWHV WKH DLU VHQVLWLYLW\ RI WKHVH SRO\PHUV DV LQGLFDWHG E\ WKH EURDG DEVRUSWLRQ EDQG DURXQG FPn 7KLV DEVRUSWLRQ LV GXH WR 6L2+ VWUHWFKLQJ ZKLFK DULVHV IURP FRQYHUVLRQ RI 6L+f 7KH R[\JHQ VHQVLWLYLW\ RI WKH SRO\VLODQH SRO\PHUV LV DWWUDFWLYH IRU VRPH DSSOLFDWLRQV HJ PXOWLOD\HU OLWKRJUDSK\f EXW WKH LQFRUSRUDWLRQ RI R[\JHQ LV VRPHWLPHV QRW GHVLUDEOH LI WKH SRO\PHU LV XVHG DV D 6L& SUHFXUVRU 5RRP WHPSHUDWXUH YXOFDQL]DWLRQ 7KH 6L+ JURXSV SUHVHQW LQ WKH SRO\VLODQH SRO\PHUV KDYH EHHQ H[SORLWHG LQ WKH SUHSDUDWLRQ RI KLJKO\ FURVVOLQNHG SRO\PHUV E\ FDWDO\WLF GHK\GURJHQDWLRQ VHH VHFWLRQ f

PAGE 83

$EVRUEDQFH )LJXUH )7,5 VSHFWUXP RI SRO\PHWK\OVLODQH SRO\PHU SUHSDUHG E\ $EX(LG HW DO >$EX@

PAGE 84

:HVW HW DO >:HV%@ KDYH FURVVOLQNHG 6L+ FRQWDLQLQJ SRO\SKHQ\OVLODQH SRO\PHUV E\ XVLQJ D YLQ\OLF VLODQH PRQRPHU HJ WULYLQ\OSKHQ\OVLODQH WULYLQ\OPHWK\OVLODQHf DV WKH FURVVOLQNLQJ DJHQW LQ WKH SUHVHQFH RI WUDFHV RI FKORURSODWLQLF DFLG DV D FDWDO\VW 'XULQJ WKH UHDFWLRQ WKH LQLWLDOO\ YLVFRXV UHDFWLRQ PL[WXUH WUDQVIRUPV WR D VROLG SRO\PHU ZKLFK LV LQVROXEOH DQG LQIXVLEOH D SURFHVV DQDORJRXV WR URRP WHPSHUDWXUH YXOFDQL]DWLRQ RI VLOLFRQH HODVWRPHUVf 7KH FURVVOLQNLQJ UHDFWLRQ FDQ EH UHSUHVHQWHG DV 3K 3K 3K ,, f§6L f§6L f§6L f§ , + + + 9L +3W&, 9Lf§6LB3K 9L 6L ‘f§6Lf§ 3K B6L f§6Lf§3K &+ f , 3K 6LSK B6LB 9L} &+ &+ 3K } &+ 3KRWRFURVV OLQNLQJ 4LX DQG 'X >4LX%@ KDYH VKRZQ WKDW ZKHQ SRO\VLODQH SRO\PHUV VXFK DV SRO\PHWK\OVLODQH DQG SRO\SKHQ\OVLODQH ZHUH LUUDGLDWHG ZLWK 89 OLJKW RI ZDYHOHQJWK

PAGE 85

QP LQ QLWURJHQ RU YDFXXP FURVVOLQNLQJ RI WKH SRO\PHU RFFXUUHG ZLWK WKH IRUPDWLRQ RI LQVROXEOH PDWHULDO 2QH RI WKH GLVDGYDQWDJHV RI SKRWRFURVV OLQNLQJ LV WKDW VRPH GHJUDGDWLRQ RI SRO\PHU PROHFXODU ZHLJKW GXH WR SKRWRVFLVVLRQf DOZD\V DFFRPSDQLHV SKRWRFURVV OLQNLQJ DV VKRZQ E\ HTXDWLRQV f f DQG ff +RZHYHU :HVW HW DO >:HV%@ REVHUYHG WKDW ZKHQ D FURVVOLQNLQJ DJHQW FRQWDLQLQJ & & GRXEOH ERQGV HJ WHWUDYLQ\OVLODQHf ZDV PL[HG ZLWK WKH SRO\PHU DQG WKHQ LUUDGLDWHG ZLWK 89 OLJKW QR GHJUDGDWLRQ LQ PROHFXODU ZHLJKW RFFXUUHG DQG DOO RI WKH SRO\PHU FRQYHUWHG WR DQ LQVROXEOH PDWHULDO 7KH SKRWR FURVVOLQNLQJ WDNHV SODFH E\ FOHDYDJH RI SRO\VLODQH FKDLQV WR IRUP UDGLFDOV DQG DGGLWLRQ RI WKHVH UDGLFDOV WR & & GRXEOH ERQGV RI YLQ\OLF VLODQHV SRO\XQVDWXUDWHG DGGLWLYHVf FDXVLQJ IRUPDWLRQ RI FURVVOLQNV DQG JHQHUDWLRQ RI QHZ FDUERQ UDGLFDOV 7KHVH QHZ FDUERQ UDGLFDOV VXVWDLQ IXUWKHU FURVVOLQNLQJ UHDFWLRQV HTXDWLRQ ff 7KH UHDFWLRQV FDQ EH UHSUHVHQWHG DV JLYHQ LQ )LJXUH $SSOLFDWLRQV RI 3RO\VLODQH 3RO\PHUV 7KHUH DUH WKUHH PDLQ WHFKQRORJLFDO DSSOLFDWLRQV RI SRO\VLODQH SRO\PHUV Lf SUHFXUVRUV IRU 6L& LLf SKRWRLQLWLDWRUV IRU UDGLFDO SRO\PHUL]DWLRQ UHDFWLRQV DQG LLLf SKRWRUHVLVWV LQ PLFURHOHFWURQLFV 3UHFXUVRU IRU %6L&
PAGE 86

V 6L 5 U, )W 5L 5 6L 6L L 6L 5 5 U 5 5 5R 7 6L 6L 6L 5 5 5 ZKHUH 5 Q&A+A 5 F&+_L KY KY KY Q&J+LD RU &+ ^ 5 f§6L 5 9 $  f§ 6L 9 f 6L 6L 5L 5 RUF&J+A f f f f )LJXUH 6FKHPH IRU SKRWR FURVVOLQNLQJ UHDFWLRQV RI SRO\VLODQH SRO\PHUV

PAGE 87

FRQYHUVLRQ RI 3'06 WR 3&6 WDNHV SODFH E\ .XPDGD UHDUUDQJHPHQW >6KL@ LQ ZKLFK LQVHUWLRQ RI &+ JURXSV LQWR WKH PDLQ FKDLQ 6L6L WDNHV SODFH OHDYLQJ D K\GURJHQ ERXQG WR VLOLFRQ DV VKRZQ EHORZ &+T &+R O 6L f§6L f§ &+&+ $UJRQ r& 6Lf§ & , + + Q f 3'06 3&6 7RU$ 7RU% 7RU 6DF$ 6DF%@ 1RQVWRLFKLRPHWULF 8) ILEHUV

PAGE 88

KDYH URRP WHPSHUDWXUH PHFKDQLFDO SURSHUWLHV VLPLODU WR WKDW RI 1LFDORQr1 ILEHUV ZLWK DYHUDJH WHQVLOH VWUHQJWKV a *3D ,Q DGGLWLRQ 8) ILEHUV VKRZHG VLJQLILFDQWO\ LPSURYHG WKHUPRPHFKDQLFDO VWDELOLW\ FRPSDUHG WR 1LFDORQ DV LQGLFDWHG E\ ORZHU ZHLJKW ORVVHV ORZHU VSHFLILF VXUIDFH DUHDV DQG LPSURYHG VWUHQJWK UHWHQWLRQ DIWHU KHDW WUHDWPHQW WR r& 1HDUVWRLFKLRPHWULF 8) ILEHUV f8)+0 )LEHUVff KDYH KLJK WHQVLOH VWUHQJWKV *3Df ILQH JUDLQ VL]HV PRVWO\ SPf KLJK EXON GHQVLWLHV JFPf DQG VPDOO UHVLGXDO SRUH VL]HV PRVWO\ SPf 7KHVH ILEHUV UHWDLQHG b RI WKHLU LQLWLDO VWUHQJWK DIWHU KHDW WUHDWPHQW LQ DUJRQ DW r& ,W LV DOVR SRVVLEOH WR FRQYHUW SRO\VLODQH SRO\PHUV WR VLOLFRQ FDUELGH ILEHUV GLUHFWO\ ZLWKRXW UHVRUWLQJ WR WKH SUHSDUDWLRQ RI LQWHUPHGLDWH SRO\FDUERVLODQH SRO\PHUV $V GLVFXVVHG LQ VHFWLRQ :HVW HW DO >:HV :HV$@ KDYH SUHSDUHG SKHQ\OPHWK\OVLODQHGLPHWK\OVLODQH FRSRO\PHUV 3RO\VLODVW\UHQH 366ff ZKLFK DIIRUG LPSURYHG SURFHVVDELOLW\ RYHU 3'06 +RZHYHU WKH ILEHUV SUHSDUHG IURP WKHVH SRO\PHUV UHTXLUH D FURVVOLQNLQJ FXULQJf VWHS WR PDNH WKHP LQIXVLEOH LQ RUGHU WR VXUYLYH S\URO\VLV 6LQFH WKH SRO\PHUV ODFN 6L+ JURXSV HOLPLQDWLQJ WKH SRVVLELOLW\ RI DLUFXULQJf WKH RQO\ RSHUDWLYH FURVVOLQNLQJ PHFKDQLVP LV E\ 89 LUUDGLDWLRQ 7KHUPRPHFKDQLFDO GDWD RQ WKH ILEHUV SUHSDUHG E\ WKLV PHWKRG KDYH QRW EHHQ UHSRUWHG /LSRZLW] HW DO >/LS@ KDYH SUHSDUHG 6L& ILEHUV IURP PHWK\OSRO\VLODQH 036f SRO\PHUV V\QWKHVL]HG EDVHG RQ %DQH\ HW DOfV UHGLVWULEXWLRQVXEVWLWXWLRQ UHDFWLRQV RI PHWK\OFKORURGLVLODQHV DV GLVFXVVHG LQ VHFWLRQ f )LEHUV ZHUH PHOW VSXQ FURVV OLQNHG FXUHGf DQG FRQYHUWHG WR 6L& E\ S\URO\VLV %\ YDU\LQJ WKH UDWLR RI DON\O WR SKHQ\O *ULJQDUG UHDJHQWV XVHG WR UHDFW WKH LQWHUPHGLDWH PHWK\OFKORURSRO\VLODQH SRO\PHUf ILEHUV ZLWK FRPSRVLWLRQ UDQJLQJ IURP VLOLFRQULFK WKURXJK VWRLFKLRPHWULF WR FDUERQULFK ZHUH SURGXFHG 7KH PHWKRG RI FURVVOLQNLQJ ZDV QRW VSHFLILHG EXW WKH UHODWLYHO\ ORZ

PAGE 89

R[\JHQ FRQWHQW LQ WKH ILEHUV ZWbf FRPSDUHG WR 1LFDORQ r1 VXJJHVWV WKDW DLUn FXULQJ VWHS ZDV QRW XVHG 7KH ORZ R[\JHQ FRQWHQW LQ WKH ILEHUV FRQWULEXWHG WR LPSURYHG WKHUPRPHFKDQLFDO VWDELOLW\ RI WKHVH ILEHUV RYHU WKDW RI 1LFDORQr1 ILEHUV 0RUH UHFHQWO\ /LSRZLW] HW DO >/LS$ /LS% /LS$ /LS% /LS@ GHYHORSHG QHDUVWRLFKLRPHWULF SRO\FU\VWDOOLQH 6L& ILEHUV XVLQJ SRO\FDUERVLODQH DQG PHWK\OSRO\GLVLO\OD]DQH SRO\PHUV )LEHUV ZHUH PHOW VSXQ R[LGDWLYHO\ FURVVOLQNHG DQG KHDW WUHDWHG DW WHPSHUDWXUHV DERYH r& LQ DUJRQ LQ RUGHU WR UHDFW H[FHVV FDUERQ DQG R[\JHQ LQ WKH ILEHUV $V QRWHG HDUOLHU 3&GHULYHG ILEHUV QRUPDOO\ EHFRPH YHU\ ZHDN DQG GHYHORS D SRURXV ODUJHJUDLQHG PLFURVWUXFWXUH GXULQJ WKLV W\SH RI KHDW WUHDWPHQW +RZHYHU /LSRZLW] HW DO LQFRUSRUDWHG D ERURQEDVHG VLQWHULQJ DGGLWLYH LQ WKH SRO\PHU ZKLFK DOORZHG ILEHUV WR EH GHQVLILHG DIWHU WKH FDUERWKHUPDO UHGXFWLRQ UHDFWLRQV GLVFXVVHG HDUOLHU 7KH UHVXOWLQJ ILEHUV KDG ILQH GLDPHWHU SPf KLJK UHODWLYH GHQVLW\ VPDOO DYHUDJH JUDLQ VL]HV LQ WKH UDQJH SP GHSHQGLQJ RQ WKH 6L& UDWLRf ORZ R[\JHQ FRQWHQW bf KLJK WHQVLOH VWUHQJWK *3Df KLJK HODVWLF PRGXOXV XS WR *3Df DQG JRRG VWUHQJWK UHWHQWLRQ DIWHU KLJK WHPSHUDWXUH r&f KHDW WUHDWPHQW LQ DUJRQ 7KH NH\ OLPLWDWLRQ LQ WKLV SURFHVV ZDV DSSDUHQWO\ D GLIILFXOW\ LQ SURGXFLQJ FRQWLQXRXV ILEHUV 7DNHGD HW DO >7DN@ KDYH UHSRUWHG WKH GHYHORSPHQW RI ORZR[\JHQFRQWHQW ZWbf ILQHGLDPHWHU SPf 6L& ILEHUV 7KHVH ILEHUV n+L1LFDORQff ZHUH SUHSDUHG LQ D VLPLODU PDQQHU DV 1LFDORQ LH E\ PHOW VSLQQLQJ RI SRO\FDUERVLODQHf H[FHSW WKDW FURVV OLQNLQJ ZDV DFFRPSOLVKHG E\ HOHFWURQ EHDP LUUDGLDWLRQ LQVWHDG RI R[LGDWLRQ 7KH KLJK WHPSHUDWXUH VWDELOLW\ RI WKH ILEHUV LQFUHDVHG GUDPDWLFDOO\ DV WKH R[\JHQ FRQWHQW RI WKH ILEHUV GHFUHDVHG )LEHUV ZLWK ZWb R[\JHQ UHWDLQHG KLJK VWUHQJWK *3Df DQG KLJK PRGXOXV *3Df DIWHU KHDW WUHDWPHQW DW r& LQ DUJRQ 7KHVH ILEHUV KDG D FKHPLFDO FRPSRVLWLRQ RI b 6L b & DQG ZWb 2 7KH PDLQ GUDZEDFN RI WKLV

PAGE 90

PHWKRG LV WKDW FURVVOLQNLQJ RI WKH SRO\PHU E\ HOHFWURQ EHDP LUUDGLDWLRQ LV D VORZHU DQG H[SHQVLYH SURFHVVLQJ VWHS 0RUH UHFHQWO\ 7DNHGD HW DO >7DN@ SURGXFHG QHDU VWRLFKLRPHWULF 6L& ILEHUV f+L1LFDORQ 7\SH 6ff E\ D PRGLILHG +L1LFDORQ SURFHVV 7KHVH ILEHUV KDG D FKHPLFDO FRPSRVLWLRQ RI b 6L DQG b & DQG H[KLELWHG EHWWHU WKHUPRPHFKDQLFDO WKDQ +L1LFDORQ ILEHUV =KDQJ HW DO >=KD =KD$ =KD%@ KDYH VROXWLRQVSXQ ILEHUV IURP SRO\PHWK\OVLODQH SRO\PHUV VHH VHFWLRQ f DQG FRQYHUWHG WKHP WR 6L& ILEHUV E\ S\URO\VLV 6LQFH WKH SUHFXUVRU SRO\PHU ZDV ORZ LQ PROHFXODU ZHLJKW LW UHTXLUHG DGGLWLRQ RI D FURVVOLQNLQJ DJHQW XQVSHFLILHG FKHPLVWU\f WR UHQGHU WKH ILEHUV LQIXVLEOH 7KH DGGLWLYH DOVR DFWHG DV D VSLQQLQJ DLG IRU WKH SRO\PHU LQ DGGLWLRQ WR SURYLGLQJ H[WUD FDUERQ WR DGMXVW WKH VWRLFKLRPHWU\ RI WKH FHUDPLF SURGXFHG WR WKDW RI SXUH 6L& 7KH 6L& ILEHUV SURGXFHG E\ =KDQJ HW DO KDG QHDUVWRLFKLRPHWULF FRPSRVLWLRQ 'HQVH ILEHUV ZHUH SURGXFHG E\ DGGLQJ D ERURQEDVHG VLQWHULQJ DGGLWLYH '5,)7 VSHFWUD RI WKH r& S\URO\]HG ILEHUV VKRZHG WKH SUHVHQFH RI D VPDOO DPRXQW RI R[\JHQ H[DFW DPRXQW QRW GHWHUPLQHGf 7KLV ZDV DWWULEXWHG WR FRQWDPLQDWLRQ GXULQJ WR KDQGOLQJ DV 306 SRO\PHUV DUH YHU\ VHQVLWLYH WRZDUGV DLU 7KHUPRPHFKDQLFDO VWDELOLW\ GDWD RQ WKHVH ILEHUV LQGLFDWH WKDW WKH\ DUH VXSHULRU WR FRPPHUFLDOO\ DYDLODEOH 1LFDORQr1 ILEHUV DOWKRXJK QR GLUHFWO\ FRPSDUDEOH GDWD ZDV UHSRUWHG 6H\IHUWK HW DO >6H\@ KDYH GHPRQVWUDWHG WKH SRWHQWLDO IRU SURGXFWLRQ RI QHDU VWRLFKLRPHWULF 6L& ILEHUV IURP SRO\PHWK\OVLODQH SRO\PHUV ZKLFK DUH FDWDO\WLFDOO\ FURVV OLQNHG VHH VHFWLRQ f +RZHYHU WKH ILEHUV QHHG DQ DGGLWLRQDO FXULQJ VWHS ZKLFK FDQ EH EURXJKW DERXW E\ 89 LUUDGLDWLRQ ,QIRUPDWLRQ RQ WKHUPRPHFKDQLFDO SURSHUWLHV RQ WKHVH ILEHUV LV QRW DYDLODEOH

PAGE 91

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fQ 6W\UHQH >3K&+6L0HfR0H6Lf@Q (WK\O DFU\ODWH >3K&+6L0Hf3K0H6Lf@Q 0HWK\O PHWKDFU\ODWH 3K0H6LfQ ,VRRFW\O DFU\ODWH >3K0H6Lf0H6Lf@Q $FU\OLF DFLG >&\+H[6L0HfQ@ 3KHQR[\HWK\O DFU\ODWH >&\+H[6L0Hf0H6Lf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

PAGE 92

KHLJKWZLGWKf RI IHDWXUHV LQ & FKLSV >0, 0,$ 0,%@ 7KH FODVVLFDO VLQJOH OD\HU UHVLVW SURFHVV XVHG LQ PLFUROLWKRJUDSK\ KDV EHHQ IRXQG WR EH LQDGHTXDWH ZKHQ GHDOLQJ ZLWK FXUUHQW WUHQGV DQG OLWKRJUDSKHUV KDYH UHVRUWHG WR PXOWLOD\HU UHVLVW SURFHVVHV WR PHHW WKH FXUUHQW UHTXLUHPHQWV )LJXUH VKRZV D FRPSDULVRQ RI VLQJOH OD\HU SURFHVV YV PXOWLOD\HU SURFHVV >0,@ 7KH FODVVLFDO VLQJOH OD\HU UHVLVW SURFHVV ZHW GHYHORSPHQWf LQYROYHV H[SRVXUH RI WKH UHVLVW DQG GHYHORSPHQW RI D SDWWHUQ XVLQJ D VXLWDEOH VROYHQW 7KHUH LV D ORVV LQ OLQH ZLGWK FRQWURO IRU VPDOO IHDWXUHV VLQFH ZHW GHYHORSPHQW SURFHVVHV DUH LVRWURSLF ,Q WKH FDVH RI PXOWLOD\HU SKRWRUHVLVW SURFHVV WKH ZDIHU LV FRYHUHG ZLWK D WKLFN LQHUW SODQDUL]LQJ SRO\PHU OD\HU IROORZHG E\ D WKLQ OD\HU RI SKRWRUHVLVW +LJK UHVROXWLRQ LQ OLQH ZLGWK FDQ EH DFKLHYHG VLQFH WKH UHVLVW OD\HU FDQ EH WKLQQHU WKDQ ZKDW LV DFFHSWDEOH LQ VLQJOH OD\HU UHVLVW SURFHVV SP FRPSDUHG WR a SP IRU VLQJOH OD\HU UHVLVWVf 6XEVHTXHQWO\ WKH SDWWHUQ FDQ EH ZHW GHYHORSHG ZLWKRXW ORVV LQ UHVROXWLRQf RU GU\ GHYHORSHG GXULQJ LPDJLQJ DEODWLYH H[SRVXUHf GRZQ WR WKH SODQDUL]LQJ OD\HU DQG WKH LPDJH FDQ EH WUDQVIHUUHG WKURXJK WKH SODQDUL]LQJ OD\HU E\ 5,( R[\JHQ UHVLVWDQW LRQ HWFKLQJf $ QHFHVVDU\ UHTXLUHPHQW IRU WKH PXOWLOD\HU UHVLVW SURFHVV LV WKDW WKH SKRWRUHVLVW UHPDLQLQJ DIWHU GHYHORSLQJ PXVW EH UHVLVWDQW WR 5,( LQ RUGHU WR PDVN WKH XQGHUO\LQJ SRO\PHU HIIHFWLYHO\ 3RO\VLODQHV KDYH EHHQ IRXQG WR EH LGHDOO\ VXLWHG IRU XVH DV SKRWRUHVLVWV VLQFH WKH\ DUH VWDEOH WR 5,( E\ IRUPLQJ D WKLQ OD\HU RI LQHUW 6L ,Q DGGLWLRQ SRO\VLODQHV SRVVHVV H[FHOOHQW SURFHVVLQJ SURSHUWLHV VXFK DV JRRG WKHUPDO VWDELOLW\ VROXELOLW\ IRU FRDWLQJV DQG LPDJHDELOLW\ WR OLJKW DQG LRQL]LQJ UDGLDWLRQ

PAGE 93

:HW 'HYHORSPHQW VLQJOH OD\HUf 'U\ 'HYHORSPHQW PXOWLOD\HUf 5HVLVW 6XEVWUDWH &RDW 5HVLVW 3ODQDUL]LQJ /D\HU 6XEVWUDWH 0DVN ([SRVH 'HYHORS 'U\ (WFK 3ODVPD 6WULS (WFK 6WULS )LJXUH &RPSDULVRQ RI VLQJOH OD\HU SKRWRUHVLVW SURFHVV YV PXOWLOD\HU SKRWRUHVLVW SURFHVV >01@

PAGE 94

&+$37(5 (;3(5,0(17$/ 352&('85(6 5ROH RI 3RO\YLQ\OVLOD]DQH DV D 6SLQQLQJ $LG IRU 3ROYFDUERVLODQH 3RO\PHU V\QWKHVLV 36= ZDV V\QWKHVL]HG DFFRUGLQJ WR WKH SURFHGXUHV GHYHORSHG E\ 7RUHNL HW DO >7RU@ 7KLV LQYROYHG SRO\PHUL]DWLRQ RI D F\FOLF YLQ\OVLOD]DQH WULPHWK\O WULYLQ\OF\FORWULVLOD]DQHrf VHH )LJXUH f LQ WKH SUHVHQFH RI D UDGLFDO LQLWLDWRU GLFXP\O SHUR[LGH '&3f 7KH UHDFWLRQ DVVHPEO\ XVHG IRU 36= V\QWKHVLV LV VKRZQ LQ )LJXUH ,Q D W\SLFDO 36= V\QWKHVLV J RI F\FOLF YLQ\OVLOD]DQH PRQRPHU ZDV PL[HG ZLWK J RI '&3 DQG J RI WROXHQH LQ D PO GRXEOHQHFNHG IODVN 3RO\PHUL]DWLRQ ZDV W\SLFDOO\ FDUULHG RXW XQGHU QLWURJHQ DW D WHPSHUDWXUH RI r& IRU K + 1 FK FK f§ 6L Vc f§ FK FK +f§1 1f§+ )LJXUH 6WUXFWXUH RI WULPHWK\OWULYLQ\OF\FORWULVLOD]DQH I 3HWUDUFK 6\VWHPV %ULVWRO 3$

PAGE 95

)LJXUH 6FKHPDWLF RI UHDFWLRQ DVVHPEO\ IRU 36= V\QWKHVLV

PAGE 96

7KH PROHFXODU ZHLJKW RI 36= ZDV FRQWUROOHG E\ VHOHFWLYHO\ UHPRYLQJ ORZ PROHFXODU ZHLJKW IUDFWLRQV fRLOVff E\ IUDFWLRQDO GLVWLOODWLRQ XVLQJ DQ RLO EDWK DW WHPSHUDWXUHV UDQJLQJ IURP WR r& 3RO\FDUERVLODQH 3&6f ZDV V\QWKHVL]HG DFFRUGLQJ WR WKH PHWKRGV UHSRUWHG E\ 7RUHNL HW DO >7RU@ DQG SURFHGXUHV GHYHORSHG DW 8QLYHUVLW\ RI )ORULGD 3&6 ZDV V\QWKHVL]HG E\ SUHVVXUH S\URO\VLV RI SRO\GLPHWK\OVLODQHr LQ D VWDLQOHVV VWHHO DXWRFODYHr XQGHU D QLWURJHQ DWPRVSKHUH DW ar& 3&6 SRO\PHUV ZHUH SUHSDUHG DQG VXSSOLHG IRU WKLV VWXG\ E\ FRZRUNHUV DW 8QLYHUVLW\ RI )ORULGD 3&6 ORWV DQG FRPELQHG LQ SURSRUWLRQf ZHUH XVHG LQ WKLV VWXG\ 7KH DYHUDJH PROHFXODU ZHLJKW ZDV 7KH *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU WKH FRPELQHG 3&6 SRO\PHU LV GLVFXVVHG LQ VHFWLRQ f 7KLV UHODWLYHO\ KLJK PROHFXODU ZHLJKW 3&6 QRW RQO\ HQDEOHG SUHSDUDWLRQ RI KLJKO\ FRQFHQWUDWHG VROXWLRQV HJ W\SLFDOO\ ZWbf EXW DOVR DOORZHG ILEHUV WR EH S\URO\]HG ZLWKRXW PHOWLQJ 6SLQ GRSH SUHSDUDWLRQ ILEHU VSLQQLQJ DQG ILEHU KHDW WUHDWPHQW 7KH ,QIOXHQFH RI SRO\YLQ\OVLOD]DQH 36=f DV D VSLQQLQJ DLG DQG D FURVVOLQNLQJ DJHQW LQ WKH ORZ WHPSHUDWXUH KHDW WUHDWPHQW RI 3&6 ILEHUV ZDV LQYHVWLJDWHG LQ WKLV VWXG\ 7ZR W\SHV RI SRO\PHU VROXWLRQV ZHUH SUHSDUHG IRU ILEHU VSLQQLQJ RQH FRQWDLQLQJ ZWb 36= DQG WKH RWKHU ZLWKRXW DQ\ 36= 7KH 3&6 SRO\PHUV XVHG LQ WKLV VWXG\ ZHUH GULHG LQ D YDFXXP IXUQDFH IRU K WR UHPRYH DQ\ DGVRUEHG PRLVWXUH WUDFHV RI VROYHQW HWF SULRU WR VROXWLRQ SUHSDUDWLRQ 7KH GULHG 3&6 SRO\PHUV ZHUH WKHQ GLVVROYHG LQ WROXHQH DW ZWb VROLGV ORDGLQJ )RU XVH LQ ILEHU VSLQ EDWFKHV 36= ZDV GLVVROYHG LQ WROXHQH DW ZWb VROLGV ORDGLQJ ILOWHUHG WKURXJK D SP ILOWHU DQG PL[HG ZLWK WKH 3&6 VROXWLRQ 7 1LVVR &RPSDQ\ 7RN\R -DSDQ r 0RGHO 3DUU ,QVWUXPHQW &RPSDQ\ 0ROLQH ,/

PAGE 97

7KH SRO\PHU VROXWLRQV ZHUH ILOWHUHG WKURXJK SP ILOWHU DQG FRQFHQWUDWHG LQ D URWDU\ HYDSRUDWRU DW ar& XQWLO ZWb VROYHQW UHPDLQHG $ fIORZ WHVWf ZDV XVHG DV D URXJK LQGLFDWLRQ WKDW DQ DSSURSULDWH YLVFRVLW\ IRU ILEHU VSLQQLQJ ZDV DWWDLQHG 7KH IORZ WHVW ZDV FDUULHG RXW E\ WLOWLQJ WKH JODVV YLDO FRQWDLQLQJ WKH FRQFHQWUDWHG SRO\PHU VROXWLRQ DW D r DQJOH DQG PHDVXULQJ WKH WLPH WDNHQ IRU WKH VROXWLRQ WR WUDYHO FP $ IL[HG VL]H RI JODVV YLDO ZDV XVHG IRU FRQFHQWUDWLQJ WKH SRO\PHU VROXWLRQ DQG FDUU\LQJ RXW WKH IORZ WHVWf 8VH RI WKH IORZ WHVW PLQLPL]HG WKH QXPEHU RI LWHUDWLRQV QHHGHG WR UHDFK WKH RSWLPXP YLVFRVLW\ IRU ILEHU VSLQQLQJ DQG HQDEOHG FRQVHUYDWLRQ RI VSLQ GRSH PDWHULDO LH E\ QRW PDNLQJ DQ\ UKHRORJLFDO PHDVXUHPHQWV XQWLO MXVW EHIRUH WKH FRQFHQWUDWHG SRO\PHU VROXWLRQ ZDV UHDG\ IRU ILEHU VSLQQLQJf 7KH UKHRORJLFDO FKDUDFWHULVWLFV RI WKH ILQDO SRO\PHU VROXWLRQ ZHUH GHWHUPLQHG E\ XVLQJ D FRQHSODWH YLVFRPHWHU $SSUR[LPDWHO\ PO RI WKH FRQFHQWUDWHG SRO\PHU VROXWLRQ ZDV XVHG IRU WKH PHDVXUHPHQW 7KH PHDVXUHPHQWV ZHUH PDGH ILUVW E\ LQFUHDVLQJ WKH VKHDU UDWH IURP WR Vn DQG WKHQ GHFUHDVLQJ WKH VKHDU UDWH EDFN WR Vn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

PAGE 98

WKRURXJKO\ EHIRUH VSLQQLQJ WR HQVXUH WKDW WKHUH ZHUH QR SDUWLFXODWHV EORFNLQJ WKH VSLQQHUHW KROHV 7KH IDFH RI VSLQQHUHW ZDV ZLSHG FOHDQ ZLWK D WROXHQHVRDNHG SDSHU WLVVXH SULRU WR FRPPHQFHPHQW RI VSLQQLQJ &RQWLQXRXV fJUHHQf ILEHUV ZHUH IRUPHG E\ ZLQGLQJ RQ D ZKHHO ZKLFK ZDV SODFHG DSSUR[LPDWHO\ FP IURP WKH VSLQQHUHW IDFH 7KH VSLQQLQJ FRQGLWLRQV ZLQGLQJ VSHHG QLWURJHQ SUHVVXUH DQG VROXWLRQ YLVFRVLW\f ZHUH NHSW FRQVWDQW WR HQDEOH FRPSDULVRQ RI ILEHUV SURGXFHG ZLWK DQG ZLWKRXW 36= 7KH VROXWLRQ YLVFRVLW\ ZDV 3D V WKH DSSOLHG JDV SUHVVXUH GXULQJ VSLQQLQJ ZDV SVL DQG WKH VSHHG RI WKH ILEHU FROOHFWLRQ ZKHHO ZDV USP OLQHDU IWPLQf 7KH VSLQQLQJ EHKDYLRU ZDV GRFXPHQWHG E\ QRWLQJ WKH QXPEHU RI ILEHU EUHDNV RFFXUULQJ DW UHJXODU LQWHUYDOV RI WLPH $IWHU ILEHU VSLQQLQJ EDWFKHV W\SLFDOO\ Jf ZHUH FXW IURP WKH ZKHHO 7KHVH EXQGOHV ZHUH ZUDSSHG LQ DOXPLQXP IRLO DV DQ FP EXQGOH WKHQ FXW LQWR IRXU FP ORQJ EXQGOHV ODEHOHG DQG VWRUHG LQ D YDFXXP GHVLFFDWRU IRU DW OHDVW K WR UHPRYH VRPH RI WKH UHVLGXDO VROYHQW IURP ILEHUVf SULRU WR S\URO\VLV 6RPH ILEHUV ZHUH S\URO\]HG E\ KHDWLQJ LQ D WXEH IXUQDFH LQ QLWURJHQ DW r&PLQ WR r& K KROG DW WHPSHUDWXUHf 7KH IORZ UDWH RI QLWURJHQ XVHG IRU S\URO\VLV ZDV VWG DWP FFPLQ ,Q RUGHU WR VWXG\ WKH HIIHFW RI R[LGDWLYH FURVVOLQNLQJ RQ ILEHU PHFKDQLFDO SURSHUWLHV VHYHUDO EDWFKHV RI 3&6 DQG 3&636= ILEHUV ZHUH KHDWWUHDWHG LQ IORZLQJ DLU WR WHPSHUDWXUHV RI sr& LQ D WXEH IXUQDFH 7KH IORZ UDWH RI DLU ZDV VWG DWP FFPLQ 7KH KHDWLQJ VFKHGXOH XVHG ZDV r&PLQ WR r& PLQ KROG DW r& r&PLQ WR r& PLQ KROG DW r& r&PLQ WR r& PLQ KROG DW r& r&PLQ WR r& PLQ KROG DW r& r&PLQ WR ILQDO WHPSHUDWXUH sr&f K KROG DW WHPSHUDWXUH 3&6 DQG 3&636= JUHHQ DQG DLUKHDW WUHDWHGf ILEHUV ZHUH DOVR KHDWWUHDWHG LQ IORZLQJ QLWURJHQ VWGDWP FFPLQf LQ D WXEH IXUQDFH IRU K DW WHPSHUDWXUHV LQ WKH UDQJH RI

PAGE 99

r& 7KH KHDW WUHDWPHQW UDWH ZDV r&PLQ WR r& DQG r&PLQ IURP r& WR WKH ILQDO WHPSHUDWXUH &KDUDFWHUL]DWLRQ RI 3&6 SRO\PHU VROXWLRQV 7KH PROHFXODU ZHLJKW GLVWULEXWLRQV RI 3&6 SRO\PHUV ZHUH GHWHUPLQHG E\ *HO 3HUPHDWLRQ &KURPDWRJUDSK\ *3&f XVLQJ SRO\VW\UHQH FROXPQV DQG VWDQGDUGV DQG 7+) WHWUDK\GURIXUDQf DV WKH VROYHQW 3&6 VROXWLRQV IRU *3& ZHUH SUHSDUHG E\ PL[LQJ ZWb RI SRO\PHU LQ 7+) DQG ILOWHULQJ WKH VROXWLRQ WKURXJK D SP ILOWHU 3RO\PHU VROXWLRQV ZHUH SDVVHG WKURXJK $ DQG $ FROXPQV FRQQHFWHG LQ VHULHV 7KH PRELOH SKDVH IRU WKH FROXPQV ZDV 7+) *3& IRU 36= SRO\PHUV ZHUH DQDO\]HG XVLQJ $ DQG $ FROXPQV FRQQHFWHG LQ VHULHV 7+) FRXOG QRW EH XVHG DV WKH PRELOH SKDVH IRU 36= VLQFH WKH FKURPDWRJUDP VKRZHG QR FOHDU HOXWLRQ SHDNV FRUUHVSRQGLQJ WR WKH GLIIHUHQW PROHFXODU ZHLJKW VSHFLHV LQ WKH SRO\PHU LH WKH FKURPDWRJUDP VKRZHG D EURDG SHDN DQG D YDOOH\f )RU WKLV UHDVRQ WROXHQH ZDV XVHG DV WKH PRELOH SKDVH DQG WKH 36= SRO\PHUV ZHUH GLVVROYHG LQ WROXHQH ZWbf LQVWHDG RI 7+) 7KH FROXPQV ZHUH FRQGLWLRQHG E\ SXUJLQJ WROXHQH WKURXJK WKHP IRU K SULRU WR DQDO\VLV 7KH LQWULQVLF YLVFRVLWLHV RI SRO\PHU VROXWLRQV ZHUH GHWHUPLQHG DFFRUGLQJ WR $670 SURFHGXUH E\ HPSOR\LQJ D 8EHOORKGH 9LVFRPHWHU W\SH &fQ 7KH PHDVXUHPHQWV ZHUH FDUULHG RXW LQ D ZDWHU EDWK PDLQWDLQHG DW r& DQG WKH FRQFHQWUDWLRQV RI SRO\PHU VROXWLRQV XVHG UDQJHG IURP WR ZWb 7KH HIIOX[ WLPH W UHTXLUHG IRU WKH VROXWLRQ WR SDVV WKURXJK WKH FDSLOODU\ RI WKH YLVFRPHWHU EHWZHHQ PDUNHG :DWHUV( 6\VWHPV &RQWUROOHU :DWHUV 'LIIHUHQWLDO 5HIUDFWRPHWHU DQG :DWHUV $XWRVDPSOHU 0LOOLSRUH &RUSRUDWLRQ :DWHUV &KURPDWRJUDSK\ 'LYLVLRQ 0LOIRUG 0$ 3KHQRPHQH[ &RUSRUDWLRQ 7RUUDQFH &$ +, ,QGXVWULDO 5HVHDUFK *ODVVZDUHV /WG 8QLRQ 1-

PAGE 100

OLQHV ZDV PHDVXUHG 7KH FRUUHVSRQGLQJ HIIOX[ WLPH W IRU WKH SXUH VROYHQW WROXHQHf ZDV DOVR PHDVXUHG 7KH VSHFLILF YLVFRVLW\ U_VS ZDV GHWHUPLQHG DFFRUGLQJ WR IRUPXOD KV3 WWRfWR f 7KH LQWULQVLF YLVFRVLW\ >U_@ ZDV FDOFXODWHG DFFRUGLQJ +XJJLQV HTXDWLRQ :H >U@ Nf >U@ F f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f LQWHUVHFWLRQ SRLQW 7KH VXEVWUDWHV XVHG IRU PHDVXUHPHQW ZHUH VWDLQOHVV VWHHO WHIORQ DQG VWDLQOHVV VWHHO ZKLFK ZHUH ILUVW FRDWHG ZLWK 3&6 RU 3&636= 7KH FRQFHQWUDWLRQV RI SRO\PHU VROXWLRQV 3&6 DQG 3&636=f ZHUH ZWb 7KH VWDLQOHVV VWHHO FP [ FPf DQG WHIORQ VXEVWUDWHV FP [ FPf ZHUH FOHDQHG LQ DQ XOWUDVRQLFDWRU EDWKrr IROORZHG E\ ULQVLQJ LQ DFHWRQH DQG GU\LQJ LQ DQ RYHQ DW r& IRU PLQ 7KH WHIORQ VXEVWUDWH ZDV SROLVKHG RQ SP GLDPRQG ZKHHO IRU PLQ WR REWDLQ D VPRRWK VXUIDFH SULRU WR PHDVXUHPHQWf ,QLWLDOO\ FRQWDFW DQJOHV RI ZDWHU DQG WROXHQH ZHUH PHDVXUHG RQ WHIORQ DQG VWDLQOHVV VWHHO VXEVWUDWHV WR HQDEOH FRPSDULVRQ ZLWK UHSRUWHG YDOXHV LQ OLWHUDWXUH %RWK DGYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV ZHUH PHDVXUHG XVLQJ WKH GURSEXLOGXS DQG GURSZLWKGUDZDO PHWKRGV $ +DPLOWRQ V\ULQJH FDOLEUDWHG XS WR PO ZDV XVHG IRU 5DPH+DUW ,QF 0RXQWDLQ /DNHV 1rr 0RGHO )6 )LVKHU 6FLHQWLILF 3LWWVEXUJK 3$

PAGE 101

DGGLQJ DQG ZLWKGUDZLQJ GURSV (IIRUWV ZHUH PDGH WR XVH ODUJHU GURS VL]HV LQ RUGHU WR PLQLPL]H OLTXLG HYDSRUDWLRQ HIIHFWV )RU WROXHQHVWDLQOHVV VWHHO FRPELQDWLRQ WKH WRWDO GURS VL]H SRVVLEOH ZDV PO EHIRUH WKH GURS ERXQGDU\ H[FHHGHG WKH ERXQGDU\ RI WKH VXEVWUDWHf ,Q H[SHULPHQWV ZLWK SXUH WROXHQH DQG WROXHQHEDVHG SRO\PHU VROXWLRQV WKH LPPHGLDWH HQYLURQPHQW ZDV VDWXUDWHG ZLWK WROXHQHVRDNHG SDSHU WLVVXHV WR PLQLPL]H WKH HIIHFWV RI OLTXLG HYDSRUDWLRQ 7KH GXUDWLRQ RI PHDVXUHPHQW IRU DGYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV ZDV a PLQ HDFK 7KH PHDVXUHPHQWV ZHUH FDUULHG RXW LQ D URRP ZKHUH DLU GUDIWV ZHUH PLQLPDO VY VXEVWUDWH VY VO
PAGE 102

3&6 DQG 3&636= SRO\PHU VROXWLRQV ZWbf ZHUH XVHG WR SUHSDUH FRDWHG VWDLQOHVV VWHHO VXEVWUDWHV 7KH FRDWLQJV ZHUH GHSRVLWHG XVLQJ D VSLQ FRDWHU RSHUDWHG IRU VHF DW USP J SRO\PHU VROXWLRQV ZHUH XVHG IRU VSLQ FRDWLQJ %RWK 3&6 DQG 3&636= VROXWLRQV IRUPHG VPRRWK ILOPV RQ VWDLQOHVV VWHHO VXEVWUDWHV 7KH FRDWHG VXEVWUDWHV ZHUH REVHUYHG LQ DQ RSWLFDO PLFURVFRSH DW ; PDJQLILFDWLRQ DQG QR URXJKQHVV RU GHIHFWV FRXOG EH GHWHFWHGf 7KH SRO\PHULF FRDWLQJV ZHUH FURVVOLQNHG E\ KHDWLQJ WKH VXEVWUDWHV DW r&PLQ WR r& K KROGf LQ QLWURJHQ :LWKRXW WKLV FURVV OLQNLQJ VWHS WKH SRO\PHU ILOPV ZRXOG EH GLVVROYHG ZKHQ WROXHQH RU WROXHQHEDVHG SRO\PHU VROXWLRQ GURSV ZHUH GHSRVLWHG RQ WKH VXEVWUDWHV IRU FRQWDFW DQJOH PHDVXUHPHQWVf 7KH VXUIDFH WHQVLRQ RI SRO\PHU VROXWLRQV ZDV PHDVXUHG XVLQJ D 5RVDQR 6XUIDFH 7HQVLRPHWHU 7KLV LQVWUXPHQW RSHUDWHV XVLQJ WKH :LOKHP\ 3ODWH PHWKRG $ ZHWWDEOH SODWLQXP EODGH ZDV LPPHUVHG LQ WKH OLTXLG DQG WKHQ WKH YHUWLFDO IRUFH QHFHVVDU\ WR SXOO WKH EODGH RXW RI WKH OLTXLG ZDV PHDVXUHG 7KH VXUIDFH WHQVLRQ LQ G\QHVFP ZDV FDOFXODWHG XVLQJ WKH IRUPXOD \ ):f r f ZKHUH \ 6XUIDFH 7HQVLRQ LQ G\QHVFP ) )RUFH LQ PJ PJ G\QHf : 3HULPHWHU RI EODGH FPf )LYH LQGHSHQGHQW PHDVXUHPHQWV ZHUH PDGH IRU HDFK VROYHQW DQG SRO\PHU VROXWLRQ LQYHVWLJDWHG DQG WKH UHVXOWV RI WKHVH PHDVXUHPHQWV ZHUH DYHUDJHG 7KH SODWLQXP EODGH ZDV FOHDQHG XVLQJ D QRQFDUERQ SURGXFLQJ IODPH LH EOXHFRORUHG IODPH WLS LQ D r 0RGHO (&'5 +HDGZD\ 5HVHDUFK ,QF *DUODQG7; i %LRODU &RUSRUDWLRQ 1RUWK *UDIWRQ 0$

PAGE 103

%XQVHQ EXUQHUf SULRU WR HDFK PHDVXUHPHQW :KHQ 3&6 VROXWLRQV ZHUH XVHG WKH SODWLQXP EODGH ZDV ILUVW VRDNHG LQ WROXHQH IRU PLQ DQG WKHQ ULQVHG LQ DFHWRQH EHIRUH IODPH FOHDQLQJ ,QLWLDOO\ VXUIDFH WHQVLRQV RI VWDQGDUG OLTXLGV VXFK DV ZDWHU DQG DFHWRQH ZHUH PHDVXUHG WR WHVW WKH DFFXUDF\ RI WKH LQVWUXPHQW 7KH PHDVXUHG VXUIDFH WHQVLRQ YDOXHV ZHUH FRPSDUHG ZLWK WKH YDOXHV UHSRUWHG LQ D WHFKQLFDO KDQGERRN >&5&@ 7ZR WROXHQHEDVHG ZWb SRO\PHU VROXWLRQV RQH ZLWK 3&6 DQG WKH RWKHU ZLWK 3&6 ZWb 36= ZHUH SUHSDUHG DQG WKH VROXWLRQV ZHUH ILOWHUHG WKURXJK SP ILOWHU SULRU WR PHDVXUHPHQW 9LVFRVLWLHV RI WKH VROXWLRQV ZHUH PHDVXUHG XVLQJ D FRQHSODWH YLVFRPHWHU E\ WKH PHWKRG GHVFULEHG LQ 6HFWLRQ $IWHU FRPSOHWLQJ WKH PHDVXUHPHQW WKH ZWb SRO\PHU VROXWLRQV ZHUH FRQFHQWUDWHG VXFFHVVLYHO\ WR DQG ZWb SRO\PHU 6XUIDFH WHQVLRQ DQG YLVFRVLW\ PHDVXUHPHQWV ZHUH PDGH IRU HDFK FRQFHQWUDWHG VROXWLRQ 6XUIDFH WHQVLRQ PHDVXUHPHQWV FRXOG QRW EH PDGH ZLWK PRUH FRQFHQWUDWHG VROXWLRQV $Q DWWHPSW ZDV PDGH WR PHDVXUH WKH VXUIDFH WHQVLRQ RI D 3&6 VROXWLRQ ZLWK ZWb VROLGV ORDGLQJ ZKLFK KDG D YLVFRVLW\ RI 3D Vf ,Q WKLV FDVH WKH SODWLQXP EODGH GLG QRW SHQHWUDWH WKH SRO\PHU VROXWLRQ DQG WKH WKUHDG DWWDFKHG WR WKH EODGH EHJDQ WR FRLO XSf *O\FHURO YLVFRVLW\ 3D Vf DQG SRO\GLPHWK\OVLOR[DQH YLVFRVLW\ 3D Vf ZKLFK KDYH YLVFRVLWLHV LQ D VLPLODU UDQJH DV WKH 3&6 DQG 3&636= VROXWLRQV FRQFHQWUDWHG WR ZWb DQG ZWb VROLGV UHVSHFWLYHO\f ZHUH XVHG WR DVVHVV WKH YDOLGLW\ RI VXUIDFH WHQVLRQ PHDVXULQJ WHFKQLTXH ZKHQ DSSOLHG WR PRUH YLVFRXV OLTXLGV 7KH VXUIDFH WHQVLRQV RI WKHVH OLTXLGV DUH UHSRUWHG LQ WHFKQLFDO KDQGERRNV >&5&@f 7KH UDWH RI VROYHQW HYDSRUDWLRQ ZDV PLQLPL]HG GXULQJ WKH PHDVXUHPHQWV E\ FRYHULQJ WKH FRQWDLQHU XVHG WR KROG WKH OLTXLGV ZLWK DOXPLQXP IRLO DQG E\ SODFLQJ WZR VPDOO EHDNHUV ILOOHG ZLWK WROXHQH QH[W WR WKH FRQWDLQHU &DUH ZDV WDNHQ WR HQVXUH WKDW WKH DOXPLQXP IRLO GLG QRW LQWHUIHUH ZLWK WKH WKUHDG XVHG WR SXOO RXW WKH SODWLQXP EODGH IURP WKH VROXWLRQ

PAGE 104

([SHULPHQWV ZLWK 3&6 DQG 3&636= VROXWLRQV ZHUH FDUULHG RXW WR DVVHVV WKH GLIIHUHQFHV LQ VROYHQW HYDSRUDWLRQ UDWHV IURP WKH WZR VROXWLRQV ,GHQWLFDO DPRXQWV RI 3&6 DQG 3&636= VROXWLRQV ZLWK LGHQWLFDO VROLGV ORDGLQJ ZWbf ZHUH SUHSDUHG 9LDOV FRQWDLQLQJ WKH SRO\PHU VROXWLRQV ZHUH SODFHG LQ DQ DQDO\WLFDO EDODQFH ZLWK DQ DFFXUDF\ XS WR GHFLPDOVf DQG WKH FKDQJH LQ ZHLJKW ZDV PRQLWRUHG DV D IXQFWLRQ RI WLPH XS WR PLQf 7KH FKDQJH LQ ZHLJKW ZDV QRWHG HYHU\ VHF XS WR PLQ HYHU\ VHF IRU WKH QH[W PLQ DQG HYHU\ VHF IRU WKH UHPDLQLQJ PLQ 7KH SHUFHQWDJH ZHLJKW FKDQJH IRU WKH SRO\PHU VROXWLRQV ZDV SORWWHG DV D IXQFWLRQ RI WLPH )LEHU H[WHQVLRQ H[SHULPHQWV ZHUH FDUULHG RXW LQVLGH D JORYH ER[ 3RO\PHU VROXWLRQV 3&6 DQG 3&636= ZWbff ZHUH FRQFHQWUDWHG WR WKH VDPH YLVFRVLWLHV XVHG LQ ILEHU VSLQQLQJ H[SHULPHQWV )LEHU H[WHQVLRQ GLVWDQFHV ZHUH GHWHUPLQHG E\ GLSSLQJ D JODVV URG a FP GLDPHWHUf LQ a J RI EXON SRO\PHU VROXWLRQ LQ D JODVV YLDOf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r& )LEHUV ZHUH DOVR WHVWHG DIWHU R[LGDWLRQ DW WHPSHUDWXUHV RI sr& )RU PHFKDQLFDO WHVWLQJ LQGLYLGXDO ILEHUV ZHUH DWWDFKHG WR SDSHU WDEV XVLQJ ZRRG JOXH DQG ORDGHG LQ WHQVLRQ PPPLQ 7LWHERQG ,, )UDQNOLQ ,QWHUQDWLRQDO &ROXPEXV 2+

PAGE 105

FURVVKHDG VSHHGf XQWLO IDLOXUH XVLQJ D PHFKDQLFDO WHVWLQJ DSSDUDWXV 7KH JDJH OHQJWK ZDV PP DQG DW OHDVW HLJKW ILEHUV EXW XVXDOO\ f ZHUH WHVWHG IRU HDFK EDWFK 7R FDOFXODWH WHQVLOH VWUHQJWKV ILEHU GLDPHWHUV ZHUH GHWHUPLQHG XVLQJ DQ RSWLFDO PLFURVFRSH HTXLSSHG ZLWK D PLFURPHWHU LQ WKH H\HSLHFH 7ZR PHDVXUHPHQWV RI ILEHU GLDPHWHU ZHUH PDGH SHU ILEHU DQG DQ DYHUDJH ILEHU GLDPHWHU ZDV XVHG IRU FDOFXODWLRQ RI WHQVLOH VWUHQJWKV )7,5 VSHFWUD RI ILEHUV DVVSXQ DQG DLUKHDW WUHDWHGf ZHUH FROOHFWHG LQ WKH UDQJH FP LQ GLIIXVH UHIOHFWDQFH PRGH )7,5 VSHFWUD ZHUH REWDLQHG E\ PL[LQJ JURXQG ILEHUV ZLWK GLDPRQG SRZGHU J ILEHUV LQ J GLDPRQG SRZGHUf 7KH ILEHUV ZHUH KHDWWUHDWHG IURP WR r& LQ QLWURJHQ DW r&PLQ DQG VSHFWUD ZHUH FROOHFWHG DW LQWHUYDOV RI r& %DFNJURXQG VSHFWUD IRU GLDPRQG ZHUH DOVR FROOHFWHG VHSDUDWHO\ DW URRP WHPSHUDWXUH DQG GXULQJ KHDW WUHDWPHQW IURP WR r& DW r&PLQ LQ QLWURJHQ )LEHUV ZHUH DOVR VHSDUDWHO\ KHDWWUHDWHG DW r&PLQ WR WHPSHUDWXUHV RI r& r& DQG r& K KROGf LQ QLWURJHQ 7KH S\URO\]HG ILEHUV ZHUH WKHQ JURXQG DQG PL[HG ZLWK GLDPRQG SRZGHU J ILEHUV LQ J GLDPRQG SRZGHUf DQG VSHFWUD ZHUH FROOHFWHG LQ WKH GLIIXVH UHIOHFWDQFH PRGH DW URRP WHPSHUDWXUH $OO LQWHQVLWLHV LQ WKH VSHFWUD ZHUH FRQYHUWHG WR .XEHOND0XQN XQLWV XVLQJ WKH FRQYHUVLRQ I5f 5f5 f ZKHUH 5 UHIOHFWDQFH LQ DEVROXWH XQLWV I5f UHIOHFWDQFH LQ .XEHOND0XQN XQLWV r 0RGHO ,QVWURQ &RUSRUDWLRQ &DQWRQ 0$ 1LFROHW 6; 6SHFWURPHWHU 1LFROHW ,QVWUXPHQWV &RPSDQ\ 0DGLVRQ :O 6L]H f (QJLV &RUSRUDWLRQ :KHHOLQJ ,/

PAGE 106

6\QWKHVLV DQG &KDUDFWHUL]DWLRQ RI 3ROYPHWK\OVLODQH 306f 3RO\PHUV 6WDUWLQJ PDWHULDOV 3RO\PHWK\OVLODQH SRO\PHU ZDV SUHSDUHG E\ :XUW]FRXSOLQJ UHDFWLRQV RI PHWK\OGLFKORURVLODQH 0'&6f DQG PHWK\OWULFKORURVLODQH 07&6f XVXDOO\ ZWb SURSRUWLRQf ZLWK VRGLXP LQ WKH SUHVHQFH RI WROXHQH WROXHQH 7+) b E\ YROXPHf RU WROXHQH GLR[DQH b E\ YROXPHf 7KH SURSHUWLHV RI YDULRXV UHDJHQWV XVHG DUH OLVWHG LQ 7DEOH 5HDFWDQW &KDUJHV 7\SLFDOf 0HWK\OGLFKORURVLODQH 0'&6f ZWbf J POf 0HWK\OWULFKORURVLODQH 07&6f ZWbf J POf 6RGLXP ZWb H[FHVV RI HTXLYDOHQW FKORULQH LQ PRQRPHUVf J 7ROXHQH PO 7+) PO :KHQ 'LR[DQH LV XVHG 7ROXHQH PO 'LR[DQH PO 7KH WROXHQH GLR[DQH UDWLRV ZHUH DQG E\ YROXPHf IRU SRO\PHUV 306 DQG 306f 3URFHGXUH IRU SRO\PHUL]DWLRQ $OO SRO\PHUL]DWLRQ UHDFWLRQV ZHUH FDUULHG RXW LQ D EODQNHW RI QLWURJHQ 7KH PRQRPHU KDQGOLQJ RSHUDWLRQV ZHUH FDUULHG RXW LQ D JORYH EDJ XQGHU DUJRQ $OO JODVVZDUHV ZHUH RYHQ GULHG DW r& IRU K DIWHU LQLWLDO FOHDQLQJ DQG WKH UHDFWLRQ 2QH H[SHULPHQW ZDV DOVR FDUULHG RXW ZLWK 0'&607&6 UDWLR

PAGE 107

7DEOH 3URSHUWLHV RI UHDJHQWV LQ V\QWKHVLV RI SRO\PHWK\OVLODQH SRO\PHUV >'HD@ &KHPLFDOV 0: 6WDWH r&f 'HQVLW\JFFf %RLOLQJ 3RLQWr& 0HWK\OGLFKORURVLODQH OLTXLG 0HWK\OWULFKORURVLODQH OLTXLG 6RGLXP D VROLG E 7ROXHQH OLTXLG 7HWUDK\GURIXUDQ 7+)f OLTXLG 'LR[DQH OLTXLG DWRPLF ZHLJKW E PHOWLQJ SRLQW

PAGE 108

DVVHPEO\ ZDV WKRURXJKO\ SXUJHG ZLWK QLWURJHQ IRU PLQ SULRU WR XVH 7KH UHDFWLRQ DVVHPEO\ VHH )LJXUH f FRQVLVWHG RI D PO WKUHHQHFNHG IODVN HTXLSSHG ZLWK D UHIOX[ FRQGHQVHU SUHVVXUHHTXDOL]LQJ DGGLWLRQ IXQQHO LQHUW JDV LQOHW SRUW D PDJQHWLF VWLUUHU RLO EDWK DQG D KHDWLQJ PDQWOH ,Q D W\SLFDO SRO\PHUL]DWLRQ J RI VRGLXP JPROHV ZWb H[FHVVf DQG PO RI WROXHQHr ZHUH KHDWHG WR UHIOX[ ar& IRU WROXHQH7+) PL[WXUH DW PP )LJ DQG ar& IRU WROXHQH GLR[DQH PL[WXUH DW PP +Jf :KHQ 7+)r DQG 'LR[DQHi ZHUH XVHG DV DGGLWLYHV WKH WRWDO YROXPH RI WKH VROYHQW PL[WXUH ZDV NHSW FRQVWDQW DW PO LQ WKH GHVLUHG SURSRUWLRQV $IWHU WKH VRGLXP PHOWHG FRPSOHWHO\ a PLQ PHOWLQJ SRLQW r&f DQG IRUPHG D ILQH GLVSHUVLRQ PO PHWK\OGLFKORURVLODQHg DQG PO RI PHWK\OWULFKORURVLODQHii PRQRPHUV LQ ZWb SURSRUWLRQ ZDV DGGHG GURS E\ GURS WKURXJK WKH DGGLWLRQ IXQQHO 7KH WRWDO WLPH IRU WKH DGGLWLRQ RI PRQRPHUVf ZDV RQH KRXU GXULQJ ZKLFK WLPH WKH KHDWLQJ PDQWOH ZDV WXUQHG RII WR SUHYHQW WKH UHDFWLRQ IURP EHFRPLQJ YLROHQWO\ H[RWKHUPLF 7KH UHDFWLRQ FRQWHQWV ZHUH WHVWHG IRU DFLGLW\ SHULRGLFDOO\ 7KLV ZDV GRQH DV IROORZV WKH UHDFWLRQ FRQWHQWV ZHUH DOORZHG WR VHWWOH IRU PLQ LH VWLUULQJ RI WKH UHDFWLRQ FRQWHQWV ZDV VWRSSHGf DQG DERXW FF RI WKH FOHDU SRO\PHU VROXWLRQ ZDV SLSHWWHG RXW DQG DGGHG WR D ZDWHUVRDNHG S+ SDSHU ,I FKORURVLODQH PRQRPHU UHPDLQV LQ WKH VROXWLRQ LW ZLOO UHDFW ZLWK ZDWHU RQ WKH S+ SDSHU WR IRUP +&, 7KLV ZLOO LQ WXUQ FDXVH WKH S+ SDSHU WR FKDQJH FRORU WR SLQN 7KH SRO\PHUL]DWLRQ ZDV FDUULHG RXW DW UHIOX[ XQWLO WKH VROXWLRQ QR ORQJHU WHVWHG DFLGLF LH S+ RI ZHW S+ SDSHU UHPDLQHG FRORUOHVV DIWHU WKH FOHDU SRO\PHU WR PP VSKHUHV $OGULFK &KHPLFDO &RPSDQ\ 0LOZDXNHH :O r *UDGH 2SWLPD )LVKHU 6FLHQWLILF &RPSDQ\ )DLU /DZQ 1W *UDGH +3/& )LVKHU 6FLHQWLILF &RPSDQ\ )DLU /DZQ 1i *UDGH $&6 )LVKHU 6FLHQWLILF &RPSDQ\ )DLU /DZQ 1g b SXULW\ $OGULFK &KHPLFDO &RPSDQ\ 0LOZDXNHH :O ii b SXULW\ $OGULFK &KHPLFDO &RPSDQ\ 0LOZDXNHH :O

PAGE 109

)LJXUH 5HDFWLRQ DVVHPEO\ IRU V\QWKHVLV RI SRO\PHWK\OVLODQH SRO\PHUV

PAGE 110

VROXWLRQ ZDV UHDFWHG ZLWK LWf 7KH UHDFWLRQ YHVVHO ZDV DOORZHG WR FRRO WR URRP WHPSHUDWXUH DQG WKH UHDFWLRQ FRQWHQWV LH 1D1D&, SUHFLSLWDWHf ZHUH FHQWULIXJHG DW USP IRU PLQ LQ PO FHQWULIXJH WXEHV 'XULQJ FHQWULIXJLQJ WKH EODFNFRORUHG 1D1D&, SUHFLSLWDWH ZDV VHSDUDWHG RXW IURP WKH FOHDU LH WUDQVSDUHQWf \HOORZFRORUHG SRO\PHU VROXWLRQ 7KH SRO\PHU VROXWLRQ ZDV GHFDQWHG DQG ILOWHUHG WKURXJK SP :KDWPDQ ILOWHU SDSHU DQG FRQFHQWUDWHG LQ D URWDU\ HYDSRUDWRUr XQGHU YDFXXP WR \LHOG D YLVFRXV FOHDU \HOORZ GXOOFRORUHG SRO\PHU 7KH URWDU\ HYDSRUDWLRQ ZDV FDUULHG RXW PLQ EH\RQG WKH SRLQW DW ZKLFK WKH VROYHQW VWRSSHG FRQGHQVLQJ LQWR WKH FROOHFWLRQ IODVN RI WKH GLVWLOODWLRQ DSSDUDWXV $IWHU URWDU\ HYDSRUDWLRQ WKH IODVN FRQWDLQLQJ WKH SRO\PHU ZDV YHQWHG WR 1 WR PLQLPL]H FRQWDPLQDWLRQ IURP DLU 7KH SRO\PHU ZDV WKHQ GLVVROYHG LQ WROXHQH a ZWbf LQ D UHIULJHUDWRU IRU IXUWKHU SURFHVVLQJFKDUDFWHUL]DWLRQ ,Q YLHZ RI WKH KD]DUGV DVVRFLDWHG ZLWK KDQGOLQJ 1D VHYHUDO VDIWH\ SUHFDXWLRQV VKRXOG EH WDNHQ f 1D VKRXOG EH ZHLJKHG LQ D GU\ EHDNHU FRQWDLQLQJ WROXHQH a POf f 7KH SRO\PHU VROXWLRQV1D1D&, VXVSHQVLRQV VKRXOG QRW EH H[SRVHG WR DWPRVSKHULF DLU GXULQJ V\QWKHVLV f 7KH 1D1D&, VXVSHQVLRQ GDUN FRORUHG fVOXGJHf FROOHFWHG LQ FHQWULIXJH WXEHVf PXVW EH QHXWUDOL]HG E\ FDUHIXOO\ DGGLQJ SURSDQRO DQG ZDWHU PO HDFKf VHTXHQWLDOO\ 7KLV ZDV GRQH WR UHPRYH H[FHVV 1D SUHVHQW LQ WKH VOXGJH VR WKDW WKH VOXGJH ZRXOG QRW FUHDWH ZDVWH GLVSRVDO KD]DUGV 7KH 2+ JURXS LQ SURSDQRO UHDFWV ZLWK 1D IRUPLQJ 1D2+ $GGLWLRQ RI ZDWHU HQDEOHV UHPRYDO RI WUDFHV RI 1D OHIW EHKLQG LQ WKH VOXGJH &RORU UDQJH IRU S+ WHVW SLQN DFLGLFf QR FRORU FKDQJH QHXWUDOf EOXHJUHHQ EDVLFf $ %XLFKL 5 %ULQNPDQ ,QVWUXPHQWV :HVWEXU\ 1<

PAGE 111

'HWHUPLQDWLRQ RI SRO\PHU \LHOG 7KH DFWXDO SRO\PHU \LHOG ZDV GHWHUPLQHG E\ FDUU\LQJ RXW D VROLGV ORDGLQJ WHVW 7KLV ZDV GRQH DV IROORZV WZR FOHDQ DOXPLQXP ZHLJKLQJ SDQV ZHUH ZHLJKHG EHIRUH DQG DIWHU DGGLQJ GURSV RI SRO\PHU VROXWLRQ 7KH ZHLJKLQJ SDQV ZHUH WKHQ TXLFNO\ WUDQVIHUUHG WR D YDFXXP RYHQ PDLQWDLQHG DW r& DQG GULHG XQGHU YDFXXP IRU K 7KH ZHLJKLQJ GLVKHV ZHUH ZHLJKHG DIWHU GU\LQJ .QRZLQJ WKH GLIIHUHQFHV LQ ZHLJKWV RI WKH DOXPLQXP SDQV EHIRUH DQG DIWHU GU\LQJ WKH VROLGV ORDGLQJV ZHUH FDOFXODWHG 7KH SRO\PHU \LHOG ZDV FDOFXODWHG IURP WKH NQRZOHGJH RI WRWDO SRO\PHU VROXWLRQ LQ KDQG DIWHU URWDU\ HYDSRUDWLRQ DQG GLVVROXWLRQ LQ WROXHQHf 6LQFH WKLV PHWKRG GRHVQfW WDNH LQWR FRQVLGHUDWLRQ WKH SRO\PHU WUDSSHG LQ WKH YRLG VSDFH EHWZHHQ 1D1D&, SUHFLSLWDWHV WKH DFWXDO \LHOG LV DQ XQGHUHVWLPDWHf )RU SRO\PHUV SUHSDUHG IURP PHWK\OGLFKORURVLODQH 0'&6f WKH UHDFWLRQ LV &+6L+&, 1D >&+6L+@[ 1D&, 7KH PROHFXODU ZHLJKW RI 0'&6 LV JJPRO DQG WKH PROHFXODU ZHLJKW RI WKH UHSHDWLQJ XQLW 58f f§ >&+6L+@[f§ LV 7KHUHIRUH VWDUWLQJ ZLWK JPROHV RI 0'&6 FRUUHVSRQGLQJ WR Jf SURGXFHV JPROH RI 58 RU J WKHRUHWLFDO \LHOGf 7KH SRO\PHU \LHOG LV FDOFXODWHG DV D SHUFHQWDJH E\ GLYLGLQJ WKH DFWXDO SRO\PHU \LHOG E\ WKH WKHRUHWLFDO \LHOG GHWHUPLQHG DERYH DQG WKHQ PXOWLSO\LQJ E\ f )RU SRO\PHUV SUHSDUHG IURP D PL[WXUH RI PHWK\OGLFKORURVLODQH 0'&6f DQG PHWK\OWULFKORURVLODQH 07&6f SURSRUWLRQ E\ ZHLJKWf WKH UHDFWLRQ LV &+6L+&, &+6L&, 1D >&+6L+@[f§>&+6L@\a 1D&, 7KH PROHFXODU ZHLJKW RI 07&6 LV JJPRO DQG WKDW RI WKH 58 >&+6L@\ LV 7KHUHIRUH JPROH RI 0'&6 FRUUHVSRQGLQJ WR Jf SURGXFHV JPROH RI 58 >&+6L+@[ RU J DQG JPROH RI 07&6 FRUUHVSRQGLQJ WR Jf SURGXFHV JPROH RI 58 >&+6L@\ RU J 7KXV WKH WRWDO \LHOG LV

PAGE 112

J 7KH SRO\PHU \LHOG LV FDOFXODWHG DV D SHUFHQWDJH RI WKHRUHWLFDO \LHOG E\ GLYLGLQJ WKH DFWXDO SRO\PHU \LHOG E\ WKH WKHRUHWLFDO \LHOG DQG WKHQ PXOWLSO\LQJ E\ f *HQHUDO SURFHGXUH IRU KHDW WUHDWPHQW RI 306EDVHG SRO\PHU VROXWLRQV 306 SRO\PHU VROXWLRQ ZWb LQ WROXHQHf ZDV PL[HG ZLWK 3&6 ZKHUH DSSOLFDEOH LQ UDWLRV RI HWFf DQG WKH VROXWLRQ ZDV ILOWHUHG WKURXJK D SP ILOWHU 7KH FRQFHQWUDWLRQ RI SRO\PHU VROXWLRQ ZDV NHSW DW ZWb DIWHU PL[LQJ ZLWK 3&6 E\ DGGLQJ WKH QHFHVVDU\ DPRXQW RI WROXHQHf 7KH DGGLWLYHV SRO\YLQ\OVLOD]DQH 36=f DPRXQWV LQ WKH UDQJH RI ZWbf GLFXP\O SHUR[LGH '&3f DPRXQWV LQ WKH UDQJH RI ZWbf DQG GHFDERUDQH '%f DPRXQWV LQ WKH UDQJH RI ZWbf ZHUH GLVVROYHG LQ WROXHQH DW ZWb VROLGV ORDGLQJ DQG VHSDUDWHO\ DGGHG ZKHUH DSSOLFDEOHf WR WKH SRO\PHU VROXWLRQV DIWHU ILOWHULQJ WKURXJK SP ILOWHU 7KH SRO\PHU VROXWLRQ ZDV WKHQ WUDQVIHUUHG WR D WHIORQ FRQWDLQHU PO VL]Hf DQG HQFDVHG LQ D VWDLQOHVV VWHHO SUHVVXUH ERPE 7KH WHIORQ FRQWDLQHU ZDV EDFNILOOHG ZLWK 1 EHIRUH HQFDVLQJ LQ WKH SUHVVXUH ERPE 7KH SRO\PHU VROXWLRQ DSSUR[LPDWHO\ Jf ZDV KHDWWUHDWHG DW WHPSHUDWXUHV LQ WKH UDQJH RI r& LQ D FRQYHFWLRQ RYHQ DQG ZHUH VRPHWLPHV JLYHQ PXOWLSOH WUHDWPHQWV DW VXFFHVVLYHO\ LQFUHDVLQJ WHPSHUDWXUHV LQ WKLV UDQJH 7KH HIIHFWV RI WKHVH KHDW WUHDWPHQWV RQ WKH SRO\PHU VROXWLRQ YLVFRVLW\ DQGRU WKH SRO\PHU PROHFXODU ZHLJKW GHWHUPLQHG E\ *3&f ZHUH GHWHUPLQHG LQ VRPH FDVHV 3RO\PHU VROXWLRQV VKRZHG LQFUHDVHV LQ YLVFRVLW\ DIWHU KHDW WUHDWPHQWV DQG WKLV ZDV WDNHQ DV D PHDVXUH RI LQFUHDVH LQ EUDQFKLQJPROHFXODU ZHLJKW RI WKH SRO\PHU 7KH YLVFRVLW\ RI WKH SRO\PHU VROXWLRQ ZDV PHDVXUHG XVLQJ D FRQHSODWH YLVFRPHWHU +HDW WUHDWPHQWV RI SRO\PHU VROXWLRQV ZHUH XVXDOO\ VWRSSHG ZKHQ LQFUHDVHV LQ YLVFRVLW\ RI DW OHDVW ab ZHUH REWDLQHG HJ LQFUHDVHV IURP P3DV WR P3DVf $IWHU KHDW WUHDWPHQWV SRO\PHU 0RGHO $& 3DUU ,QVWUXPHQW &RPSDQ\ 0ROLQH ,/ 0RGHO /97 %URRNILHOG (QJLQHHULQJ /DERUWDRULHV 6WRXJKWRQ 0$

PAGE 113

VROXWLRQV ZHUH WUDQVIHUUHG WR JODVV YLDOV DQG ILOWHUHG WKURXJK SP SP DQG SP ILOWHUV ZKHUH DSSOLFDEOHf DQG VWRUHG LQ D UHIULJHUDWRU IRU XVH LQ ILEHU VSLQQLQJ H[SHULPHQWV 6RPH YDULDWLRQV LQ WKH VROXWLRQ SUHSDUDWLRQKHDW WUHDWPHQW SURFHGXUHV DUH QRWHG DV IROORZV f 7KH RULJLQDO VWRFN VROXWLRQV 306$ DQG 306$ ZHUH GLYLGHG LQWR WZR SDUWV 7\SH % 3&6 ZDV DGGHG WR RQH SDUW 306$3 DQG 306$3f DQG W\SH & 3&6 ZDV DGGHG WR WKH RWKHU SDUW 306$3 DQG 306$3f 7KH KHDW WUHDWPHQW ZDV WKHQ FDUULHG RXW VHSDUDWHO\ IRU WKHVH SRO\PHU VROXWLRQV f ,Q WKH FDVH RI 306$ 306$3 DQG 306$3 WKH RULJLQDO VWRFN VROXWLRQV ZHUH GLYLGHG LQWR WZR SDUWV HDFK DQG KHDW WUHDWPHQWV ZHUH FDUULHG RXW VHSDUDWHO\ f 306$3 VWRFN VROXWLRQ ZDV GLYLGHG LQWR WZR SRUWLRQV 306$3 DQG 306$3f $IWHU WKH ILUVW KHDW WUHDWPHQW 306$3+f WKH WRWDO DPRXQW RI 36= LQ WKH SRO\PHU VROXWLRQ ZDV UDLVHG WR ZWb LQ WKH VHFRQG SRUWLRQ DQG KHDW WUHDWPHQW ZDV FDUULHG RXW VHSDUDWHO\ 306$3+f 3URFHGXUH IRU IUDFWLRQDO SUHFLSLWDWLRQ RI 306 SRO\PHUV 7KH DVV\QWKHVL]HG 306 SRO\PHUV VWRUHG LQ WROXHQHf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

PAGE 114

PHWKDQRO GURSZLVH DQG ZLWK YLJRURXV VWLUULQJ 7KH SUHFLSLWDWHG SRO\PHU VROXWLRQ ZDV WUDQVIHUUHG WR WHIORQ FHQWULIXJH WXEHV DQG FHQWULIXJHG DW USP IRU PLQ 7KH FOHDU VXSHUQDWDQW ZDV GHFDQWHG RXW 7KH fZHWf FDNH FROOHFWHG DW WKH HQG RI FHQWULIXJDWLRQ ZDV SODFHG LQ D JODVV YLDO DQG GULHG LQ D YDFXXP RYHQ DW URRP WHPSHUDWXUH 7R SUHYHQW VSODVKLQJ RI WKH SRO\PHU IURP YLDO GXULQJ YDFXXP GU\LQJ WKH YLDO ZDV FRYHUHG ZLWK DQ DOXPLQXP IRLO ZKLFK KDG EHHQ SHUIRUDWHG ZLWK WLQ\ KROHV $IWHU GU\LQJ WKH JODVV YLDO FRQWDLQLQJ WKH SRO\PHU ZDV UHPRYHG IURP WKH YDFXXP RYHQ E\ YHQWLQJ WR 1f DQG EDFNILOOHG ZLWK 1 7KH GULHG SRO\PHU ZDV GLVVROYHG LQ WROXHQH ZWbf DQG VWRUHG LQ D UHIULJHUDWRU IRU IXUWKHU SURFHVVLQJ ILEHU VSLQQLQJf 3RO\PHUV 306 WKURXJK 306 ZHUH IUDFWLRQDOO\ SUHFLSLWDWHG E\ DGGLWLRQ RI DFHWRQH 7KH DFHWRQH WR SRO\PHU UDWLRV PO RI DFHWRQH SHU J RI SRO\PHUf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fi 6DPSOHV ZHUH KHDWWUHDWHG LQ DUJRQ DW r&PLQ WR r& QR KROG WLPHf 6DPSOH SUHSDUDWLRQ IRU 7*$ LQYROYHG XVLQJ URWDU\ HYDSRUDWLRQ WR FRQFHQWUDWH WKH RULJLQDO SRO\PHU VROXWLRQV ZWb LQ WROXHQHf WR ZWb DQG WKHQ GU\LQJ WKH FRQFHQWUDWHG SRO\PHUV VROXWLRQ LQ D YDFXXP RYHQ DW r& IRU PLQ WR GULYH RII DQ\ UHVLGXDO VROYHQW FRPSOHWHO\ 7KH YDFXXP RYHQ ZDV YHQWHG WR QLWURJHQ WR SUHYHQW R[\JHQ FRQWDPLQDWLRQ 0RGHO 67$ 1HW]FK &RPSDQ\ ([WRQ 3$

PAGE 115

LQ WKH VDPSOHf 7KH GULHG SRO\PHU VROXWLRQ ZDV TXLFNO\ PLQf WUDQVIHUUHG WR D 7*$ VDPSOH KROGHU WR PLQLPL]H H[SRVXUH WR DLU ,Q VRPH FDVHV WKH FHUDPLF \LHOG ZDV GHWHUPLQHG E\ S\URO\]LQJ SRO\PHUV LQ D WXEH IXUQDFH WR r& LQ QLWURJHQ DW r&PLQ 7KH FHUDPLF \LHOG ZDV GHWHUPLQHG E\ PHDVXULQJ WKH ZHLJKWV EHIRUH DQG DIWHU S\URO\VLVf ,Q WKH FDVH RI SRO\PHUV IUDFWLRQDOO\SUHFLSLWDWHG E\ QRQVROYHQWV D SRUWLRQ RI WKH GULHG SRO\PHU ZDV VXEMHFWHG WR S\URO\VLV WR GHWHUPLQH LI WKH SRO\PHU PHOWHG GXULQJ S\URO\VLV fPHOWf WHVWf DV ZHOO DV WR HYDOXDWH FHUDPLF \LHOG 7KH GULHG SRO\PHU ZDV FUXVKHG LQWR FRDUVH SRZGHU ZHLJKHG DQG WUDQVIHUUHG LQWR D WXEH IXUQDFH TXLFNO\ PLQf 7KH S\URO\VLV VFKHGXOH XVHG IRU WKH PHOW WHVW ZDV r&PLQ WR r& LQ QLWURJHQ ZLWK QR KROG DW WHPSHUDWXUH 7KH SRO\PHU ZDV FRQVLGHUHG WR KDYH XQGHUJRQH QR PHOWLQJ LI WKH S\URO\]HG SRO\PHU UHWDLQHG VKDUS FRUQHUV DQG HGJHV ,W ZDV FRQVLGHUHG SDUWLDOO\ PHOWHG LI VRPH URXQGLQJ RI HGJHV DQG FRUQHUV RFFXUUHG DQG LI WKH S\URO\]HG FKXQNV ZHUH VWXFN WR WKH DOXPLQD ERDW XVHG IRU S\URO\VLV 3KDVH DQDO\VHV RI WKH S\URO\]HG VDPSOHV ZDV FDUULHG RXW E\ ;UD\ GLIIUDFWLRQ ;5'fii $OO WKH VDPSOHV IRU;5' ZHUH KHDWWUHDWHG LQ DUJRQ DW r&PLQ WR r& QR KROG WLPHf 7KH S\URO\]HG UHVLGXHV ZHUH VOLJKWO\ JURXQG ZLWK D PRUWDU DQG SHVWOH DQG VXEVHTXHQWO\ PL[HG ZLWK FROORGLDQDP\O DFHWDWH YROXPH UDWLRf 7KH PL[WXUH ZDV GHSRVLWHG RQ D JODVV VOLGH DQG GULHG DW URRP WHPSHUDWXUH SULRU WR DQDO\VLV 7KH FU\VWDOOLWH VL]HV IRU WKH 6L DQG 6L& SKDVHV ZHUH GHWHUPLQHG E\ WKH ;5' OLQH EURDGHQLQJ PHWKRG XVLQJ 6FKHPHUfV IRUPXOD W ;, % &RVf f ZKHUH W FU\VWDOOLWH VL]H LQ $ i 0RGHO $3' 3KLOOLSV ,QVWUXPHQWV &RPSDQ\ 0W 9HUQRQ 1<

PAGE 116

$ ZDYHOHQJWK LQ $ % IXOO ZLGWK KDOI PD[LPXP ):+0f LQ UDGLDQV %UDJJ DQJOH LQ GHJUHHV (OHPHQWDO DQDO\VHV IRU 6L & DQG RQ S\URO\]HG VDPSOHV r& RU r& LQ QLWURJHQf ZHUH REWDLQHG XVLQJ DQ (OHFWURQ 0LFURSUREH $QDO\]HUnn (0$f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r& LQ D QLWURJHQ DWPRVSKHUH 7KH SRURXV VDPSOH ZDV WKHQ PRXQWHG LQ D WKHUPRVHWWLQJ UHVLQQ 7KH PRXQWHG VDPSOHV ZHUH JURXQG ZLWK 6L& SRZGHU VOXUULHV RQ D JODVV SODWH 7KH IROORZLQJ JULW VL]HV RI SRZGHUV ZHUH XVHG LQ VXFFHVVLRQ DQG $IWHU ILQH JULQGLQJ VDPSOHV ZHUH SROLVKHG XVLQJ DQ DXWRPDWLF SROLVKHUrr FRQWDLQLQJ D )H6L VXVSHQVLRQ RQ D SROLVKLQJ JUDGH FORWKr1 Y -(2/ 6XSHUSUREH -DSDQ (OHFWUR2SWLFV /WG -(2/f 7RN\R -DSDQ W7 4XLFNPRXQW )XOWRQ 0HWDOOXUJLFDO 3URGXFWV &RUS 6D[RQEXUJ 3$ rr 9LEURPHW 3ROLVKLQJ :KHHO %XHKOHU /WG /DNH %OXII ,/ 0DVWHU3ROLVK ,, %XHKOHU /WG /DNH %OXII ,/ 3RO\PHW %XHKOHU /WG /DNH %OXII ,/

PAGE 117

7KLV SROLVKLQJ VWHS ZDV W\SLFDOO\ FDUULHG RXW IRU GD\V $IWHU SROLVKLQJ VDPSOHV ZHUH FOHDQHG LQ DQ XOWUDVRQLF FOHDQHU ZLWK GHLRQL]HG ZDWHU )7,5r VSHFWUD RI SRO\PHU VDPSOHV ZHUH FROOHFWHG LQ WKH UHJLRQ FPn 7KH VSHFWUD ZHUH FROOHFWHG LQ WKH GLIIXVH UHIOHFWDQFH PRGH 6DPSOH SUHSDUDWLRQ IRU REWDLQLQJ )7,5 VSHFWUD IRU WKH SRO\PHUV LQYROYHG PL[LQJ J RI ZWb SRO\PHU VROXWLRQ ZLWK GLDPRQG SRZGHU KHDWLQJ WKH PL[WXUH RQ D KRWVWDJHg WR r& IRU K LQ QLWURJHQ WR UHPRYH WROXHQHf DQG WKHQ FRROLQJ EDFN WR URRP WHPSHUDWXUH 3\URO\VLV EHKDYLRU RI WKH SRO\PHUV LQ WKH )7,5 PRGH ZDV VWXGLHG E\ XVLQJ WKH KRW VWDJH WR KHDW WUHDW WKH VDPSOHV IURP r& WR r& LQ 1 DW r&PLQ DQG FROOHFWLQJ VSHFWUD LQVLWX DW UHJXODU LQWHUYDOV RI WHPSHUDWXUH LH HYHU\ r&f )7,5 VSHFWUD RI VDPSOHV S\URO\]HG WR DQG r& r&PLQ WR WHPSHUDWXUH LQ QLWURJHQ ZLWK QR KROG WLPHf ZHUH FROOHFWHG VHSDUDWHO\ 7KH LQWULQVLF YLVFRVLWLHV RI SRO\PHU VROXWLRQV ZHUH GHWHUPLQHG DFFRUGLQJ WR $670 SURFHGXUH E\ HPSOR\LQJ D 8EHOORKGH 9LVFRPHWHU W\SH %f DV GHVFULEHG LQ VHFWLRQ 7KH FRQFHQWUDWLRQV RI SRO\PHU VROXWLRQV XVHG ZHUH LQ WKH UDQJH RI WR ZWb 6SLQQLQJ DQG &KDUDFWHUL]DWLRQ RI )LEHUV 3UHSDUHG IURP 306EDVHG 3RO\PHUV 6SLQ GRSH SUHSDUDWLRQ ILEHU VSLQQLQJ DQG ILEHU KHDW WUHDWPHQW 7KH DVSUHSDUHG RU IUDFWLRQDOO\SUHFLSLWDWHG 306 SRO\PHU VROXWLRQV ZHUH JHQHUDOO\ ILOWHUHG WKURXJK SP 37)( ILOWHU +RZHYHU VRPH SRO\PHU VROXWLRQV ZHUH ILOWHUDEOH RQO\ WKURXJK SP RU SP ILOWHUVf ,W LV LPSRUWDQW WR ILOWHU WKH SRO\PHU 1LFROHW 6; 6SHFWURPHWHU 1LFROHW ,QVWUXPHQWV &RPSDQ\ 0DGLVRQ :O g +DUULFN &RUSRUDWLRQ 2VVLQLQJ 1<

PAGE 118

VROXWLRQV WKURXJK WKH VPDOOHVWVL]HG ILOWHU SRVVLEOH LQ RUGHU WR HOLPLQDWH VWUHQJWKOLPLWLQJ GHIHFWV LQ ILEHU EDWFKHV VSXQ IURP WKHVH VROXWLRQV 7KH DGGLWLYHV IRU ILEHU VSLQQLQJ 36= DQG '% ZHUH ILOWHUHG VHSDUDWHO\ WKURXJK SP ILOWHUV DQG DGGHG WR WKH 306 VROXWLRQ 7KH DPRXQW RI 36= DGGHG UDQJHG IURP WR ZWb DQG WKH DPRXQW RI '% DGGHG UDQJHG IURP WR ZWb 36= LV D KLJKO\ YLVFRXV OLTXLG DW URRP WHPSHUDWXUH )RU XVH LQ ILEHU VSLQ EDWFKHV 36= ZDV GLVVROYHG LQ WROXHQH DW ZWb VROLGV ORDGLQJ DQG ILOWHUHG WKURXJK D SP ILOWHU 'HFDERUDQH '%f %+f ZDV SXUFKDVHG FRPPHUFLDOO\r '% ZDV GLVVROYHG LQ WROXHQH DW ZWb VROLGV ORDGLQJ DQG ILOWHUHG WKURXJK D SP ILOWHU SULRU WR XVH LQ ILEHU VSLQ EDWFKHV n 7KH SRO\PHU VROXWLRQ FRQWDLQLQJ DGGLWLYHV ZDV FRQFHQWUDWHG LQ D URWDU\ HYDSRUDWRU DW ar& XQWLO a ZWb VROYHQW UHPDLQHG $ nIORZ WHVWf ZDV XVHG DV D URXJK LQGLFDWLRQ WKDW DQ DSSURSULDWH YLVFRVLW\ IRU ILEHU VSLQQLQJ ZDV DWWDLQHG VHH VHFWLRQ f 7KH UKHRORJLFDO FKDUDFWHULVWLFV RI WKH ILQDO SRO\PHU VROXWLRQ ZHUH GHWHUPLQHG E\ XVLQJ D FRQHSODWH YLVFRPHWHU GHVFULEHG LQ VHFWLRQ f )LEHU VSLQQLQJ ZDV FDUULHG RXW LQVLGH D JORYH ER[ 7KH JORYH ER[ ZDV SXUJHG ZLWK QLWURJHQ WKUHH WLPHV SULRU WR HDFK VSLQQLQJ H[SHULPHQW 7KH VSLQ GRSH ZDV WUDQVIHUUHG WR VSLQQHUHW DVVHPEO\ LQVLGH WKH JORYH ER[ 7KUHHKROH VSLQQHUHWV RI a SP RU IRXUKROH VSLQQHUHWV RI a SP KROH VL]HV ZHUH XVHG IRU ILEHU VSLQQLQJ &DUH ZDV WDNHQ WR FOHDQ WKH VSLQQHUHWV WKRURXJKO\ EHIRUH VSLQQLQJ WR HQVXUH WKDW WKHUH ZHUH QR SDUWLFXODWHV EORFNLQJ WKH VSLQQHUHW KROHV 7KH IDFH RI VSLQQHUHW ZDV ZLSHG FOHDQ ZLWK D WROXHQHVRDNHG SDSHU WLVVXH SULRU WR FRPPHQFHPHQW RI VSLQQLQJ )LEHUV ZHUH IRUPHG DW URRP WHPSHUDWXUH E\ H[WUXGLQJ WKH SRO\PHU VROXWLRQV WKURXJK WKH VSLQQHUHW XQGHU r &RQVXPHU +HDOWK 5HVHDUFK /RV $QJHOHV &$ 0RGHO +%7 %URRNILHOG (QJLQHHULQJ /DERUDWRULHV,QF 6WRXJKWRQ 0$

PAGE 119

QLWURJHQ SUHVVXUH 1LWURJHQ SUHVVXUHV XVHG LQ VSLQQLQJ RI 306EDVHG ILEHUV UDQJHG IURP WR SVL 7KUHH ILODPHQWV ZHUH H[WUXGHG VLPXOWDQHRXVO\ LQ PRVW H[SHULPHQWV &RQWLQXRXV fJUHHQf ILEHUV ZHUH FROOHFWHG E\ ZLQGLQJ DW VSHHGV RI USPf RQ D ZKHHO GLDPHWHU a LQf ZKLFK ZDV SODFHG DSSUR[LPDWHO\ FP EHORZ WKH VSLQQHUHW ,Q VRPH FDVHV WKH VSLQQLQJ EHKDYLRU ZDV GRFXPHQWHG E\ QRWLQJ WKH QXPEHU RI ILEHU EUHDNV RFFXUULQJ GXULQJ VSLQQLQJ $IWHU ILEHU VSLQQLQJ EDWFKHV W\SLFDOO\ Jf ZHUH FXW IURP WKH ZKHHO 7KHVH EXQGOHV ZHUH ZUDSSHG LQ DOXPLQXP IRLO DV DQ a FP EXQGOH WKHQ FXW LQWR IRXU a FP ORQJ EXQGOHV ODEHOHG DQG VWRUHG LQ D YDFXXP GHVLFFDWRU IRU DW OHDVW K WR UHPRYH VROYHQW WUDFHV IURP ILEHUVf SULRU WR S\URO\VLV 7KH SUHSDUDWLRQ RI ILEHUV IURP 3063&6 SRO\PHU EOHQGV LQYROYHG PL[LQJ 306 VROXWLRQf ZLWK 3&6 VROLGf LQ GHVLUHG SURSRUWLRQV f DQG ILOWHULQJ WKH SRO\PHU VROXWLRQV WKURXJK VPDOOHVWVL]HG ILOWHU SRVVLEOH LH SP SP RU SPf :KHQ 3&6 ZDV PL[HG ZLWK 306 WKH RYHUDOO VROLGV ORDGLQJ ZDV NHSW DW ZWb E\ DGGLQJ WKH UHTXLUHG DPRXQW RI WROXHQH WR WKH 3063&6 EOHQG $GGLWLYHV ZHUH PL[HG ZLWK WKH 3063&6 EOHQG DV LQ WKH FDVH GHVFULEHG DERYH IRU 306 SRO\PHUV 7KH VSLQ GRSH SUHSDUDWLRQ DQG ILEHU VSLQQLQJ SURFHGXUHV ZHUH LGHQWLFDO WR WKH SURFHGXUHV XVHG IRU VSLQQLQJ RI ILEHUV IURP 306 SRO\PHUV ,Q WKH FDVH RI KHDWWUHDWHG 306 SRO\PHU DQG KHDWWUHDWHG 3063&6 SRO\PHU EOHQGV FRQWDLQLQJ DGGLWLYHVf WKH VROXWLRQV ZHUH ILOWHUHG DQG FRQFHQWUDWHG GLUHFWO\ E\ URWDU\ HYDSRUDWLRQ 7KH ILEHU VSLQQLQJ SURFHGXUHV ZHUH LGHQWLFDO WR WKDW RI 306 SRO\PHUV GHVFULEHG DERYH 7KH ILEHUV ZHUH S\URO\]HG LQ D WXEH IXUQDFHr LQ D IORZLQJ QLWURJHQ DWPRVSKHUH VWG DWPFF PLQf )LEHUV ZHUH WUDQVIHUUHG IURP WKH YDFXXP GHVLFFDWRU WR WKH IXUQDFH TXLFNO\ PLQf LQ RUGHU WR PLQLPL]H R[\JHQ FRQWDPLQDWLRQ IURP H[SRVXUH WR DLU 7KH g 0RGHO /LQGEHUJ )XUQDFHV :DWHUWRZQ :O

PAGE 120

ILEHUV ZHUH SODFHG LQ D JUDSKLWH IRLO ERDW XSRQ UHPRYDO IURP WKH YDFXXP GHVLFFDWRU 7KH IXUQDFH ZDV SXUJHG ZLWK QLWURJHQ IRU a PLQ SULRU WR KHDW WUHDWPHQW )LEHUV ZHUH KHDWHG WR HLWKHU r& RU r& ZLWK K KROG DW PD[LPXP WHPSHUDWXUH 7KH KHDWLQJ UDWH ZDV r&PLQ WR r& DQG r&PLQ WR PD[LPXP WHPSHUDWXUH +HDW WUHDWPHQW RI WKH r& RU r&S\URO\]HG ILEHUV WR r& ZDV FDUULHG RXW LQ D WXEH IXUQDFH DW r&PLQ LQ D IORZLQJ DUJRQ DWPRVSKHUH VWG DWPFF PLQf ZLWK K KROG +HDW WUHDWPHQW WR r& ZDV FDUULHG RXW DW r&PLQ LQ D ER[ IXUQDFH LQ DUJRQ DW r&PLQ ZLWK K KROG )LEHU FKDUDFWHUL]DWLRQ )LEHU WHQVLOH VWUHQJWKV ZHUH PHDVXUHG DW URRP WHPSHUDWXUH DFFRUGLQJ WR $670 SURFHGXUH >$67@ GHVFULEHG LQ VHFWLRQ 3\URO\]HG ILEHUV r& RU r& KHDW WUHDWPHQWf DQG LQ VRPH FDVHV ILEHUV ZKLFK ZHUH KHDWWUHDWHG WR r& DQG r& ZHUH WHVWHG )LEHUV ZHUH H[DPLQHG E\ VFDQQLQJ HOHFWURQ PLFURVFRS\ 6(0f 7KH DFFHOHUDWLQJ YROWDJHV XVHG ZHUH N9 DQG N9 IRU JUHHQ DQG KHDWWUHDWHG ILEHUV UHVSHFWLYHO\ $Q DOXPLQXP PRXQW f GLDPHWHU DQG WKLFNQHVV ZDV XVHG WR KROG ILEHUV ,Q RUGHU WR REVHUYH WKH ILEHU FURVVVHFWLRQ D QDUURZ VOLW PP ZLGHf ZDV FUHDWHG LQ WKH FHQWHU RI WKH PRXQW IRU SODFLQJ WKH ILEHUV YHUWLFDOO\ 7KH ILEHUV ZHUH DWWDFKHG WR D VPDOO SLHFH RI DOXPLQXP IRLO DQG KHOG LQ SODFH ZLWK D GRXEOHVLGHG DGKHVLYH WDSH 7KH IRLO ZLWK ILEHUV SODFHG XSULJKW ZDV LQVHUWHG LQWR WKH QDUURZ VOLW 7R REVHUYH WKH ILEHU VXUIDFHV WKH ILEHUV ZHUH ODLG IODW RQ WKH DOXPLQXP IRLO DQG KHOG LQ SODFH ZLWK D GRXEOH r *UDIRLO r1 8&DU 3LWWVEXUJK 3$ i 0RGHO 0 &HQWRUU 9DFXXP ,QGXVWULHV 1DVKXD 1+ 0RGHO -60 -(2/ 7RN\R -DSDQ

PAGE 121

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f RI WKH IUDFWXUHG ILEHU UHPDLQHG DWWDFKHG WR WKH SDSHU WDE DIWHU WHVWLQJ 7KH ILEHU IUDJPHQWV ZHUH WDSHG WR VWLII DOXPLQXP IRLO SLHFHV FXW IURP DOXPLQXP ZHLJKLQJ GLVKHVf 7KH IUDJPHQWV ZHUH VXEVHTXHQWO\ VRQLFDWHG IRU VHF LQ 1 +1 VROXWLRQ WKHQ VHF LQ 1 1+2+ DQG ILQDOO\ PLQ LQ PHWKDQRO 7KLV SURFHVV HQDEOHG UHPRYDO RI GHEULV DQG GXVW DGKHUHG WR WKH IUDFWXUH VXUIDFHV 7KH ILEHUV ZHUH WKHQ PRXQWHG RQ DQ DOXPLQXP VWXE DV GHVFULEHG HDUOLHU LQ WKH VHFWLRQ IRU REVHUYLQJ WKH FURVVVHFWLRQDO IHDWXUHV E\ 6(0 r 'HQWRQ 9DFXXP 'LYLVLRQ 0RRUHVWRZQ 1-

PAGE 122

&+$37(5 5(68/76 $1' ',6&866,21 (IIHFW RI 36= DV D &URVVOLQNLQT3URFHVVLQT $LG IRU 6SLQQLQJ RI )LEHUV IURP 3&6 6ROXWLRQ 7KLV VHFWLRQ JLYHV GHWDLOHG UHVXOWV DQG DQDO\VHV IRU LQYHVWLJDWLRQV LQYROYLQJ XVH RI 3RO\YLQ\OVLOD]DQH 36=f DV D VSLQQLQJ DLGFURVVOLQNLQJ DJHQW LQ WKH SUHSDUDWLRQ RI ILEHUV IURP 3&6 VSLQ GRSHV 5HVXOWV RI ILEHU VSLQQLQJ H[SHULPHQWV DQG FKDUDFWHUL]DWLRQ RI SRO\PHU VROXWLRQV DQG ILEHUV DUH GLVFXVVHG )LEHU VSLQQLQJ FKDUDFWHULVWLFV 3&6 DQG 3&636= VSLQ GRSHV ZHUH SUHSDUHG ZLWK VLPLODU FKDUDFWHULVWLFV VHH VHFWLRQ f 6ROXWLRQV ZHUH LQLWLDOO\ ILOWHUHG XQGHU WKH VDPH FRQGLWLRQV SP DW SVLf DQG VSLQ GRSHV ZHUH SUHSDUHG ZLWK HVVHQWLDOO\ WKH VDPH YLVFRVLW\ a 3D Vf 7KH VSLQ GRSHV ZHUH VSXQ XVLQJ WKH VDPH DSSOLHG SUHVVXUH SVL QLWURJHQf DQG VSLQQLQJ VSHHG LH OLQHDU IWPLQf )LJXUH DQG VKRZ W\SLFDO SORWV RI VKHDU VWUHVV YV VKHDU UDWH DQG YLVFRVLW\ YV VKHDU UDWH UHVSHFWLYHO\ IRU SRO\PHU VSLQ GRSHV 3&6 DQG 3&636=f XVHG LQ ILEHU VSLQQLQJ 7KH UKHRORJLFDO IORZ EHKDYLRU IRU YDULRXV 3&6 DQG 3&636= VSLQ GRSHV XVHG LQ WKLV VWXG\ DUH VKRZQ LQ $SSHQGL[ $f 7KH VSLQQLQJ VROXWLRQV VKRZHG HVVHQWLDOO\ 1HZWRQLDQ UKHRORJLFDO IORZ EHKDYLRU 7KH W\SLFDO YLVFRVLWLHV RI WKH VROXWLRQV XVHG LQ ILEHU VSLQQLQJ ZHUH 3D V 3&6 VROXWLRQ KDG D ORZHU VROLGV ORDGLQJ bf WKDQ 3&636= bf DW FRPSDUDEOH YLVFRVLWLHV %RWK 3&6 DQG 3&636= VSLQ GRSHV KDYH VLPLODU UKHRORJLFDO IORZ EHKDYLRU 7KH VROXWLRQV VKRZHG HVVHQWLDOO\ QR

PAGE 123

72 4 UH X F &2 Z WR WR 2 Â’ ,QFUHDVLQJ 6KHDU 5DWH 'HFUHDVLQJ 6KHDU 5DWH $f 6KHDU 5DWH V f Z UH &/ ef fWR R R m 2 ,QFUHDVLQJ 6KHDU 5DWH Â’ 'HFUHDVLQJ 6KHDU 5DWH i k aWa %f 6KHDU 5DWH Vnf )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU D 3&6 VSLQ GRSH VROLGV FRQFHQWUDWLRQ a ZWb EDWFK Vf

PAGE 124

BB UR &/ 2 ,QFUHDVLQJ 6KHDU 5DWH Â’ 'HFUHDVLQJ 6KHDU 5DWH $ &2 &/ Lr 9f R R 9f 2 ,QFUHDVLQJ 6KHDU 5DWH Â’ 'HFUHDVLQJ 6KHDU 5DWH 2 4 %f 6KHDU 5DWH Vnf )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU D 3&636= VSLQ GRSH VROLGV FRQFHQWUDWLRQ a ZWb EDWFK Vf

PAGE 125

WKL[RWURS\ XQGHU WKH PHDVXULQJ FRQGLWLRQV 7KH 3&6 DQG 3&636= VROXWLRQV VKRZHG D VOLJKW GHFUHDVH LQ YLVFRVLW\ DW ORZ VKHDU UDWHV 7KLV LV SUHVXPDEO\ EHFDXVH VWUHVV PHDVXUHPHQW LV LQDFFXUDWH DW ORZ VKHDU UDWHVr $OVR YLVFRVLW\ YDOXHV ZHUH VOLJKWO\ KLJKHU IRU fGRZQ FXUYHVf LH GHFUHDVLQJ VKHDU UDWHVf WKDQ IRU fXS FXUYHVf LH LQFUHDVLQJ VKHDU UDWHVf DW ORZ VKHDU UDWHV 7KLV LV SUREDEO\ GXH WR VRPH VOLJKW VROYHQW HYDSRUDWLRQ IURP VSLQ GRSH GXULQJ UKHRORJ\ PHDVXUHPHQWV 6ROYHQW HYDSRUDWLRQ ZRXOG LQFUHDVH WKH SRO\PHU FRQFHQWUDWLRQ DQG UHVXOW LQ KLJKHU VROXWLRQ YLVFRVLW\f 7KH LQFUHDVH LQ VROLGV ORDGLQJ IRU WKH 3&636= VROXWLRQ LQ FRPSDULVRQ ZLWK 3&6 VROXWLRQ DW VLPLODU YLVFRVLWLHV PD\ EH H[SODLQHG DV IROORZV 7KH 36= SRO\PHU SXUH QRW FRQWDLQLQJ DQ\ VROYHQWf LV D OLTXLG DQG KDV D YLVFRVLW\ RI a 3D V )LJXUH VKRZV WKDW D 3&6 VROXWLRQ ZLWK ZWb SRO\PHU KDV D YLVFRVLW\ RI a 3D V ,I VRPH 36= ZLWK QR VROYHQWf ZHUH DGGHG WR WKH ODWWHU 3&6 VROXWLRQ WKH RYHUDOO YLVFRVLW\ RI WKH QHZ VROXWLRQ ZRXOG EH ORZHU ,Q RUGHU WR UDLVH WKH YLVFRVLW\ EDFN WR a 3D V LW ZRXOG EH QHFHVVDU\ WR UHPRYH VRPH VROYHQW +HQFH LW LV REYLRXV WKDW WKH PL[HG 36=3&6 VROXWLRQ ZLOO KDYH D KLJKHU SRO\PHU FRQFHQWUDWLRQ FRPSDUHG WR D SXUH 3&6 VROXWLRQ DW D IL[HG YLVFRVLW\ 7DEOH VKRZV WKH UHVXOWV REWDLQHG IURP VSLQQLQJ WKH 3&6 DQG 3&636= VSLQ GRSHV 7KH GHWDLOHG ILEHU VSLQQLQJ FKDUDFWHULVWLFV LH QXPEHU RI EUHDNV YV WLPHf IRU LQGLYLGXDO ILEHU EDWFKHV LV SUHVHQWHG LQ $SSHQGL[ % ,W LV HYLGHQW IURP WKH WDEOH WKDW DGGLWLRQ RI 36= WR 3&6 JUHDWO\ LPSURYHG WKH VSLQQLQJ RI ILEHUV )RU H[DPSOH 3&6 VSLQ GRSHV VKRZHG VSLQ OLQH EUHDNDJH UDWHV LH QXPEHU RI EUHDNV SHU PLQXWH SHU VSLQQHUHW KROHf RI a ,Q FRQWUDVW WKH UDWHV ZHUH RQO\ a IRU WKH 3&636= VSLQ GRSHV :LWK OHVV EUHDNV DQG WKHUHIRUH OHVV LQWHUUXSWLRQV RI WKH ILEHU FROOHFWLRQ r 7KH VKHDU VWUHVV YV VKHDU UDWH GDWD LV XVXDOO\ FXUYHILWWHG WKURXJK WKH RULJLQ OLQHDU ILWf DQG WKH YLVFRVLW\ YV VKHDU UDWH GDWD LV REWDLQHG IURP WKH FXUYHILWWHG GDWD

PAGE 126

7DEOH )LEHU VSLQQLQJ FKDUDFWHULVWLFV IRU 3&6 DQG 3&636= VSLQ GRSHV VSXQ XQGHU LGHQWLFDO FRQGLWLRQV f 3&6 )LEHU EDWFKHV %DWFK $PRXQW RI VSLQ GRSH Jf $PRXQW RI SRO\PHU Jf $PRXQW RI ILEHUV FROOHFWHG Jf b RI ILEHUV \LHOGHG 'XUDWLRQ RI VSLQQLQJ PLQf 7RWDO QXPEHU RI EUHDNV 1XPEHU RI EUHDNVn V V V V f 3&636= ILEHU EDWFKHV %DWFK $PRXQW RI VSLQ GRSH Jf $PRXQW RI SRO\PHU Jf $PRXQW RI ILEHUV FROOHFWHG Jf bRI ILEHUV \LHOGHG 'XUDWLRQ RI VSLQQLQJ PLQf 7RWDO QXPEHU RI EUHDNV 1XPEHU RI EUHDNV V V V $PRXQW RI VSLQ GRSH DPRXQW RI SRO\PHU DPRXQW RI VROYHQW E 3HUFHQWDJH \LHOG [ $PRXQW RI ILEHUV FROOHFWHG$PRXQW RI SRO\PHU LQ WKH VSLQ GRSHf F 1XPEHU RI EUHDNV GXULQJ VSLQQLQJ SHU PLQXWH SHU VSLQQHUHW KROH )LEHUV ZHUH VSXQ XVLQJ D IRXUKROH SP KROH GLDPHWHU VSLQQHUHW

PAGE 127

SURFHVVf LW ZDV DOVR SRVVLEOH WR REWDLQ PRUH ILEHUV XVLQJ WKH 3&636= VSLQ GRSHV VHH 7DEOH f ,W ZDV REVHUYHG LQ WKH FRXUVH RI VSLQQLQJ ILEHUV IURP 3&6 VSLQ GRSHV WKDW JOREXOHV RI SRO\PHU IRUPHG SHULRGLFDOO\ DSSUR[LPDWHO\ HYHU\ PLQf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fOHDUQLQJ FXUYHf LQYROYHG LQ VSLQQLQJ RI WKHVH ILEHUV ,PSURYHG VSLQQLQJ RFFXUUHG LH ORZHU EUHDNDJH UDWHV DQG KLJKHU \LHOG RI ILEHUV ZHUH REVHUYHGf DV WKH ILEHU VSLQQLQJ RSHUDWRU JDLQHG PRUH H[SHULHQFH LQ KDQGOLQJ RI WKH VSLQ GRSH ,W LV HYLGHQW IRU H[DPSOH WKDW LPSURYHG VSLQQLQJ RFFXUUHG ZLWK VXFFHVVLYH EDWFKHV IRU WKH IRXU 3&6 VSLQ GRSHV 7DEOH f 1HYHUWKHOHVV WKH EHVW EDWFK SUHSDUHG ZLWK 3&6 VSLQ GRSH LH EDWFK Vf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

PAGE 128

)LJXUH Df 6FKHPDWLF LOOXVWUDWLRQ RI JOREXOH IRUPDWLRQ GXULQJ VSLQQLQJ RI ILEHUV IURP 3&6 VSLQ GRSH Df WRS YLHZ Ef IURQW YLHZ RI WKH VSLQQHUHW DVVHPEO\

PAGE 129

H[SHULPHQWV YL] 3D Vf DQG GUDZLQJ ILEHUV XQWLO WKH\ EHFDPH VHSDUDWHG IURP WKH EXON VROXWLRQ $YHUDJH ILEHU H[WHQVLRQV DUH VKRZQ LQ 7DEOH ZKLOH WKH UHVXOWV IRU LQGLYLGXDO ILEHUV DUH VKRZQ LQ $SSHQGL[ & 7DEOH VKRZV WKDW WKH DYHUDJH ILEHU H[WHQVLRQ IRU WKH 3&636= VROXWLRQ ZDV b JUHDWHU WKDQ WKH DYHUDJH H[WHQVLRQ IRU WKH 3&6 VROXWLRQ 7KH GLIIHUHQFHV LQ ILEHU H[WHQVLRQ PD\ EH UHODWHG WR D GLIIHUHQFH LQ GU\LQJ EHKDYLRU RI WKH SRO\PHU VROXWLRQV VHH VHFWLRQ f 7KH UDWH RI HYDSRUDWLRQ RI VROYHQW WROXHQHf LV JUHDWHU IRU 3&6 VROXWLRQV WKDQ IRU 3&636= VROXWLRQVf 3RO\PHU VROXWLRQ FKDUDFWHULVWLFV 7R XQGHUVWDQG WKH GLIIHUHQFHV LQ VSLQQLQJ FKDUDFWHULVWLFV RI 3&6 DQG 3&636= VSLQ GRSHV WKH SRO\PHU VROXWLRQV ZHUH FKDUDFWHUL]HG E\ PHDVXULQJ PROHFXODU ZHLJKW DQG LQWULQVLF YLVFRVLW\ ZHWWDELOLW\ RQ GLIIHUHQW VXEVWUDWHV VXUIDFH WHQVLRQ DQG UDWH RI HYDSRUDWLRQ RI VROYHQW IURP VSLQ GRSHV 0ROHFXODU ZHLJKW DQG LQWULQVLF YLVFRVLW\ PHDVXUHPHQWV )LJXUH VKRZV *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU WKH 3&6 DQG 36=r SRO\PHUV ,W FDQ EH VHHQ WKDW PROHFXODU ZHLJKWV 0Q DQG 0Zf DQG SRO\GLVSHUVLW\ LQGLFHV 3',fVf IRU WKH WZR SRO\PHUV DUH VLPLODU +RZHYHU 36= KDV D ELPRGDO PROHFXODU ZHLJKW GLVWULEXWLRQ )LJXUH VKRZV SORWV RI UcVSF YV F ZKHUH UfVS LV WKH VSHFLILF YLVFRVLW\ DQG F LV FRQFHQWUDWLRQ LQ JGOf IRU 3&6 36= DQG 3&636= VROXWLRQV $OVR VKRZQ DUH WKH LQWULQVLF YLVFRVLW\ >U_@ YDOXHV ZKLFK DUH WKH \D[LV LQWHUFHSWV REWDLQHG E\ H[WUDSRODWLRQ WR F f RI WKH OHDVW VTXDUHV ILW RI WKH GDWD 'HWDLOV RI FDOFXODWLRQV RI LQWULQVLF YLVFRVLWLHV IRU WKHVH VROXWLRQV DUH VKRZQ LQ $SSHQGL[ 7KH LQWULQVLF YLVFRVLWLHV RI 3&6 36= DQG r 3&6 XVHG LQ WKLV VWXG\ ZDVSUHSDUHG E\ 6WDDE DW 8QLYHUVLW\ RI )ORULGD r 36= XVHG LQ WKLV VWXG\ ZDVSUHSDUHG E\ 6FKLHIIHOH DW 8QLYHUVLW\ RI )ORULGD

PAGE 130

7DEOH $YHUDJH ILEHU H[WHQVLRQ GLVWDQFHV IRU 3&6 DQG 3&636= VSLQ GRSHV DW WKH VDPH YLVFRVLWLHV XVHG LQ WKH ILEHU VSLQQLQJ H[SHULPHQWV 3RO\PHU EDWFK RI ILEHUV GUDZQ $YHUDTH ILEHU H[WHQVLRQ FP 3&6 3&636= s )LEHU H[WHQVLRQ GLVWDQFH ZDV GHWHUPLQHG E\ GLSSLQJ D JODVV URG LQ WKH EXON SRO\PHU VROXWLRQ DQG GUDZLQJ ILEHUV XQWLO WKH\ EHFDPH VHSDUDWHG IURP WKH EXON VROXWLRQ

PAGE 131

GZWGORJ0f GZWGORJ0f $f %f )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU $f 3&6 DQG %f 36=

PAGE 132

$f %f &f )LJXUH 3ORWV RI U_6F YV FRQFHQWUDWLRQ IRU $f 3&6 %f 3&636= DQG &f 36= VROXWLRQV

PAGE 133

3&636= VROXWLRQV DUH VLPLODU 7KLV LV VRPHZKDW VXUSULVLQJ EHFDXVH 36= KDV D ODUJHU IUDFWLRQ RI KLJKHU PROHFXODU ZHLJKW PROHFXOHV FRPSDUHG WR 3&6 ,I RWKHU IDFWRUV ZHUH FRQVWDQW WKLV VKRXOG UHVXOW LQ D KLJKHU LQWULQVLF YLVFRVLW\ +RZHYHU WKH LQWULQVLF YLVFRVLW\ DOVR GHSHQGV RQ WKH SRO\PHUVROYHQW LQWHUDFWLRQV WKH SRO\PHU PROHFXODU VKDSH HJ OLQHDU YV HTXLD[HGf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b SRO\PHU )LJXUHV D DQG E VKRZ WKH SHUFHQWDJH ZHLJKW FKDQJH YV WLPH DQG DEVROXWH ZHLJKW FKDQJH YV WLPH UHVSHFWLYHO\ IRU ERWK SRO\PHU VROXWLRQV ,W LV HYLGHQW WKDW WKH WROXHQH HYDSRUDWLRQ UDWH ZDV PXFK VORZHU IRU WKH 3&636= VROXWLRQ 7KLV VXJJHVWV WKDW UDWH RI HYDSRUDWLRQ RI VROYHQW QHDU WKH VSLQQHUHW IDFH ZLOO EH ORZHU IRU 3&636= VSLQ GRSH FRPSDUHG WR 3&6 DQG KHQFH GU\LQJ HIIHFWV DW WKH VSLQQHUHW IDFH ZLOO EH PLQLPL]HG DOVRf :KHQ WKH SRO\PHU VSLQ GRSH GULHV UDSLGO\ RQ WKH VSLQQHUHW IDFH LW PD\ IRUP GULHU PDWHULDO ZKLFK FRXOG REVWUXFW WKH VSLQQHUHW KROHV DQG LQWHUIHUH ZLWK ILEHU IRUPDWLRQ DQG VSLQQLQJ ,Q DGGLWLRQ D IDVWHU GU\LQJ UDWH PD\ KDYH DQ DGYHUVH HIIHFW RQ ILODPHQW H[WHQVLRQ DQG ZLQGLQJ ,W ZDV VKRZQ LQ VHFWLRQ WKDW ILEHU H[WHQVLRQV ZHUH ORZHU IRU 3&6 SRO\PHU VROXWLRQ FRPSDUHG WR 3&636= VROXWLRQ VHH 7DEOH f 7KLV PLJKW EH FDXVHG E\ D IDVWHU GU\LQJ UDWH RI WKH ILODPHQW SXOOHG IURP WKH SRO\PHU 7KH UHJUHVVLRQ FRHIILFLHQW LQ WKH LQWULQVLF YLVFRVLW\ FDOFXODWLRQV IRU 36= ZDV FRQVLGHUDEO\ ORZHU WKDQ WKH YDOXHV REWDLQHG IRU WKH 3&6 DQG 3&636= VROXWLRQV

PAGE 134

:(,*+7 &+$1*( bf )LJXUH $f 3HUFHQW FKDQJH LQ ZHLJKW RI 3&6 DQG 3&636= VSLQ GRSH DV D IXQFWLRQ RI WLPH GXH WR HYDSRUDWLRQ RI WROXHQH DQG %f DEVROXWH ZHLJKW FKDQJH DV D IXQFWLRQ IRU 3&6 DQG 3&636= VROXWLRQV

PAGE 135

$%62/87( :(,*+7 &+$1*( Jf )LJXUH &RQWnGf

PAGE 136

VROXWLRQ LH IDVWHU GU\LQJ RI WKH ILODPHQW ZRXOG FDXVH LW WR EHFRPH VROLGOLNH DQG EULWWOH PRUH TXLFNO\ DQG FDXVH LW WR VHSDUDWH IURP WKH EXON VROXWLRQ DW D VKRUWHU GLVWDQFHf 7KH ORZHU UDWH RI HYDSRUDWLRQ IRU 3&636= VROXWLRQ LV SUHVXPDEO\ FDXVHG E\ KLJKHU ELQGLQJ HQHUJ\ RI WROXHQH WR 36= 7KHUHIRUH LW UHTXLUHV KLJKHU WKHUPDO HQHUJ\ LQ RUGHU WR UHOHDVH WROXHQH PROHFXOHV IURP 36=f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f DQG GURSZLWKGUDZDO PHWKRG UHPRYLQJ GURSOHWV RI IL[HG VL]H IURP DQ H[LVWLQJ GURSOHWf 'XH WR WKH KLJKHU HYDSRUDWLRQ UDWH GXULQJ PHDVXUHPHQW RI UHFHGLQJ FRQWDFW DQJOH WKH HUURU LQYROYHG LQ WKH PHDVXUHPHQW LV OLNHO\ WR EH ODUJH DQG IRU WKLV UHDVRQ RQO\ DGYDQFLQJ FRQWDFW DQJOHV ZHUH WDNHQ LQWR FRQVLGHUDWLRQ LQ WKH DQDO\VLV RI UHVXOWV $OWKRXJK HIIRUWV ZHUH PDGH WR VDWXUDWH WKH ORFDO DWPRVSKHUH ZLWK WKH VROYHQW IRU ZKLFK WKH FRQWDFW DQJOH ZDV PHDVXUHG LW ZDV QRW SRVVLEOH WR FRPSOHWHO\ DYRLG VROYHQW HYDSRUDWLRQ IURP WKH VHVVLOH GURS GXULQJ WKH FRXUVH RI WKH PHDVXUHPHQWf (LJKW GURS VL]HV ZHUH XVHG IRU WKH PHDVXUHPHQW RI WKH FRQWDFW DQJOH RI ZDWHU RQ WHIORQ IURP D PLQLPXP FXPXODWLYH GURS VL]H RI PO WR D PD[LPXP FXPXODWLYH GURS VL]H RI PO 7KH DGYDQFLQJ FRQWDFW FRQWDFW DQJOHV UHPDLQHG FRQVWDQW DW r ZKHQ GURS VL]H ZDV LQFUHDVHG IURP PO WR PO ZKHUHDV WKH UHFHGLQJ FRQWDFW DQJOHV GHFUHDVHG IURP r WR r 7KH GHWDLOHG UHVXOWV DUH VKRZQ LQ )LJXUH 7KH PHDVXUHG FRQWDFW DQJOHV ZHUH LQ UHDVRQDEOH DJUHHPHQW ZLWK WKH UHSRUWHG YDOXHV LQ

PAGE 137

&217$&7 $1*/( 'HJUHHVf &217$&7 $1*/( 'HJUHHVf '523 92/80( POf 2 $GYDQFLQJ &RQWDFW $QJOH Â’ 5HFHGLQJ &RQWDFW $QJOH 2 2 2 2 2 2 4 Â’ Â’ Â’ Â’ Â’ Â’ $f 2 $GYDQFLQJ &RQWDFW $QJOH Â’ 5HFHGLQJ &RQWDFW $QJOH 22222224 %c f Â’ 2 r r r 7 n , n '523 92/80( POf )LJXUH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU ZDWHU RQ $f WHIORQ VXEVWUDWH %f VWDLQOHVV VWHHO VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH 2 $GYDQFLQJ &RQWDFW $QJOH Â’ 5HFHGLQJ &RQWDFW $QJOH 22222224 Â’ Â’ Â’ Â’ Â’ Â’

PAGE 138

OLWHUDWXUH >:X@ :X REWDLQHG DQ DGYDQFLQJ FRQWDFW DQJOH RI r DQG UHFHGLQJ FRQWDFW DQJOH RI r 1R LQIRUPDWLRQ ZDV DYDLODEOH RQ GURS VL]HV RU KRZ WKH PHDVXUHPHQWV ZHUH FDUULHG RXWf )RU ZDWHU RQ VWDLQOHVV VWHHO WKH DGYDQFLQJ FRQWDFW DQJOH YDULHG IURP WR r ZKHQ WKH GURS VL]H ZDV LQFUHDVHG IURP PO WR PO 7KH UHFHGLQJ FRQWDFW DQJOHV GHFUHDVHG IURP WR r IRU WKH VDPH UDQJH RI GURS VL]HV &RQWDFW DQJOHV RI WROXHQH ZHUH PHDVXUHG RQ WHIORQ DQG VWDLQOHVV VWHHO VXEVWUDWHV )RU WROXHQH RQ WHIORQ WKH DGYDQFLQJ FRQWDFW DQJOHV UDQJHG IURP WR r IRU GURS VL]HV RI WR PO VHH )LJXUH f PO ZDV WKH ODUJHVW GURS VL]H SRVVLEOH IRU WKLV SDUWLFXODU PHDVXUHPHQW EHFDXVH RI WKH VPDOO VXEVWUDWH VL]Hf 7ROXHQH ZDV FRQVLGHUDEO\ PRUH ZHWWLQJ RQ VWDLQOHVV VWHHO ZLWK DGYDQFLQJ FRQWDFW DQJOHV LQ WKH UDQJH RI RQO\ WR r IRU D GURS VL]HV RI WR PO VHH )LJXUH f )RU WROXHQH RQ VWDLQOHVV VWHHO WKH PD[LPXP GURS VL]H SRVVLEOH ZDV PO GXH WR LWV UDSLG VSUHDGLQJ RQ VWDLQOHVV VWHHO &RQWDFW DQJOHV IRU 3&6 DQG 3&636= VROXWLRQV SRO\PHU FRQFHQWUDWLRQV RI ZWb LQ WROXHQHf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

PAGE 139

&217$&7 $1*/( 'HJUHHVf &217$&7 $1*/( 'HJUHHVf 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO ’ 5HFHGLQJ &RQWDFW $QJOH 2 2 ’ 2 ’ 2 2 ’ 2 ’ '523 92/80( POf 2 $GYDQFLQJ &RQWDFW $QJOH MUcDO 5HFHGLQJ &RQWDFW $QJOH ’ Q R R R ’ ’ 2 ’ ’ + L L f§Lf§Wf§f§f§f§nf§f§f§ '523 92/80( POf )LJXUH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU WROXHQH RQ WHIORQ VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO ’ 5HFHGLQJ &RQWDFW $QJOH ’ ? ’ ’ ’ ’ '523 92/80( POf

PAGE 140

&217$&7 $1*/( 'HJUHHVf &217$&7 $1*/( 'HJUHHVf 2 $GYDQFLQJ &RQWDFW $QJOH Â’ 5HFHGLQJ &RQWDFW $QJOH 2 2 Â’ Â’ Â’ Q U Â’ 7ULDO 2 2 2 2 2 U '523 92/80( POf '523 92/80( POf )LJXUH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU WROXHQH RQ VWDLQOHVV VWHHO VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO Â’ 5HFHGLQJ &RQWDFW $QJOH 2 2 2 2 2 2 Â’ Â’ Â’ Â’ Â’ Â’

PAGE 141

&217$&7 $1*/( 'HJUHHVf &217$&7 $1*/( 'HJUHHVf '523 92/80( POf 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO Â’ 5HFHGLQJ &RQWDFW $QJOH 2 Â’ 2 Â’ Â’ '523 92/80( POf )LJXUH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU 3&6 ZWbfWROXHQH VROXWLRQ RQ VWDLQOHVV VWHHO VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH 2 $GYDQFLQJ &RQWDFW $QJOH Â’ 5HFHGLQJ &RQWDFW $QJOH 7ULDO 2 Â’ 2 Â’ R Â’ R Â’

PAGE 142

&217$&7 $1*/( 'HJUHHVf &217$&7 $1*/( 'HJUHHVf '523 92/80( POf 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO Â’ 5HFHGLQJ &RQWDFW $QJOH Â’ R Â’ R Â’R H '523 92/80( POf )LJXUH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU 3&636= ZWbfWROXHQH VROXWLRQ RQ VWDLQOHVV VWHHO VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH 2 $GYDQFLQJ &RQWDFW $QJOH Â’ 5HFHGLQJ &RQWDFW $QJOH 2 Â’ R Â’ R Â’ R Â’ 7ULDO

PAGE 143

&217$&7 $1*/( 'HJUHHVf &217$&7 $1*/( 'HJUHHVf '523 92/80( POf 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO Â’ 5HFHGLQJ &RQWDFW $QJOH 2 2 2 2 Â’ '523 92/80( POf )LJXUH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU 3&6 ZWbfWROXHQH VROXWLRQ RQ WHIORQ VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO Â’ 5HFHGLQJ &RQWDFW $QJOH 2 4 2 2 Â’ R Â’ Â’ Â’

PAGE 144

&217$&7 $1*/( 'HJUHHVf &217$&7 $1*/( 'HJUHHVf '523 92/80( POf 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO ’ 5HFHGLQJ &RQWDFW $QJOH R H 2 2 ’ ’ ’ R ’ Q 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO ’ 5HFHGLQJ &RQWDFW $QJOH R H 2 2 ’ ’ ’ R ’ f§Lf§Wf§ '523 92/80( POf )LJXUH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU 3&636= ZWbfWROXHQH VROXWLRQ RQ WHIORQ VXEVWUDWH DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH

PAGE 145

,W LV SRVVLEOH WKDW VSLQQHUHW KROHV EHFRPH FRDWHG ZLWK D WKLQ ILOP RI WKH SRO\PHU VROXWLRQ GXULQJ WKH SURFHVV RI ILEHU VSLQQLQJ )RU WKLV UHDVRQ FRQWDFW DQJOHV RI 3&6 a ZWbfWROXHQH VROXWLRQ DQG 3&636= a ZWbfWROXHQH VROXWLRQ ZHUH PHDVXUHG RQ VWDLQOHVV VWHHO VXEVWUDWHV ZKLFK KDG EHHQ SUHYLRXVO\ FRDWHG ZLWK WKLQ ILOPV RI 3&6 DQG 3&636= UHVSHFWLYHO\ $V GHVFULEHG LQ &KDSWHU WKLQ ILOPV ZHUH SUHSDUHG E\ VSLQ FRDWLQJ WKH VDPH VROXWLRQV WKDW ZHUH XVHG WR IRUP WKH VHVVLOH GURSV IRU WKH FRQWDFW DQJOH PHDVXUHPHQWVf )LJXUH VKRZV WKH FRQWDFW DQJOHV IRU 3&6 VROXWLRQ RQ 3&6 FRDWHG VWDLQOHVV VWHHO 7KH FRQWDFW DQJOHV DUH FRQVLGHUDEO\ KLJKHU HVSHFLDOO\ WKH DGYDQFLQJ DQJOHVf FRPSDUHG WR WKH FRQWDFW DQJOHV IRU 3&6 VROXWLRQ RQ XQFRDWHG VWDLQOHVV VWHHO )LJXUH f 7KH DGYDQFLQJ FRQWDFW DQJOHV LQ )LJXUH UDQJH IURP WR r ZKLOH WKH DGYDQFLQJ DQJOHV LQ )LJXUH UDQJH IURP WR rf ,Q FRQWUDVW WR WKHVH UHVXOWV WKH FRQWDFW DQJOHV RI 3&636= VROXWLRQ RQ 3&636=f FRDWHG VWDLQOHVV VWHHO )LJXUH f UHPDLQ ORZ DQG KDYH VLPLODU YDOXHV WR WKH FRQWDFW DQJOHV IRU 3&636= VROXWLRQ RQ XQFRDWHG VWDLQOHVV VWHHO )LJXUH f 7KH DGYDQFLQJ DQJOHV UDQJH IURP WR r DQG WR r LQ )LJXUHV DQG UHVSHFWLYHO\f 7KH SRRUHU ZHWWLQJ EHKDYLRU LH KLJKHU FRQWDFW DQJOHVf IRU 3&6 VROXWLRQV RQ 3&6FRDWHG VWDLQOHVV VWHHO PD\ EH D IDFWRU UHODWHG WR WKH SUREOHPV HJ JOREXOH IRUPDWLRQf LQ VSLQQLQJ ILEHUV IURP 3&6 VROXWLRQV ZLWK QR 36=f &RQWDFW DQJOH K\VWHUHVLV LH GLIIHUHQFHV LQ DGYDQFLQJ DQG UHFHGLQJ DQJOHV IRU D IL[HG GURS VL]Hf ZDV REVHUYHG LQ DOO WKH PHDVXUHPHQWV PDGH LQ WKLV VWXG\ &RQWDFW DQJOH K\VWHUHVLV KDV EHHQ REVHUYHG LQ PDQ\ RWKHU VWXGLHV DOVR )RU H[DPSOH +HU]EHUJ DQG 0DULDQ >+HU@ KDYH UHSRUWHG FRQWDFW DQJOH K\VWHUHVLV IRU ZDWHU RQ SRO\PHWK\OPHWKDFU\ODWH DQG SRO\HWK\OHQH VXEVWUDWHV 5HDVRQV IRU FRQWDFW DQJOH K\VWHUHVLV LQFOXGH f GLIIHUHQFHV LQ HYDSRUDWLRQ RI VROYHQW IURP WKH VXEVWUDWH VXUIDFH HQFRXQWHUHG GXULQJ PHDVXUHPHQW RI DGYDQFLQJ FRQWDFW DQJOHV DQG UHFHGLQJ FRQWDFW

PAGE 146

&217$&7 $1*/( 'HJUHHVf &217$&7 $1*/( 'HJUHHVf '523 92/80( POf 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO Â’ 5HFHGLQJ &RQWDFW $QJOH R R R R 2 Â’ Â’ Â’ Â’ 7 '523 92/80( POf )LJXUH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU 3&6 ZWbfWROXHQH VROXWLRQ RQ D VWDLQOHVV VWHHO VXEVWUDWH FRDWHG ZLWK 3&6 DV D IXQFWLRQ RI FXPXODWLYH GURS YROXPH 2 $GYDQFLQJ &RQWDFW $QJOH Â’ 5HFHGLQJ &RQWDFW $QJOH 7ULDO 2 2 2 Â’ R 2 Â’ Â’

PAGE 147

&217$&7 $1*/( 'HJUHHVf &217$&7 $1*/( 'HJUHHVf '523 92/80( POf 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO Â’ 5HFHGLQJ &RQWDFW $QJOH 2 2 Â’ 2 2 Â’ D Â’ Â’ '523 92/80( POf 2 $GYDQFLQJ &RQWDFW $QJOH 7ULDO Â’ 5HFHGLQJ &RQWDFW $QJOH 2 Â’ 2 r Â’ 2 Â’ Â’ )LJXUH $GYDQFLQJ DQG UHFHGLQJ FRQWDFW DQJOHV IRU 3&636= ZWbfWROXHQH VROXWLRQ RQ D VWDLQOHVV VWHHO VXEVWUDWH FRDWHG ZLWK 3&636= DV D IXQFWLRQ RI GURS YROXPH

PAGE 148

DQJOHV DQG f VXUIDFH URXJKQHVV RI WKH VXEVWUDWHV >:X +HU@ :X HW DO >:X@ KDYH REVHUYHG WKDW K\VWHUHVLV LQFUHDVHV ZLWK LQFUHDVH LQ VXUIDFH URXJKQHVV ,Q WKH SUHVHQW VWXG\ ODUJHU K\VWHUHVLV ZDV REVHUYHG IRU PHDVXUHPHQWV RI ZDWHU DQG WROXHQH RQ WHIORQ FRPSDUHG WR WKDW REVHUYHG IRU PHDVXUHPHQWV RQ VWDLQOHVV VWHHO )LJXUHV D DQG f 7KLV PD\ EH GXH WR WKH JUHDWHU URXJKQHVV RI WKH WHIORQ VXEVWUDWHV 7KH WHIORQ VXEVWUDWHV ZHUH SROLVKHG RQ D SP GLDPRQG ZKHHO EXW WKH\ VWLOO KDG URXJKHU VXUIDFHV WKDQ VWDLQOHVV VWHHOf ,W ZDV DOVR REVHUYHG WKDW 3&6 DQG 3&636= VROXWLRQV VKRZHG JUHDWHU FRQWDFW DQJOH K\VWHUHVLV RQ WHIORQ )LJXUHV DQG UHVSHFWLYHO\f FRPSDUHG WR WKH VDPH VROXWLRQV RQ VWDLQOHVV VWHHO )LJXUHV DQG UHVSHFWLYHO\f $ ODUJH FRQWDFW DQJOH K\VWHUHVLV ZDV REVHUYHG IRU WKH 3&6 VROXWLRQ RQ 3&6 FRDWHG VWDLQOHVV VWHHO )LJXUH f LH FRPSDUHG WR WKH K\VWHUHVLV REVHUYHG IRU WKH 3&6 VROXWLRQ RQ XQFRDWHG VWDLQOHVV VWHHO )LJXUH f 7KH UHDVRQ IRU WKLV GLIIHUHQFH LV XQFOHDU 7KHUH ZDV DOVR D WHQGHQF\ IRU FRQWDFW DQJOH K\VWHUHVLV WR EH JUHDWHU ZLWK 3&6 VROXWLRQV FRPSDUHG WR 3&636= VROXWLRQV 7KLV ZDV PRVW SURQRXQFHG ZKHQ FRDWHG VWDLQOHVV VWHHO VXEVWUDWHV ZHUH XVHG )LJXUHV DQG f ,Q FRQWUDVW WKHUH ZDV QR VLJQLILFDQW GLIIHUHQFH LQ FRQWDFW DQJOH K\VWHUHVLV IRU WKH H[SHULPHQWV ZLWK XQFRDWHG VWDLQOHVV VWHHO )LJXUHV DQG ff 7KLV HIIHFW PD\ EH UHODWHG WR WKH GLIIHUHQFHV LQ VROYHQW HYDSRUDWLRQ UDWHV IURP WKH VROXWLRQV $V LQGLFDWHG LQ )LJXUHV D DQG E WROXHQH HYDSRUDWHG DW D KLJKHU UDWH LQ WKH HDUO\ VWDJHV IURP D 3&6 VROXWLRQ FRPSDUHG WR D 3&636= VROXWLRQf 6XUIDFH WHQVLRQ PHDVXUHPHQWV ([SHULPHQWV ZHUH FDUULHG RXW WR GHWHUPLQH LI WKHUH ZHUH FKDQJHV LQ VXUIDFH WHQVLRQ FKDUDFWHULVWLFV RI WKH 3&6 SRO\PHU VROXWLRQ DV D UHVXOW RI DGGLWLRQ RI 36= WR 3&6 ,Q RUGHU WR HVWDEOLVK PHDVXUHPHQW SURWRFROV VXUIDFH WHQVLRQ H[SHULPHQWV ZHUH FDUULHG RXW IRU ZDWHU DFHWRQH DQG WROXHQH DQG FRPSDUHG ZLWK SXEOLVKHG UHVXOWV

PAGE 149

>&5&@ 7KH GHWDLOHG UHVXOWV DUH SUHVHQWHG LQ $SSHQGL[ ( 7KH PHDVXUHG YDOXHV ZHUH ZLWKLQ b RI SXEOLVKHG VXUIDFH WHQVLRQ YDOXHV IRU HDFK OLTXLG 7DEOH VKRZV VXUIDFH WHQVLRQ YDOXHV IRU 3&6 DQG 3&636= VROXWLRQV DW WKUHH GLIIHUHQW VROLGV ORDGLQJ ZWb ZWb DQG ZWbf 7KH UKHRORJLFDO EHKDYLRU RI WKH SRO\PHU VROXWLRQV DW WKHVH FRQFHQWUDWLRQV DUH VKRZQ LQ )LJXUHV 7KH VROXWLRQV H[KLELWHG HVVHQWLDOO\ QHDU1HZWRQLDQ UKHRORJLFDO EHKDYLRU +RZHYHU WKH PRVW FRQFHQWUDWHG 3&6 VROXWLRQ ZWbf LQ )LJXUH VKRZHG VOLJKW VKHDU WKLQQLQJ EHKDYLRUf )LJXUHV DQG VKRZ SORWV RI VXUIDFH WHQVLRQ YV FRQFHQWUDWLRQ DQG VXUIDFH WHQVLRQ YV YLVFRVLW\ IRU WKHVH VROXWLRQV $W WKH ORZHVW FRQFHQWUDWLRQ ZWb SRO\PHUf WKH VXUIDFH WHQVLRQ RI WKH 3&6 VROXWLRQ ZDV RQO\ VOLJKWO\ KLJKHU WKDQ 3&636= VROXWLRQ 7KH GLIIHUHQFHV LQ VXUIDFH WHQVLRQ YDOXHV LQFUHDVHG VOLJKWO\ ZLWK LQFUHDVLQJ SRO\PHU FRQFHQWUDWLRQV ,W VKRXOG EH QRWHG WKDW WKH HUURU LQYROYHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW SUREDEO\ EHFRPHV ODUJHU DW KLJKHU FRQFHQWUDWLRQV DQG KLJKHU YLVFRVLWLHVf DQG WKH DEVROXWH YDOXHV UHSRUWHG PD\ QRW EH UHOLDEOH )RU H[DPSOH WKH PDUJLQ RI HUURU LQYROYHG LQ PHDVXUHPHQW RI VXUIDFH WHQVLRQ IRU JO\FHURO ZKLFK KDV D YLVFRVLW\ RI a 3D Vf ZDV b PHDVXUHG YDOXH 1P $SSHQGL[ (f UHSRUWHG YDOXH 1P >&5&@f 6LPLODUO\ WKH PDUJLQ RI HUURU LQYROYHG LQ WKH PHDVXUHPHQW RI VXUIDFH WHQVLRQ IRU SRO\GLPHWK\OVLOR[DQH ZKLFK KDG D YLVFRVLW\ RI 3D Vf ZDV b PHDVXUHG YDOXH 1P $SSHQGL[ (f UHSRUWHG YDOXH 1P >$QG@ii ,Q WKH FDVH RI SRO\PHU VROXWLRQV SRVVLEOH VRXUFHV RI HUURU DOVR PD\ UHVXOW IURP Lf HYDSRUDWLRQ RI VROYHQW DQG LLf UHVLGXDO SRO\PHU UHPDLQLQJ RQ WKH SODWLQXP EODGH XVHG 7KH SRO\GLPHWK\OVLOR[DQH XVHG LQ WKH SUHVHQW VWXG\ 3'06 f ZDV PDQXIDFWXUHG E\ *( 6LOLFRQHV &LQFLQQDWL 2+ 7KH VXUIDFH WHQVLRQ YDOXHV SXEOLVKHG E\ $QGHUVRQ HW DO >$QG@ ZDV REWDLQHG RQ DQ LGHQWLFDO SRO\PHU $QGHUVRQ HW DO GLG QRW UHSRUW WKH WHFKQLTXH XVHG IRU VXUIDFH WHQVLRQ PHDVXUHPHQW

PAGE 150

7DEOH 6XUIDFH WHQVLRQ YDOXHV IRU 3&6 DQG 3&636= VROXWLRQV LQ WROXHQH DW GLIIHUHQW VROLGVORDGLQJV 6ROLGVORDGLQJ b 6XUIDFH WHQVLRQ 1Pf 3&6 3&636= s s s s s s 1XPEHU RI PHDVXUHPHQWV

PAGE 151

I WR &O ( f R R Z A 2 ,QFUHDVLQJ 6KHDU 5DWH 3&6 ZWbf Â’ 'HFUHDVLQJ 6KHDU 5DWH a 4 ',' 4 Z IFM %f 6KHDU 5DWH Vnf )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&6 VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW

PAGE 152

9LVFRVLW\ 3D Vf 6KHDU 6WUHVV 3Df 2 ,QFUHDVLQJ 6KHDU 5DWH Â’ 'HFUHDVLQJ 6KHDU 5DWH 3&6 ZWbf %f 'Hn OL L U 6KHDU 5DWH Vnf )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&6 VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW

PAGE 153

Q &/ R R m A 2 ,QFUHDVLQJ 6KHDU 5DWH 3&6 ZWbf Â’ 'HFUHDVLQJ 6KHDU 5DWH 4 4 O 6KHDU 5DWH Vnf %f )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&6 VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW

PAGE 154

9f UD ( 9f R R ! 2 ,QFUHDVLQJ 6KHDU 5DWH 3&636= ZWbf ’ 'HFUHDVLQJ 6KHDU 5DWH MLf§# t f7 %f 6KHDU 5DWH Vnf )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&636= VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW

PAGE 155

9LVFRVLW\ 3D Vf 6KHDU 6WUHVV 3Df R ,QFUHDVLQJ 6KHDU 5DWH 3&636= ZWbf Â’ 'HFUHDVLQJ 6KHDU 5DWH Â’Â’ 2 $ &%f 6KHDU 5DWH Vnf )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU D ZWb 3&636= VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW

PAGE 156

m U &/ Q R R ! 2 ,QFUHDVLQJ 6KHDU 5DWH 3&636= ZWbf ’ 'HFUHDVLQJ 6KHDU 5DWH f§ 6 %f 6KHDU 5DWH Vnf )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YVVKHDU UDWH IRU D ZWb 3&636= VROXWLRQ XVHG LQ VXUIDFH WHQVLRQ PHDVXUHPHQW

PAGE 157

685)$&( 7(16,21 1Pf )LJXUH 6XUIDFH WHQVLRQ DV D IXQFWLRQ RI FRQFHQWUDWLRQ IRU 3&6 DQG 3&636= VROXWLRQV

PAGE 158

685)$&( 7(16,21 1Pf f§ 2 3&6 f 3&636= 9,6&26,7< 3DVf )LJXUH 6XUIDFH WHQVLRQ DV D IXQFWLRQ RI YLVFRVLW\ IRU 3&6 DQG 3&636= VROXWLRQV

PAGE 159

LQ VXUIDFH WHQVLRQ PHDVXUHPHQW E\ :LOKHP\ 3ODWH WHFKQLTXH 7KH ILUVW IDFWRU GRHV QRW DSSHDU WR EH VLJQLILFDQW 7KLV LV VXJJHVWHG E\ WKH REVHUYDWLRQ WKDW WKH VXUIDFH WHQVLRQ LQFUHDVHG E\ 1P ZKHQ WKH SRO\PHU FRQFHQWUDWLRQ LQFUHDVHG IURP WR ZWb 7KH DPRXQW RI VROYHQW ORVV GXULQJ WKH PHDVXUHPHQW ZRXOG EH IDU OHVV WKDQ WKLV FRQFHQWUDWLRQ FKDQJH DQG KHQFH VROYHQW ORVV VKRXOG KDYH PLQLPDO HIIHFW RQ WKH VXUIDFH WHQVLRQ YDOXH 2Q WKH RWKHU KDQG DQ\ SRO\PHU UHPDLQLQJ RQ WKH SODWLQXP EODGH GXULQJ WKH VXUIDFH WHQVLRQ PHDVXUHPHQW ZRXOG FDXVH WKH VXUIDFH WHQVLRQ UHDGLQJ WR EH KLJKHU WKDQ WKH WUXH YDOXH >:X@ ,W ZRXOG EH H[SHFWHG WKDW PRUH SRO\PHU ZRXOG UHPDLQ RQ WKH EODGH GXULQJ WKH PHDVXUHPHQW ZKHQ PRUH FRQFHQWUDWHG LH PRUH YLVFRXVf SRO\PHU VROXWLRQV DUH XVHG +HQFH WKLV PD\ H[SODLQ WKH LQFUHDVH LQ VXUIDFH WHQVLRQ ZLWK LQFUHDVLQJ SRO\PHU FRQFHQWUDWLRQ WKDW ZDV VKRZQ LQ )LJXUH &KDUDFWHUL]DWLRQ RI ILEHUV 3&6 DQG 3&636= ILEHUV ZHUH FKDUDFWHUL]HG LQ WKH JUHHQ VWDWH DQG DIWHU YDULRXV KHDW WUHDWPHQWV LQ DLU DW s r& DQG LQ QLWURJHQ DW WHPSHUDWXUHV LQ WKH UDQJH RI r&f )LEHUV ZHUH FKDUDFWHUL]HG XVLQJ GLIIXVH UHIOHFWDQFH )RXULHU WUDQVIRUP LQIUDUHG VSHFWURVFRS\ '5,)7f DQG WHQVLOH WHVWLQJ &KDUDFWHUL]DWLRQ RI ILEHUV E\ )7,5 )7,5 VSHFWUD RI 3&6EDVHG ILEHUV JUHHQ DQG KHDWWUHDWHG LQ DLU DW r&f ZHUH FROOHFWHG DW URRP WHPSHUDWXUH r&f DQG GXULQJ KHDW WUHDWPHQW IURP r& LQ QLWURJHQ )LJXUH VKRZV WKH URRP WHPSHUDWXUH )7,5 VSHFWUD IRU JUHHQ 3&6 ILEHUV EDWFK 8)VfQRW FRQWDLQLQJ DQ\ DGGLWLYHVf 7KH SHDN DVVLJQPHQWV IRU WKHVH ILEHUV DUH VKRZQ LQ 7DEOH 7KH URRP WHPSHUDWXUH )7,5 VSHFWUD WUDQVPLVVLRQ PRGHf IRU SRO\GLPHWK\OVLODQH 3'06f WKH SUHFXUVRU IRU 3&6 LV VKRZQ LQ )LJXUH 7DEOH VKRZV D OLVW RI FKDUDFWHULVWLF DEVRUSWLRQ EDQGV IRU 3'06 6LQFH 3'06 FRQVLVWV RI D 6L6L EDFNERQH ZLWK DWWDFKHG PHWK\O JURXSV WKH PDMRU DEVRUSWLRQ EDQGV LQ WKH )7,5

PAGE 160

$%625%$1&( .XEHOND0XQN 8QLWVf $ FR L L L L L L L U :DYHQXPEHU FPnf )LJXUH 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI JUHHQ 3&6 ILEHUV EDWFK Vf

PAGE 161

7DEOH )7,5 SHDN DVVLJQPHQWV IRU SRO\FDUERVLODQH 3&6f ILEHUV 3HDN FPf $VVLTQPHQW 5HIHUHQFHV YDV &+f YV &+f Y 6L+f DV &+f IURP 6L&+ &+f IURP 6L &+ 6L 6 &+f IURP 6L&+ WR &+f IURP 6L &+ 6L 3DV &+f IURP 6L &+ YDV 6L&f Y VWUHWFKLQJ EHQGLQJ FR EHQGLQJ S URFNLQJ f : .ULQHU 2UJ &KHP f f $/ 6PLWK &KHP 3K\V f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f

PAGE 162

$%625%$1&( :$9(180%(5 FPnf )LJXUH 5RRP WHPSHUDWXUH )7,5 VSHFWUD WUDQVPLVVLRQ PRGHf RI 3RO\GLPHWK\OVLODQH 3'06f 1LVVR &RUSRUDWLRQ -DSDQf

PAGE 163

7DEOH )7,5 SHDN DVVLJQPHQWV IRU SRO\GLPHWK\OVLODQH3'06f SRO\PHU 3HDN FPnf $VVLJQPHQW 5HIHUHQFHV YDV &+f YV &+f 6DV &+f IURP 6L&+ 6 &+f IURP 6L&+ 6DV 6L26L RU 6L2&f 6 6L26L RU 6L2&f 3DV &+f IURP 6L &+ SV &+f IURP 6L &+ YDV 6L&f 9V 6L&f Y VWUHWFKLQJ EHQGLQJ FR EHQGLQJ S URFNLQJ f : .ULQHU 2UJ &KHP f f $/ 6PLWK &KHP 3K\V f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f

PAGE 164

VSHFWUD DUH GXH WR YDULRXV PRGHV RI YLEUDWLRQV RI 6L&+ JURXSV ,Q WKH FDVH RI 3&6 LW LV SRVVLEOH WKDW VRPH UHVLGXDO 6L6L ERQGV PD\ EH UHPDLQLQJ LQ WKH SRO\PHU VWUXFWXUH GHSHQGLQJ RQ V\QWKHVLV FRQGLWLRQV $ FRPSDULVRQ RI )7,5 VSHFWUD RI 3'06 DQG 3&6 ZLOO HQDEOH GHWHUPLQDWLRQ RI ZKHWKHU WKH 3'06 WR 3&6 FRQYHUVLRQ LV HVVHQWLDOO\ FRPSOHWH $ PRVWO\ FRQYHUWHG 3&6 VKRZV DQ LQWHQVH DEVRUSWLRQ EDQG DW FPn GXH WR 6L+ ERQG 7KLV DEVRUSWLRQ EDQG LV DEVHQW LQ 3'06 GXH WR WKH ODFN RI 6L+ ERQGV LQ WKH VWUXFWXUH RI 3'06 $ FRPSDULVRQ RI DEVRUSWLRQ EDQGV DW FPn DQG FPn IRU 3'06 DQG 3&6 ZLOO DOVR HQDEOH GHWHUPLQDWLRQ RI WKH H[WHQW RI FRQYHUVLRQ WR 3&6 ,Q WKH FDVH RI 3'06 WKHUH LV DQ DEVRUSWLRQ EDQG DW FPn DQG QRQH DW FPn 7KLV LV FRQVLVWHQW ZLWK WKH VWUXFWXUH RI 3'06 ZKLFK VKRZV &+ JURXSV DWWDFKHG DV VLGH JURXSV WR WKH PDLQ 6L6L EDFNERQH $IWHU FRQYHUVLRQ WR 3&6 RQH RI WKH VLGH JURXSV &+f LV UHSODFHG E\ &+ ZKLFK DWWDFKHV LQ WKH PDLQ FKDLQ DV D 6L&+6L OLQNDJH DQG + ZKLFK LV DWWDFKHG WR 6L DV VLGH JURXS +HQFH WKH FRQWULEXWLRQ IURP 6L&+6L DOVR VKRZV XS LQ WKH )7,5 VSHFWUD IRU 3&6 DV DQ DEVRUSWLRQ EDQG DW FPn 6LQFH WKH &+ JURXS LV DWWDFKHG WR WKH 6L DWRP LQ WKH EDFNERQH LWV DEVRUSWLRQ LQWHQVLW\ LV KLJKHU WKDQ WKDW RI WKH 6L&+ LQ ZKLFK WKH &+ LV DWWDFKHG WR D 6L DWRP DV D VLGH JURXS 7KXV LQ D PRVWO\ FRQYHUWHG 3&6 WKH DEVRUSWLRQ LQWHQVLW\ DW FPn LV JUHDWHU WKDQ WKH DEVRUSWLRQ LQWHQVLW\ DW FPn ,W ZDV H[SHFWHG WKDW WKH DEVRUSWLRQ LQWHQVLWLHV DW FPn DQG FPn ZRXOG EH KLJKHU IRU 3'06 EHFDXVH WZR &+ JURXSV DUH DWWDFKHG WR HDFK 6L DWRP LQ WKH EDFNERQH RI WKH UHSHDWLQJ XQLW 58f FRPSDUHG WR 3&6 ZKHUH RQO\ RQH &+ JURXS LV DWWDFKHG WR HDFK 6L DWRP LQ WKH EDFNERQH RI WKH 58 +RZHYHU WKLV ZDV QRW REVHUYHG IURP )LJXUHV DQG ,W LV QRW FOHDU LI WKLV LV UHODWHG WR WKH IDFW WKDW WKH 3&6 ILEHUV ZHUH DQDO\]HG LQ WKH GLIIXVH UHIOHFWDQFH PRGH ZKLOH WKH 3'06 VDPSOH ZDV DQDO\]HG LQ WKH WUDQVPLVVLRQ PRGHf

PAGE 165

)7,5 VSHFWUD RI 3&6 ILEHUV GXULQJ KHDW WUHDWPHQW LQ 1 7KH FKDQJHV LQ WKH VWUXFWXUH RI 3&6 ILEHUV GXULQJ S\URO\VLV WR r& LQ QLWURJHQ DUH VKRZQ LQ )LJXUH 7KH UHODWLYH FKDQJHV LQ LQWHQVLWLHV RI YDULRXV SHDNV DV D IXQFWLRQ RI WHPSHUDWXUH DUH VKRZQ LQ )LJXUH 1R VLJQLILFDQW FKDQJHV ZHUH REVHUYHG LQ WKH DEVRUSWLRQ EDQGV IRU 3&6 XS WR ar& 7KH LQWHQVLW\ RI WKH DEVRUSWLRQ EDQG IRU 6L+ LQFUHDVHG VWHDGLO\ UHDFKHG D PD[LPXP DW ar& DQG WKHQ VWDUWHG WR GHFUHDVH 7KH LQLWLDO LQFUHDVH LQ LQWHQVLW\ LV SRVVLEO\ GXH WR WKH IRUPDWLRQ RI DGGLWLRQDO 6L+ JURXSV DV D UHVXOW RI PHWK\OHQH LQVHUWLRQ UHDFWLRQV DOVR NQRZQ DV .XPDGD UHDUUDQJHPHQW UHDFWLRQV >6KL@f 0HWK\OHQH LQVHUWLRQ UHDFWLRQ HTXDWLRQ ff LV WKH PHFKDQLVP E\ ZKLFK FRQYHUVLRQ RI SRO\GLPHWK\OVLODQH 3'06f WR SRO\FDUERVLODQH 3&6f WDNHV SODFH + ,, 6L6L 6L&+S6L f ,,  6FKPLGW HW DO >6FK@ KDYH DOVR REVHUYHG VLPLODU LQFUHDVHV LQ LQWHQVLWLHV RI WKH 6L+ DEVRUSWLRQ EDQG EHWZHHQ WKH WHPSHUDWXUHV RI r& GXULQJ WKH S\URO\WLF FRQYHUVLRQ RI YLQ\OLF SRO\VLODQH WR VLOLFRQ FDUELGH DQG KDYH VXJJHVWHG WKDW WKH PHFKDQLVP UHVSRQVLEOH IRU WKLV REVHUYDWLRQ LV WKH PHWK\OHQH LQVHUWLRQ UHDFWLRQ 7KLV FRQFOXVLRQ ZDV EDVHG RQ + &5$036 &RPELQHG 5RWDWLRQ DQG 0XOWLSOH 3XOVH 6SHFWURVFRS\f & 0$6 105 0DJLF $QJOH 6SLQQLQJ 1XFOHDU 0DJQHWLF 5HVRQDQFHf DQG 6L 0$6 105 VSHFWUDf )LJXUH DOVR VKRZV WKDW WKH DEVRUSWLRQ EDQG DW FPn GXH WR FR &+f RI 6L&+6Lf VWDUWHG WR LQFUHDVH UHODWLYH WR WKH DEVRUSWLRQ EDQG DW FPn GXH WR DV &+f RI 6L&+f LQ WKH WHPSHUDWXUH UHJLPH RI r& ,Q DGGLWLRQ )LJXUH VKRZV WKDW WKH LQWHQVLW\ RI DEVRUSWLRQ EDQG GXH WR FR&+f RI 6L&+6L LQFUHDVHV UHODWLYH WR

PAGE 166

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH )7,5 VSHFWUD IRU 3&6 ILEHUV EDWFK Vf GXULQJ KHDW WUHDWPHQW WR r& DW r&PLQ LQ QLWURJHQ DWPRVSKHUH

PAGE 167

,QWHQVLW\ .XEHOND0XQN 8QLWVf $ Y6L+f > FPn@ YDV&+f RI &+ &+ > FPn@ Y&+f RI &+ &+ > FPn@ DV&+f RI Vc&+ > FPn@ 7HPSHUDWXUH r&f )LJXUH ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD IRU 3&6 JUHHQf ILEHUV EDWFK Vf

PAGE 168

,QWHQVLW\ .XEHOND0XQN 8QLWVf 7HPSHUDWXUH r&f )LJXUH &RQWnGf

PAGE 169

&+f RI 6L&+6c 7KLV LV DOVR FRQVLVWHQW ZLWK WKH PHWK\OHQH LQVHUWLRQ UHDFWLRQV WKDW RFFXU LQ WKH 3'06 WR 3&6 FRQYHUVLRQ ,Q WKH ODWWHU FDVH WKH LQWHQVLW\ RI WKH DEVRUSWLRQ EDQG FR&+f RI 6L&+6L IRUPHG GXULQJ WKH 3'06 WR 3&6 FRQYHUVLRQ LV VLJQLILFDQWO\ JUHDWHU WKDQ WKH LQWHQVLW\ RI WKH DEVRUSWLRQ EDQG &+f RI 6L&+6L DV LQGLFDWHG LQ )LJXUH f +RZHYHU )LJXUH VKRZV WKDW WKH SDV&+f RI 6L&+ DEVRUSWLRQ EDQG DW FPnf LQFUHDVHG VLJQLILFDQWO\ DQG WKH 6&+f RI 6L&+ DEVRUSWLRQ EDQG DW FPnf LQFUHDVHG VOLJKWO\ LQ WKLV WHPSHUDWXUH UDQJH 7KLV REVHUYDWLRQ VHHPV WR EH LQFRQVLVWHQW ZLWK WKH RFFXUUHQFH RI PHWK\OHQH LQVHUWLRQ UHDFWLRQV +RZHYHU WKH UHODWLYH LQWHQVLW\ UDWLRV IRU SDV&+f ZLWK UHVSHFW WR YDV&+f DQG DV&+f ZLWK UHVSHFW WR YDV&+f LQFUHDVH RQO\ VOLJKWO\ GXULQJ KHDW WUHDWPHQW 7KLV LV FRQVLVWHQW ZLWK ZKDW LV REVHUYHG LQ WKH PHWK\OHQH LQVHUWLRQ UHDFWLRQV ZKHUH WKHVH UDWLRV DUH H[SHFWHG WR LQFUHDVH VOLJKWO\ GXULQJ KHDW WUHDWPHQW +DVHJDZD HW DL >+DV@ VXJJHVWHG WKDW WKH PDLQ UHDVRQ IRU WKH LQFUHDVH LQ LQWHQVLW\ RI 6L+ DEVRUSWLRQ EDQG GXULQJ KHDW WUHDWPHQW EHWZHHQ r& DQG r& ZDV WKH H[LVWHQFH RI D SRO\VLODQH VNHOHWRQ LQ 3&6 7KH UHVLGXDO SRO\VLODQH VNHOHWRQ JHWV FRQYHUWHG WR SRO\FDUERVLODQH VNHOHWRQ LQ WKLV WHPSHUDWXUH UHJLPH 6XFK D FRQYHUVLRQ PHFKDQLVP FRUUHVSRQGV WR DQ LQFUHDVH LQ 6L+ DQG 6L&+6L ERQGV ZLWK DQ LQFUHDVH LQ KHDW WUHDWPHQW WHPSHUDWXUHf +DVHJDZDfV )7,5 VSHFWUD VKRZHG D GHFUHDVH LQ LQWHQVLW\ RI 6L+ DEVRUSWLRQ EDQG EH\RQG r& 7KLV LV SRVVLEO\ GXH WR FURVVOLQNLQJ E\ GHK\GURJHQDWLRQ UHDFWLRQV RI 6L+ ERQGV 0RFDHU HW DO >0RF@ KDYH DOVR UHSRUWHG VLPLODU GHFUHDVHV LQ LQWHQVLW\ RI 6L+ DEVRUSWLRQ EDQG LQ WKH S\URO\VLV RI SRO\FDUERVLOD]DQH SRO\PHU 7KH HYLGHQFH IRU GHK\GURJHQDWLRQ ZDV REWDLQHG E\ JDV FKURPDWRJUDSK\ ZKLFK VKRZHG WKH HYROXWLRQ RI + ,Q WKLV WHPSHUDWXUH UDQJH WKH 6L+

PAGE 170

IXQFWLRQDOLW\ DSSHDUV WR EH WKH UDGLFDO VRXUFH IRU WKH S\URO\WLF FRQYHUVLRQ WR VLOLFRQ FDUELGH VLQFH LW KDV WKH ORZHVW ERQG HQHUJ\ LQ WKH 3&6 VNHOHWRQ 6XEWUDFWLRQ VSHFWUD RI 3&6 ILEHUV EHIRUH DQG DIWHU KHDW WUHDWPHQW LQ QLWURJHQ DW r& LH r&f LV VKRZQ LQ )LJXUH $ GLUHFW FRPSDULVRQ RI WKH VSHFWUD DW WKHVH WHPSHUDWXUHV LV VKRZQ LQ )LJXUH 7KH DEVRUEDQFH RI EDQG GXH WR 6&+f IURP 6L&+ DW FPn LQFUHDVHG RQO\ VOLJKWO\ XS WR r& ZKHUHDV WKH DEVRUEDQFH RI EDQGV GXH WR YV&+f DW FPn DV&+f IURP 6L&+ DW FPn DQG &+f IURP 6L&+6L DW FPn GHFUHDVHG VOLJKWO\ 7KH DEVRUEDQFH RI Y6L+f DW FPn FR&+f IURP 6L&+6L DW FPn DQG SDV&+f RI 6L&+ DW FPn LQFUHDVHG VLJQLILFDQWO\ DQG WKHVH FKDQJHV PD\ EH DWWULEXWHG WR WKH PHWK\OHQH LQVHUWLRQ UHDFWLRQV DV H[SODLQHG SUHYLRXVO\ +DVHJDZD HW DO DQG %XRLOORQ HW DO >%XR@ VWXGLHG WKH FKDQJHV LQ WKH )7,5 DEVRUSWLRQ VSHFWUD RI 3&6 XSRQ S\URO\VLV WR r& 7KH\ UHSRUWHG WKDW LQWHQVLWLHV RI PRVW DEVRUSWLRQ EDQGV FKDQJHG RQO\ VOLJKWO\ GXULQJ KHDW WUHDWPHQW WR r& VLPLODU WR REVHUYDWLRQV PDGH LQ WKH SUHVHQW VWXG\ 1R VLJQLILFDQW JDV HYROXWLRQ ZDV GHWHFWHG E\ JDV FKURPDWRJUDSK\f LQ WKLV WHPSHUDWXUH UDQJH 0HWK\OHQH LQVHUWLRQ UHDFWLRQV WRRN SODFH EHWZHHQ r& DQG r& UHVXOWLQJ LQ LQFUHDVHV LQ LQWHQVLWLHV RI DEVRUSWLRQ EDQGV GXH WR Y6L+f DW FPn DQG Y &+f RI 6L&+6L DW FPn 7KHUH ZDV QR VLJQLILFDQW FKDQJH LQ WKH LQWHQVLWLHV RI RWKHU DEVRUSWLRQ EDQGV LQ WKH )7,5 VSHFWUD XQWLO r& 7KLV LV LQGLFDWLYH RI WKH IDFW WKDW SRO\PHU GHJUDGHV VORZO\ XS WR r& LH IHZ RUJDQRVLOLFRQ ERQGV DUH EURNHQf $IWHU r& GHFRPSRVLWLRQ RI WKH VLGH FKDLQV RI WKH SRO\PHU VWDUWHG WR WDNH SODFH OHDGLQJ WR WKH IRUPDWLRQ RI DQ DPRUSKRXV LQRUJDQLF PDWHULDO 7KLV ZDV PDQLIHVWHG E\ D UDSLG GHFUHDVH LQ LQWHQVLWLHV RI DOO DEVRUSWLRQ EDQGV

PAGE 171

,17(16,7< DUELWUDU\ XQLWVf )LJXUH 6XEWUDFWLRQ VSHFWUD IRU 3&6 ILEHUV EDWFK Vf KHDW WUHDWHG LQ 1 r&

PAGE 172

,QWHQVLW\ .XEHOND0XQN 8QLWVf :DYHQXPEHU FPnf )LJXUH &RPSDULVRQ RI )7,5 VSHFWUD RI 3&6 ILEHUVEDWFK Vf EHIRUH DQG DIWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ

PAGE 173

LQ WKH )7,5 VSHFWUD $W ar& D ZHOOGHILQHG DEVRUSWLRQ EDQG GXH WR YDV 6L&f DW FPn IRUPHG )7,5 VSHFWUD RI 3&6 ILEHUV KHDWWUHDWHG LQ DLU )LJXUH VKRZV )7,5 VSHFWUD DW r& RI 3&6 ILEHUV DIWHU KHDW WUHDWPHQW LQ DLU DW r& IRU K 7KH ILEHUV KDG D ZHLJKW JDLQ RI ZWb DIWHU WKLV WUHDWPHQWf 7DEOH VKRZV SHDN DVVLJQPHQWV IRU 3&6 ILEHUV KHDWWUHDWHG LQ DLU ,Q DGGLWLRQ WR WKH FKDUDFWHULVWLF DEVRUSWLRQ EDQGV IRU QRUPDO 3&6 DV GHVFULEHG DERYH VHFWLRQ f WKH VSHFWUD DOVR VKRZV DEVRUSWLRQ EDQGV DW FP DQG FPn GXH WR IUHH 2+ DQG ERQGHG 2+ UHVSHFWLYHO\f FPn GXH WR & f DQG D EURDG DEVRUSWLRQ EDQG DW FPn GXH WR 6L26L RU 6L&2f 7KH DEVRUSWLRQ EDQG DW FPn FRXOG QRW EH LGHQWLILHG ,W LV VXVSHFWHG WKDW WKLV SHDN PD\ KDYH EHHQ GXH WR VRPH FRQWDPLQDWLRQ RI WKH VDPSOH GXULQJ YDFXXP GU\LQJ SULRU WR ORDGLQJ WKH VDPSOH LQ WKH )7,5 KRW VWDJHf 'XULQJ KHDW WUHDWPHQW RI 3&6 ILEHUV LQ DLU 6L+ 6L&+ DQG 6L&+6L JURXSV JHW R[LGL]HG UHVXOWLQJ LQ WKH IRUPDWLRQ RI 6L2+ 6L26L 6L&2 6L2& DQG & OLQNDJHV ,Q WKH FDVH RI 3&6 ILEHUV EHIRUH KHDW WUHDWPHQW LQ DLU WKH LQWHQVLW\ RI WKH DEVRUSWLRQ EDQG &+f IURP 6L&+ DW FPn ZDV OHVV WKDQ WKDW GXH WR 6&+f IURP 6L&+6L DW FPn $IWHU WKH DLUKHDW WUHDWPHQW LW FDQ EH FOHDUO\ VHHQ WKDW WKH DEVRUSWLRQ EDQG GXH WR &+f IURP 6L&+ EHFDPH KLJKHU LQ LQWHQVLW\ WKDQ WKH DEVRUSWLRQ EDQG &+f IURP 6L&+6L 7KLV LV DWWULEXWHG WR WKH FRQYHUVLRQ RI 6L&+6L ERQGV WR 6L&2 ERQGV GXULQJ KHDW WUHDWPHQW LQ DLU +DVHJDZD HW DO DUJXH WKDW 6L &+r UDGLFDOV IRUP ZKHQ WKH 6L&+6L FKDLQ LV VHYHUHG DQG WKDW WKHVH UDGLFDOV DUH R[LGL]HG HDVLO\ DQG IRUP 6L&2 QHWZRUNV >+DV@f )LJXUH VKRZV D VXEWUDFWLRQ 7KHUH ZRXOG VWLOO EH FRQWULEXWLRQV IURP WR &+f RI 6L&+U6L YLEUDWLRQV DW FPn

PAGE 174

$%625%$1&( .XEHOND0XQN 8QLWVf :DYHQXPEHU FPnf )LJXUH 5RRP WHPSHUDWXUH )7,5 VSHFWUD IRU 3&6 ILEHUV EDWFK Vf KHDWWUHDWHG LQ DLU DW r&

PAGE 175

7DEOH )7,5 SHDN DVVLJQPHQWV IRU 3&6 ILEHUV EDWFK Vf KHDWWUHDWHG LQ DLU DW r& 3HDN FPnf $VVLTQPHQW 5HIHUHQFHV Y 2+f YDV &+f YV &+f Y 6L+f Y & f 6DV &+f IURP 6L&+ &+f IURP 6L &+ 6L 6 &+f IURP 6L&+ 6L26L RU 6L2&f FR &+f IURP 6L &+ 6L 3DV &+f IURP 6L &+ YDV 6L&f Y VWUHWFKLQJ EHQGLQJ FR EHQGLQJ S URFNLQJ f : .ULQHU 2UJ &KHP f f $/ 6PLWK &KHP 3K\V f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f

PAGE 176

,17(16,7< DUELWUDU\ XQLWVf :$9(180%(5 FPnf )LJXUH 6XEWUDFWLRQ VSHFWUD IRU 3&6 ILEHUV KHDWWUHDWHG LQ DLU DW r& EDWFK Vf DQG 3&6 JUHHQ ILEHUV EDWFK Vf

PAGE 177

VSHFWUD DW r&f RI ILEHUV EHIRUH DQG DIWHU DLUKHDW WUHDWPHQW )LJXUH VKRZV D FRPSDULVRQ RI VSHFWUD DW r& EHIRUH DQG DIWHU DLUKHDW WUHDWPHQW ,W FDQ EH VHHQ WKDW DOO WKH RULJLQDO DEVRUSWLRQ EDQGV H[FHSW DV&+f IURP 6L&+ DW FPn GHFUHDVHG LQ LQWHQVLW\ DIWHU DLUKHDW WUHDWPHQW 7KH VSHFWUXP IRU WKH DLUKHDW WUHDWHG ILEHUV DOVR VKRZV WKH IRUPDWLRQ RI Y& f JURXSV DW FPnf GXH WR R[LGDWLRQ RI PHWK\O JURXSV DQG Y2+f JURXSV GXH WR R[LGDWLRQ RI 6L+ JURXSV )7,5 VSHFWUD RI DLUKHDW WUHDWHG 3&6 ILEHUV GXULQJ KHDW WUHDWPHQW LQ 1 )LJXUH VKRZV )7,5 VSHFWUD RI R[LGL]HG 3&6 ILEHUV EDWFK 8)Vf GXULQJ KHDW WUHDWPHQW WR r& LQ QLWURJHQ DWPRVSKHUH )LJXUH VKRZV WKH FKDQJHV LQ LQWHQVLWLHV RI VSHFLILF DEVRUSWLRQ EDQGV DV D IXQFWLRQ RI WHPSHUDWXUH ,Q WKH UDQJH a r& WKH LQWHQVLWLHV DVVRFLDWHG ZLWK WKH 6L2+ DQG 6L+ DEVRUSWLRQV GHFUHDVHG VLJQLILFDQWO\ DQG WKDW DVVRFLDWHG ZLWK WKH 6L26L DEVRUSWLRQV LQFUHDVHG VLJQLILFDQWO\ 7KLV VXJJHVWV WKDW 6L2+ DQG 6L+ JURXSV DUH LQYROYHG LQ FRQGHQVDWLRQ UHDFWLRQV WR IRUP 6L26L OLQNDJHV DV LQGLFDWHG EHORZ ? ? f§6L2+ +26Lf§ f§ 6L2f§ 6Lf§ +S2 f ? ? f§6L2+ +6Lf§ f§6Lf§2f§6Lf§ +R f ? ?  ,FKLNDZD HW DO >,FK@ KDYH DOVR REVHUYHG D UDSLG GHFUHDVH LQ LQWHQVLW\ RI 6L2+ JURXSV GXULQJ KHDW WUHDWPHQW RI DLUKHDW WUHDWHG 3&6 ORZ PROHFXODU ZHLJKWf LQ QLWURJHQ WR r& )LJXUH VKRZV ,FKLNDZD HW DOfV )7,5 VSHFWUD RI DLUKHDW WUHDWHG 3&6 SRO\PHU DV D IXQFWLRQ RI KHDW WUHDWPHQW WHPSHUDWXUH 7KH\ UHSRUW WKDW WKH DEVRUSWLRQ 1LSSRQ &DUERQ &RPSDQ\ -DSDQ

PAGE 178

,QWHQVLW\ .XEHOND0XQN 8QLWVf L f§7 7 O L > L :DYHQXPEHU FPnf )LJXUH &RPSDULVRQ RI )7,5 VSHFWUD RI 3&6 ILEHUV DW r& EHIRUH DQG DIWHU KHDW WUHDWPHQW LQ DLU r& EHIRUH KHDW WUHDWPHQW LQ DLU JUHHQ ILEHUVf EDWFK Vf r& DIWHU KHDW WUHDWPHQW LQ DLU DW r& EDWFK Vf

PAGE 179

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH )7,5 VSHFWUD IRU DLUKHDW WUHDWHG r&f 3&6 ILEHUV EDWFK Vf GXULQJ KHDW WUHDWPHQW WR r& DW r&PLQ LQ QLWURJHQ DWPRVSKHUH

PAGE 180

,QWHQVLW\ DEVROXWH XQLWVf 7HPSHUDWXUH r&f )LJXUH ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD IRU 3&6 DLUKHDW WUHDWHG DW r&f ILEHUV EDWFK Vf GXULQJ KHDW WUHDWPHQW LQ 1AR r&

PAGE 181

,QWHQVLW\ DEVROXWH XQLWVf $ 7 3DV&+f RI 6L&+ > FPn@ $ FR&+f RI 6L&+6L Y 6L26L RU 6L2&f > FPn@ AfA > FPn@ &+f RI 6L&+6L > FPn@ Y& f > FPn@ A A 7HPSHUDWXUH r&f )LJXUH &RQWnGf

PAGE 182

Y FPf )LJXUH )7,5 VSHFWUD RI DLUKHDW WUHDWHG 1LSSRQ 3&6 ILEHUV GXULQJ KHDW WUHDWPHQW LQ QLWURJHQ WR r& IURP ,FKLNDZD HW DO >,FK@f

PAGE 183

LQWHQVLW\ RI 6L+ JURXSV GHFUHDVHG DIWHU r& VLPLODU WR WKH REVHUYDWLRQ PDGH LQ WKLV VWXG\ SUHVXPDEO\ GXH WR UHDFWLRQ RI 6L+ JURXSV ZLWK 6L2+ JURXSV HTXDWLRQ ff )LJXUH VKRZV WKDW WKH EDQG 6 &+f RI 6L&+ DW FPnf LQFUHDVHG VOLJKWO\ DURXQG r& DQG WKHQ VWDUWHG WR GHFUHDVH EH\RQG r& IRU WKH 3&6 ,Q DGGLWLRQ WKH LQWHQVLW\ RI DEVRUSWLRQ EDQG SDV &+f RI 6L&+ DW FPnf VKRZHG DQ LQFUHDVH DW DURXQG r& DQG GHFUHDVH EH\RQG r& 7KHVH WUHQGV DUH VLPLODU WR WKRVH REVHUYHG GXULQJ KHDW WUHDWPHQW RI WKH ILEHUV SUHSDUHG ZLWKRXW DLU KHDW WUHDWPHQW DOWKRXJK WKH PDJQLWXGH RI WKH LQFUHDVHV LQ LQWHQVLW\ DUH FRQVLGHUDEO\ VPDOOHU VHH )LJXUH f ,Q FRQWUDVW WR WKHVH UHVXOWV ,FKLNDZD HW DO >,FK@ REVHUYHG FRQWLQXRXVO\ GHFUHDVLQJ LQWHQVLW\ IRU WKHVH DEVRUSWLRQ EDQGV 6 &+f DQG SDV &+f IURP 6L&+f XS WR r& )LJXUH f ,FKLNDZD HW DO DWWULEXWHG WKH GHFUHDVH LQ WKH LQWHQVLWLHV RI WKH DEVRUSWLRQ EDQGV WR UHDFWLRQV f DQG f VKRZQ EHORZ ? ? W$ $? 6 L 2 + &+6L f§6LRf§ 6Lf§ &+ D f ? ? ? ? f§ 6L+ &+R6L f§6Lf§&+Rf§6Lf§ +R f ? ? )LJXUH DOVR VKRZV WKDW f WKH DEVRUSWLRQ LQWHQVLW\ DW FPn ZKLFK UHSUHVHQWV D FRPELQDWLRQ RI WKH DEVRUSWLRQ LQWHQVLWLHV RI p&+f RI 6L&+6L DQG Y6L 26L 6L&2f LQFUHDVHG VWHDGLO\ XS WR r& f WKH DEVRUSWLRQ LQWHQVLW\ DW FPn &+f RI 6L&+6Lf UHPDLQHG XQFKDQJHG DOO WKH ZD\ WR r& DQG f WKH DEVRUSWLRQ GXH WR Y& f JURXS REVHUYHG DW FPn VWHDGLO\ GHFUHDVHG DERYH ar& XQWLO LW GLVDSSHDUHG DW ar& $OO RI WKH UHVXOWV DUH UHDVRQDEO\ FRQVLVWHQW ZLWK WKH UHVXOWV LQ )LJXUH IURP WKH VWXG\ E\ ,FKLNDZD HW DO

PAGE 184

)LJXUH VKRZV D GLUHFW FRPSDULVRQ RI WKH VSHFWUD IRU R[LGL]HG ILEHUV KHDW WUHDWHG DW r& DQG r& )LJXUH VKRZV WKH VSHFWUD REWDLQHG E\ VXEWUDFWLQJ WKH r& VSHFWUXP IURP WKH r& VSHFWUXP ,W FDQ EH VHHQ WKDW DIWHU KHDW WUHDWPHQW DW r& WKH DEVRUSWLRQ EDQGV GXH WR R[LGDWLRQ KDYH FRPSOHWHO\ GLVDSSHDUHG )7,5 VSHFWUD RI 36= GXULQJ KHDW WUHDWPHQW LQ 1 )LJXUH VKRZV WKH )7,5 VSHFWUD IRU SRO\YLQ\OVLOD]DQH 36= EDWFK $f DW r& 7KH FKDUDFWHULVWLF DEVRUSWLRQ EDQGV IRU 36= DUH VKRZQ LQ 7DEOH )LJXUH VKRZV WKH )7,5 VSHFWUD IRU 36= KHDWWUHDWHG WR r& LQ QLWURJHQ 7KH FKDQJHV LQ LQWHQVLWLHV RI YDULRXV JURXSV LQ 36= DV D IXQFWLRQ RI WHPSHUDWXUH DUH VKRZQ LQ )LJXUH )LJXUH VKRZV WKDW WKH LQWHQVLWLHV IRU DOO DEVRUSWLRQ EDQGV RI 36= UHDFKHG D PD[LPXP DW r& DQG WKHQ VWDUWHG WR GHFUHDVH 5HFDOO IURP VHFWLRQ WKDW WKH 36= ZDV SUHSDUHG E\ SRO\PHUL]LQJ D WULIXQFWLRQDO YLQ\OLF VLLD]DQH PRQRPHU DW r& IRU K LQ WKH SUHVHQFH RI D UDGLFDO LQLWLDWRU GLFXP\O SHUR[LGHf 7KH LQFUHDVH LQ )7,5 SHDN LQWHQVLWLHV EHWZHHQ DQG r& LQGLFDWHV WKDW WKHUH LV FRQWLQXHG SRO\PHUL]DWLRQ DQG FURVVOLQNLQJ RI WKH DVSUHSDUHG 36= )RU H[DPSOH WKH ODUJHVW LQFUHDVH LQ LQWHQVLW\ RFFXUV IRU WKH 6L16Lf DEVRUSWLRQ DW FP $Q LQFUHDVH LQ 6L1 ERQGV LV FRQVLVWHQW ZLWK LQFUHDVHG SRO\PHUL]DWLRQ DQG FURVVOLQNLQJ RI WKH 36= SRO\PHU $V KHDW WUHDWPHQW RI 36= ZDV FRQWLQXHG DERYH r& WKH DEVRUSWLRQ LQWHQVLWLHV GHFUHDVHG UDSLGO\ LQGLFDWLYH RI WKH WUDQVLWLRQ IURP DQ RUJDQRVLOLFRQ SRO\PHU WR DQ LQRUJDQLF FHUDPLF $IWHU KHDW WUHDWPHQW DW r& WKH UHVLGXDO DEVRUSWLRQ SHDNV ZHUH WKH YDV &+f RI &+ DW FP YV &+f RI &+ DW FPn 6 &+f RI 6L&+ DW FPn FPn GXH WR 6L16Lf EURDG SHDNf 1+f DW FPn 6 &+ &+f DW FPn DQG SV&+f RI 6L&+ DW FPn 7KH DEVRUSWLRQ EDQG DW FPn GXH WR 6 &)1&)\ VKRZHG D VOLJKW LQFUHDVH LQ LQWHQVLW\ EHWZHHQ r&

PAGE 185

,QWHQVLW\ .XEHOND0XQN 8QLWVf :DYHQXPEHU FPnf )LJXUH &RPSDULVRQ RI VSHFWUD RI DLUKHDW WUHDWHG r&f 3&6 ILEHUV EDWFK Vf EHIRUH DQG DIWHU KHDW WUHDWPHQW DW r& LQ 1

PAGE 186

,17(16,7< DUELWUDU\ XQLWVf :$9(180%(5 FPnf )LJXUH 6XEWUDFWLRQ VSHFWUD IRU DLUKHDW WUHDWHG r&f 3&6 ILEHUV EDWFK Vf KHDWWUHDWHG LQ r&

PAGE 187

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH 5RRP WHPSHUDWXUH )7,5 VSHFWUD IRU 36= SRO\PHU EDWFK $f

PAGE 188

7DEOH )7,5 SHDN DVVLJQPHQWV IRU SRO\YLQ\OVLOD]DQH 36=f SRO\PHU 3HDN FPf $VVLTQPHQW 5HIHUHQFHV Y 1+f Y &+ &+f IURP 6L&+ &+ YDV &+f YV &+f &+ &+f IURP 6L&+ &+ DV &+f IURP 6L&+ 6 &+f IURP 6L&+ 1+f &+ &+f IURP 6L&+ &+ 6L16Lf 3DV &+f IURP 6L&+ SV &+f IURP 6L &+ YDV 6L&f Y VWUHWFKLQJ EHQGLQJ S URFNLQJ f : .ULQHU 2UJ &KHP f f $/ 6PLWK &KHP 3K\V f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f 6H\IHUWK *+ :LVHPDQ DQG & 3UXGfKRPPH $P&HUDP 6RF && f f : 7RUHNL 1$ &UHHG DQG &' %DWLFK 3RO\PHU 3UHSULQWV $P &KHP 6RF >@ f f 50 6LOYHUVWHLQ *& %DVVOHU DQG 7& 0RUULOO 6SHFWURPHWULF ,GHQWLILFDWLRQ RI 2UJDQLF &RPSRXQGV -RKQ :OH\ 1HZ
PAGE 189

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH )7,5 VSHFWUD IRU SRO\YLQ\OVLOD]DQH SRO\PHU GXULQJ KHDW WUHDWPHQW WR r& DW r&PLQ LQ QLWURJHQ DWPRVSKHUH

PAGE 190

$%625%$1&( .XEHLND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH &RQWnGf

PAGE 191

,QWHQVLW\ .XEHOND0XQN 8QLWVf Y&+f > FPn@ Y1+f > FPn@ Y&+ &+f > FPn@ YV&+f > FPn@ DV &+ &+f > FPn@ $ 7HPSHUDWXUH r&f )LJXUH ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD RI 36=

PAGE 192

,QWHQVLW\ .XEHOND0XQN 8QLWVf $ )LJXUH &RQWnGf

PAGE 193

,QWHQVLW\ .XEHOND0XQN 8QLWVf )LJXUH &RQWnGf

PAGE 194

)7,5 VSHFWUD RI 3&636= ILEHUV GXULQJ KHDW WUHDWPHQW LQ 1 )LJXUH VKRZV )7,5 VSHFWUD RI 3&6 ILEHUV FRQWDLQLQJ ZWb 36= 3&636=f DW r& 7DEOH VKRZV )7,5 SHDN DVVLJQPHQWV IRU 3&636= ILEHUV 7KH VSHFWUD VKRZV DOO WKH PDMRU FKDUDFWHULVWLF DEVRUSWLRQ EDQGV GXH WR 3&6 DV ZHOO DV D IHZ PDMRU DEVRUSWLRQ SHDNV GXH WR 36= YL] WKH DEVRUSWLRQ SHDN DW FPn GXH WR 1 +ff FPn GXH WR Y &+ &+f IURP 6L&+ &+f FPn GXH WR DV &+ &+f RI 6L&+ &+f FPn GXH WR 1+ff DQG FPn GXH WR 6L16Lff )LJXUH VKRZV WKH )7,5 VSHFWUD RI 3&636= GXULQJ KHDW WUHDWPHQW WR r& LQ QLWURJHQ )LJXUH VKRZV SORWV RI WKH LQWHQVLWLHV RI YDULRXV DEVRUSWLRQ SHDNV YV WHPSHUDWXUH IRU 3&636= ILEHUV 7KH DEVRUSWLRQ LQWHQVLW\ RI WKH 6L+ JURXSV LQFUHDVHG RQO\ VOLJKWO\ XS WR ar& UHPDLQHG FRQVWDQW XQWLO r& DQG WKHQ VWDUWHG WR GHFUHDVH 7KH LQWHQVLW\ RI WKH DEVRUSWLRQ EDQG &+f RI 6L&+6L GHFUHDVHG VOLJKWO\ EH\RQG r& 7KH DEVRUSWLRQ LQWHQVLW\ DW FPn GXH WR FR &+f RI 6L&+6Lf DOVR GHFUHDVHG DW DURXQG ar& 7KH LQWHQVLW\ RI DEVRUSWLRQ EDQG DW FPn GXH WR DV &+f RI 6L&+f GHFUHDVHG UDSLGO\ VWDUWLQJ DW r& )LJXUH VKRZV D GLUHFW FRPSDULVRQ RI 3&636= VSHFWUD EHIRUH DQG DIWHU KHDW WUHDWPHQW LQ QLWURJHQ DW r& )LJXUH VKRZV WKH VXEWUDFWLRQ VSHFWUD IRU WKH VDPH ,W FDQ EH VHHQ WKDW WKH DEVRUSWLRQ LQWHQVLW\ RI DV &+f RI 6L&+ DW FPn GHFUHDVHG VLJQLILFDQWO\ DIWHU WKH KHDW WUHDWPHQW ,Q DGGLWLRQ WKH DEVRUSWLRQ LQWHQVLWLHV RI DOO EDQGV GXH WR 36= GLVDSSHDUHG DIWHU KHDW WUHDWPHQW DW r& 7KLV REVHUYDWLRQ LV DOVR VXSSRUWHG E\ WKH VXEWUDFWLRQ RI WKH VSHFWUD IRU 3&6 ILEHUV Vf IURP WKH VSHFWUD IRU WKH 3&636= ILEHUV Vf DW r& )LJXUH f DQG r& )LJXUH f $W r& WKH VXEWUDFWLRQ VSHFWUD FOHDUO\ VKRZV WKH SUHVHQFH RI DEVRUSWLRQ EDQGV GXH WR 36= $IWHU r& KHDW WUHDWPHQW LQ QLWURJHQ WKH DEVRUSWLRQ EDQGV GXH WR 36= ZHUH DEVHQW

PAGE 195

,QWHQVLW\ .XEHOND0XQN 8QLWVf $ L L W L W L 7 L W W U :DYHQXPEHU FPnf )LJXUH 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI JUHHQ 3&636= ILEHUV EDWFK Vf

PAGE 196

7DEOH )7,5 SHDN DVVLJQPHQWV IRU 3&636= ILEHUV 3HDN FPf $VVLTQPHQW 5HIHUHQFHV Y 1+f Y &+ &+f IURP 6L&+ &+ YDV &+f YV &+f Y 6L+f &+ &+f IURP 6L &+ &+ 6DV &+f IURP 6L&+ &+f IURP 6L&+6L 6 &+f IURP 6L&+ 1+f FR &+f IURP 6L &+ 6L 6L16Lf 3DV &+f IURP 6L &+ 3V &+f IURP 6L &+ YDV 6L&f Y VWUHWFKLQJ EHQGLQJ FR EHQGLQJ S URFNLQJ f : .ULQHU 2UJ &KHP f f $/ 6PLWK &KHP 3K\V f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f 6H\IHUWK *+ :LVHPDQ DQG & 3UXGfKRPPH $P&HUDP 6RF && f f : 7RUHNL 1$ &UHHG DQG &' %DWLFK 3RO\PHU 3UHSULQWV $P &KHP 6RF >@ f f 50 6LOYHUVWHLQ *& %DVVOHU DQG 7& 0RUULOO 6SHFWURPHWULF ,GHQWLILFDWLRQ RI 2UJDQLF &RPSRXQGV -RKQ :OH\ 1HZ
PAGE 197

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH )7,5 VSHFWUD RI 3&636= JUHHQ ILEHUV EDWFK Vf GXULQJ KHDW WUHDWPHQW WR r& LQ QLWURJHQ DWPRVSKHUH

PAGE 198

,QWHQVLW\ .XEHOND0XQN XQLWVf $ Y6L+f > FPn@ YDV&+f RI&+ > FPn@ YV&+f RI &+ > FPn@ DV&+f RI6L2+M > FPn@ 7HPSHUDWXUH r&f )LJXUH ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD RI 3&636= ILEHUV EDWFK Vf

PAGE 199

,QWHQVLW\ .XEHOND0XQN 8QLWVf $ SDV&+f RI 6L&+ > FPn@ FR&+f RI 6L&+6L > FPn@ V&+f RI 6L&+ > FPn@ &+f RI 6L&+6L > FPn@ L L L L L >f§ 7HPSHUDWXUH r&f )LJXUH &RQWnGf

PAGE 200

,QWHQVLW\ .XEHOND0XQN 8QLWVf $ 1+f > FPn@ Y&+ &+fRI6L&+ &+ > FPn@ Y1+f > FPn@ DV&+ &+f RI 6L&+ &+ > FPn@ )LJXUH &RQWnGf

PAGE 201

,QWHQVLW\ .XEHOND0XQN 8QLWVf :DYHQXPEHU FPf )LJXUH &RPSDULVRQ RI )7,5 VSHFWUD RI 3&636= ILEHUV Vf EHIRUH DQG DIWHU KHDWWUHDWPHQW DW r& LQ QLWURJHQ

PAGE 202

,17(16,7< DUELWUDU\ XQLWVf , , , 7 , :$9(180%(5 FPf )LJXUH 6XEWUDFWLRQ VSHFWUD IRU 3&636= ILEHUV EDWFK Vf r&

PAGE 203

,17(16,7< DUELWUDU\ XQLWVf :$9(180%(5 FPf )LJXUH 6XEWUDFWLRQ VSHFWUD IRU 3&636= EDWFK Vf DQG 3&6 EDWFK Vf ILEHUV DW r&

PAGE 204

,17(16,7< DUELWUDU\ XQLWVf :$9(180%(5 FPf )LJXUH 6XEWUDFWLRQ VSHFWUD IRU 3&636= EDWFK Vf DQG 3&6 EDWFK Vf ILEHUV DW r&

PAGE 205

7KH LQIOXHQFH RI 36= RQ FURVVOLQNLQJ RI 3&6 FDQ EH DVFHUWDLQHG E\ FRPSDULQJ WKH )7,5 VSHFWUD )LJXUHV DQG f DQG WKH VXEWUDFWLRQ VSHFWUD IRU 3&6 DQG 3&636= GXULQJ WKH KHDW WUHDWPHQW IURP r& WR r& LQ QLWURJHQ )LJXUHV DQG f ,Q WKH FDVH RI 3&6 WKH DEVRUSWLRQ LQWHQVLW\ IRU 6L+ JURXSV LQFUHDVHG VLJQLILFDQWO\ XQWLO r& SUHVXPDEO\ GXH WR PHWK\OHQH LQVHUWLRQ UHDFWLRQVf DQG WKHQ VWDUWHG WR GHFUHDVH VHH )LJXUH f 7KH VXEWUDFWLRQ VSHFWUD IRU 3&6 ILEHUV EHIRUH DQG DIWHU KHDW WUHDWPHQW LQ QLWURJHQ )LJXUH f DOVR VKRZ WKH SUHVHQFH RI D VWURQJ 6L+ DEVRUSWLRQ EDQG DIWHU r& 7KLV ZDV QRW WKH FDVH IRU 3&636= 7KH DEVRUSWLRQ LQWHQVLW\ RI 6L+ JURXSV LQFUHDVHG RQO\ PDUJLQDOO\ XS WR ar& UHPDLQHG FRQVWDQW WLOO r& DQG WKHQ VWDUWHG WR GHFUHDVH )LJXUH f 7KH DEVRUSWLRQ LQWHQVLW\ DW FPn &+f IURP 6L&+6Lf GHFUHDVHG YHU\ VOLJKWO\ EH\RQG r& IRU 3&636= ZKLOH LW UHPDLQHG HVVHQWLDOO\ FRQVWDQW XS WR r& IRU 3&6 7KH LQWHQVLW\ RI DEVRUSWLRQ SHDN DW FPn GXH WR DV &+f RI 6L&+ f GHFUHDVHG PXFK PRUH UDSLGO\ VWDUWLQJ DW r& IRU 3&636= FRPSDUHG WR 3&6 $OO RI WKHVH REVHUYDWLRQV VXJJHVW WKDW PHWK\OHQH LQVHUWLRQ UHDFWLRQV DUH LQKLELWHG LQ WKH FDVH RI 3&636= PRVW OLNHO\ GXH WR WKH LQWHUDFWLRQ RI 36= ZLWK 3&6 5HFDOO WKDW WKH )7,5 VSHFWUD IRU 36= DORQH )LJXUH f VKRZHG D UDSLG LQFUHDVH LQ WKH LQWHQVLWLHV RI DOO WKH DEVRUSWLRQ SHDNV GXULQJ KHDW WUHDWPHQW IURP WR r& 7KLV ZDV DWWULEXWHG WR FRQWLQXHG SRO\PHUL]DWLRQFURVVOLQNLQJ RI WKH 36= GXULQJ WKH LQLWLDO KHDW WUHDWPHQW :LWK IXUWKHU KHDW WUHDWPHQW DERYH r& UDSLG GHFUHDVHV LQ SHDN LQWHQVLWLHV ZHUH REVHUYHG IRU DOO WKH DEVRUSWLRQ SHDNV )LJXUH f 6LJQLILFDQWO\ GLIIHUHQW EHKDYLRU ZDV REVHUYHG IRU WKH DEVRUSWLRQ SHDN LQWHQVLWLHV DVVRFLDWHG ZLWK WKH 36= GXULQJ KHDW WUHDWPHQW RI WKH 3&636= ILEHUV )LUVW WKHUH ZHUH QR LQFUHDVHV LQ WKH DEVRUSWLRQ LQWHQVLWLHV EHWZHHQ DQG r& )LJXUH f 6HFRQG WKH SHDN LQWHQVLWLHV

PAGE 206

HLWKHU GHFUHDVHG PRUH JUDGXDOO\ LH IRU Y &+ &+f RI 6L&+ &+ DW FPnf Y 1+f DW FPnf DQG DV &+ &+f RI 6L&+ &+ DW FPnff RU ,QFUHDVHG VOLJKWO\ LH IRU 1+f DW FPnff EHWZHHQ DQG r& 7KHVH UHVXOWV VXJJHVW WKDW 36= GRHV QRW XQGHUJR FRQWLQXHG SRO\PHUL]DWLRQFURVVOLQNLQJ ZKHQ SUHVHQW LQ WKH 3&636= ILEHUV 3RVVLEOH UHDVRQV PLJKW LQFOXGH ,f 7KH 36= LV GLOXWHG LH LW LV RQO\ b RI WKH SRO\PHUf LQ WKH 3&6 fPDWUL[ DQG WKLV OLPLWV WKH SK\VLFDO FRQWDFW EHWZHHQ 36= PROHFXOHV LLf 7KH 36= LQWHUDFWV ZLWK WKH 3&6 SRO\PHU $Q LQWHUDFWLRQ EHWZHHQ 36= DQG 3&6 ZDV DOVR LQGLFDWHG E\ REVHUYDWLRQV WKDW VROXWLRQV SUHSDUHG ZLWK 3&6 EHFDPH FORXG\ DERXW PLQXWHV DIWHU 36= ZDV DGGHG WR WKH VROXWLRQV )7,5 VSHFWUD RI DLUKHDW WUHDWHG 3&636= ILEHUV GXULQJ KHDW WUHDWPHQW LQ 1 )LJXUH VKRZV WKH )7,5 VSHFWUD RI DLUKHDW WUHDWHG r&f 3&636= ILEHUV EDWFK Vf DW r& 7DEOH VKRZV SHDN DVVLJQPHQWV IRU WKH VDPH 7KH ILEHUV VKRZHG D ZHLJKW JDLQ RI b DIWHU KHDW WUHDWPHQW LQ DLU DW r&K 7KH VSHFWUD FOHDUO\ VKRZV WKH DEVRUSWLRQ EDQGV GXH WR R[LGDWLRQ YL] DW FPn IUHH 2+ VWUHWFKLQJf FPn ERQGHG 2+ VWUHWFKLQJf DQG FPn GXH WR & VWUHWFKLQJf LQ DGGLWLRQ WR DOO WKH PDMRU DEVRUSWLRQ EDQGV IRU 3&6 +RZHYHU SHDNV GXH WR 36= ZKLFK ZHUH FOHDUO\ VHHQ LQ WKH VSHFWUD RI JUHHQ 3&636= ILEHUV )LJXUH f DUH PRVWO\ PDVNHG E\ WKH R[LGDWLRQ SHDNV )RU H[DPSOH WKH DEVRUSWLRQ SHDN DW FPn GXH WR Y 1+f LV QRW REVHUYHGf 7KH RQO\ GLVWLQFW SHDNV GXH WR 36= DUH WKH DV &+ &+f DW FPn DQG 1+f DW FPn $ SP ILOWHUHG VROXWLRQ RI ZWb 36= LQ WROXHQH ZDV DGGHG WR D SP ILOWHUHG VROXWLRQ RI ZWb 3&6 LQ WROXHQH 7KH DPRXQW RI 36= VROXWLRQ DGGHG JDYH D 36=3&6 ZHLJKW UDWLR RI f 7KH VROXWLRQ FKDQJHG IURP DQ LQLWLDOO\ FOHDU DSSHDUDQFH WR D FORXG\ VWDWH LQ PLQ LH LQGLFDWLYH RI PLFURJHO IRUPDWLRQ 7KLV VROXWLRQ FDQ VWLOO EH ILOWHUHG WKURXJK D SP ILOWHU DOWKRXJK WKLV RFFXUV PRUH VORZO\ ZKHQ FRPSDUHG WR ILOWUDWLRQ RI VLPLODU DPRXQWV RI 3&6 RU 36= VROXWLRQ

PAGE 207

$%625%$1&( .XEHOND0XQN 8QLWVf L L n L _ 7 _ UB :DYHQXPEHU FPnf )LJXUH 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI 3&636= ILEHUV EDWFK Vf KHDWWUHDWHG LQ DLU DW r&

PAGE 208

7DEOH )7,5 SHDN DVVLJQPHQWV IRU 3&636= ILEHUV EDWFK Vf KHDWWUHDWHG LQ DLU DW r& 3HDN FPnf $VVLTQPHQW 5HIHUHQFHV Y 2+f Y1+f Y &+ &+f IURP 6L&+ &+ YDV &+f YV &+f Y 6L+f Y & f &+ &+f IURP 6L &+ &+ DV &+f IURP 6L&+ &+f IURP 6L &+ 6L 6 &+f IURP 6L&+ 1+f 6L26L RU 6L2&f k &+f IURP 6L &+ 6L 6L16Lf 3DV &+f IURP 6L &+ 3V &+f IURP 6L &+ YDV 6L&f Y VWUHWFKLQJ EHQGLQJ WR EHQGLQJ S URFNLQJ f : .ULQHU 2UJ &KHP f f $/ 6PLWK &KHP 3K\V f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f 6H\IHUWK *+ :LVHPDQ DQG & 3UXGnKRPPH $P&HUDP 6RF && f f : 7RUHNL 1$ &UHHG DQG &' %DWLFK 3RO\PHU 3UHSULQWV $P &KHP 6RF >@ f f 50 6LOYHUVWHLQ *& %DVVOHU DQG 7& 0RUULOO 6SHFWURPHWULF ,GHQWLILFDWLRQ RI 2UJDQLF &RPSRXQGV -RKQ :OH\ 1HZ
PAGE 209

)LJXUH VKRZV )7,5 VSHFWUD RI DLUKHDW WUHDWHG 3&636= ILEHUV GXULQJ KHDW WUHDWPHQW WR r& LQ QLWURJHQ )LJXUH VKRZV SORWV RI WKH LQWHQVLWLHV RI YDULRXV DEVRUSWLRQ SHDNV IRU WKHVH ILEHUV )LJXUH VKRZV D GLUHFW FRPSDULVRQ EHWZHHQ VSHFWUD RI DLUKHDW WUHDWHG 3&636= ILEHUV EHIRUH DQG DIWHU KHDW WUHDWPHQW LQ QLWURJHQ DW r& )LJXUH VKRZV WKH VXEWUDFWLRQ VSHFWUD IRU WKH VDPH ,W FDQ EH VHHQ WKDW LQWHQVLWLHV RI DEVRUSWLRQ EDQGV GXH WR 6L2+ DW FPnf DQG & DW FPnf JUDGXDOO\ GHFUHDVHG VWDUWLQJ DERYH r& DQG FRPSOHWHO\ GLVDSSHDUHG E\ r& 7KH Y6L+f SDV&+f DQG DV &+f DEVRUSWLRQ SHDNV VKRZ VPDOO GHFUHDVHV LQ LQWHQVLW\ XSRQ KHDWLQJ WR r& 7KH GHFUHDVH LQ 6L2+ DQG 6L+ ERQGV ZRXOG EH H[SHFWHG WR EH DFFRPSDQLHG E\ DQ LQFUHDVH LQ VLOR[DQH ERQGV 6L26Lf LH DFFRUGLQJ WR HTXDWLRQV f DQG f 7KH VOLJKW LQFUHDVH LQ LQWHQVLW\ RI WKH DEVRUSWLRQ EDQG LQ WKH UDQJH RI FPn )LJXUH f LV FRQVLVWHQW ZLWK WKH IRUPDWLRQ RI 6L26L ERQGV 7KH UHVW RI WKH DEVRUSWLRQ SHDNV DVVRFLDWHG ZLWK 3&6 VKRZHG OLWWOH FKDQJH GXULQJ WKH KHDW WUHDWPHQW 7KLV FRXOG PHDQ WKDW PHWK\OHQH LQVHUWLRQ UHDFWLRQV DUH LQKLELWHG GXULQJ KHDW WUHDWPHQW DV VXJJHVWHG SUHYLRXVO\ IRU WKH FDVH RI JUHHQ 3&636= ILEHUV ZLWK QR DLU KHDW WUHDWPHQWf XQGHUJRLQJ WKH VDPH KHDW WUHDWPHQW LQ QLWURJHQ )LJXUHV DQG VKRZ FRPSDULVRQ SORWV RI )7,5 VSHFWUD RI DLUKHDW WUHDWHG 3&636= DQG 3&6 ILEHUV DW r& DQG DIWHU KHDW WUHDWPHQW LQ 1 DW r& UHVSHFWLYHO\ ,W LV HYLGHQW WKDW 6L+ SHDN LQWHQVLW\ GHFUHDVHG FRQVLGHUDEO\ IRU 3&6 ILEHUV WKDQ 3&636= ILEHUV $OVR WKH LQWHQVLW\ RI DEVRUSWLRQ EDQG DW FPn GXH WR FR &+f IURP 6L&+6L Y 6L26L RU 6L26Lf LV JUHDWHU IRU DLUKHDW WUHDWHG 3&6 WKDQ 3&636= ILEHUV 7KXV WKHVH REVHUYDWLRQV DOVR VXJJHVW WKDW PHWK\OHQH LQVHUWLRQ UHDFWLRQV DUH LQKLELWHG IRU DLUKHDW WUHDWHG 3&636= ILEHUV UHODWLYH WR DLUKHDW WUHDWHG 3&6 ILEHUV

PAGE 210

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPf )LJXUH )7,5 VSHFWUD RI DLUKHDW WUHDWHG r&f 3&636= ILEHUV EDWFK Vf GXULQJ KHDW WUHDWPHQW WR r& LQ QLWURJHQ

PAGE 211

,QWHQVLW\ .XEHOND0XQN XQLWVf 7HPSHUDWXUH r&f )LJXUH ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD RI DLUKHDW WUHDWHG r&f 3&636= ILEHUV EDWFK Vf

PAGE 212

,QWHQVLW\ .XEHOND0XQN XQLWVf $ SDV&+f RI 6L&+ > FPn@ R&+f RI 6L&+6L > FPn@ Y 6L26Lf > FPn@ 6V&+Jf RI 6L&+ > FPn@ &+f RI 6L&+6L > FPn@ Y& f > FPn@ 7HPSHUDWXUH r&f )LJXUH &RQWnGf

PAGE 213

,QWHQVLW\ .XEHOND0XQN 8QLWVf :DYHQXPEHU FPnf )LJXUH &RPSDULVRQ RI VSHFWUD RI DLUKHDW WUHDWHG 3&636= ILEHUV EDWFK Vf r&f EHIRUH DQG DIWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ

PAGE 214

,17(16,7< DUELWUDU\ XQLWVf :$9(180%(5 FPf )LJXUH 6XEWUDFWLRQ VSHFWUD IRU DLUKHDW WUHDWHG r&f 3&636= ILEHUV EDWFK Vf r&

PAGE 215

,QWHQVLW\ .XEHOND0XQN 8QLWVf :DYHQXPEHU FPnf )LJXUH &RPSDULVRQ RI VSHFWUD RI DLUKHDW WUHDWHG 3&6 ILEHUV EDWFK Vf DQG 3&636= ILEHUV EDWFK Vf DW r&

PAGE 216

,QWHQVLW\ .XEHOND0XQN 8QLWVf :DYHQXPEHU FPnf )LJXUH &RPSDULVRQ RI VSHFWUD RI DLUKHDW WUHDWHG 3&6 ILEHUV EDWFK Vf DQG 3&636= ILEHUV EDWFK Vf DIWHU KHDW WUHDWPHQW LQ 1

PAGE 217

0HFKDQLFDO SURSHUWLHV RI ILEHUV 7HQVLOH VWUHVVVWUDLQ PHDVXUHPHQWV ZHUH FDUULHG RXW RQ JUHHQ DQG KHDWWUHDWHG ILEHUV IURP GLIIHUHQW 3&6 DQG 3&636= VSLQ EDWFKHV )LEHUV ZHUH WHVWHG DVVSXQ DQG DIWHU YDULRXV KHDW WUHDWPHQWV DLU DW sr& K DQGRU QLWURJHQ DW r& Kf $SSHQGL[ ) VKRZV ZHLJKW JDLQV DIWHU KHDW WUHDWPHQW LQ DLU DW sr& IRU 3&6 DQG 3&636= ILEHUV 7DEOH VKRZV DYHUDJH WHQVLOH VWUHQJWKV DQG UXSWXUH VWUDLQV IRU GLIIHUHQW EDWFKHV RI 3&6 DQG 3&636= ILEHUV )LJXUHV DQG VKRZ EDU FKDUWV RI DYHUDJH WHQVLOH VWUHQJWKV DQG DYHUDJH UXSWXUH VWUDLQV IRU WKH VDPH 3&6 DQG 3&636= JUHHQ ILEHUV KDG VLPLODU VWUHQJWKV DQG UXSWXUH VWUDLQV 03D DQG b UHVSHFWLYHO\f +RZHYHU DIWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ 3&636= ILEHUV VKRZHG PXFK ODUJHU LQFUHDVHV LQ WHQVLOH VWUHQJWK 03Df DQG UXSWXUH VWUDLQ abf FRPSDUHG WR 3&6 ILEHUV 7ZR r& KHDW WUHDWHG 3&6 ILEHU EDWFKHV V DQG Vf VKRZHG VLPLODU WHQVLOH VWUHQJWK DQG UXSWXUH VWUDLQ DV WKH JUHHQ ILEHUV ZKLOH WZR RWKHU r& EDWFKHV V DQG Vf VKRZHG UHODWLYHO\ VPDOO LQFUHDVHV LQ WHQVLOH VWUHQJWKV DQG 03D UHVSHFWLYHO\f DQG UXSWXUH VWUDLQ DQG b UHVSHFWLYHO\f 3&6 DQG 3&636= ILEHUV KHDWWUHDWHG LQ DLU DW sr& VKRZHG PXFK KLJKHU VWUHQJWKV DQG 03D UHVSHFWLYHO\f DQG UXSWXUH VWUDLQV b DQG b UHVSHFWLYHO\f FRPSDUHG WR JUHHQ ILEHUV 3&6 DQG 3&636= ILEHUV KHDWWUHDWHG LQ DLU DW sr& DQG VXEVHTXHQWO\ KHDWWUHDWHG LQ QLWURJHQ DW r& VKRZHG HYHQ KLJKHU WHQVLOH VWUHQJWKV DQG 03D UHVSHFWLYHO\f DQG UXSWXUH VWUDLQV DQG b UHVSHFWLYHO\f FRPSDUHG WR ILEHUV JLYHQ MXVW RQH RI WKH KHDW WUHDWPHQWV 2WKHU VWXGLHV >+DV@ KDYH DOVR VKRZQ WKDW WKH WHQVLOH VWUHQJWK DQG UXSWXUH VWUDLQ ERWK LQFUHDVH DIWHU FXUHG R[LGL]HGf JUHHQ ILEHUV DUH KHDWWUHDWHG +DVHJDZD HW DO UHSRUWHG D UXSWXUH VWUDLQ RI b DQG D WHQVLOH VWUHQJWK RI NJIPP 03Df IRU

PAGE 218

7DEOH $YHUDJH WHQVLOH VWUHQJWKV DQG UXSWXUH VWUDLQV IRU 3&6 DQG 3&636= ILEHUV JUHHQ KHDW WUHDWPHQW LQ DLU DW sr& KHDW WUHDWPHQW LQ QLWURJHQ DW r& DQG KHDW WUHDWPHQW LQ DLU DW sr& IROORZHG E\ KHDW WUHDWPHQW LQ QLWURJHQ DW r&f 3&6 ILEHUV 3&636= ILEHUV )LEHU EDWFK 7HQVLOH 5XSWXUH )LEHU EDWFK 7HQVLOH 5XSWXUH VWUHQJWK *3Df VWUDLQ bf VWUHQJWK *3Df VWUDLQ bf *UHHQ V s s V s s V$ s s V s s V% s s V s s $YHUDJH IRU Vf s s V s s V s s r& sr&$LU V s s V s s V s s r&1LWURTHQ V s s V s s V$ s s V s s V% s s V s s $YHUDJH IRU Vf s s V$ s s V% s s V& s s $YHUDJH IRU Vf s s V s s r& sr&$LU Lr&1LWURTHQ V s s V s s

PAGE 219

*UHHQ QR 36= f& 1Mf QR 36= f& s n& $LUf QR 36= O8O r& sr& $LUf r& 1f QR 36= _ *UHHQ 36= PX f& 1Mf 36= _ & sn& $LUf 36= > @ f& sn& $LUf r& 1f 36= &2 &2 ] 2 9f &2 WR S R R 8f &2 WR &2 2 Z O2 &2 2 2 R 7I 8f &7f &2 f &2 V V V V 3&6 ILEHUV V V V 3&6 36= ILEHUV 1 ] R R R R 2 R %$7&+ '(6,*1$7,21 )LJXUH $YHUDJH WHQVLOH VWUHQJWKV IRU 3&6 3&636= ILEHUV DVVSXQ DQG DIWHU KHDW WUHDWPHQW LQ LfQLWURJHQ DW r& LLf DLU DW sr& DQG LQf DLU DW sr& IROORZHG E\ 1 DW r& &'

PAGE 220

’ *UHHQ QR 36= ’ r& 1Mf QR 36= _e O n& sr& $LUf QR 36= c‹OOL & s& $LUf p& 1f QR 36= _ *UHHQ 36= +LOO r& 1f 36= r& sr& $LUf 36= ++f r& sr& $LUf r& 1f 36= 2 R R &2 WR F 4f 2 V R 2 R f LQ WR V V V V 3&6 ILEHUV V V V 3&6 36= ILEHUV F 2f WR 2 R 2 ‘+ R O! R Ur} %$7&+ '(6,*1$7,21 )LJXUH $YHUDJH UXSWXUH VWUDLQV IRU 3&6 3&636= ILEHUV DVVSXQ DQG DIWHU KHDW WUHDWPHQW LQ LfQLWURJHQ DW r& !‘ LLf DLU DW sr& DQG LLLf DLU DW sr& IROORZHG E\ 1 DW r& 6

PAGE 221

ORZ PROHFXODUZHLJKW 3&6 ILEHUV ZKLFK ZHUH ILUVW KHDWWUHDWHG LQ DLU DW ar&f DQG WKHQ KHDWWUHDWHG DW r& LQ QLWURJHQ 7KH REVHUYDWLRQ RI LQFUHDVHG WHQVLOH VWUHQJWK DQG UXSWXUH VWUDLQ LV QRW JHQHUDOO\ REVHUYHG IRU RUJDQLF SRO\PHULF PDWHULDOV ZKLFK XQGHUJR FURVVOLQNLQJ $Q LQFUHDVH LQ WHQVLOH VWUHQJWK DOPRVW DOZD\V UHVXOWV LQ GHFUHDVHG UXSWXUH VWUDLQ )RU H[DPSOH XQYXOFDQL]HG HODVWRPHUV H[KLELW ORZ WHQVLOH VWUHQJWKV DQG ODUJH VWUDLQ abf $IWHU YXOFDQL]LQJ FURVVOLQNLQJf WKHVH HODVWRPHUV ZLWK VXOIXU WKH WHQVLOH VWUHQJWK LQFUHDVHV PDQ\ WLPHV EXW D GHFUHDVH LQ VWUDLQ WR abf LV REVHUYHG >%,@ 0DWKXU HW DO >0DW@ PHDVXUHG WKH WHQVLOH VWUHQJWK DQG UXSWXUH VWUDLQ RI SRO\DFU\ORQLWULOH 3$1f ILEHUV D SUHFXUVRU IRU FDUERQ ILEHUVf XSRQ KHDW WUHDWPHQW LQ DLU LH LQ RUGHU WR DFKLHYH R[LGDWLYH FURVVOLQNLQJf )LJXUH VKRZV WKDW WKH UXSWXUH VWUDLQ LQLWLDOO\ LQFUHDVHG EXW WKH WHQVLOH VWUHQJWK GHFUHDVHG XSRQ KHDW WUHDWPHQW WR ar& ,W LV QRW FOHDU ZKDW PHFKDQLVPVf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f 2Q WKLV EDVLV LW LV VXJJHVWHG WKDW KHDW WUHDWPHQW LQ QLWURJHQ DORQH WR r&f OHDGV WR RQO\ D OLPLWHG LQFUHDVH LQ PROHFXODU ZHLJKW LQFOXGLQJ VRPH EUDQFKLQJ DQG

PAGE 222

(ORQJDWLRQ RW %UHDN bf 7HQVLOH VWUHQJWK *3Df 2 2 7HPSHUDWXUH & %f )LJXUH 3ORWV RI Df WHQVLOH VWUHQJWK YV KHDW WUHDWPHQW WHPSHUDWXUH Ef b HORQJDWLRQ YV WHPSHUDWXUH IRU SRO\DFU\ORQLWULOH 3$1f ILEHUV >0DWM

PAGE 223

FURVVOLQNLQJ UHDFWLRQV IRU WKH 3&6 ILEHUV XVHG LQ WKLV VWXG\r 7KXV RQO\ UHODWLYHO\ VPDOO LQFUHDVHV LQ WHQVLOH VWUHQJWK DQG UXSWXUH VWUDLQ ZHUH REVHUYHGf ,Q FRQWUDVW KHDW WUHDWPHQW LQ DLU UHVXOWV LQ WKH IRUPDWLRQ RI D VLJQLILFDQW DPRXQW RI 6L26L 6L2& DQG 6L&2 ERQGV HJ VHH WKH VFKHPDWLF LOOXVWUDWLRQ LQ )LJXUH f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f 7KH VLJQLILFDQW LQFUHDVH LQ ERWK WHQVLOH VWUHQJWK DQG UXSWXUH VWUDLQ IRU WKH 3&636= ILEHUV KHDW WUHDWHG LQ QLWURJHQ RQO\ WR r&f LQGLFDWHV WKDW 36= LV DOVR HIIHFWLYH LQ LQFUHDVLQJ WKH SRO\PHU PROHFXODU ZHLJKW DQG WKH H[WHQW RI FURVVOLQNLQJ 7KH 36= FRQWDLQV PDQ\ XQVDWXUDWHG FDUERQFDUERQ GRXEOH ERQGVr ZKLFK FDQ SUHVXPDEO\ UHDFW ZLWK 3&6 WR IRUP DGGLWLRQDO 6L& JURXSV LQ WKH SRO\PHU EDFNERQH 5HFDOO WKDW WKH )7,5 VSHFWUD )LJXUH LQ VHFWLRQ f IRU 3&636= ILEHUV VKRZHG D VOLJKW LQFUHDVH LQ WKH LQWHQVLW\ RI WKH DEVRUSWLRQ SHDNV DVVRFLDWHG ZLWK WR 6L&+6Lf XSRQ KHDW WUHDWPHQW LQ QLWURJHQf ,Q DGGLWLRQ LW LV SUHVXPHG WKDW WKH YLQ\O JURXSV LQ WKH 36= DOVR SURPRWH FURVVOLQNLQJ E\ UHDFWLRQ ZLWK WKH 3&6 VLGH JURXSV 7DEOHV DQG VKRZ WHQVLOH SURSHUWLHV RI 3&6 DQG 3&636= ILEHUV ERWK DVVSXQ DQG DLUKHDW WUHDWHG DW sr&f KHDWWUHDWHG WR YDULRXV WHPSHUDWXUHV LQ WKH r +DVHJDZD HW DO >+DV@ XVHG JHO SHUPHDWLRQ FKURPDWRJUDSK\ WR FRQILUP WKDW WKH PROHFXODU ZHLJKW RI 3&6 GRHV LQFUHDVH XSRQ KHDW WUHDWPHQW LQ QLWURJHQ WR r& 7KH 3&6 XVHG E\ +DVHJDZD HW DO KDG ORZHU PROHFXODU ZHLJKW WKDQ WKH 3&6 XVHG LQ WKH SUHVHQW VWXG\f r 36= FRQWDLQV D QXPEHU RI XQUHDFWHG YLQ\O &+ &+f JURXSV 7KLV LV HYLGHQFHG E\ WKH SUHVHQFH RI YLQ\O DEVRUSWLRQV DW FPn FPn DQG FPn LQ WKH )7,5 VSHFWUD RI WKH SRO\PHU VHH VHFWLRQ f

PAGE 224

)LJXUH 6FKHPDWLF RI VWUXFWXUDO FKDQJHV WDNLQJ SODFH LQ 3&6 GXULQJ KHDW WUHDWPHQW LQ DLU DW sr& >2ND@

PAGE 225

7DEOH 7HQVLOH SURSHUWLHV RI DVVSXQ DQG DLUKHDW WUHDWHG r&f 3&6 ILEHUV KHDW WUHDWHG WR YDULRXV WHPSHUDWXUHV EHWZHHQ r& LQ QLWURJHQ 7HPSHUDWXUH RI KHDW WUHDWPHQW r&f RI ILEHUV WHVWHG 'LDPHWHU SPf 5XSWXUH VWUDLQ bf 7HQVLOH VWUHQJWK 03Df 3&6 ILEHUV Vf 1RQH s s s s s s s s s s s s s s s s s s s s s s D s s D 3&6 ILEHUV KHDW WUHDWHG LQ DLU DW r& Vf 1RQH s s s s s s s s s s s s s s s s s s $YHUDJH IRU IRXU VHSDUDWH KHDW WUHDWPHQWV LQGLYLGXDO UHVXOWV DUH SURYLGHG LQ $SSHQGL[ +f

PAGE 226

7DEOH 7HQVLOH SURSHUWLHV RI DVVSXQ DQG DLUKHDW WUHDWHG r&f 3&636= ILEHUV KHDW WUHDWHG WR YDULRXV WHPSHUDWXUHV EHWZHHQ r& LQ QLWURJHQ 7HPSHUDWXUH RI KHDW RI ILEHUV 'LDPHWHU 5XSWXUH 7HQVLOH VWUHQJWK WUHDWPHQW r&f WHVWHG SPf VWUDLQ bf 03Df 3&636= ILEHUV Vf 1RQH s s s s s s s s s s s s s s s s s s s s s s s s s s s s E s E s E 3&636= ILEHUV KHDW WUHDWHG LQ DLU DW r& Vf 1RQH s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s E $YHUDJH IRU IRXU VHSDUDWH KHDW WUHDWPHQWV ,QGLYLGXDO UHVXOWV DUH SURYLGHG LQ $SSHQGL[ +f

PAGE 227

UDQJH r& LQ QLWURJHQ $SSHQGL[ VKRZV WKH ZHLJKW ORVVHV WKDW RFFXU XSRQ S\URO\VLV RI WKH ILEHUV DW r& LQ QLWURJHQf 7KH GDWD IRU DVVSXQ 3&6 ILEHUV DVVSXQf LV VKRZQ IRU WKH KLJKHVW VWUHQJWK ILEHU EDWFK 8)V 7KH GDWD IRU 3&6 ILEHUV ZKLFK ZHUH LQLWLDOO\ KHDWWUHDWHG LQ DLU LV VKRZQ IRU EDWFK 8)V 7KH VHOHFWLRQ RI D SDUWLFXODU EDWFK IRU DLUKHDW WUHDWPHQW DQGRU KHDW WUHDWPHQW LQ QLWURJHQ ZDV WR VRPH H[WHQW GHWHUPLQHG E\ WKH DPRXQW RI ILEHUV DYDLODEOHf )LJXUHV D DQG E VKRZ D FRPSDULVRQ RI DYHUDJH UXSWXUH VWUDLQV DV D IXQFWLRQ RI WHPSHUDWXUH IRU 3&6 DQG 3&636= ILEHUV KHDWWUHDWHG LQ QLWURJHQ ,Q ERWK FDVHV WKH DYHUDJH UXSWXUH VWUDLQV UHDFKHG PD[LPXP YDOXHV DIWHU KHDW WUHDWPHQWV LQ UDQJH RI ar& DQG WKHQ GHFUHDVHG UDSLGO\ DIWHU KHDW WUHDWPHQWV DW KLJKHU WHPSHUDWXUHV 7KH GHFUHDVH LQ UXSWXUH VWUDLQ LV GXH WR WKH WUDQVLWLRQ IURP DQ RUJDQRVLOLFRQ SRO\PHU WR DQ LQRUJDQLF 6L&EDVHG FHUDPLF LH WKH EUDQFKHG SRO\PHU FKDLQV ORVH PHWK\O JURXSV DQG K\GURJHQ IURP WKH 6L& EDFNERQH DQG IRUP DQ DPRUSKRXV 6L& QHWZRUNf 6XFK D UDSLG GHFUHDVH LQ UXSWXUH VWUDLQV EH\RQG r& ZDV DOVR UHSRUWHG E\ +DVHJDZD HW DO >+DV@ IRU ORZPROHFXODU ZHLJKW 1LFDORQW\SH ILEHUV ZKHUH UXSWXUH VWUDLQV GHFUHDVHG IURP b DW r& WR b DW r& )LJXUHV D DQG E VKRZ D FRPSDULVRQ RI DYHUDJH UXSWXUH VWUDLQV DV D IXQFWLRQ RI KHDW WUHDWPHQW WHPSHUDWXUH LQ QLWURJHQf IRU 3&6 DQG 3&636= ILEHUV ZKLFK ZHUH LQLWLDOO\ KHDWWUHDWHG LQ DLU DW ar& 7KH WUHQGV ZHUH VLPLODU WR WKH ILEHUV KHDWWUHDWHG RQO\ LQ QLWURJHQ H[FHSW WKDW WKH PD[LPXP UXSWXUH VWUDLQV ZHUH KLJKHU DQG ZHUH UHDFKHG DW ORZHU WHPSHUDWXUHV IRU WKH DLUKHDW WUHDWHG ILEHUV )LJXUHV D DQG E VKRZ SORWV RI DYHUDJH WHQVLOH VWUHQJWK YV WKH KHDW WUHDWPHQW WHPSHUDWXUH LQ QLWURJHQf IRU WKH 3&6 ILEHUV EDWFK Vf DQG 3&636= ILEHUV EDWFK Vf 7KHVH SORWV VKRZ WKH VDPH GDWD DV LQ 7DEOHV DQG ,W ZDV QRWHG HDUOLHU WKDW Lf 7KH DGGLWLRQ RI 36= KDG HVVHQWLDOO\ QR HIIHFW RQ WKH JUHHQ VWUHQJWK LLf %DWFKHV ZLWK 36= VKRZHG VRPHZKDW JUHDWHU LQFUHDVHV LQ VWUHQJWK GXULQJ KHDW

PAGE 228

$9(5$*( 583785( 675$,1 bf $9(5$*( 583785( 675$,1 bf $f )LJXUH $YHUDJH UXSWXUH VWUDLQ YV WHPSHUDWXUH IRU $f 3&6 ILEHUV EDWFK Vf DQG %f 3&636= ILEHUV EDWFK Vf

PAGE 229

$9(5$*( 583785( 675$,1 bf $9(5$*( 583785( 675$,1 bf )LJXUH $YHUDJH UXSWXUH VWUDLQ YV WHPSHUDWXUH IRU ILEHUV KHDWWUHDWHG LQ DLU $f 3&6 EDWFK V r& DLU KHDW WUHDWPHQWf DQG %f 3&636= EDWFK V r& DLU KHDW WUHDWPHQWf

PAGE 230

$9(5$*( 7(16,/( 675(1*7+ 03Df $9(5$*( 7(16,/( 675(1*7+ 03Df )LJXUH $YHUDJH WHQVLOH VWUHQJWK YV WHPSHUDWXUH IRU $f 3&6 ILEHUV EDWFK Vf DQG %f 3&636= ILEHUV EDWFK Vf

PAGE 231

WUHDWPHQW DW r& ,Q WKLV FDVH EDWFK V KDG WKH KLJKHVW VWUHQJWK IRU WKH EDWFKHV SUHSDUHG ZLWKRXW 36= DQG LWV VWUHQJWKV ZHUH FORVH WR WKDW REVHUYHG IRU WKH 3&636= EDWFK Vf 7KLV ZDV DWWULEXWHG WR D WHQGHQF\ IRU D JUHDWHU GHJUHH RI FURVVOLQNLQJ GXULQJ KHDW WUHDWPHQW LQ ILEHUV ZKLFK FRQWDLQ 36= 7KH DGGLWLRQDO GDWD LQ 7DEOHV DQG DOVR VKRZ WKDW Lf 7KHUH DUH QR LQFUHDVHV LQ VWUHQJWK XSRQ KHDW WUHDWPHQW WR r& IRU ILEHUV SUHSDUHG ZLWK DQG ZLWKRXW 36= LLf 7KH GLIIHUHQFHV LQ VWUHQJWK IRU WKH 3&6 DQG 3&636= ILEHUV UHPDLQ UHODWLYHO\ VPDOO IRU KHDW WUHDWPHQWV XS WR DW OHDVW r& 7KH VWUHQJWK LQFUHDVHV VLJQLILFDQWO\ DV WKH RUJDQRVLOLFRQ SRO\PHU ILEHUV DUH KHDW WUHDWHG DW WHPSHUDWXUHV DERYH r& DQG EHFRPH FRQYHUWHG WR FHUDPLFEDVHG ILEHUV 7KH 3&636= ILEHUV GHYHORS KLJKHU VWUHQJWKV WKDQ WKH 3&6 ILEHUV DW WKHVH WHPSHUDWXUHV 7KH KLJKHU VWUHQJWKV DUH EHOLHYHG WR EH DVVRFLDWHG ZLWK WKH LPSURYHG VSLQQLQJ EHKDYLRU ZKLFK LQ WXUQ UHVXOWV LQ ILEHU EXQGOHV ZLWK IHZHU DQG SRVVLEO\ VPDOOHUf GHIHFWV $V VKRZQ LQ VHFWLRQ ILEHUV VSXQ ZLWKRXW 36= KDYH PRUH EUHDNV GXULQJ VSLQQLQJ DQG WKHUHIRUH PRUH UHVWDUWV LQ WKH VSLQQLQJ DUH UHTXLUHG 7KH EUHDNV GXULQJ VSLQQLQJ UHVXOW LQ ILEHUV ZLWK PRUH YDULDEOH GLDPHWHUV LQFOXGLQJ VRPH ILEHUV ZLWK VLJQLILFDQWO\ ODUJHU GLDPHWHUV /DUJHU ILEHU GLDPHWHUV QRUPDOO\ UHVXOW LQ ORZHU WHQVLOH VWUHQJWK >:\Q 7RU$
PAGE 232

7DEOHV DQG VKRZ WKH DYHUDJH WHQVLOH VWUHQJWKV DQG GLDPHWHUV IRU YDULRXV EDWFKHV RI 3&6 DQG 3&636= ILEHUV UHVSHFWLYHO\ ZKLFK ZHUH S\URO\]HG DW r& LQ QLWURJHQ 7KH WHQVLOH VWUHQJWK GDWD IRU LQGLYLGXDO ILEHU EDWFKHV DUH VKRZQ LQ $SSHQGL[ +f +LVWRJUDP SORWV RI WKH WHQVLOH VWUHQJWK DQG GLDPHWHU GLVWULEXWLRQV IRU WKH FRPELQHG EDWFKHV RI WKH 3&6 DQG 3&636= ILEHUV DUH VKRZQ LQ )LJXUHV DQG UHVSHFWLYHO\ $V H[SHFWHG IURP WKH GDWD VKRZQ IRU EDWFKHV V DQG V 7DEOH )LJXUH D DQG 7DEOH )LJXUH E UHVSHFWLYHO\f WKH WHQVLOH VWUHQJWKV DUH KLJKHU IRU EDWFKHV SUHSDUHG ZLWK 36= $V QRWHG DERYH WKLV LV DWWULEXWHG WR LPSURYHG VSLQQLQJ EHKDYLRU ZKLFK LQ WXUQ VKRXOG UHVXOW LQ IHZHU ODUJH GHIHFWV LQ WKH EXQGOHVf )LJXUH VKRZV WKDW WKH DYHUDJH GLDPHWHUV IRU WKH WZR W\SHV RI ILEHUV ZHUH DOPRVW WKH VDPH 7KH GLVWULEXWLRQ LV VRPHZKDW EURDGHU IRU WKH 3&6 ILEHUV 7KLV PLJKW EH GXH WR WKH LQFUHDVHG IUHTXHQF\ RI EUHDNV GXULQJ VSLQQLQJ RI WKH 3&6 ILEHUV )LJXUHV D DQG E VKRZ SORWV RI DYHUDJH WHQVLOH VWUHQJWK YV WHPSHUDWXUH RI KHDW WUHDWPHQW LQ QLWURJHQf IRU WKH 3&6 ILEHUV EDWFK Vf DQG 3&636= ILEHUV EDWFK Vf ZKLFK ZHUH R[LGL]HG LQ DLU sr&f SULRU WR WKH KHDW WUHDWPHQWV 7KHVH SORWV VKRZ WKH VDPH GDWD DV LQ 7DEOHV DQG $V QRWHG HDUOLHU ILEHUV JLYHQ WKH LQLWLDO DLUKHDW WUHDWPHQW KDYH KLJKHU VWUHQJWKV LQ WKH JUHHQ VWDWH DQG DIWHU KHDW WUHDWPHQW LQ QLWURJHQ DW r& FRPSDUHG WR WKH FRUUHVSRQGLQJ ILEHUV ZLWKRXW WKH LQLWLDO DLU KHDW WUHDWPHQW 7DEOH DQG DOVR VKRZ WKDW WKLV WUHQG LV REVHUYHG DIWHU KHDW WUHDWPHQWV LQ QLWURJHQ DW RWKHU WHPSHUDWXUHV XS WR r& 7KH 36= KDV UHODWLYHO\ OLWWOH HIIHFW RQ WKH WHQVLOH VWUHQJWKV RI WKH DLUKHDW WUHDWHG ILEHUV GXULQJ WKH HDUO\ VWDJHV RI KHDW WUHDWPHQW LQ QLWURJHQ $OWKRXJK 7DEOHV DQG VKRZ WKDW WKH VWUHQJWKV RI WKH 3&636= ILEHUV DUH VOLJKWO\ KLJKHU WKDQ WKH 3&6 ILEHUV XS WKURXJK WKH r& KHDW WUHDWPHQWV WKH GLIIHUHQFHV DUH ZLWKLQ H[SHULPHQWDO HUURU RI WKH PHDVXUHPHQWV +HQFH WKH VWUHQJWKV WKDW GHYHORS DV D UHVXOW RI WKHVH UHODWLYHO\ ORZ WHPSHUDWXUH KHDW

PAGE 233

7DEOH 3URSHUWLHV RI 6L& ILEHUV VSXQ IURP 3&6 )LEHU EDWFK RI ILEHUV WHVWHG 'LDPHWHU SPf 7HQVLOH VWUHQJWK *3Df V s s V s s V s s V s s 7DEOH 3URSHUWLHV RI 6L& ILEHUV VSXQ IURP 3&6 36= )LEHU EDWFK RI ILEHUV WHVWHG 'LDPHWHU SPf 7HQVLOH VWUHQJWK *3Df V s s V s s V s s 3\URO\VLV FRQGLWLRQV ; QLWURJHQ DWPRVSKHUH

PAGE 234

180%(5 3(5&(17 180%(5 3(5&(17 %DWFKHV ILEHUVf 0HDQ *3D NVLf 6WG 'HY *3D NVLf $f 7(16,/( 675(1*7+ *3Df 3&6 36= %DWFKHV ILEHUVf 0HDQ *3D NVLf 6WG 'HY *3D NVLf %f 7(16,/( 675(1*7+ *3Df )LJXUH 'LVWULEXWLRQ RI WHQVLOH VWUHQJWKV RI ILEHUV DIWHU S\URO\VLV DW r& LQ QLWURJHQ $f 3&6 %f 3&636=

PAGE 235

180%(5 3(5&(17 180%(5 3(5&(17 ',$0(7(5 SPf 3&6 36= %DWFKHV ILEHUVf 0HDQ 'LDP SP 6WG 'HY SP %f ',$0(7(5 SPf )LJXUH 'LVWULEXWLRQ RI GLDPHWHUV IRU ILEHUV DIWHU S\URO\VLV DW r& LQ QLWURJHQ $f 3&6 %f 3&636=

PAGE 236

$9(5$*( 7(16,/( 675(1*7+ 03Df $9(5$*( 7(16,/( 675(1*7+ 03Df )LJXUH $YHUDJH WHQVLOH VWUHQJWK YV WHPSHUDWXUH IRU ILEHUV KHDWWUHDWHG LQ DLU $f 3&6 EDWFK V r& DLU KHDW WUHDWPHQW DQG %f 3&636= EDWFK V r& DLU KHDW WUHDWPHQWf

PAGE 237

WUHDWPHQWV LQ QLWURJHQ DSSHDU WR EH FRQWUROOHG ODUJHO\ E\ WKH HIIHFWV RI WKH LQLWLDO R[LGDWLYH FURVVOLQNLQJ :LWK IXUWKHU KHDW WUHDWPHQW r&f LQ QLWURJHQ WKH DLUKHDW WUHDWHG 3&636= ILEHUV KDYH VRPHZKDW KLJKHU VWUHQJWKV WKDQ WKH DLUKHDW WUHDWHG 3&6 ILEHUV $V LQ WKH FDVH RI WKH FRUUHVSRQGLQJ ILEHUV ZKLFK ZHUH QRW JLYHQ WKH LQLWLDO DLUKHDW WUHDWPHQW WKLV GLIIHUHQFH LV DWWULEXWHG WR WKH LPSURYHG VSLQQLQJ EHKDYLRU ZKLFK UHVXOWV LQ IHZHU ODUJH GHIHFWV LQ WKH S\URO\]HG EXQGOHV ,W LV DOVR QRWHG WKDW WKH DLUKHDW WUHDWHG ILEHUV ERWK 3&6 DQG 3&636=f KDYH ORZHU VWUHQJWKV WKDQ WKH FRUUHVSRQGLQJ ILEHUV ZLWKRXW WKH DLU KHDW WUHDWPHQW IRU VDPSOHV S\URO\]HG LQ QLWURJHQ LQ WKH UDQJH RI r& 7KH UHDVRQ IRU WKLV EHKDYLRU LV QRW FOHDU EXW PD\ UHIOHFW GLIIHUHQFHV LQ SKDVH FRPSRVLWLRQ 7KH r&S\URO\]HG ILEHUV SUHSDUHG ZLWKRXW DLU KHDW WUHDWPHQW FRQVLVW PRVWO\ RI YHU\ ZHDNO\ FU\VWDOOLQH 6L& DQG DPRUSKRXV FDUERQ 7KH FRUUHVSRQGLQJ DLUKHDW WUHDWHG ILEHUV FRQWDLQ WKHVH SKDVHV EXW DOVR FRQWDLQV DQ DPRUSKRXV VLOLFDOLNH DQGRU VLOLFRQ R[\FDUELGH PDWHULDOf

PAGE 238

6\QWKHVLV DQG &KDUDFWHUL]DWLRQ RI 3ROYPHWKYOVLODQH 306f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,@ )RU H[DPSOH ZKHQ D WULIXQFWLRQDO PRQRPHU LV DGGHG WR D GLIXQFWLRQDO PRQRPHU LQ :XUW]FRXSOLQJ SRO\PHUL]DWLRQ WKH UHVXOWLQJ SRO\PHU EHFRPHV FURVVOLQNHG GXH WR WKH LQWURGXFWLRQ RI DGGLWLRQDO EUDQFKLQJ VLWHV 7KLV LV LOOXVWUDWHG VFKHPDWLFDOO\ IRU :XUW] SRO\PHUL]DWLRQ RI PHWK\OGLFKORURVLODQH 0'&6 IXQFWLRQDOLW\ f DQG PHWK\OWULFKORURVLODQH 07&6 IXQFWLRQDOLW\ f ZLWK VRGLXP LQ )LJXUH ,Q WKH SUHVHQW VWXG\ 306 V\QWKHVLV ZDV FDUULHG RXW E\ XVLQJ :XUW] SRO\PHUL]DWLRQ LQ VRGLXP XVLQJ 0'&6 DQG 07&6 LQ ZWb SURSRUWLRQ 7KH VHOHFWLRQ RI WKLV UDWLR ZDV EDVHG RQ REVHUYDWLRQV WKDW PL[WXUHV SUHSDUHG ZLWK KLJKHU 07&6 FRQWHQWV VKRZ ORZHU UHDFWLRQ UDWHV DQGRU ORZHU UHDFWLRQ \LHOGV >4LX$ 6DO@f 3RO\PHUV ZHUH DOVR V\QWKHVL]HG XVLQJ 0'&6 PRQRPHU DORQH IRU FRPSDULVRQ 7KH SRO\PHU \LHOGV LQ WKH :XUW]FRXSOLQJ SRO\PHUL]DWLRQ RI 0'&6 DQG 0'&607&6 H J ZWbf ZLWK 1D DUH W\SLFDOO\ ORZ 7KHUH PD\ EH VHYHUDO UHDVRQV IRU WKH REVHUYHG ORZ \LHOGV f 7KHUH PD\ EH LQVROXEOH SRO\PHU SURGXFW IRUPHG GXULQJ SRO\PHUL]DWLRQ :RRG >:RR@ KDV UHSRUWHG WKH IRUPDWLRQ RI XS WR b RI LQVROXEOH SRO\PHU SURGXFW LQ WKH SRO\PHUL]DWLRQ RI 0'&6 ZLWK 1D LQ KH[DQH7+) E\ YROXPHf f 6RPH VROXEOH SRO\PHU FRXOG EH WUDSSHG LQ WKH SUHFLSLWDWLQJ 1D1D&, FROORLGV GXULQJ

PAGE 239

FK &O 6L &O + 0HWK\OGLFKORURVLODQH IXQFWLRQDOLW\ I f )LJXUH 6FKHPDWLF FK 1D6ROYHQW5HIOX[ 2 6L D 1D&, + 0HWK\OGLFKORURVLODQH IXQFWLRQDOLW\ I f Df FK &+F 1D6ROYHQW5HIOX[ &O 6L &O 1D&, D 0HWK\OWULFKORURVLODQH IXQFWLRQDOLW\ I f Ef FK FK FK + &+Rf§6Lf§+ + FK FK FK f§ 6L 6L 6L f§ 6L 6L 6L Q + &+f§6Lf§+ + FK FK 6L 6L 6L + &+ IRU :XUW] SRO\PHUL]DWLRQ RI Df PHWK\OGLFKORURVLODQH DQG Ef PHWK\OGLFKORURVLODQHPHWK\OWULFKORURVLODQH PL[WXUH

PAGE 240

SRO\PHUL]DWLRQ f ,I WKH UDWH RI SRO\PHUL]DWLRQ LV VORZ DV LQ WKH FDVH RI SRO\PHUL]DWLRQ RI 0'&607&6 ZLWK 1D LQ WROXHQHf VRPH PRQRPHUV FRXOG EH ORVW GXH WR HYDSRUDWLRQ ,W PD\ EH UHFDOOHG WKDW 0'&6 DQG 07&6 KDYH UHODWLYHO\ ORZ ERLOLQJ SRLQWV DQG r& UHVSHFWLYHO\f f 0'&6 LV NQRZQ WR XQGHUJR GLVSURSRUWLRQDWLRQ XQGHU YLJRURXV UHDFWLRQ FRQGLWLRQV HPSOR\HG LQ :XUW] SRO\PHUL]DWLRQ >$WW@ 7KLV FRXOG UHVXOW LQ WKH ORVV RI VRPH PRQRPHU DV YRODWLOH 6LFRQWDLQLQJ SURGXFWV :RRG >:RR@ KDV VKRZQ E\ + 105 RI HYROYHG JDVHV GXULQJ SRO\PHUL]DWLRQ WKDW 0'&6 GLVSURSRUWLRQDWHG LQWR PHWK\OVLODQH &+6L+f DQG PHWK\OFKORURVLODQH &+6L+&,f JDVHV ,W ZDV VKRZQ LQ VHFWLRQ WKDW WKH W\SH RI VROYHQW XVHG LQ WKH :XUW] FRXSOLQJ SRO\PHUL]DWLRQ RI GLFKORURVLODQHV ZLWK VRGLXP KDG DQ HIIHFW RQ WKH SRO\PHU \LHOG >0LO 0LO@ 3RODU VROYHQWV DUH VRPHWLPHV DGGHG LQ :XUW]FRXSOLQJ SRO\PHUL]DWLRQ WR LQFUHDVH WKH SRO\PHU \LHOG %DVHG RQ SULRU LQYHVWLJDWLRQV >4LX$ 01 *DX *DX@ 7+) DQG GLR[DQH ZHUH VHOHFWHG DV WKH SRODU VROYHQW DGGLWLYHV IRU WKLV VWXG\ :XUW] FRXSOLQJ SRO\PHUL]DWLRQV ZHUH FDUULHG RXW XVLQJ VROYHQW PL[WXUHV RI YROb WROXHQH7+) DQG YROb WROXHQH GLR[DQH 7+) KDV D ORZ ERLOLQJ SRLQW r&f DQG XVH RI 7+) LQ DPRXQWV YROb ZRXOG FDXVH WKH UHIOX[ WHPSHUDWXUH RI WKH VROYHQW PL[WXUH WR EH OHVV WKDQ WKH PHOWLQJ SRLQW RI 1D r&f DQG ZRXOG OHDG WR LQFRPSOHWH PHOWLQJ RI 1D 'LR[DQH RQ WKH RWKHU KDQG KDV D UHODWLYHO\ KLJK ERLOLQJ SRLQW r&f DQG ZRXOG QRW FDXVH VXFK SUREOHPV LI XVHG LQ KLJKHU DPRXQWVf 7DEOH VKRZV WKH V\QWKHVLV FRQGLWLRQV DQG FKDUDFWHULVWLFV RI YDULRXV SRO\PHUV SUHSDUHG 'HWDLOHG V\QWKHVLV FKDUDFWHULVWLFV IRU LQGLYLGXDO SRO\PHUV DUH VKRZQ LQ $SSHQGLFHV / DQG 0f 6L[ GLIIHUHQW PRQRPHUVROYHQW FRPELQDWLRQV ZHUH VWXGLHG f 0'&6 WROXHQH EDWFK $f f 0'&6 WROXHQH7+) PL[WXUH b E\ YROXPHf EDWFK %f f 0'&6 WROXHQH'LR[DQH b E\ YROXPHf EDWFK &f f 0'&607&6

PAGE 241

7DEOH 6\QWKHVLV FRQGLWLRQV DQG FKDUDFWHULVWLFV IRU 306 SRO\PHUV %DWFK GHVLJQDWLRQ 0RQRPHUVf 6ROYHQWVf 5HDFWLRQ FRQGLWLRQV 3RO\PHU \LHOG bf 0Q 0Z 3', &HUDPLF \LHOG bf $ 0'&6 7ROXHQH K 5HIOX[ D D D % 0'*6 7ROXHQH7+) YRLbf K 5HIOX[ & 0'&6 7ROXHQH 'LR[DQH YRObf K 5HIOX[ E s E s E s E s E s 0'&607&6 ZWbff 7ROXHQH K 5HIOX[ D D D ( 0'&607&6 ZWbff 7ROXHQH7+) YRLbf K 5HIOX[ F s E s E s E s E s ) 0'&607&6 ZWbff 7ROXHQH 'LR[DQH YRObf K 5HIOX[ G s G s G s G s E s D $YHUDJH IRU EDWFKHV E $YHUDJH IRU EDWFKHV $YHUDJH IRU EDWFKHV G $YHUDJH IRU EDWFKHV ,QGLYLGXDO UHVXOWV DUH VKRZQ LQ $SSHQGLFHV / DQG 0 2LO EDWK WHPSHUDWXUH ZDV PDLQWDLQHG DW r& IRU DOO V\QWKHVHV UHDFWLRQV

PAGE 242

PL[WXUH b E\ ZHLJKWf WROXHQH EDWFK 'f f 0'&607&6 PL[WXUH b E\ ZHLJKWf WROXHQH7+) b E\ YROXPHf EDWFK (f f 0'&607&6 PL[WXUH b E\ ZHLJKWf WROXHQH'LR[DQH b E\ YROXPHf EDWFK )f %DWFKHV $%' DQG ( UHTXLUHG K IRU FRPSOHWLRQ RI UHDFWLRQ ZKHUHDV EDWFKHV & DQG ) UHTXLUHG K IRU FRPSOHWLRQ 5HDFWLRQV ZHUH FRQVLGHUHG HVVHQWLDOO\ FRPSOHWH ZKHQ WKH VROXWLRQV ZHUH QR ORQJHU DFLGLF LH DFFRUGLQJ WR WKH PHWKRG GHVFULEHG LQ VHFWLRQ f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fSRRU VROYHQW YV JRRG VROYHQW FRQFHSW LQ =HLJOHUfV PRGHO >=HL@ 3ULRU WR D GLVFXVVLRQ RI WKHVH PHFKDQLVPV LW ZLOO EH KHOSIXO WR LOOXVWUDWH WKDW D WROXHQHGLR[DQH PL[WXUH LV D SRRUHU VROYHQW IRU 306 SRO\PHUV FRPSDUHG WR WROXHQH DORQH 7KLV ZDV DFFRPSOLVKHG E\ LQWULQVLF YLVFRVLW\ PHDVXUHPHQWV ,Q D SRRU VROYHQW WKH SRO\PHU FKDLQV DUH WLJKWO\ FRLOHG 7KLV UHVXOWV LQ SRO\PHU FKDLQV ZLWK VPDOOHU UDGLL DQG KHQFH WKH SRO\PHU VROXWLRQ KDV ORZHU LQWULQVLF YLVFRVLW\ ,Q D JRRG VROYHQW SRO\PHU FKDLQV DVVXPH DQ H[SDQGHG

PAGE 243

GZWGORJ 0f GZWGORJ 0f GZWGORJ 0f $f %f )LJXUH Df *HO SHUPHDWLRQ FKURPDWRJUDPV IRU SRO\PHUV SUHSDUHG IURP 0'&6 $f7ROXHQH %f 7ROXHQH7+) YRObf &f 7ROXHQH 'LR[DQH YRObf

PAGE 244

GZWGORJ 0f GZWGORJ 0f GZWGORJ 0f $f %f )LJXUH Ef *HO SHUPHDWLRQ FKURPDWRJUDPV IRU SRO\PHUV SUHSDUHG IURP 0'&6 DQG 07&6 ZWbf $f 7ROXHQH %f 7ROXHQH7+) YRObf &f 7ROXHQH 'LR[DQH YRObf

PAGE 245

02/(&8/$5 :(,*+7 U ’ 0Z ‘‘ 0f $ 7ROXHQH % 7ROXHQH7+) 9RO bf & 7ROXHQH'LR[DQH 9RO bf )LJXUH (IIHFW RI FRVROYHQWV RQ PROHFXODU ZHLJKW RI 306 SRO\PHUV $% DQG & SUHSDUHG XVLQJ b 0'&6f

PAGE 246

02/(&8/$5 :(,*+7 U , 0Z +L 0f 7ROXHQH ( 7ROXHQH7+) 9RO bf ) 7ROXHQH'LR[DQH 9RO bf ( ) 32/<0(5 %$7&+ )LJXUH (IIHFW RI FRVROYHQWV RQ PROHFXODU ZHLJKW RI 306 SRO\PHUV '( DQG ) SUHSDUHG XVLQJ 0'&607&6 ZWbff

PAGE 247

FRQILJXUDWLRQ DQG KHQFH WKH K\GURG\QDPLF UDGLL DUH ODUJHU DQG WKH LQWULQVLF YLVFRVLW\ RI WKH SRO\PHU VROXWLRQ LV KLJKHU )LJXUHV DQG VKRZ WKDW WKH LQWULQVLF YLVFRVLW\ RI 306 SRO\PHU LQ SXUH WROXHQH POJf LV KLJKHU WKDQ LQ WROXHQHGLR[DQH PL[WXUH POJf ,Q D VHSDUDWH H[SHULPHQW LW ZDV REVHUYHG WKDW QHDUO\ SXUH GLR[DQH LH PO RI GLR[DQH DQG PO RI WROXHQHf DFWV DV D QRQVROYHQW IRU WKH SRO\PHU $ FORXG\ \HOORZ SUHFLSLWDWH IRUPHG ZKHQ PO RI GLR[DQH ZDV DGGHG WR J RI FRQFHQWUDWHG SRO\PHU VROXWLRQ ZWb LQ WROXHQHff &RQVLGHU WKH :XUW]FRXSOLQJ SRO\PHUL]DWLRQ RI 0'&6 LQ WROXHQH VFKHPDWLFDOO\ LOOXVWUDWHG LQ )LJXUH Df 7ROXHQH LV D JRRG VROYHQW IRU WKH 306 SRO\PHU VR WKH SRO\PHU PROHFXOHV WHQG WR UHPDLQ LQ WKH VROYHQW LH DV RSSRVHG WR DGVRUELQJ RQ WKH 1D SDUWLFOHVf 7KLV DOORZV WKH UHPDLQLQJ PRQRPHU PROHFXOHV WR GLIIXVH WRZDUG 1D SDUWLFOHV XQLPSHGHG WKHUHE\ UHVXOWLQJ LQ WKH FUHDWLRQ RI QHZ SRO\PHU FKDLQV 7KLV OLPLWV WKH FKDLQ H[WHQVLRQ WKDW FDQ WDNH SODFH E\ FROOLVLRQ RI PRQRPHU PROHFXOHV ZLWK WKH FKDLQHQGV +HQFH WKH SRO\PHU SURGXFW DIWHU FRPSOHWH UHDFWLRQ KDV D ORZ PROHFXODU ZHLJKW 7DEOH f 1RZ FRQVLGHU WKH SRO\PHUL]DWLRQ RI 0'&6 LQ D PL[WXUH RI WROXHQHGLR[DQH b E\ YROXPHf VFKHPDWLFDOO\ LOOXVWUDWHG LQ )LJXUH Ef $V LQGLFDWHG E\ LQWULQVLF YLVFRVLW\ PHDVXUHPHQWV )LJXUHV DQG f WKH WROXHQH GLR[DQH PL[WXUH LV D SRRUHU VROYHQW IRU 306 FRPSDUHG WR WROXHQH DORQHf +HQFH LW PLJKW EH H[SHFWHG WKDW PRUH SRO\PHU FKDLQV DUH DGVRUEHG RQ WKH 1D SDUWLFOH VXUIDFHV 7KH PRQRPHU PROHFXOHV ZRXOG EH IRUFHG WR GLIIXVH WKURXJK SRO\PHU FKDLQV WR DFFHVV 1D VXUIDFH +HQFH LW LV PRUH OLNHO\ WKDW H[WHQVLRQ RI H[LVWLQJ SRO\PHU FKDLQV ZLOO RFFXU DQG WKDW OHVV FKDLQV ZLOO EH IRUPHG 7KXV SRO\PHUL]DWLRQ RI 0'&6 LQ WKH WROXHQHGLR[DQH PL[WXUH OHDGV WR KLJKHU PROHFXODU ZHLJKW 7DEOH f $ VLPLODU WUHQG ZDV REVHUYHG IRU SRO\PHUL]DWLRQ RI 0'&607&6 PRQRPHUV ZWbf LQ WROXHQH DQG WROXHQHGLR[DQH VROYHQW PL[WXUH

PAGE 248

,F GOJf F JGOf )LJXUH 3ORW RI U?V-F YV F IRU SRO\PHU ) EDWFK 306f 0'&607&6 ZWbf WROXHQHGLR[DQH ff LQ WROXHQH

PAGE 249

,F GOJf F JGOf )LJXUH 3ORW RI U_VSF YV F IRU SRO\PHU ) EDWFK 306f 0'&607&6 f WROXHQHGLR[DQH ff LQ D PL[WXUH RI WROXHQH DQG GLR[DQH YRObf

PAGE 250

3RO\PHUL]DWLRQ LQ WROXHQH 3RO\PHUL]DWLRQ LQ D PL[WXUH E\ YROXPHf RI WROXHQH DQG GLR[DQH Df Ef )LJXUH 6FKHPDWLF LOOXVWUDWLRQ IRU VROYHQW HIIHFWV IRU SRO\PHUL]DWLRQ RI 0'&6 Df LQ WROXHQH DQG Ef LQ D PL[WXUH RI WROXHQHGLR[DQH

PAGE 251

(IIHFW RI V\QWKHVLV FRQGLWLRQV RQ SRO\PHU \LHOG $V GLVFXVVHG HDUOLHU WKH SXUSRVH RI DGGLQJ D WULIXQFWLRQDO PRQRPHU 07&6f WR D GLIXQFWLRQDO PRQRPHU 0'&6f ZDV WR LQFUHDVH WKH GHJUHH RI FURVVOLQNLQJ LQ WKH SRO\PHU $ KLJKHU GHJUHH RI FURVVOLQNLQJ ZLOO UHVXOW LQ LQFUHDVHG FHUDPLF \LHOG ZKLFK LV GHVLUDEOHf +RZHYHU WKH DGGLWLRQ RI 07&6 WR 0'&6 DOVR UHVXOWV LQ D VLJQLILFDQW GHFUHDVH LQ WKH SRO\PHU \LHOG LQ WKH DEVHQFH RI FRVROYHQWV )RU H[DPSOH 7DEOH VKRZV WKDW \LHOG IRU SRO\PHUL]DWLRQ RI 0'&6 LQ WROXHQH ZDV b RI WKHRUHWLFDO \LHOGf ZKHUHDV WKH \LHOG GHFUHDVHG WR b ZKHQ ZWb 07&6 ZDV DGGHG WR 0'&6 ,W LV WKHUHIRUH QHFHVVDU\ WR DGG D SRODU VROYHQW VXFK DV 7+) RU GLR[DQH WR WROXHQH WR LQFUHDVH \LHOG IRU WKH SRO\PHUL]DWLRQ UHDFWLRQ ,W LV ZHOONQRZQ LQ OLWHUDWXUH WKDW SRODU DQG GLSRODU VROYHQWV VXFK DV 7+) DQG GLR[DQHf SURPRWH DQLRQLF SRO\PHUL]DWLRQ DLGLQJ WKH WUDQVIHU RI HOHFWURQV IURP 1D WR WKH PRQRPHUV DQG IDYRULQJ WKH IRUPDWLRQ RI VLO\O DQLRQ UDGLFDOV >01@ >*DX@ff $V VKRZQ LQ )LJXUH DQG 7DEOH ZKHQ D YROb RI 7+) YROb WROXHQH PL[WXUH ZDV XVHG LQ WKH SRO\PHUL]DWLRQ RI 0'&607&6 WKH SRO\PHU \LHOG LQFUHDVHG a WLPHV IURP b WR bf FRPSDUHG WR SRO\PHUL]DWLRQ LQ WROXHQH DORQH 7KH SRO\PHU \LHOG LQFUHDVHG a WLPHV IURP b WR bf ZKHQ D YROb GLR[DQH YROb WROXHQH PL[WXUH ZDV XVHG IRU SRO\PHUL]DWLRQ )LJXUH DQG 7DEOH f 7KH KLJKHU \LHOGV IRU SRO\PHUL]DWLRQ RI 0'&607&6 PL[WXUHV ZLWK WKH DGGLWLRQ RI SRODU VROYHQWV DUH DSSDUHQWO\ DVVRFLDWHG ZLWK D KLJKHU UHDFWLRQ UDWH $V QRWHG HDUOLHU SURORQJHG UHDFWLRQ WLPHV FDQ UHVXOW LQ ORZHU \LHOGV GXH WR WKH ORVV RI 6LFRQWDLQLQJ YRODWLOHVf 7KH FRUUHODWLRQ EHWZHHQ WKH SRO\PHU \LHOG DQG WKH UHDFWLRQ UDWH LV VXJJHVWHG IURP REVHUYDWLRQV RI FRORU FKDQJHV WKDW RFFXUUHG GXULQJ WKH UHDFWLRQV $V GLVFXVVHG LQ VHFWLRQ WKHUH LV D FKDQJH LQ FRORU WR SXUSOHf GXULQJ :XUW]FRXSOLQJ

PAGE 252

32/<0(5 <,(/' bf 7ROXHQH ( 7ROXHQH7+) 9RO bf ) 7ROXHQH'LR[DQH 9RO bf ( ) 32/<0(5 %$7&+ )LJXUH (IIHFW RI FRVROYHQWV RQ \LHOG IRU 306 SRO\PHUV '( DQG ) SUHSDUHG IURP 0'&607&6 ZWbff

PAGE 253

SRO\PHUL]DWLRQ UHDFWLRQVr ,Q WKLV VWXG\ WKH SXUSOH FRORU DSSHDUHG LQ a a DQG PLQXWHV IRU SRO\PHUL]DWLRQ RI 0'&607&6 ZW UDWLRf LQ WROXHQHGLR[DQH YRO UDWLRf WROXHQH7+) YRO UDWLRf DQG WROXHQH UHVSHFWLYHO\ 1RWH WKDW WKLV FRUUHODWHV ZLWK GHFUHDVLQJ \LHOGV RI DQG b UHVSHFWLYHO\f ,W ZDV DOVR REVHUYHG WKDW WKH UHDFWLRQ ZDV HVVHQWLDOO\ FRPSOHWH LH DV LQGLFDWHG E\ WKH DFLGLW\ WHVW GHVFULEHG HDUOLHUf LQ K IRU WKH SRO\PHUL]DWLRQ FDUULHG RXW LQ WROXHQHGLR[DQH YRO UDWLRf ZKLOH K ZDV UHTXLUHG IRU WKH SRO\PHUL]DWLRQ FDUULHG RXW LQ WROXHQH DORQH ,Q FRQWUDVW WR WKH UHVXOWV GLVFXVVHG DERYH WKHUH ZDV D QHJOLJLEOH HIIHFW RI WKH VROYHQW RQ WKH SRO\PHU \LHOG ZKHQ WKH SRO\PHUL]DWLRQ UHDFWLRQV ZHUH FDUULHG RXW XVLQJ 0'&6 DORQH VHH )LJXUH DQG 7DEOH f 7KLV DSSDUHQWO\ UHIOHFWV WKH KLJK UHDFWLRQ UDWH IRU SRO\PHUL]DWLRQV FDUULHG RXW ZLWK 0'&6 LH UHJDUGOHVV RI WKH VROYHQWf 7KH SXUSOH FRORU DSSHDUHG LQ a PLQ ZLWK HDFK W\SH RI VROYHQW XVHG LQ WKH SRO\PHUL]DWLRQ 7KH UHODWLYHO\ KLJK UHDFWLRQ UDWHV DUH DJDLQ FRQVLVWHQW ZLWK WKH UHODWLYHO\ KLJK SRO\PHU \LHOGV LH b IRU SRO\PHUV $ % DQG & SUHSDUHG ZLWK 0'&6 DORQHf 7R IXUWKHU FRQILUP WKH DERYH WUHQGV D SRO\PHUL]DWLRQ UHDFWLRQ ZDV FDUULHG RXW XVLQJ D PL[WXUH RI ZWb 07&6 DQG ZWb 0'&6 LQ WROXHQH $V H[SHFWHG WKH UHDFWLRQ RFFXUUHG PRUH VORZO\ DQG WKH SRO\PHU \LHOG GHFUHDVHG ZLWK WKH KLJKHU SURSRUWLRQ RI 07&6 7KH SXUSOH FRORU FKDQJH GLG QRW RFFXU XQWLO K DIWHU WKH VWDUW RI WKH UHDFWLRQ LH FRPSDUHG WR DQG PLQXWHV IRU WKH SRO\PHUL]DWLRQV FDUULHG RXW XVLQJ ZWb 07&6 ZWb 0'&6 LQ WROXHQH DQG b 0'&6 LQ WROXHQH UHVSHFWLYHO\f 7KH SRO\PHU \LHOG ZDV RQO\ b LH FRPSDUHG WR b DQG b IRU WKH SRO\PHUL]DWLRQV r ,W LV ZHOONQRZQ LQ :XUW]FRXSOLQJ SRO\PHUL]DWLRQ WKDW D FRORU FKDQJH WR SXUSOH LQGLFDWHV VLJQLILFDQW SRO\PHUL]DWLRQ >%HQ@ >=HL$@ >0,@ >0,@f 0LOOHU HW DO >0,@ UHSRUWHG WKDW LQ WKH FDVH RI :XUW] FRXSOLQJ SRO\PHUL]DWLRQ RI DU\OGLFKORURVLODQHV WKH SXUSOH FRORU DSSHDUHG ZLWKLQ a PLQ RI PRQRPHU DGGLWLRQ WR 1D DW ZKLFK SRLQW b RI PRQRPHU ZDV FRQVXPHG

PAGE 254

32/<0(5 <,(/' bf $%& 32/<0(5 %$7&+ $ 7ROXHQH % 7ROXHQH7+) 9RO bf & 7ROXHQH'LR[DQH 9RO bf )LJXUH (IIHFW RI FRVROYHQWV RQ SRO\PHU \LHOG IRU 306 SRO\PHUV $% DQG & SUHSDUHG IURP b 0'&6f

PAGE 255

FDUULHG RXW XVLQJ ZWb 07&6 ZWb 0'&6 LQ WROXHQH DQG b 0'&6 LQ WROXHQH UHVSHFWLYHO\f &KDUDFWHUL]DWLRQ RI 306 SRO\PHUV DQG FHUDPLF UHVLGXHV UHVXOWLQJ IURP S\URO\VLV :HLJKW ORVV EHKDYLRU 7KH ZHLJKW ORVV EHKDYLRU RI 306 SRO\PHUV $) ZHUH VWXGLHG E\ 7KHUPDO *UDYLPHWULF $QDO\VLV 7*$f 7KH GDWD RQ FHUDPLF \LHOG DUH SUHVHQWHG LQ 7DEOH )LJXUH VKRZV 7*$ SORWV IRU SRO\PHUV SUHSDUHG E\ SRO\PHUL]DWLRQ RI 0'&6 LQ WROXHQH SRO\PHU $f WROXHQH7+) YRObf SRO\PHU %f DQG WROXHQH GLR[DQH YRObf SRO\PHU &f 7KH XVH RI FRVROYHQWV 7+) DQG GLR[DQHf UHVXOWHG LQ SRO\PHUV ZLWK VOLJKWO\ KLJKHU FHUDPLF \LHOGV :RRG >:@ DOVR UHSRUWHG D EHQHILFLDO HIIHFW RQ FHUDPLF \LHOG ZKHQ XVLQJ D SRODU VROYHQW LQ :XUW]FRXSOLQJ SRO\PHUL]DWLRQ :KHQ SRO\PHUL]DWLRQ ZDV FDUULHG RXW LQ D PL[WXUH RI KH[DQH DQG 7+) E\ YROXPHf WKH FHUDPLF \LHOG ZDV RQO\ a ZWb +RZHYHU ZKHQ SRO\PHUL]DWLRQ ZDV FDUULHG RXW HQWLUHO\ LQ 7+) WKH UHVXOWDQW SRO\PHU KDG D FHUDPLF \LHOG RI ZWb 7KH LQFUHDVH LQ FHUDPLF \LHOG IRU SRO\PHUV V\QWKHVL]HG LQ SRODU VROYHQWV FDQ EH OLQNHG WR WKH LQFUHDVH LQ PROHFXODU ZHLJKW DQG SUHVXPDEO\ DQ LQFUHDVHG GHJUHH RI SRO\PHU FURVVOLQNLQJf )LJXUH VKRZV 7*$ SORWV IRU SRO\PHUV SUHSDUHG E\ SRO\PHUL]DWLRQ RI 0'&607&6 ZWbf LQ WKH SUHVHQFH RI WROXHQH SRO\PHU 'f WROXHQH7+) YRObf SRO\PHU (f DQG WROXHQH GLR[DQH YRObf SRO\PHU )f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

PAGE 256

b :(,*+7 )LJXUH 7*$ SORWV b ZHLJKW YV WHPSHUDWXUHf IRU SRO\PHUV SUHSDUHG ZLWK b 0'&6 7KH VROYHQWV XVHG LQ SRO\PHUL]DWLRQ ZHUH WROXHQH SRO\PHU $ EDWFK 306f WROXHQH7+) YRO UDWLRf SRO\PHU % EDWFK 306f DQG WROXHQHGLR[DQH YRO UDWLRf SRO\PHU & EDWFK 306f

PAGE 257

b :(,*+7 )LJXUH 7*$ SORWV b ZHLJKW YV WHPSHUDWXUHf IRU SRO\PHUV SUHSDUHG ZLWK ZWb 0'&607&6 7KH VROYHQWV XVHG LQ SRO\PHUL]DWLRQ ZHUH WROXHQH SRO\PHU EDWFK 306f WROXHQH7+) YRO UDWLRf SRO\PHU ( EDWFK 306f DQG WROXHQHGLR[DQH YRO UDWLRf SRO\PHU ) EDWFK 306f

PAGE 258

RI WKH PRUH SRODU VROYHQWV 7KLV LV DOVR VXJJHVWHG E\ WKH IDFW WKDW WKH FHUDPLF \LHOGV DUH DOO KLJKHU IRU WKH SRO\PHUV SUHSDUHG IURP WKH 0'&607&6 PL[WXUHV LH FRPSDUHG WR WKH SRO\PHUV SUHSDUHG ZLWK 0'&6 DORQHf )LJXUH VKRZV WKDW SRO\PHU & KDV DQ DEUXSW ZHLJKW ORVV RI a ZWb VWDUWLQJ DW r& 3RO\PHU % VKRZV D ZHLJKW ORVV RI DERXW b VWDUWLQJ DW r& $ VLPLODU a ZWbf KLJK WHPSHUDWXUH ZHLJKW ORVV ZDV REVHUYHG E\ =KDQJ HW DO >=KD@ GXULQJ 7*$ DQDO\VLV RI 306 SRO\PHUV ,W LV VXJJHVWHG WKDW WKHVH KLJK WHPSHUDWXUH ZHLJKW ORVVHV DUH DWWULEXWHG WR WKH HYROXWLRQ RI K\GURJHQ DULVLQJ IURP WKH GHFRPSRVLWLRQ RI 6L+f FRQWDLQLQJ VWUXFWXUHV ,W LV QRWHG WKDW WKLV W\SH RI KLJK WHPSHUDWXUH ZHLJKW ORVV ZDV QRW REVHUYHG GXULQJ WKH KHDW WUHDWPHQW RI SRO\PHUV SUHSDUHG IURP 0'&607&6 PL[WXUHV )LJXUH f 7KLV LV FRQVLVWHQW ZLWK WKH H[SHFWDWLRQ WKDW OHVV 6L+ JURXSV DUH UHWDLQHG LQ WKHVH SRO\PHUV VLQFH WKHVH JURXSV DUH OLNHO\ WR EH FRQVXPHG GXULQJ FURVVOLQNLQJ UHDFWLRQV SURPRWHG E\ WKH XVH RI WKH WULIXQFWLRQDO PRQRPHU 07&6 )7,5 VSHFWURVFRS\ VWXGLHV RQ 306 SRO\PHUV )7,5 VSHFWUD RQ 306 SRO\PHUV & EDWFK 306f DQG ) EDWFK 306f SRO\PHUV V\QWKHVL]HG IURP 0'&6 DQG 0'&607&6 LQ ZW UDWLRf UHVSHFWLYHO\ LQ WROXHQHGLR[DQH VROYHQWf ZHUH FROOHFWHG LQ WKH GLIIXVH UHIOHFWDQFH PRGH DW URRP WHPSHUDWXUH DQG GXULQJ KHDW WUHDWPHQW IURP r& LQ QLWURJHQ DWPRVSKHUH )LJXUH DQG VKRZ WKH URRP WHPSHUDWXUH VSHFWUD RI SRO\PHUV 306& DQG 306) UHVSHFWLYHO\ 7KH SHDN DVVLJQPHQWV IRU WKHVH SRO\PHUV DUH VKRZQ LQ 7DEOH DQG 7DEOH 3RO\PHU & SUHSDUHG IURP 0'&6f PD\ EH ULFKHU LQ 6L+ JURXSV FRPSDUHG WR SRO\PHU 306) SUHSDUHG IURP PL[WXUH RI 0'&607&6f 7KLV LV VXJJHVWHG IURP WKH VSOLWWLQJ RI WKH 6L+ DEVRUSWLRQ LQWR WKH DV\PPHWULF VWUHWFKLQJ SHDN DW FPnf DQG V\PPHWULF VWUHWFKLQJ SHDN DW FPnf $V QRWHG HDUOLHU LW LV EHOLHYHG WKDW WKH KLJK WHPSHUDWXUH DERYH r&f ZHLJKW ORVVHV LQ WKH SRO\PHUV % DQG & SUHSDUHG IURP

PAGE 259

,17(16,7< .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI 306 SRO\PHU & EDWFK 306f SUHSDUHG IURP b 0'&6 LQ WROXHQHGLR[DQH VROYHQWf

PAGE 260

,17(16,7< .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH 5RRP WHPSHUDWXUH )7,5 VSHFWUD RI 306 SRO\PHU ) EDWFK 306f SUHSDUHG IURP ZWb 0'&607&6 LQ WROXHQHGLR[DQH VROYHQWf

PAGE 261

7DEOH )7,5 SHDN DVVLJQPHQWV IRU SRO\PHWK\OVLODQH 306f SRO\PHU 306& EDWFK 306f 3HDN FPnf $VVLTQPHQW 5HIHUHQFHV YDV &+f IURP 6L&+ YV &+f IURP 6L&+ YV &+f IURP 6L&+ YDV 6L+f YV 6L+f DV &+f IURP 6L&+ 6 &+f IURP 6L&+ Y 6L26Lf Y 6L2&f 3DV &+f IURP 6L &+ 3V &+f IURP 6L &+ Y VWUHWFKLQJ EHQGLQJ S URFNLQJ f : .ULQHU 2UJ &KHP f f $/ 6PLWK &KHP 3K\V f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f 50 6LOYHUVWHLQ *& %DVVOHU DQG 7& 0RUULOO 6SHFWURVFRSLF ,GHQWLILFDWLRQ RI 2UJDQLF &RPSRXQGV -RKQ :LOH\ 1HZ
PAGE 262

7DEOH )7,5 SHDN DVVLJQPHQWV IRU SRO\PHWK\OVLODQH 306f SRO\PHU 306) EDWFK 306f 3HDN FPnf $VVLTQPHQW 5HIHUHQFHV YDV &+f IURP 6L&+ YV &+f IURP 6L&+ YV &+f IURP 6L&+ YV 6L+f 6DV &+f IURP 6L&+ 6 &+f IURP 6L&+ Y 6L26Lf Y 6L2&f 6L+f 3DV &+f IURP 6L &+ 3V &+f IURP 6L &+ YV 6L&f Y VWUHWFKLQJ EHQGLQJ S URFNLQJ f : .ULQHU 2UJ &KHP f f $/ 6PLWK &KHP 3K\V f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f $/ 6PLWK 6SHFWURFKLPLFD $FWD f f 50 6LOYHUVWHLQ *& %DVVOHU DQG 7& 0RUULOO 6SHFWURVFRSLF ,GHQWLILFDWLRQ RI 2UJDQLF &RPSRXQGV -RKQ :LOH\ 1HZ
PAGE 263

0'&6 UHIOHFWV KLJKHU 6L+ FRQWHQWVf 7KH )7,5 VSHFWUXP IRU SRO\PHUV & DQG ) VKRZ DQ DEVRUSWLRQ EDQG LQ WKH UDQJH RI FPn 7KLV DEVRUSWLRQ LV DWWULEXWHG WR 6L 26L DQG 6L2& EDQGV DULVLQJ IURP R[\JHQ FRQWDPLQDWLRQ HJ GXULQJ SRO\PHU V\QWKHVLV )7,5 VDPSOH SUHSDUDWLRQ HWFf 7KH DEVRUSWLRQ LV FRQVLGHUDEO\ PRUH LQWHQVH UHODWLYH WR WKH RWKHU SHDNVf LQ SRO\PHU & 7KLV LV DWWULEXWHG WR D JUHDWHU DPRXQW RI UHDFWLYH 6L+ JURXSV 7KLV LV FRQVLVWHQW ZLWK WKH HDUOLHU VXJJHVWLRQ EDVHG RQ WKH 7*$ UHVXOWV LQ VHFWLRQ WKDW WKH 0'&6GHULYHG SRO\PHUV KDYH PRUH UHVLGXDO 6L+ JURXSV FRPSDUHG WR WKH SRO\PHUV SUHSDUHG IURP 0'&607&6 PL[WXUHVf )LJXUH VKRZV WKH )7,5 VSHFWUD IRU SRO\PHU 306& GXULQJ KHDW WUHDWPHQW IURP WR r& LQ QLWURJHQ DWPRVSKHUH DW r&PLQ 7KH FKDQJHV LQ LQWHQVLWLHV RI YDULRXV DEVRUSWLRQ EDQGV DV D IXQFWLRQ RI WHPSHUDWXUH DUH VKRZQ LQ )LJXUH 1R VLJQLILFDQW FKDQJHV LQ LQWHQVLWLHV IRU DEVRUSWLRQ EDQGV DUH REVHUYHG IRU DOO JURXSV XS WR ar& 7KH LQWHQVLW\ RI DEVRUSWLRQ EDQG DW FPn GXH WR V\PPHWULF VWUHWFK YLEUDWLRQ RI 6L+f LQFUHDVHV VWDUWLQJ DW r& UHDFKHV D PD[LPXP DURXQG r& DQG WKHQ GHFUHDVHV 7KLV LV SRVVLEO\ GXH WR WKH IRUPDWLRQ RI DGGLWLRQDO 6L+ JURXSV DV D UHVXOW RI PHWK\OHQH LQVHUWLRQ UHDFWLRQV 6FKPLGW HW DO >6FK@ KDYH DOVR UHSRUWHG VLPLODU LQFUHDVHV LQ 6L+ DEVRUSWLRQ LQWHQVLWLHV EHWZHHQ r& GXULQJ WKH S\URO\WLF FRQYHUVLRQ RI YLQ\OLF SRO\VLODQH WR VLOLFRQ FDUELGH DQG KDYH VXJJHVWHG WKH PHWK\OHQH LQVHUWLRQ UHDFWLRQ DV WKH PHFKDQLVP IRU WKH LQFUHDVH LQ LQWHQVLW\ RI DEVRUSWLRQ EDQG 7KH PHWK\OHQH LQVHUWLRQ UHDFWLRQ RFFXUULQJ LQ 306 LH FRQYHUVLRQ WR D SRO\FDUERVLODQH VWUXFWXUHf FDQ EH UHSUHVHQWHG DV VKRZQ LQ HTXDWLRQ f $FFRPSDQ\LQJ WKH LQFUHDVH LQ WKH LQWHQVLW\ RI 6L+ DEVRUSWLRQ EDQG LV WKH RQVHW RI DEVRUSWLRQ EDQG GXH WR 6 &+f RI 6L&+6L FPnf DW ar& ZKLFK FRUUHVSRQGV WR WKH LQVHUWLRQ RI &+ JURXSV LQ WKH PDLQ 6L6L FKDLQ 7KLV ZDV DOVR UHSRUWHG E\ =KDQJ HW DO >=KD@ LQ WKH S\URO\WLF FRQYHUVLRQ RI 306 SUHSDUHG E\

PAGE 264

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPf )LJXUH )7,5 VSHFWUD RI 306 SRO\PHU & b 0'&6 WROXHQH GLR[DQH YRObff r& WR r& DW r&PLQ LQ QLWURJHQ

PAGE 265

:$9(180%(5 FPnf $%625%$1&( .XEHOND0XQN 8QLWVf

PAGE 266

,QWHQVLW\ .XEHOND0XQN 8QLWVf )LJXUH ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD IRU 306 SRO\PHU & b 0'&6 WROXHQH GLR[DQH YRObff

PAGE 267

,QWHQVLW\ .XEHOND0XQN 8QLWVf $ 3DV&+! RI 6c&+ > FPn@ 3V&+f RI 6L&+ > FPn@ V&+fRI6L&+ > FPn@ ‘$f§ Y 6L26Lf Y 6L2&f > FPn@ ‘f§ &+f RI 6L&+6L > FPn@ 7HPSHUDWXUH r&f )LJXUH &RQWnGf

PAGE 268

GHK\GURFRXSOLQJ RI PHWK\OVLODQHf WR VLOLFRQ FDUELGH DW r& :KLOH WKHVH FKDQJHV FDQ EH DWWULEXWHG WR IRUPDWLRQ RI D 3&6W\SH EDFNERQH IURP 306 GXULQJ S\URO\VLV LW LV XQFOHDU ZK\ WKH DEVRUSWLRQ LQWHQVLWLHV GXH WR WKH V\PPHWULF SV &+f YLEUDWLRQ RI 6L&+ DW FPn DV\PPHWULF SDV &+f YLEUDWLRQ RI 6L&+ DW FPn DQG V\PPHWULF VWUHWFK RI &+ RI 6L&+ DW FPn ILUVW LQFUHDVH IURP EHORZ r& WR DW OHDVW r&f DQG WKHQ GHFUHDVH DW KLJKHU WHPSHUDWXUHV &+&M+&M+ &+ &+ &+ &+ 6L6L6L6L f§f§ 6L 6L +6L6L ,,, ,, ,, + + + + + + + $ + 6L 6L a &+S , + + &+R &+R , 6L 6L , + + f 7KH LQWHQVLWLHV RI PRVW RI WKH RULJLQDO DEVRUSWLRQ EDQGV IURP 306& KDYH GHFUHDVHG E\ r& %\ r& WKH ZHOOGHILQHG SHDNV RULJLQDOO\ DVVRFLDWHG ZLWK WKH RUJDQRVLOLFRQ SRO\PHU KDYH PRVWO\ GLVDSSHDUHG OHDYLQJ EURDG SHDNV DVVRFLDWHG ZLWK & + VWUHWFKLQJ FPnf 6L+ VWUHWFKLQJ FPnf DQG 6L& FPnf VHH )LJXUH f $IWHU KHDW WUHDWPHQW DW r& WKH RQO\ UHPDLQLQJ SHDNV DUH WKRVH DVVRFLDWHG ZLWK S6L& 7KHVH SHDNV DUH DW FPn Y 6L&f DQG FPn XQLGHQWLILHG YLEUDWLRQ PRGHf >*UH )HQ +DQ =KD%@ )LJXUH VKRZV )7,5 VSHFWUD RI SRO\PHU 306) FROOHFWHG GXULQJ KHDW WUHDWPHQW IURP r& LQ QLWURJHQ DWPRVSKHUH DW r&PLQ 7KH FKDQJHV LQ LQWHQVLWLHV RI YDULRXV DEVRUSWLRQ EDQGV DV D IXQFWLRQ RI WHPSHUDWXUH DUH VKRZQ LQ )LJXUH

PAGE 269

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH )7,5 VSHFWUD RI 306 SRO\PHU & b 0'&6 WROXHQH GLR[DQH YRObffr& WR r& DW r&PLQ LQ QLWURJHQ

PAGE 270

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH )7,5 VSHFWUD RI 306 SRO\PHU ) 0'&607&6 ZWbff WROXHQH GLR[DQH YRObf r& WR r& DW r&PLQ LQ QLWURJHQ

PAGE 271

:$9(180%(5 FPnf $%625%$1&( .XEHOND0XQN 8QLWVf 4 & f§L ER 2 R

PAGE 272

,QWHQVLW\ .XEHOND0XQN 8QLWVf 7HPSHUDWXUH r&f )LJXUH ,QWHQVLW\ YV WHPSHUDWXUH IURP )7,5 VSHFWUD RI 306 SRO\PHU ) 0'&6 07&6 ZWbf WROXHQH GLR[DQH YRObff

PAGE 273

,QWHQVLW\ .XEHOND0XQN 8QLWVf )LJXUH &RQWnGf

PAGE 274

8QOLNH SRO\PHU 306& ZKHUH QR VLJQLILFDQW FKDQJHV ZHUH REVHUYHG IRU PRVW RI WKH DEVRUSWLRQ EDQGV XS WR r& SRO\PHU 306) VKRZHG FKDQJHV HDUO\ RQ LQ WKH KHDW WUHDWPHQW 7KH LQWHQVLW\ GXH WR WKH VWUHWFKLQJ YLEUDWLRQ RI 6L+ DW FPnf LQFUHDVHG IURP r& UHDFKHG D PD[LPXP DW DURXQG r& DQG WKHQ VWDUWHG WR GHFUHDVH 7KLV LQFUHDVH LV DJDLQ DWWULEXWHG WR PHWK\OHQH LQVHUWLRQ UHDFWLRQ VKRZQ LQ HTXDWLRQ f 7KLV ZDV DOVR VXJJHVWHG E\ WKH RQVHW RI WKH DEVRUSWLRQ EDQG GXH WR iV &+f RI 6L&+6L DW ar& ZKLFK FRUUHVSRQGV WR WKH LQVHUWLRQ RI &+ JURXSV LQ WKH PDLQ 6L6L FKDLQ +RZHYHU VRPH UHVXOWV DUH LQFRQVLVWHQW ZLWK WKH K\SRWKHVLV WKDW PHWK\OHQH LQVHUWLRQ UHDFWLRQ RFFXUV )LUVW WKH LQFUHDVH LQ WKH Y 6L+f YLEUDWLRQ LV FRQVLGHUDEO\ JUHDWHU WKDQ WKH LQFUHDVH LQ WKH 6 &+f YLEUDWLRQ DQG WKH LQFUHDVH RFFXUV DW PXFK ORZHU WHPSHUDWXUH 6HFRQG WKH LQWHQVLWLHV GXH WR V\PPHWULF SV &+f YLEUDWLRQ RI 6L&+ DW FPn DV\PPHWULF SDV &+f YLEUDWLRQ RI 6L&+ DW FPn DQG V\PPHWULF VWUHWFK RI &+ RI 6L&+ DW FQU LQFUHDVH VWDUWLQJ DW UHODWLYHO\ ORZ WHPSHUDWXUHV DQG LQFUHDVLQJ XS WR ar& 7KH )7,5 VSHFWUD DIWHU KHDW WUHDWPHQW RI 306) DW WHPSHUDWXUHV LQ WKH UDQJH RI r& DUH VLPLODU WR WKRVH REVHUYHG LQ 306& VHH )LJXUH f $ERYH r& WKH LQWHQVLW\ RI DEVRUSWLRQ EDQG GXH WR VWUHWFKLQJ YLEUDWLRQ RI 6L& DW FPnf LV EURDGHU FRPSDUHG WR WKDW RI SRO\PHU 306& 7KLV PD\ EH GXH WR D OHVVHU GHJUHH RI FU\VWDOOL]DWLRQ IRU WKH 6L& IRUPHG IURP SRO\PHU 306) 7KLV LV VXJJHVWHG E\ ;5' UHVXOWV IRU KHDWWUHDWHG 306) DQG 306& VDPSOHV DV GLVFXVVHG EHORZ LQ VHFWLRQ f ;5' FKDUDFWHULVWLFV )LJXUHV DQG VKRZ UHSUHVHQWDWLYH ;5' SDWWHUQV RI WKH UHVLGXHV REWDLQHG IURP YDULRXV 0'&6GHULYHG DQG 0'&607&6GHULYHG SRO\PHUV DIWHU KHDW

PAGE 275

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPf )LJXUH )7,5 VSHFWUD RI 306 SRO\PHU ) 0'&6 07&6 ZWbff WROXHQH GLR[DQH YRObf r& WR r& DW r&PLQ LQ QLWURJHQ

PAGE 276

,17(16,7< FSVf ,17(16,7< FSVf ,17(16,7< FSVf )LJXUH ;5' 3DWWHUQV IRU 306 SRO\PHUV SUHSDUHG IURP PRQRPHU 0'&6 $f b WROXHQH %f WROXHQH7+) 9RObf &f WROXHQHGLR[DQH 9RObf

PAGE 277

,17(16,7< FSVf ,17(16,7< FSVf ,17(16,7< FSVf 'HJUHHVf )LJXUH ;5' 3DWWHUQV IRU 306 SRO\PHUV SUHSDUHG IURP PRQRPHUV 0'&607&6 ZWbf $f b WROXHQH %f WROXHQH7+) 9RObf &f WROXHQH GLR[DQH 9RObf

PAGE 278

WUHDWPHQW DW r&PLQ WR r& QR KROG WLPHf LQ DUJRQ 7KH GVSDFLQJV %UDJJ DQJOHV DQG WKH FRUUHVSRQGLQJ LQWHQVLWLHV RI GLIIUDFWLRQ SODQHV DUH VKRZQ LQ 7DEOH 7KH ;5' SDWWHUQV ZHUH HVVHQWLDOO\ WKH VDPH IRU DOO VDPSOHV 7KH PDMRU SKDVH LQ WKHVH VDPSOHV LV 6L& 6LOLFRQ LV SUHVHQW DV D PLQRU SKDVH 7KH S\URO\WLF GHFRPSRVLWLRQ RI 306 SRO\PHUV WR D 6L&6L PL[WXUH ZDV UHSRUWHG E\ VHYHUDO SUHYLRXV ZRUNHUV >6H\ =KD$@ 7KH FU\VWDOOLWH VL]HV IRU WKH 6L DQG 6L& SKDVHV ZHUH GHWHUPLQHG E\ WKH OLQH EURDGHQLQJ PHWKRG XVLQJ 6FKHPHUfV IRUPXOD GHVFULEHG LQ VHFWLRQ f DQG WKH UHVXOWV DUH WDEXODWHG LQ 7DEOH 7KH 6L& FU\VWDOOLWH VL]HV DUH YLUWXDOO\ WKH VDPH LQ WKH UDQJH RI QPf IRU DOO VDPSOHV 7KH 6L FU\VWDOOLWH VL]HV DUH VOLJKWO\ VPDOOHU IRU WKH VDPSOHV SUHSDUHG IURP WKH 0'&607&6 SRO\PHUV LH FRPSDUHG WR WKH VDPSOHV SUHSDUHG IURP 0'&6 DORQHf +RZHYHU WKH GLIIHUHQFHV DUH QRW SDUWLFXODUO\ VLJQLILFDQW JLYHQ WKH UDQJH RI H[SHULPHQWDO YDULDELOLW\ REVHUYHG ZKHQ PXOWLSOH VDPSOHV ZHUH DQDO\]HG (0$ DQDO\VLV 7DEOH VKRZV UHVXOWV RI (OHFWURQ 0LFURSUREH $QDO\VLV (0$f IRU VDPSOHV REWDLQHG DIWHU S\URO\VLV RI 306 SRO\PHUV DW r& LQ QLWURJHQ 5HVXOWV DUH VKRZQ IRU VDPSOHV SUHSDUHG IURP SRO\PHU 306$ DQ DVV\QWKHVL]HG EDWFK RI SRO\PHU )f DQG SRO\PHU 306) D KLJKHU PROHFXODU ZHLJKW SRUWLRQ RI 306$ SUHSDUHG E\ IUDFWLRQDO SUHFLSLWDWLRQ VHH VHFWLRQ f 7KH IRUPHU VDPSOH VKRZHG D 6LULFK FRPSRVLWLRQ FRPSDUHG WR WKDW RI VWRLFKLRPHWULF 6L& 6WRLFKLRPHWULF 6L& KDV D FRPSRVLWLRQ RI ZWb 6L ZWb &f 306 SRO\PHUV ZLWK 6LULFK FRPSRVLWLRQ KDYH EHHQ UHSRUWHG SUHYLRXVO\ E\ RWKHU UHVHDUFKHUV >6H\ =KD$ =KD%@ 7KH UHVXOW LQ WKLV VWXG\ LV DOVR FRQVLVWHQW ZLWK WKH REVHUYDWLRQ RI IUHH 6L LQ WKH ;5' SDWWHUQ IRU D VLPLODU 306 VDPSOH SRO\PHU ) EDWFK 306f ZKLFK ZDV S\URO\]HG DW r& LQ DUJRQf DV VKRZQ LQ )LJXUH

PAGE 279

7DEOH GVSDFLQJV DQG %UDJJ DQJOHV 6L VWUXFWXUH GLDPRQG FXELFf GVSDFLQJ $ GHJUHHV ,QWHQVLW\ K N LQGH[ S6L& VWUXFWXUH VLPSOH FXELFf GVSDFLQJ $ GHJUHHV ,QWHQVLW\ K N LQGH[ D -&3'6 &DUG ,QWHUQDWLRQDO 'LIIUDFWLRQ &RPPLWWHH 6ZDUWKPRUH 3$ f E-&3'6 &DUG ,QWHUQDWLRQDO 'LIIUDFWLRQ &RPPLWWHH 6ZDUWKPRUH 3$ f

PAGE 280

7DEOH &U\VWDOOLWH VL]HV IRU 6L DQG 6L& FDOFXODWHG E\ 6FKHUUHUfV IRUPXOD IRU YDULRXV SRO\PHUV S\URO\]HG DW r& LQ QLWURJHQ DW r&PLQ ZLWK QR KROG 3RO\PHU 0RQRPHUVf 6ROYHQWVVf 6L FU\VWDOOLWH VL]H QPf 6L& FU\VWDOOLWH VL]H QPf $ 0'&6 7ROXHQH % 0'&6 7ROXHQH7+) f & 0'&6 7ROXHQH'LR[DQH f s EDWFKHVf s EDWFKHVf 0'&607&6 f 7ROXHQH ( 0'&607&6 7ROXHQH7+) s s f f EDWFKHVf EDWFKHVf ) 0'&607&6 f 7ROXHQH'LR[DQH f

PAGE 281

7DEOH 5HVXOWV RI (OHFWURQ 0LFURSUREH $QDO\VLV (0$f RQ S\URO\]HG FHUDPLF IURP 306 SRO\PHUV %DWFK 6DPSOH GHVFULSWLRQ RI SRLQWV DQDO\]HG (OHPHQWDO FRPSRVLWLRQ $VPHDVXUHG 1RUPDOL]HG 6L b &b b 7RWDOb 6Lb &b b 306 $ $V SUHSDUHG WKHQ S\URO\]HG WR r& LQ 1 s s s s s s s 306 ) )UDFWLRQDWHG LQ DFHWRQH WKHQ S\URO\]HG WR r& LQ 1 s s s s s s s 306 $ 2[LGL]HG LQ VWDWLF DLU WKHQ S\URO\]HG WR r& LQ 1 s s s s s s s

PAGE 282

7KH VDPSOH SUHSDUHG IURP 306) SRO\PHU VKRZHG D FRPSRVLWLRQ FORVH WR WKDW RI VWRLFKLRPHWULF 6L& 7KLV VXJJHVWV WKDW WKH KLJKHU PROHFXODU ZHLJKW DQG SUHVXPDEO\ PRUH FURVVOLQNHGf SRUWLRQV RI WKH 306 SRO\PHUV HLWKHU DUH FRPSRVLWLRQDOO\ GLIIHUHQW LH KDYH ORZHU 6L& UDWLRf RU KDYH GLIIHUHQW S\URO\VLV EHKDYLRU LH ZKLFK OHDGV WR WKH ORZHU 6L& UDWLRf FRPSDUHG WR WKH ORZHU PROHFXODU ZHLJKW SRUWLRQV LQ WKH DV V\QWKHVL]HG 306 SRO\PHUV 7KH R[\JHQ SUHVHQW LQ WKH VDPSOH SUHSDUHG IURP WKH 306$ SRO\PHU LV SUHVXPDEO\ GXH WR FRQWDPLQDWLRQ E\ H[SRVXUH WR DLU GXULQJ KDQGOLQJ 7KLV PD\ KDYH RFFXUUHG ZKHQ WKH DVSUHSDUHG SRO\PHU ZDV LQLWLDOO\ FRQFHQWUDWHG DQG UHFRYHUHG DIWHU WKH :XUW]FRXSOLQJ SRO\PHUL]DWLRQ UHDFWLRQ LH SULRU WR VWRUDJH DV D GLOXWH VROXWLRQ LQ WROXHQHf +RZHYHU WKLV VHHPV XQOLNHO\ VLQFH 306) ZDV SUHSDUHG IURP 306 $ DQG \HW WKH S\URO\]HG VDPSOH IURP 306) VKRZHG YHU\ OLWWOH R[\JHQ FRQWDPLQDWLRQ $QRWKHU SRVVLELOLW\ LV WKDW WKH R[\JHQ FRQWDPLQDWLRQ UHVXOWHG IURP H[SRVXUH WR DLU ZKHQ WKH 306$ VDPSOH ZDV UHPRYHG IURP WKH GLOXWH VWRUDJH VROXWLRQf GULHG DQG WUDQVIHUUHG WR WKH S\URO\VLV IXUQDFH 6HQVLWLYLW\ RI 306 SRO\PHUV WR R[\JHQ FRQWDPLQDWLRQ ,W LV ZHOO NQRZQ WKDW 306 SRO\PHUV DUH VHQVLWLYH WR FRQWDPLQDWLRQ IURP H[SRVXUH WR R[\JHQ DQG ZDWHU YDSRU >=KD% :RR 4LX$ $EX@ 7KLV ZDV REVHUYHG IRU 306 SRO\PHUV SUHSDUHG LQ WKLV VWXG\ )LJXUH VKRZV )7,5 VSHFWUD DV D IXQFWLRQ RI WLPH IRU SRO\PHU 306& SUHSDUHG IURP 0'&6 LQ WROXHQHGLR[DQHf ZKLFK ZDV H[SRVHG WR DLU DW URRP WHPSHUDWXUH )LJXUH VKRZV SORWV RI LQWHQVLW\ YV WLPH IRU YDULRXV DEVRUSWLRQ SHDNV ,W LV HYLGHQW WKDW VXEVWDQWLDO R[\JHQ FRQWDPLQDWLRQ RFFXUUHG ZLWKLQ WKH ILUVW KRXU RI DLU H[SRVXUH $ VXEVWDQWLDO LQFUHDVH LQ LQWHQVLW\ LV REVHUYHG IRU WKH 6L2+ VWUHWFKLQJ YLEUDWLRQ a FPnf 7KLV FRUUHODWHV ZLWK WKH GLVDSSHDUDQFH RI DV\PPHWULF 6L+ VWUHWFKLQJ YLEUDWLRQ DW FPn 7KH V\PPHWULF 6L+ VWUHWFKLQJ

PAGE 283

$%625%$1&( .XEHOND0XQN 8QLWVf :$9(180%(5 FPnf )LJXUH )7,5 VSHFWUD RI SRO\PHU 306& b 0'&6 WROXHQHGLR[DQH YRObff H[SRVHG WR DLU VKRZQ DV D IXQFWLRQ RI WLPH

PAGE 284

,QWHQVLW\ .XEHOND0XQN 8QLWVf 7,0( Kf )LJXUH ,QWHQVLW\ YV WLPH RI H[SRVXUH WR DLU IURP )7,5 VSHFWUD IRU 306 SRO\PHU 306& b 0'&6 WROXHQH GLR[DQH YRObff

PAGE 285

,QWHQVLW\ .XEHOND0XQN 8QLWVf )LJXUH &RQWnGf

PAGE 286

YLEUDWLRQ DW FPn RQO\ GHFUHDVHV VOLJKWO\ RYHU WKH K H[SRVXUH SHULRGf 7KH DEVRUSWLRQ SHDN DVVRFLDWHG ZLWK WKH 6L26L VWUHWFKLQJ YLEUDWLRQ FPnf DOVR LQFUHDVHV ,W LV SUHVXPHG WKDW WKLV SHDN PD\ GHYHORS GXH WR ERWK FRQGHQVDWLRQ UHDFWLRQV EHWZHHQ 6L2+ DQG GLUHFW R[LGDWLRQ RI WKH 6L6L EDFNERQH RI WKH 306 SRO\PHUVf 7KH & VWUHWFKLQJ YLEUDWLRQ FPnf DOVR LQFUHDVHV VLJQLILFDQWO\ GXULQJ WKH ILUVW KRXU RI DLU H[SRVXUH 7KLV FRUUHODWHV ZLWK WKH GHFUHDVHV LQ LQWHQVLW\ IRU WKH DEVRUSWLRQV DVVRFLDWHG ZLWK WKH &+ VWUHWFKLQJ DQG GHIRUPDWLRQ YLEUDWLRQV IURP 6L&+ JURXSVf DW DQG FPn DQG LQGLFDWHV WKDW GLUHFW R[LGDWLRQ RI PHWK\O JURXSV RFFXUV ,Q D VHSDUDWH H[SHULPHQW D 306 SRO\PHU 306 SRO\PHU ( LQ 7DEOH f VDPSOH ZDV H[SRVHG WR VWDWLF DLU IRU K 7KH VDPSOH FKDQJHG FRORU GXULQJ WKLV SHULRG IURP WUDQVSDUHQW \HOORZ WR FORXG\ ZKLWH 7KH SRO\PHU ZDV WKHQ S\URO\]HG WR r& IRU K LQ D QLWURJHQ DWPRVSKHUH DQG DQDO\]HG E\ (0$ 7DEOH VKRZV WKDW WKH VDPSOH FRQWDLQHG ZWb R[\JHQ +HQFH LW LV FOHDU WKDW H[WHQVLYH SUHFDXWLRQV PXVW EH WDNHQ WR DYRLG R[\JHQ FRQWDPLQDWLRQ E\ DWPRVSKHUH H[SRVXUH LI WKH 306 SRO\PHUV SUHSDUHG LQ WKLV VWXG\ DUH WR EH XVHIXO DV SUHFXUVRUV IRU WKH IDEULFDWLRQ RI 6L& ILEHUV

PAGE 287

3UHSDUDWLRQ RI 6LOLFRQ &DUELGH )LEHUV IURP 3ROYPHWKYOVLODQH 3RO\PHUV 7KHUH DUH VHYHUDO UHTXLUHPHQWV IRU VXFFHVVIXO FRQYHUVLRQ RI 306 SRO\PHUV WR 6L& ILEHUV 7KH\ DUH DV IROORZV Lf )LEHU IRUPDWLRQOQIXVLELOLWY 7KH SRO\PHU VKRXOG EH D VROLG DW URRP WHPSHUDWXUH RU VKRXOG VROLGLI\ GXULQJ WKH FRXUVH RI ILEHU VSLQQLQJ WR SUHYHQW ILEHUV IURP VWLFNLQJ WR WKH VSLQQLQJ ZKHHO RU WR HDFK RWKHU ,Q DGGLWLRQ HYHQ LI WKH SRO\PHU LV VROLG DW URRP WHPSHUDWXUH LW VKRXOG QRW PHOW DW KLJKHU WHPSHUDWXUHV LH GXULQJ FRQYHUVLRQ WR FHUDPLFf $Q\ PHOWLQJ FRXOG FDXVH WKH ILEHUV WR VWLFN WR HDFK RWKHU 3ULRU H[SHULHQFH ZLWK VRPH 306 SRO\PHUV KDV VKRZQ WKDW LI WKH PROHFXODU ZHLJKW EHFRPHV WRR ORZ HJ f LW ZLOO PHOW XSRQ S\URO\VLV 6XFK SRO\PHUV FRXOG EH UHQGHUHG LQIXVLEOH E\ FDUU\LQJ RXW D FURVVOLQNLQJ RU FXULQJf WUHDWPHQW EHORZ WKH PHOWLQJ WHPSHUDWXUH RI WKH SRO\PHU $OWHUQDWLYHO\ WKH PROHFXODU ZHLJKWGHJUHH RI FURVVOLQNLQJ RI WKH SRO\PHU FRXOG EH LQFUHDVHG SULRU WR VSLQQLQJ +RZHYHU WKLV ZRXOG UHGXFH WKH PD[LPXP FRQFHQWUDWLRQ RI SRO\PHU WKDW FRXOG EH GLVVROYH LQ VROYHQWV XVHG LQ VROXWLRQ VSLQQLQJf LLf 6ROXELOLW\ ,I ILEHUV DUH IRUPHG E\ GU\ RU ZHW VSLQQLQJ WKHQ WKH VROLG SRO\PHU PXVW KDYH JRRG VROXELOLW\ LQ DQ DSSURSULDWH VROYHQW *RRG VROXELOLW\ LV GHVLUHG WR DFKLHYH KLJK SRO\PHU FRQFHQWUDWLRQ LQ WKH VSLQ GRSH VR WKDW OHVV VROYHQW QHHGV WR EH UHPRYHG GXULQJ VSLQQLQJ &RPPRQ VROYHQWV IRU RUJDQRVLOLFRQ SRO\PHUV LQFOXGH WROXHQH [\OHQH 7+) HWF ,Q GU\ RU ZHW VSLQQLQJ D YLVFRXV VSLQ GRSH LV SUHSDUHG DQG LV H[WUXGHG WKURXJK D VSLQQHUHW WR IRUP ILEHUVf LLLf 0ROHFXODU ZHLJKW GHJUHH RI FURVVOLQNLQJ ,I WKH SRO\PHU PROHFXODU ZHLJKW LV WRR KLJK HJ IRU VRPH RUJDQRVLOLFRQ SRO\PHUVf RU LI LW LV KLJKO\ FURVVOLQNHG WKH SRO\PHU ZLOO QRW EH UHDGLO\ VROXEOH LQ FRPPRQ RUJDQLF VROYHQWV 7KLV ZLOO OHDG WR GLIILFXOWLHV LQ VSLQ GRSH SUHSDUDWLRQ DQG ILEHU VSLQQLQJ HJ GLIILFXOW\ LQ ILOWUDWLRQ RI

PAGE 288

WKH SRO\PHU VROXWLRQ WR UHPRYH DQ\ PLFURJHOV SUHVHQW ORZ FRQFHQWUDWLRQ RI SRO\PHU LQ WKH VSLQ GRSH ZKLFK QHFHVVLWDWHV JUHDWHU UHPRYDO RI VROYHQW LQ IRUPLQJ WKH ILEHUf LYf 9LVFRVLW\ 7KH VSLQ GRSH VKRXOG KDYH RSWLPXP YLVFRVLW\ IRU SUHSDUDWLRQ RI XVHIXO ILEHUV )RU H[DPSOH LI WKH YLVFRVLW\ LV WRR KLJK LW ZLOO EH GLIILFXOW WR H[WUXGH VSLQ GRSH WKURXJK WKH VSLQQHUHW 7KLV WHQGV WR UHVXOW LQ GLVFRQWLQXRXV EULWWOH ILEHUV ZLWK URXJK VXUIDFHV ,I WKH YLVFRVLW\ LV WRR ORZ ILEHUV ZLOO QRW PDLQWDLQ WKHLU VKDSH DIWHU H[LWLQJ WKH VSLQQHUHW DQG ILEHUV PD\ DOVR VWLFN WRJHWKHU $W JUHDWHU H[WUHPHV LQ YLVFRVLW\ LW ZLOO QRW HYHQ EH SRVVLEOH WR IRUP ILEHUVf Yf 6ROYHQW HYDSRUDWLRQ ILEHU fVROLGLILFDWLRQff ,Q GU\ VSLQQLQJ WKH UDWH RI VROYHQW HYDSRUDWLRQ IURP ILEHUV H[LWLQJ IURP VSLQQHUHW PXVW EH KLJK HQRXJK VR WKDW ILEHUV UHPDLQ VHSDUDEOH LH WKH\ GR QRW VWLFN WRJHWKHUf ZKHQ WKH\ DUH FROOHFWHG RQ D ZLQGLQJ GUXP 7KH UDWH RI HYDSRUDWLRQ GXULQJ ILEHU VSLQQLQJ GHSHQGV RQ PDQ\ IDFWRUV VXFK DV WKH YDSRU SUHVVXUH RI WKH VROYHQW WHPSHUDWXUH RI WKH VSLQ GRSH WHPSHUDWXUH LQ WKH VSLQQLQJ FROXPQ VSLQQHUHW JHRPHWU\ H[WUXVLRQ SUHVVXUH ZLQGLQJ SUHVVXUH HWF &RQGLWLRQV ZKLFK SURPRWH WKH IRUPDWLRQ RI ILQHGLDPHWHU ILEHUV DUH KHOSIXO LQ DOORZLQJ ILEHUV WR fVROLGLI\f TXLFNO\ LH SULRU WR WKH ILEHUV UHDFKLQJ WKH ZLQGLQJ GUXPf 7KLV LV EHFDXVH D VPDOOHU TXDQWLW\ RI VROYHQW QHHGV WR EH UHPRYHG GXULQJ VSLQQLQJ LH DVVXPLQJ RWKHU IDFWRUV VXFK DV WKH QXPEHU RI ILEHUV VSXQf UHPDLQV FRQVLVWHQW ,Q DGGLWLRQ ILQHU ILEHUV ZLOO KDYH D JUHDWHU VSHFLILF VXUIDFH DUHD DYDLODEOH IRU HYDSRUDWLRQ VR WKH HYDSRUDWLRQ UDWH PD\ EH KLJKHUf 3URFHVV YDULDEOHV ZKLFK OHDG WR ILQHUGLDPHWHU ILEHUV LQFOXGH VPDOOHU KROH GLDPHWHU LQ WKH VSLQQHUHW DQG KLJKHU ZLQGLQJ VSHHG YLf 6WDELOLW\ 7KH SRO\PHU VKRXOG EH VWDEOH DW URRP WHPSHUDWXUH RU DW WKH WHPSHUDWXUH RI VWRUDJH 7KH SRO\PHU VKRXOG QRW VKRZ ODWHQW UHDFWLYLW\ WR IRUP JHOOLNH SDUWLFOHV RU UHDFW ZLWK WKH HQYLURQPHQW ,Q VRPH FDVHV VXFK SUREOHPV FDQ EH DYRLGHG E\ VWRULQJ

PAGE 289

WKH SRO\PHU RU SRO\PHU VROXWLRQf DW ORZ WHPSHUDWXUH XQGHU DQ LQHUW DWPRVSKHUH $ PDMRU SUREOHP ZLWK 306 SRO\PHUV LV WKHLU KLJK DIILQLW\ WR UHDFW ZLWK R[\JHQ ,W LV ZHOO NQRZQ WKDW WKH SUHVHQFH RI R[\JHQ LV GHWULPHQWDO WR WKH WKHUPRPHFKDQLFDO VWDELOLW\ RI 6L&EDVHG ILEHUV DW KLJK WHPSHUDWXUHV !r&f >,VK@ >0DK@ >6LP@ >&OD@ $V UHSRUWHG LQ VHFWLRQ )7,5 VSHFWURVFRS\ )LJXUH f VKRZHG WKDW D 306 SRO\PHU V\QWKHVL]HG LQ WKLV VWXG\ SLFNHG XS D VXEVWDQWLDO DPRXQW RI R[\JHQ ZLWKLQ K RI H[SRVXUH WR DLU 2[\JHQ FRQWDPLQDWLRQ ZDV DOVR GHPRQVWUDWHG IURP (0$ UHVXOWV FDUULHG RXW RQ D VDPSOH ZKLFK ZDV S\URO\]HG XQGHU DQ LQHUW DWPRVSKHUH 7KH 306 SRO\PHU ZDV ILUVW H[SRVHG WR DLU IRU K DQG WKHQ S\URO\]HG DW r& LQ QLWURJHQ (0$ 7DEOH f VKRZHG DQ R[\JHQ FRQWHQW RI a ZWb LQ WKH S\URO\]HG SURGXFWf 2[\JHQ FRQWDPLQDWLRQ FDQ EH PLQLPL]HG E\ FDUU\LQJ RXW DOO SRO\PHU V\QWKHVLV DQG KDQGOLQJ RSHUDWLRQV LQ DQ LQHUW DWPRVSKHUH HJ QLWURJHQf 7KLV PD\ QRW EH SUDFWLFDO EH\RQG WKH ODERUDWRU\ VHWWLQJ HVSHFLDOO\ VLQFH RWKHU ILEHU SURFHVVLQJ VWHSV VSLQ GRSH SUHSDUDWLRQ ILEHU VSLQQLQJ DQG ILEHU S\URO\VLVf ZRXOG DOVR KDYH WR EH FRQGXFWHG LQ DQ LQHUW HQYLURQPHQW WR DYRLG R[\JHQ FRQWDPLQDWLRQf YLLf &RPSRVLWLRQ ,Q RUGHU WR SUHSDUH QHDUVWRLFKLRPHWULF 6L& ILEHUV LW ZRXOG EH GHVLUDEOH WR KDYH D SRO\PHU ZLWK DQ HOHPHQWDO 6L& UDWLR RI ,W LV ZHOONQRZQ WKDW ILEHUV SUHSDUHG IURP SRO\FDUERVLODQH 3&6f SRO\PHUV KDYH D VLJQLILFDQW DPRXQW RI H[FHVV FDUERQ >+DV$@ >7RU%@f $VV\QWKHVL]HG 3&6 SRO\PHUV KDYH D 6L& UDWLR RI a $IWHU S\URO\VLV 6L& UDWLRV DUH W\SLFDOO\ LQ WKH UDQJH >+DV$@ 7RU%@f ,Q FRQWUDVW 306 SRO\PHUV KDYH DQ a DWRPLF UDWLR RI 6L& ,W LV NQRZQ WKDW S\URO\VLV RI WKHVH SRO\PHUV UHVXOWV LQ HLWKHU QHDUVWRLFKLRPHWULF 6L& RU 6L& ZLWK DQ H[FHVV RI 6L >6H\@ >=KD$@ >0X$@f ,W LV K\SRWKHVL]HG WKDW PL[WXUHV RI 306 DQG 3&6 FRXOG EH XVHG WR SUHSDUH QHDUVWRLFKLRPHWULF 6L& ILEHUV

PAGE 290

7KH 306 SRO\PHUV SUHSDUHG LQ WKLV VWXG\ KDYH ORZ PROHFXODU ZHLJKW LQ WKH DV SUHSDUHG VWDWH 0Q DQG 0Z f DQG DUH YLVFRXV OLTXLGV DW URRP WHPSHUDWXUH 7KH PROHFXODU ZHLJKW QHHGV WR EH LQFUHDVHG LQ RUGHU IRU WKH SRO\PHUV WR EH XVHIXO IRU ILEHU SURFHVVLQJ 7ZR DSSURDFKHV ZHUH XWLOL]HG WR UDLVH WKH PROHFXODU ZHLJKW RI WKH SRO\PHU Lf IXUWKHU SRO\PHUL]DWLRQ DQG FURVVOLQNLQJ E\ KHDW WUHDWPHQW ZLWK DQG ZLWKRXW DGGLWLYHV DQG LLf IUDFWLRQDO SUHFLSLWDWLRQ RI KLJKHU PROHFXODU ZHLJKW IUDFWLRQV 7KH UHVXOWV IURP WKHVH DSSURDFKHV DUH GHVFULEHG LQ VHFWLRQ 6HFWLRQ GHVFULEHV WKH UHVXOWV RI ILEHU VSLQQLQJ H[SHULPHQWV IURP WKHVH SRO\PHUV 0HWKRGV WR LQFUHDVH PROHFXODU ZHLJKW RI 306 SRO\PHUV +HDW WUHDWPHQW RI 306 SRO\PHUV +HDW WUHDWPHQW RI 306 SRO\PHUV UHVXOWHG LQ LQFUHDVHG PROHFXODU ZHLJKW DQG FURVVOLQNLQJ RI WKH SRO\PHUV 7KLV LV SUHVXPHG WR RFFXU E\ GHK\GURJHQDWLRQ UHDFWLRQV LQYROYLQJ 6L+ JURXSV 6L+ JURXSV DUH EHOLHYHG WR KDYH WKH ORZHVW ERQG HQHUJ\ LQ WKH 306 SRO\PHUV >6FK @ >+DV$@f +DVHJDZD HW DO >+DV$@ KDYH VWXGLHG KHDW WUHDWPHQW RI 3&6 SRO\PHUV E\ ,5 VSHFWURVFRS\ DQG SURSRVHG WKDW GHK\GURJHQDWLRQ UHDFWLRQV LQYROYLQJ 6L+ RFFXUUHG DW WHPSHUDWXUHV ar& 6FKPLGW HW DO >6FK@ KDYH DOVR VXJJHVWHG IURP ,5 UHVXOWV WKDW GHK\GURJHQDWLRQ UHDFWLRQV LQYROYLQJ 6L+ JURXSV WDNH SODFH GXULQJ ORZ WHPSHUDWXUH KHDW WUHDWPHQW RI YLQ\OLF SRO\VLODQH SRO\PHUV )7,5 VSHFWUD VKRZHG D GHFUHDVH LQ WKH DEVRUSWLRQ SHDN GXH WR WKH 6L+ YLEUDWLRQ IRU SRO\PHUV KHDWHG DW r& $OO SRO\PHUV XVHG IRU KHDW WUHDWPHQW LQ WKLV VWXG\ ZHUH V\QWKHVL]HG IURP D PL[WXUH RI PHWK\OGLFKORURVLODQH 0'&6f DQG PHWK\OWULFKORURVLODQH 07&6f PRQRPHUV LQ ZWb SURSRUWLRQf 7KH VROYHQW XVHG LQ WKH V\QWKHVLV ZDV D PL[WXUH RI WROXHQH DQG WHWUDK\GURIXUDQ YRObf 3RO\YLQ\OVLOD]DQH 36=f ZWbf GLFXP\O SHUR[LGH '&3 ZWbf DQG GHFDERUDQH %+f ZHUH LQYHVWLJDWHG DV SRWHQWLDO FURVVOLQNLQJ

PAGE 291

DLGV IRU WKH 306 SRO\PHUV 7KH SRO\PHU VROXWLRQ YLVFRVLW\ ZDV JHQHUDOO\ PRQLWRUHG EHIRUH DQG DIWHU KHDW WUHDWPHQW ,QFUHDVHV LQ YLVFRVLW\ LQGLFDWHG WKDW SRO\PHU PROHFXODU ZHLJKW LQFUHDVHG ,Q PRVW FDVHV WKH PROHFXODU ZHLJKW ZDV DOVR GLUHFWO\ GHWHUPLQHG E\ *3&f EHIRUH DQG DIWHU KHDW WUHDWPHQW 7DEOH VKRZV WKH KHDW WUHDWPHQW FRQGLWLRQV IRU GLIIHUHQW 306 SRO\PHU EDWFKHV ZLWK DQG ZLWKRXW DGGLWLYHVf DQG WKH UHVXOWLQJ HIIHFWV RQ YLVFRVLW\ DQG PROHFXODU ZHLJKW 7KH QRPHQFODWXUH RI WKH 306 SRO\PHUV XVHG LQ WKLV VWXG\ LV VKRZQ LQ 7DEOH 7KH PDLQ SUREOHPV LQ WKH KHDW WUHDWPHQW DSSURDFK WR UDLVLQJ PROHFXODU ZHLJKW RI 306 SRO\PHUV ZHUH SRRU FRQWURO RYHU WKH PROHFXODU ZHLJKW LQFUHDVHV DQG ODFN RI UHSURGXFLELOLW\ LH WKH LQFUHDVH LQ PROHFXODU ZHLJKW ZDV QRW XQLIRUP IURP EDWFK WR EDWFKf 7KH SRRU FRQWURO RYHU WKH PROHFXODU ZHLJKW LQFUHDVHV PHDQW WKDW LW ZDV GLIILFXOW WR DYRLG PLFURJHO IRUPDWLRQ DQG LQ VRPH FDVHV FRPSOHWH JHODWLRQ RI WKH VROXWLRQ 0LFURJHO IRUPDWLRQ LV KLJKO\ XQGHVLUDEOH EHFDXVH LW FDXVHV GLIILFXOW\ LQ ILOWHULQJ VROXWLRQV DQG UHVXOWV LQ ORZHU VROLGV ORDGLQJ LQ WKH VROXWLRQV RU KLJKHU YLVFRVLWLHV IRU D IL[HG VROLGV ORDGLQJff 7KH ODFN RI UHSURGXFLELOLW\ PD\ KDYH EHHQ GXH WR WKH YDULDWLRQ LQ WKH FKDUDFWHULVWLFV RI DVSUHSDUHG SRO\PHUV IURP EDWFK WR EDWFK 7KH PRQRPHUV XVHG LQ WKH SRO\PHU V\QWKHVLV 0'&6 DQG 07&6f DUH KLJKO\ UHDFWLYH HJ WKH\ DUH KLJKO\ VHQVLWLYH WRZDUGV PRLVWXUHf DQG PD\ DJH ZLWK WLPH HYHQ WKRXJK VDPSOHV ZHUH VWRUHG DIWHU EDFNILOOLQJ ZLWK QLWURJHQ DQG DOO KDQGOLQJ RSHUDWLRQV ZHUH FDUULHG RXW XQGHU DUJRQ LQ D JORYH EDJ ,Q DGGLWLRQ LW LV VSHFXODWHG WKDW WKH SRO\PHUV PD\ DJH LH XQGHUJR LQFUHDVHV LQ PROHFXODU ZHLJKW ZLWK WLPHf GXH WR ODWHQW UHDFWLYLW\ RI 6L+ JURXSV 7KH ODFN RI UHSURGXFLELOLW\ LQ WKH SRO\PHU V\QWKHVHV LV LQGLFDWHG E\ WKH LQLWLDO FKDUDFWHULVWLFV RI SRO\PHU 306 306 DQG 306 LQ 7DEOH $OWKRXJK V\QWKHVL]HG XQGHU LGHQWLFDO FRQGLWLRQV 306 VKRZHG D PXFK KLJKHU LQLWLDO PROHFXODU ZHLJKW FRPSDUHG WR 306 DQG 306 $OVR WKH FKDQJHV LQ YLVFRVLW\ DQG

PAGE 292

7DEOH &RQGLWLRQV IRU KHDW WUHDWPHQW RI 306 SRO\PHUV FRQWDLQLQJ 36= '&3 DQG '% ,QLWLDO SRO\PHU EDWFK $GGLWLYHV ZWbf 36= '&3 '% +HDW WUHDWPHQW FRQGLWLRQV WLPHKfWHPSr&f ,QLWLDO YLVFRVLW\ P3DV )LQDO YLVFRVLW\ P3DV b YLVFRVLW\ FKDQJH ,QLWLDO 0QW ,QLWLDO ,QLWLDO 3', )LQDO 0Q )LQDO f 0Z )LQDO 3', 306$ f r r r 306$ f 306$ f r r r 306$ f 306$ f r r r r r r 306$ f f 306$' f r r r r r r 306$' f f 306$' f VROXWLRQ JHOOHG r r r r r r 306$' f f r r r 306$' f f r r r 306$' f FORVH WR JHO SRLQW 306$' f VROXWLRQ JHOOHG r r r r r r 306 f 306 f r r r 306 f + VROLGVORDGLQJ RI VWDUWLQJ SRO\PHU VROXWLRQ ZDV ZWb r 'DWD QRW DYDLODEOH I 0ROHFXODU ZHLJKWV RI 306 ZLWK DGGLWLYHV

PAGE 293

7DEOH 1RPHQFODWXUH RI 306 SRO\PHUV XVHG LQ WKH KHDW WUHDWPHQW H[SHULPHQWV 3RO\PHU GHVLJQDWLRQ 'HVFULSWLRQ 306;;; $VV\QWKHVL]HG SRO\PHU QR DGGLWLYHVf 306;;;+ +HDWWUHDWHG 306;;; SRO\PHU 306;;;$ $VSUHSDUHG 306;;; ZLWK 36= DQG '&3 DGGLWLYHV 306;;;$+ +HDWWUHDWHG 306;;;$ 306;;;$ $ VHFRQG SRUWLRQ RI DVSUHSDUHG 306;;;$ ZLWK 36= DQG '&3 DGGLWLYHV 306;;;$+ +HDWWUHDWHG 306;;;$ 306;;;$3 $VSUHSDUHG 306;;; ZKLFK FRQWDLQV 3&6 DQG 36= DV SRO\PHU DGGLWLYHV ,W DOVR FRQWDLQV '&3 306;;;$3+ +HDWWUHDWHG 306;;;$3 306;;;$3E $ VHFRQG SRUWLRQ RI DVSUHSDUHG 306;;; ZKLFK FRQWDLQV 3&6 DQG 36= DGGLWLYHV ,W DOVR FRQWDLQV '&3 306;;;$3+ +HDWWUHDWHG 306;;;$3 306;;;$' $VSUHSDUHG 306;;; ZKLFK FRQWDLQV '% DQG 36= SRO\PHU DV DGGLWLYHV ,W PD\ DOVR FRQWDLQ '&3 DV DQ DGGLWLYH 306;;;$'+ +HDWWUHDWHG 306;;;$' 306;;;$' $ VHFRQG SRUWLRQ RI 306;;;$' ZKLFK FRQWDLQV '% DQG 36= SRO\PHU DV DGGLWLYHV ,W PD\ DOVR FRQWDLQ '&3 DV DQ DGGLWLYH 306;;;$'+ +HDWWUHDWHG 306;;;$' 306;;;$3' $VSUHSDUHG 306;;; ZKLFK FRQWDLQV '% 3&6 SRO\PHU DQG 36= SRO\PHU DV DGGLWLYHV ,W PD\ DOVR FRQWDLQ '&3 DV DQ DGGLWLYH 306;;;$3'+ +HDWWUHDWHG 306;;;$3' 306;;;$3'D $VSUHSDUHG 306;;; ZLWK WKH VDPH DGGLWLYHV DV 306 ;;;$3' EXW ZLWK GLIIHUHQW FRQFHQWUDWLRQV RI WKH DGGLWLYHV 306;;;$3'D+ +HDWWUHDWHG 306;;;$3'D ;;; UHIHUV WR WKH EDWFK QXPEHU H J HWFf E 306$3 DQG 306$3 ZHUH SUHSDUHG IURP WKH RULJLQDO VWRFN VROXWLRQV 306$3 DQG 306 $3 UHVSHFWLYHO\ 306$3 ZDV SUHSDUHG E\ LQFUHDVLQJ WKH DPRXQW RI 36= LQ WKH VROXWLRQ WR ZWb DQG '&3 WR ZWb 306$3 DQG 306$3 FRQWDLQHG W\SH & 3&6 ZKHUHDV 306$3 DQG 306$3 FRQWDLQHG W\SH % 3&6

PAGE 294

PROHFXODU ZHLJKW ZLWK KHDW WUHDWPHQW ZHUH PXFK GLIIHUHQW DPRQJ WKHVH SRO\PHUV 306 VKRZHG D UHODWLYHO\ VPDOO LQFUHDVH LQ PROHFXODU ZHLJKW DIWHU KROGLQJ IRU K DW r& 'HVSLWH DQ LQLWLDO PROHFXODU ZHLJKW VLPLODU WR 306 306 VKRZHG D PXFK ODUJHU LQFUHDVH LQ PROHFXODU ZHLJKW DIWHU KHDW WUHDWPHQW 306 VKRZHG DQ HYHQ ODUJHU LQFUHDVH LQ PROHFXODU ZHLJKW ZLWK KHDW WUHDWPHQW EXW WKLV LV QRW VXUSULVLQJ FRQVLGHULQJ WKH KLJK LQLWLDO PROHFXODU ZHLJKWf 7KH RFFXUUHQFH RI DJLQJ LQ WKH SRO\PHUV LV VKRZQ E\ WKH REVHUYDWLRQ WKDW WKH PROHFXODU ZHLJKW RI 306 SRO\PHU 306f LQFUHDVHG VLJQLILFDQWO\ XSRQ VWRUDJH DW URRP WHPSHUDWXUH XQGHU QLWURJHQf IRU GD\V 0Q LQFUHDVHG IURP WR DQG 0Z IURP WR VHH )LJXUH f 7DEOH VKRZV FRQGLWLRQV IRU KHDW WUHDWPHQW RI 306 SRO\PHUV FRQWDLQLQJ ERWK 36= DQG '&3 DGGLWLYHV ILUVW VL[ HQWULHVf +HDW WUHDWPHQW ZDV FDUULHG RXW DW WHPSHUDWXUHV LQ WKH UDQJH RI r& LQ D WHIORQ FRQWDLQHU HQFDVHG LQ D SUHVVXUH ERPE DV GHVFULEHG LQ VHFWLRQ ,QFUHDVHV LQ PROHFXODU ZHLJKW ZHUH REWDLQHG EXW WKHUH ZHUH DOVR LQFUHDVHV LQ SRO\GLVSHUVLW\ 7KLV ZDV WUXH IRU DOPRVW DOO KHDW WUHDWPHQWV ZKLFK UHVXOWHG LQ VLJQLILFDQW LQFUHDVHV LQ PROHFXODU ZHLJKW $Q H[FHSWLRQ ZDV IRU WKH KHDW WUHDWPHQW RI 306 DV VKRZQ LQ 7DEOH f $OWKRXJK GDWD LV OLPLWHG WKH LQFUHDVHV LQ WKH PROHFXODU ZHLJKW DQG SRO\GLVSHUVLW\ DIWHU KHDW WUHDWPHQW DSSHDUHG WR EH JUHDWHU ZKHQ WKH 36= ZWbf'&3 ZWbf DGGLWLYHV ZHUH XVHG )LJXUH VKRZV D SORW RI SRO\GLVSHUVLW\ LQGH[ YV ZHLJKW DYHUDJH PROHFXODU ZHLJKW IRU WKHVH SRO\PHUV EHIRUH DQG DIWHU KHDW WUHDWPHQW )LJXUHV D DQG E VKRZ *3& PROHFXODU ZHLJKW GLVWULEXWLRQV RI SRO\PHU 306$ DQG 306$+ EHIRUH DQG DIWHU KHDW WUHDWPHQW UHVSHFWLYHO\f 7KH KHDWWUHDWHG SRO\PHU VKRZV D ELPRGDO GLVWULEXWLRQ 7KH PRGHV IRU WKH ORZ PROHFXODU ZHLJKW SRUWLRQV RI WKH SRO\PHUV UHPDLQ LQ QHDUO\ WKH VDPH SRVLWLRQ EHIRUH DQG DIWHU KHDW WUHDWPHQW ,W LV FOHDU IURP WKHVH

PAGE 295

GZWGORJ 0f GZWGORJ 0f GZWGORJ 0f &f )LJXUH *HO SHUPHDWLRQ FKURPDWRJUDPV IRU 306 SRO\PHU $f DIWHU GD\V RI VWRUDJH %f DIWHU GD\V RI VWRUDJH DQG &f DIWHU KHDW WUHDWPHQW 306+f

PAGE 296

02/(&8/$5 :(,*+7 032/<',63(56,7< ,1'(; 3',f )LJXUH 3RO\GLVSHUVW\ LQGH[ YV PROHFXODU ZHLJKW IRU 306 SRO\PHUV FRQWDLQLQJ ZWb 36= DQG ZWb '&3f DV DGGLWLYHV ,QLWLDO 3', YV ,QLWLDO 0: )LQDO 3', YV )LQDO 0: ‘

PAGE 297

GZWGORJ0f GZWGORJ0f ORJ 0: )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU $f 306$ DQG %f 306$+

PAGE 298

REVHUYDWLRQV WKDW QRW DOO RI WKH PROHFXOHV ZKLFK IRUP GXULQJ WKH LQLWLDO SRO\PHUL]DWLRQ UHDFWLRQ SDUWLFLSDWH LQ WKH SRO\PHUL]DWLRQFURVVOLQNLQJ UHDFWLRQV WKDW OHDG WR WKH LQFUHDVHG DYHUDJH PROHFXODU ZHLJKW DIWHU KHDW WUHDWPHQW )LJXUHV D E DQG VKRZ *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306$ 306$+ DQG 306$+ UHVSHFWLYHO\ 306$ ZDV SUHSDUHG DW WKH VDPH WLPH DV 306$ DQG KDG D FRPSRVLWLRQ LGHQWLFDO WR WKDW RI 306$ 7KHVH SRO\PHUV FRQWDLQHG ZWb 36= DQG ZWb '&3 DV DGGLWLYHVf 306$+ VKRZHG D ODUJHU LQFUHDVH LQ PROHFXODU ZHLJKW WKDQ 306$+ 7KLV LV SUHVXPDEO\ GXH WR KLJKHU KHDW WUHDWPHQW WHPSHUDWXUH r& YV r&f $V QRWHG HDUOLHU KRZHYHU LW ZDV REVHUYHG WKDW 306 SRO\PHUV FDQ XQGHUJR DJLQJ GXULQJ VWRUDJH HJ PROHFXODU ZHLJKW LQFUHDVHV ZHUH REVHUYHG XSRQ URRP WHPSHUDWXUH VWRUDJHf $OWKRXJK WKH 306$ DQG 306$ OLVWHG LQ 7DEOH DUH GLIIHUHQW SRUWLRQV RI WKH VDPH VROXWLRQ KHDW WUHDWPHQW WR SURGXFH 306$+ ZDV FDUULHG RXW GD\V DIWHU WKH KHDW WUHDWPHQW ZDV FDUULHG RXW WR SURGXFH 306$+ 7KXV 306$ VROXWLRQ ZDV DJHG IRU GD\V ORQJHU WKDQ 306$ SULRU WR KHDW WUHDWPHQWf +HQFH LW LV SRVVLEOH WKDW WKH LQLWLDO PROHFXODU ZHLJKW IRU 306$ PD\ KDYH EHHQ KLJKHU WKDQ WKDW RI 306$ ,Q IDFW WKLV LV VXJJHVWHG IURP WKH KLJKHU LQLWLDO YLVFRVLW\ P3DrV YV P3DrVf DOWKRXJK WKH GLIIHUHQFH PD\ EH ZLWKLQ WKH H[SHULPHQWDO HUURU RI WKH PHDVXUHPHQWf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r&

PAGE 299

GZWGORJ0f GZWGORJ0f %f )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU $f 306$ DQG %f 306$+

PAGE 300

GZWGORJ0f )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$+

PAGE 301

Kf RI 306$ ZLWK ZWb 36= ZHUH VLPLODU WR 306$ )LJXUHV D DQG E VKRZ *3& PROHFXODU ZHLJKW GLVWULEXWLRQV EHIRUH DQG DIWHU KHDW WUHDWPHQW IRU D 306 $ VROXWLRQ ZKLFK FRQWDLQHG ZWb 36= DQG ZWb '&3 DV DGGLWLYHVf 7KH LQFUHDVH LQ PROHFXODU ZHLJKW XSRQ KHDW WUHDWPHQW ZDV VLPLODU LQ PDJQLWXGH WR WKDW REVHUYHG LQ WKH 306$+ VDPSOH +HQFH WKH ELPRGDOLW\ LQ WKH PROHFXODU ZHLJKW GLVWULEXWLRQ ZDV FOHDUO\ REVHUYHGf 7KH ODUJH LQFUHDVH LQ PROHFXODU ZHLJKW XSRQ KHDW WUHDWPHQW RI WKH 306$ VROXWLRQ SUREDEO\ UHIOHFWV WKH KLJK WHPSHUDWXUHV XVHG LH DQG r& ZKLFK LV VLPLODU WR WKH PD[LPXP WHPSHUDWXUH XVHG ZLWK 306$f 7KHUH LV QR FOHDU HYLGHQFH IURP WKLV VWXG\ LI WKH KLJKHU 36= DQG '&3 FRQFHQWUDWLRQV KDG DQ\ HIIHFW RQ WKH H[WHQW RI WKH PROHFXODU ZHLJKW LQFUHDVH GXULQJ KHDW WUHDWPHQWf 7DEOH DOVR VKRZV UHVXOWV RI KHDW WUHDWPHQW IRU 306 SRO\PHUV FRQWDLQLQJ ZWb '% DQG ZWb 36= :KHQ '% ZDV SUHVHQW WKH SRO\PHU VROXWLRQV VKRZHG VLJQLILFDQW LQFUHDVHV LQ YLVFRVLW\ DQG RIWHQ JHOOHG 7KH SRO\PHU VROXWLRQ RIWHQ FKDQJHG LQ FRORU IURP \HOORZ WR EURZQ GXULQJ WKH KHDW WUHDWPHQW 7KH PROHFXODU ZHLJKW GLVWULEXWLRQV ZHUH GHWHUPLQHG EHIRUH DQG DIWHU KHDW WUHDWPHQW LQ RQO\ RQH FDVH LH IRU VDPSOHV SUHSDUHG ZLWK 306$' DV VKRZQ LQ )LJXUHV D DQG Ef 1R VLJQLILFDQW GLIIHUHQFH LQ PROHFXODU ZHLJKW GLVWULEXWLRQ ZDV REVHUYHG XSRQ KHDW WUHDWPHQW GHVSLWH WKH REVHUYHG LQFUHDVH LQ YLVFRVLW\ IRU WKH KHDWWUHDWHG VROXWLRQ 7KH UHDVRQ IRU WKLV EHKDYLRU LV QRW NQRZQ 7DEOH VKRZV WKH KHDW WUHDWPHQW FRQGLWLRQV XVHG DQG WKH UHVXOWLQJ HIIHFWV RQ WKH VROXWLRQ YLVFRVLW\ DQG WKH SRO\PHU PROHFXODU ZHLJKW IRU 3063&6 SRO\PHU EOHQGV SURSRUWLRQ E\ ZHLJKWf FRQWDLQLQJ YDULRXV DGGLWLYHV 36= '&3 DQGRU '%f 7KH PROHFXODU ZHLJKWV RI WKH 3&6 SRO\PHUV XVHG LQ WKH KHDW WUHDWPHQW H[SHULPHQWV DUH JLYHQ LQ 7DEOH )LUVW FRQVLGHU WKH UHVXOWV IRU 306$3 306$3 DQG 306 $3 7KH VWDUWLQJ VROXWLRQV IRU WKHVH VDPSOHV DOO FRQWDLQHG WKH VDPH W\SH DQG

PAGE 302

GZWGORJ0f GZWGORJ0f )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU $f306$ DQG %f 306$+

PAGE 303

GZWGORJ0f GZWGORJ0f )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU $f 306$' DQG %f 306$'+

PAGE 304

7DEOH &RQGLWLRQV DQG UHVXOWV RI KHDW WUHDWPHQW IRU 3063&6 SRO\PHU EOHQGV 3RO\PHU EDWFK $GGLWLYHV ZWbf 3&6 36= '% '&3 +HDW WUHDWPHQW FRQGLWLRQV WLPHKfWHPSr&f ,QLWLDO YLVFRVLW\ P3DV )LQDO YLVFRVLW\ P3DV b YLVFRVLW\ FKDQJH ,QLWLDO 0Qr ,QLWLDO 0:7 ,QLWLDO 3', )LQDO 0Q )LQDO 0Z )LQDO 3', 306$3 >$@ f 306$3 >$@ f 306 $3Q >$@ f r r r 306$3 >%@ f 306$3 >%@ f f VROXWLRQ JHOOHG r 306$3 >%@ f VROXWLRQ JHOOHG r 306$3 >%@ f VROXWLRQ JHOOHG rr 306$3 >%@ f VROXWLRQ JHOOHG r 306$3 >&@ f 306$3 >%@ f VROXWLRQ JHOOHG rr 306$3 >&@ f 306$3' >&@ f r 306$3' D WWW >&@ f r r r 306$3' >'@ f VROXWLRQ JHOOHG rr 306$3' >'@ f f r r r r r + VROLGVORDGLQJ RI VWDUWLQJ SRO\PHU VROXWLRQ ZDV ZWb r 'DWD QRW DYDLODEOH r +HDWWUHDWPHQW VWRSSHG DIWHU K DV WKH VROXWLRQ WXUQHG FORXG\ >$@ 3&6 >%@ 3&6 >&@ 3&6 >'@ 3&6 WKH FKDUDFWHULVWLFV RI WKHVH 3&6 SRO\PHUV DUH VKRZQ LQ 7DEOH r 0ROHFXODU ZHLJKW RI 3063&6 EOHQG ZLWK DGGLWLYHV Q 0ROHFXODU ZHLJKW QRW PHDVXUHG VHSDUDWHO\ IRU WKH VHFRQG SRUWLRQ RI 306$3 P 0ROHFXODU ZHLJKW QRW PHDVXUHG VHSDUDWHO\ IRU WKH VHFRQG SRUWLRQ RI 306$3' rr 'DWD QRW FROOHFWHG IRU JHOOHG VDPSOHV

PAGE 305

7DEOH 0ROHFXODU ZHLJKW GLVWULEXWLRQV RI 3&6 SRO\PHUV XVHG LQ WKH KHDW WUHDWPHQW RI 3063&6 EOHQGV 3&6 EDWFK 0ROHFXODU ZHLTKW GLVWULEXWLRQ 0Q 0Z 3RO\GLVSHUVLW\ 3&6 $f 3&6 %f 3&6 &f 3&6 'f

PAGE 306

DPRXQW RI 3&6 ZWb W\SH $f DQG 36= ZWbf 7KH PROHFXODU ZHLJKW GLVWULEXWLRQV IRU WKH KHDWWUHDWHG SRO\PHUV DUH VKRZQ LQ )LJXUHV DQG UHVSHFWLYHO\ 7KH PROHFXODU ZHLJKWV LQFUHDVH ZLWK LQFUHDVLQJ KHDW WUHDWPHQW WHPSHUDWXUH LH WKH PD[LPXP KHDW WUHDWPHQW WHPSHUDWXUHV ZHUH DQG r& UHVSHFWLYHO\f ,W LV DOVR REVHUYHG IURP )LJXUH WKDW WKH LQFUHDVH LQ PROHFXODU ZHLJKW IRU WKH 306$3 VDPSOH ZDV ODUJH HQRXJK WKDW WKH ELPRGDOLW\ RI WKH GLVWULEXWLRQ EHFDPH PRUH SURQRXQFHG 306$3 DQG 306$3 DOVR VKRZHG D VLPLODU HIIHFW DV QRWHG LQ UHJDUG WR 306$ DQG 306$ LH WKH VROXWLRQ ZKLFK ZDV DJHG ORQJHU EHIRUH KHDW WUHDWPHQW 306$3f KDG D KLJKHU LQLWLDO YLVFRVLW\f 306$3 KDG KLJKHU PROHFXODU ZHLJKW VHH )LJXUH f FRPSDUHG WR WKH 306$3 306$3 DQG 306$3 ,Q DGGLWLRQ 306$3 JHOOHG XSRQ KHDW WUHDWPHQW 2QH IDFWRU UHVSRQVLEOH IRU WKHVH HIIHFWV ZDV SUHVXPDEO\ WKH KLJKHU KHDW WUHDWPHQW WHPSHUDWXUHV r&f KRZHYHU WKHUH ZHUH PDQ\ RWKHU YDULDEOHV WKDW ZHUH FKDQJHG VR LW LV QRW SRVVLEOH WR GUDZ DQ\ GHILQLWLYH FRQFOXVLRQV 7KH LQLWLDO PROHFXODU ZHLJKW RI WKH 3063&6 EOHQG WKH PROHFXODU ZHLJKW RI WKH 3&6 WKH DPRXQW RI 36= DQG WKH DPRXQW RI '&3 ZHUH DOO KLJKHU IRU WKHVH WZR 306 VDPSOHV LH FRPSDUHG WR WKH FRUUHVSRQGLQJ 306 DQG 306 VDPSOHV OLVWHG LQ 7DEOH $OO RI WKHVH FRXOG EH IDFWRUV FRQWULEXWLQJ WR WKH KLJKHU PROHFXODU ZHLJKW RI WKH KHDWWUHDWHG 306$3 VDPSOHV 7KHUH LV VRPH HYLGHQFH WR LQGLFDWH WKDW XVLQJ D 3&6 ZLWK KLJKHU PROHFXODU ZHLJKW UHVXOWV LQ D KHDWWUHDWHG SRO\PHU ZLWK KLJKHU PROHFXODU ZHLJKW 306$ VROXWLRQ ZDV SUHSDUHG IURP 306 SRO\PHU ZLWK ZWb 36= DQG ZWb '&3 306$3 ZDV SUHSDUHG E\ DGGLQJ ZWb W\SH % 3&6 WR VRPH 306$ VROXWLRQ 306$3 ZDV SUHSDUHG E\ DGGLQJ ZWb W\SH & 3&6 WR VRPH 306$ VROXWLRQ 7\SH & 3&6 KDV D ORZHU PROHFXODU ZHLJKW WKDQ W\SH % 3&6 'HVSLWH WKLV WKH

PAGE 307

GZWGORJ0f GZWGORJ0f )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+

PAGE 308

GZWGORJ0f GZWGORJ0f )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+ )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+

PAGE 309

306$3 VDPSOH KDV D VOLJKWO\ KLJKHU LQLWLDO YLVFRVLW\ FRPSDUHG WR WKH 306 $3 VDPSOH 7KLV PD\ UHIOHFW WKH ORQJHU DJLQJ WLPH IRU WKH 306$ VROXWLRQ EHIRUH WKH DGGLWLRQ RI WKH 3&6f $IWHU KHDW WUHDWPHQW WKH VDPSOH SUHSDUHG ZLWK KLJKHU PROHFXODUZHLJKW 3&6 LH 306$3+f JHOOHG HYHQ WKRXJK WKH KHDW WUHDWPHQW WLPH DW WKH PD[LPXP WHPSHUDWXUH r&f ZDV RQO\ K ,Q FRQWUDVW WKH VDPSOH SUHSDUHG ZLWK ORZHUPROHFXODUZHLJKW 3&6 LH 306$3+f KDG D PROHFXODU ZHLJKW RI RQO\ GHVSLWH D KHDW WUHDWPHQW WLPH RI K DW r& 7KH PROHFXODU ZHLJKW GLVWULEXWLRQ IRU WKLV VDPSOH LV VKRZQ LQ )LJXUH 7KH VDPH HIIHFW ZDV REVHUYHG XSRQ KHDW WUHDWPHQW RI WKH 306$3 DQG 306$3 VDPSOHV LH WKH VDPSOHV SUHSDUHG ZLWK KLJKHUPROHFXODUZHLJKW 3&6 JHOOHG GHVSLWH D VKRUWHU KHDW WUHDWPHQW WLPH DW WKH PD[LPXP WHPSHUDWXUH 7KH PROHFXODU ZHLJKW GLVWULEXWLRQ IRU WKH KHDWWUHDWHG VDPSOH ZKLFK ZDV SUHSDUHG ZLWK ORZHU PROHFXODU ZHLJKW 3&6 LH VDPSOH 306$3+f LV VKRZQ LQ )LJXUH ,W LV DOVR QRWHG WKDW WKH ELPRGDOLW\ LQ WKH GLVWULEXWLRQ LV PRUH SURQRXQFHG IRU 306$3+ FRPSDUHG WR 306$3+ ZKLFK DJDLQ LV FRQVLVWHQW ZLWK WKH KLJKHU RYHUDOO DYHUDJH PROHFXODU ZHLJKW IRU WKH IRUPHU VDPSOHf ,W LV QRWHG WKDW PRVW RI WKH VDPSOHV LQ 7DEOH WKDW FRQWDLQHG ZWb 36= HLWKHU JHOOHG RU VKRZHG VLJQLILFDQW LQFUHDVHV LQ PROHFXODU ZHLJKW HYHQ DW KHDW WUHDWPHQW WHPSHUDWXUHV DV ORZ DV r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

PAGE 310

GZWGORJ0f GZWGORJ0f ORJ 0: )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQ IRU 306$3+

PAGE 311

KHDWWUHDWHG SRO\PHUV KDYH ELPRGDO PROHFXODU ZHLJKW GLVWULEXWLRQV 7KLV LV XQGHVLUDEOH IRU WZR UHDVRQV )LUVW WKH ORZPROHFXODUZHLJKW SRUWLRQV RI WKH SRO\PHUV ZRXOG SUHVXPDEO\ EH OLTXLGV LI WKH\ ZHUH LVRODWHG IURP WKH KLJKPROHFXODUZHLJKW SRUWLRQVf $V QRWHG HDUOLHU VROLG SRO\PHUV DUH QHHGHG IRU ILEHU IRUPDWLRQ 6HFRQG WKH KLJKHU PROHFXODU ZHLJKW SRUWLRQV WHQG WR PDNH ILOWUDWLRQ RI WKH SRO\PHU VROXWLRQV GLIILFXOW DQG WHQG WR PDNH WKH SRO\PHU VROXWLRQV XQVWDEOH WRZDUG JHODWLRQ +HQFH WKHVH SRO\PHUV DUH QRW SDUWLFXODUO\ VXLWDEOH IRU ILEHU IRUPDWLRQ )UDFWLRQDO SUHFLSLWDWLRQ )UDFWLRQDO SUHFLSLWDWLRQ ZDV FDUULHG RXW RQ SRO\PHU EDWFKHV WKDW ZHUH V\QWKHVL]HG E\ UHDFWLQJ D PL[WXUH RI 0'&6 DQG 07&6 LQ ZWb SURSRUWLRQf ZLWK VRGLXP LQ D PL[WXUH RI WROXHQH DQG GLR[DQH DW WKH UHIOX[ WHPSHUDWXUH RI WKH VROYHQW PL[WXUH 7KH WROXHQH GLR[DQH YROXPH UDWLRV XVHG ZHUH IRU 306 IRU 306 DQG IRU 306) WKURXJK 306) 7ROXHQHGLR[DQH ZDV XVHG IRU WKH V\QWKHVLV EHFDXVH WKH SRO\PHU \LHOGV ZHUH PXFK KLJKHU FRPSDUHG WR SRO\PHUV V\QWKHVL]HG XVLQJ WROXHQH DORQH RU D WROXHQH7+) PL[WXUH DV UHSRUWHG LQ VHFWLRQ f 4LX DQG 'X >4LX@ KDYH UHSRUWHG WKDW DGGLWLRQ RI D SRODU VROYHQW VXFK DV WHWUDK\GURIXUDQ 7+)f WR D 306 SRO\PHU VROXWLRQ SUHSDUHG ZLWK D OHVV SRODU VROYHQW HJ WROXHQHf DLGV LQ WKH IUDFWLRQDO SUHFLSLWDWLRQ RI WKH SRO\PHU 7KH\ IUDFWLRQDOO\ SUHFLSLWDWHG WKH 306 SRO\PHU E\ DGGLQJ D E\ YROXPHf PL[WXUH RI PHWKDQRO DQG SURSDQRO WR WKH SRO\PHU GLVVROYHG LQ 7+) )ROORZLQJ WKLV DSSURDFK WKH DVSUHSDUHG SRO\PHU VROXWLRQV LQ WKLV VWXG\ ZHUH ILUVW VXEMHFWHG WR URWDU\ HYDSRUDWLRQ XQGHU YDFXXP LQ RUGHU WR UHPRYH WKH WROXHQH DQG GLR[DQH VROYHQWV $IWHU URWDU\ HYDSRUDWLRQ WKH IODVN FRQWDLQLQJ WKH SRO\PHU ZDV YHQWHG WR 1 WR PLQLPL]H FRQWDPLQDWLRQ IURP DLU 7KHQ 7+) ZDV DGGHG WR WKH SRO\PHU LQ WKH SURSRUWLRQV OLVWHG LQ 7DEOH

PAGE 312

7DEOH &RQGLWLRQV RI IUDFWLRQDO SUHFLSLWDWLRQ RI 306 SRO\PHUV )UDFWLRQDWHG SRO\PHU GHVLJQDWLRQ 3RO\PHU QRQn VROYHQWV SURSRUWLRQ 1RQVROYHQW SRO\PHU UDWLR POJf 7+) SRO\PHU UDWLR POJf 1RQVROYHQW 7+) UDWLR POJf ,QLWLDO 0Q ,QLWLDO 0Z ,QLWLDO 3', )LQDO 0Q )LQDO 0Z )LQDO 3',
PAGE 313

7DEOH FRQWfGf 3RO\PHU GHVLJQDWLRQ 3RO\PHU QRQn VROYHQWV SURSRUWLRQ 1RQVROYHQW SRO\PHU UDWLR POJf 7+) SRO\PHU UDWLR POJf 1RQVROYHQW 7+) UDWLR POJf ,QLWLDO 0Q ,QLWLDO 0Z ,QLWLDO 3', )LQDO 0Q )LQDO 0Z )LQDO 3',
PAGE 314

)UDFWLRQDO SUHFLSLWDWLRQ ZDV DFFRPSOLVKHG E\ XVLQJ DOFRKROV IRU SRO\PHUV 306 ) WKURXJK 306)f DQG DFHWRQH IRU SRO\PHUV 306) WKURXJK 306 )f DV QRQVROYHQWV 7KH DOFRKROV XVHG ZHUH SURSDQRO DQG PHWKDQRO LQ D YROXPH UDWLR )UDFWLRQDO SUHFLSLWDWLRQ ZDV FDUULHG RXW E\ DGGLQJ WKH SURSDQROPHWKDQRO PL[WXUH GURSZLVH WR WKH 306 SRO\PHU7+) VROXWLRQV ZKLFK ZHUH YLJRURXVO\ VWLUUHG GXULQJ WKH DOFRKRO DGGLWLRQVf 7DEOH VKRZV WKH SURSRUWLRQV RI 306 QRQVROYHQW DQG 7+) XVHG LQ WKH IUDFWLRQDWLRQ H[SHULPHQWV $OVR VKRZQ DUH WKH LQLWLDO DQG ILQDO 306 PROHFXODU ZHLJKWV LH EHIRUH DQG DIWHU IUDFWLRQDWLRQf WKH SRO\PHU \LHOG LH WKH SHUFHQWDJH RI LQLWLDO SRO\PHU ZKLFK ZDV UHFRYHUHG DIWHU IUDFWLRQDWLRQf DQG WKH UHVXOWV RI WKH fPHOW WHVWf VHH VHFWLRQ f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f 7DEOH VKRZV WKDW WKUHH RI WKH IRXU VDPSOHV IUDFWLRQDWHG ZLWK WKH DOFRKRO PL[WXUH GLG QRW PHOW XSRQ S\URO\VLV ZKLOH RQH RI WKH VDPSOH XQGHUZHQW SDUWLDO PHOWLQJ $ PHOW WHVW ZDV FDUULHG RXW E\ S\URO\]LQJ FKXQNV RI GULHG SRO\PHU WR r& LQ D QLWURJHQ DWPRVSKHUH DW r&PLQ 7KH SRO\PHU ZDV FRQVLGHUHG WR KDYH XQGHUJRQH QR PHOWLQJ LI WKH S\URO\]HG SRO\PHU UHWDLQHG VKDUS FRUQHUV DQG HGJHV ,W ZDV FRQVLGHUHG SDUWLDOO\ PHOWHG LI VRPH URXQGLQJ RI HGJHV DQG FRUQHUV RFFXUUHG DQG LI WKH S\URO\]HG FKXQNV ZHUH VWXFN WR WKH DOXPLQD ERDW XVHG IRU S\URO\VLV

PAGE 315

GZWGORJ0f GZWGORJ0f )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DOFRKRO PL[WXUH

PAGE 316

$OWKRXJK IUDFWLRQDO SUHFLSLWDWLRQ ZLWK WKH DOFRKRO PL[WXUH DOORZHG WKH SUHSDUDWLRQ RI 306 SRO\PHUV ZLWK VXIILFLHQWO\ KLJK PROHFXODU ZHLJKW IRU ILEHU SURFHVVLQJ WKH PHWKRG WXUQHG RXW WR EH XQVDWLVIDFWRU\ EHFDXVH LW UHVXOWHG LQ ODUJH DPRXQWV RI R[\JHQ FRQWDPLQDWLRQ LQ WKH SRO\PHUV 7KLV ZDV GHWHUPLQHG IURP (0$ UHVXOWV WKDW ZHUH REWDLQHG RQ D VDPSOH SUHSDUHG E\ S\URO\VLV r& LQ QLWURJHQf RI 306) 7DEOH VKRZV WKDW WKH S\URO\]HG VDPSOH FRQWDLQHG a ZWb R[\JHQ ,W LV SUHVXPHG WKDW WKLV KLJK R[\JHQ FRQWHQW UHVXOWHG IURP UHDFWLRQV WKDW RFFXUUHG EHWZHHQ WKH DOFRKROV DQG WKH 306 GXULQJ WKH IUDFWLRQDWLRQ SURFHVV 6XFK UHDFWLRQV ZRXOG LQFRUSRUDWH K\GUR[\O JURXSV LH LQ WKH IRUP RI 6L2+ JURXSVf LQ WKH SRO\PHU ,W LV H[SHFWHG WKDW WKH VLODQRO JURXSV ZRXOG FRQGHQVH XSRQ KHDW WUHDWPHQW WR IRUP VLOR[DQH ERQGVf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f DQGRU WKH DPRXQW RI DOFRKRO HJ WKH DOFRKROSRO\PHU UDWLRf XVHG LQ WKH SUHFLSLWDWLRQ SURFHVV )UDFWLRQDO SUHFLSLWDWLRQ ZDV FDUULHG RXW XVLQJ DFHWRQH EHFDXVH RI WKH ODUJH DPRXQW RI R[\JHQ FRQWDPLQDWLRQ WKDW RFFXUUHG ZKHQ WKH DOFRKRO PL[WXUH ZDV XVHG 7DEOH VKRZV WKDW WKH SRO\PHU \LHOGV REWDLQHG XVLQJ DFHWRQH ZHUH LQ WKH UDQJH RI b LH OHVV LQ PRVW FDVHVf WKDQ \LHOGV REWDLQHG E\ XVLQJ WKH DOFRKRO PL[WXUH +RZHYHU WKH PHWKRG ZDV VXFFHVVIXO LQ SURGXFLQJ 306 SRO\PHUV ZLWK LQFUHDVHG PROHFXODU ZHLJKW )LJXUH VKRZV D SORW RI WKH DYHUDJH PROHFXODU ZHLJKW DIWHU

PAGE 317

7DEOH 5HVXOWV RI (OHFWURQ 0LFURSUREH $QDO\VHV (0$f RQ IUDFWLRQDOO\SUHFLSLWDWHG r& S\URO\]HG QLWURJHQf SRO\PHUV 6DPSOH 'HVFULSWLRQ (OHPHQWDO FRPSRVLWLRQ $VPHDVXUHG ZWbf 1RUPDOL]HG ZWbf 6L & 7RWDO 6L &2 306 ) 3UHFLSLWDWHG XVLQJ DOFRKROV s s s s s s s 306 $ $VSUHSDUHG SRO\PHU s s s s s s s 306 ) 3UHFLSLWDWHG ZLWK DFHWRQH s s s s s s s

PAGE 318

),1$/ 0 )LJXUH 3ORW RI QRQVROYHQW WR SRO\PHU UDWLR YV ILQDO 0Z IRU SRO\PHUV SUHFLSLWDWHG XVLQJ DFHWRQH DV QRQVROYHQW

PAGE 319

IUDFWLRQDO SUHFLSLWDWLRQ YV WKH DFHWRQHSRO\PHU UDWLR XVHG LQ WKH SURFHVV 7KH PROHFXODU ZHLJKW JHQHUDOO\ LQFUHDVHG DV WKH DFHWRQH306 UDWLR GHFUHDVHG 7KLV LV FRQVLVWHQW ZLWK REVHUYDWLRQV PDGH IRU RWKHU IUDFWLRQDO SUHFLSLWDWLRQ SURFHVVHV >%1@f )LJXUH VKRZV DQ H[DPSOH RI WKH FKDQJH LQ WKH *3& PROHFXODU ZHLJKW GLVWULEXWLRQ DIWHU IUDFWLRQDWLRQ 7KH *3& UHVXOWV IRU WKH RWKHU SRO\PHUV IUDFWLRQDWHG ZLWK DFHWRQH DUH VKRZQ LQ $SSHQGL[ -f 7KH IUDFWLRQDWHG SRO\PHUV SUHSDUHG XVLQJ DFHWRQH ZHUH QRW FRQWDPLQDWHG ZLWK R[\JHQ 7KLV ZDV LOOXVWUDWHG E\ (0$ PHDVXUHPHQWV ZKLFK ZHUH FDUULHG RXW RQ D S\URO\]HG r& LQ QLWURJHQf VDPSOH 7DEOH VKRZV WKDW WKH R[\JHQ FRQWHQW RI D VDPSOH S\URO\]HG IURP 306) ZDV RQO\ ZWb 7DEOH LQGLFDWHV WKDW WKLV LV OHVV WKDQ WKH R[\JHQ FRQWHQW RI D S\URO\]HG VDPSOH SUHSDUHG IURP WKH DVV\QWKHVL]HG 306 SRO\PHU ,W LV LQFRQFHLYDEOH WKDW ORZPROHFXODUZHLJKW HJ ROLJRPHULFf SRUWLRQV RI WKH 306 SRO\PHUV ZKLFK DUH UHPRYHG GXULQJ IUDFWLRQDWLRQf DUH WKH PRVW VXVFHSWLEOH WR R[\JHQ LQFRUSRUDWLRQ GXULQJ H[SRVXUH WR R[\JHQ DQG ZDWHU YDSRU LQ WKH DWPRVSKHUH +RZHYHU WKH GLIIHUHQFH LQ R[\JHQ FRQWHQW REVHUYHG EHWZHHQ 306 DQG 306) LV SUREDEO\ ZLWKLQ H[SHULPHQWDO HUURU )LUVW YDULDWLRQV RI DW OHDVW b LQ WKH R[\JHQ FRQWHQW KDYH EHHQ REVHUYHG LQ 6L& ILEHUV SUHSDUHG E\ S\URO\VLV RI RUJDQRVLOLFRQ SRO\PHUVf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

PAGE 320

GZWGORJ0f GZWGORJ0f )LJXUH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH

PAGE 321

GHWHUPLQH LI WKHUH UHDOO\ LV D WUHQG RI ORZHU R[\JHQ FRQWHQW IRU WKH DFHWRQHIUDFWLRQDWHG SRO\PHUVf 7DEOH VKRZV WKDW PRVW RI WKH DFHWRQHIUDFWLRQDWHG SRO\PHUV GLG QRW PHOW XSRQ S\URO\VLV +RZHYHU VRPH PHOWLQJ ZDV REVHUYHG IRU 306) DQG 306 ) ,W LV XQFOHDU ZK\ WKHVH WZR SRO\PHUV VKRZHG VRPH PHOWLQJ ZKLOH VHYHUDO SRO\PHUV ZLWK ORZHU PROHFXODU ZHLJKW HJ 306) 306) 306) DQG 306 )f GLG QRW (YHQ WKRXJK VWDUWLQJ PROHFXODU ZHLJKWV ZHUH DOO VLPLODU WKHUH PD\ EH RWKHU GLIIHUHQFHV LQ 306 FKDUDFWHULVWLFV HJ GHJUHH RI EUDQFKLQJ DPRXQW RI 6L+ JURXSVf ZKLFK DIIHFW WKH IUDFWLRQDWLRQ EHKDYLRU DQG WKH SUHFLSLWDWHG SRO\PHU FKDUDFWHULVWLFV 6SLQQLQJ RI ILEHUV IURP 306EDVHG SRO\PHUV 6SLQQLQJ RI ILEHUV IURP DVSUHSDUHG EOHQGV RI 3063&6 SRO\PHUV 7KH HDUOLHVW ZRUN RQ VSLQQLQJ RI ILEHUV LQ WKLV VWXG\ ZDV FDUULHG RXW XVLQJ EOHQGV RI DVSUHSDUHG QRQKHDWWUHDWHGf 306 DQG 3&6 SRO\PHUV 7DEOH VKRZV WKH FRQGLWLRQV IRU ILEHU VSLQQLQJ H[SHULPHQWV IURP 3063&6 SRO\PHU EOHQGV QRQKHDW WUHDWHGf 7KUHH 3063&6 UDWLRV ZHUH XVHG LQ WKH VSLQ GRSH SUHSDUDWLRQ YL] DQG 7KH DPRXQW RI VSLQQLQJ DGGLWLYH 36= XVHG LQ DOO WKH ILEHU EDWFKHV ZDV ZWb EDVHG RQ WRWDO DPRXQW RI SRO\PHU LH 3063&636=f 7KH 306 SRO\PHUV XVHG LQ WKHVH EOHQGV ZHUH VWRUHG LQ FRQFHQWUDWHG IRUP ,W ZDV VXEVHJXHQWO\ OHDUQHG WKDW WKHVH SRO\PHUV ZHUH VXEMHFW WR VLJQLILFDQW DJLQJ HIIHFWV HVSHFLDOO\ ZKHQ VWRUHG LQ FRQFHQWUDWHG IRUPf ZKLFK ZDV LQGLFDWHG E\ YLVXDO REVHUYDWLRQV RI fPLFURJHO IRUPDWLRQ RYHU WLPH f0LFURJHOf IRUPDWLRQ LV DWWULEXWHG WR ODWHQW SRO\PHUL]DWLRQ DQG FURVVOLQNLQJ UHDFWLRQV DW UHDFWLYH VLWHV LQ 306 SRO\PHUVf 'XH WR WKH PLFURJHO IRUPDWLRQ PRVW RI WKH SRO\PHU VROXWLRQV ZHUH HLWKHU GLIILFXOW WR ILOWHU WKURXJK SP ILOWHUV HJ VSLQ EDWFKHV 8)V 8)V 8)V 8)V DQG 8) Vf RU WKH\ ZHUH ILOWHUDEOH RQO\ WKURXJK SP ILOWHUV HJ 8)V WKURXJK 8)Vf

PAGE 322

7DEOH &RQGLWLRQV IRU ILEHU VSLQQLQJ H[SHULPHQWV IURP DVSUHSDUHG 3063&6 SRO\PHU EOHQGV QRQKHDW WUHDWHGf %DWFK $PRXQW RI 3&6 f $PRXQW RI 306 Jf 3063&6 UDWLR ZWbf 36=i ZWb )LOWUDWLRQ FRQGLWLRQ )LOWHU SPfWLPH PLQf )ORZ WHVW WLPHr Vf )LQDO VROLGV ORDGLQJ bf 9LVFRVLW\ 3DVf 6SLQ VSHHG USPf 3UHVVXUH SVLf 5HPDUNV 8)V r r r 6SLQQLQJ DYHUDJH 8)V VHWVf r r 6SXQ ZHOO 8)V r 6SXQ SRRUO\ 8)6 r r 6SXQ ZHOO 8)V VHWVf r 6SXQ SRRUO\ 8)V r r 6SXQ ZHOO 8)V r 6SXQ ZHOO 8)6 r 6SXQ SRRUO\ 8)6 6SXQ SRRUO\ 8)6 r r r 6SXQ SRRUO\ 8)6 r r 6SXQ ZHOO 8)6 r r 6SXQ ZHOO r )ORZ WHVW WLPH LV WKH WLPH WDNHQ E\ WKH SRO\PHU VROXWLRQ WR WUDYHO FP DW r DQJOH 7KH PHDVXUHPHQW ZDV GRQH LQ D FDSSHG YLDO 7KH SURFHGXUH LV GHVFULEHG LQ PRUH GHWDLO LQ VHFWLRQ r 'DWD QRW DYDLODEOH 7LPH WDNHQ IRU ILOWUDWLRQ WKURXJK VSHFLILHG ILOWHU DW SVL QLWURJHQ SUHVVXUH 3HUFHQWDJH EDVHG RQ WRWDO DPRXQW RI SRO\PHU 3063&636=f

PAGE 323

)ORZ WHVW WLPHV ZHUH PHDVXUHG IRU VSLQ EDWFKHV DV DQ LQGLFDWRU RI WKH YLVFRVLW\ RI WKH VSLQ GRSHV 6HH VHFWLRQ IRU WKH GHWDLOV RI WKH IORZ WHVW PHDVXUHPHQWf 7KH IORZ WHVW ZDV XVHG LQVWHDG RI YLVFRVLW\ PHDVXUHPHQWV IRU WZR UHDVRQV )LUVW WKH WHVW GRHV QRW FRQVXPH PDWHULDO 5KHRORJLFDO WHVWV UHVXOW LQ OHVV PDWHULDO EHLQJ DYDLODEOH IRU VSLQQLQJf 6HFRQG UKHRORJLFDO PHDVXUHPHQWV UHVXOW LQ DGGLWLRQDO H[SRVXUH RI WKH DLU VHQVLWLYH VSLQ GRSH WR WKH DPELHQW DWPRVSKHUH 7KH LQLWLDO EDVLV IRU FKRRVLQJ WKH IORZ WHVW WLPH ZDV WKH SULRU H[SHULHQFH ZLWK 3&6 SRO\PHU VROXWLRQV $V GLVFXVVHG LQ VHFWLRQ IORZ WLPHV RQ WKH RUGHU RI V ZLWK FRUUHVSRQGLQJ YLVFRVLWLHV RI a 3D Vf ZHUH W\SLFDOO\ XVHG IRU VSLQQLQJ ,W ZDV VXEVHTXHQWO\ GLVFRYHUHG VHH EHORZf KRZHYHU WKDW KLJKHU IORZ WLPHV DQG YLVFRVLWLHVf ZHUH UHTXLUHG IRU VSLQ GRSHV SUHSDUHG ZLWK 3063&6 LQ RUGHU WR REWDLQ ERWK JRRG VSLQQLQJ EHKDYLRU DQG JUHHQ ILEHUV ZKLFK ZHUH QRW VWXFN WRJHWKHU DIWHU VSLQQLQJ 7DEOH VKRZV WKDW WKUHH EDWFKHV ZLWK 3063&6 FRPSRVLWLRQ ZHUH VSXQ LH 8)V 8)V DQG 8)V 2QO\ 8)V VSXQ ZHOOr 8)V ZDV WKH HDUOLHVW VSLQ EDWFK SUHSDUHG DQG VSLQQLQJ WHFKQLTXHV ZHUH QRW \HW SHUIHFWHG )RU H[DPSOH ZLQGLQJ RI ILEHUV ZDV GLIILFXOW GXH WR DLU GUDIW HIIHFWV LQ WKH ODERUDWRU\ 7KXV VXEVHTXHQW H[SHULPHQWV ZHUH FDUULHG RXW LQ D JORYH ER[f 8)V DOVR VSXQ SRRUO\ EXW WKLV ZDV SUREDEO\ GXH WR PLFURJHO SDUWLFOHV LQ WKH VSLQ GRSH 7KH VROXWLRQ ZDV RQO\ ILOWHUDEOH WKURXJK SP EXW QRW SPf ILOWHUVf 6L[ EDWFKHV RI ILEHUV ZHUH VSXQ ZLWK WKH 3063&6 FRPSRVLWLRQ %DWFKHV ZLWK KLJK IORZ WHVW WLPHV LH Vf GLG QRW VSLQ ZHOO HJ 8)V 8)V DQG 8) Vf 7KH UHPDLQLQJ WKUHH ILEHU EDWFKHV ZLWK UHODWLYHO\ ORZHU YLVFRVLW\ LH IORZ WHVW WLPHV RI Vf VSXQ ZHOO 8)V ZKLFK KDG D IORZ WHVW WLPH RI RQO\ V VSXQ ZHOO r )LEHU VSLQQLQJ EHKDYLRU ZDV FRQVLGHUHG fJRRGf ZKHQ WKHUH ZHUH Lf IHZHU ILEHU EUHDNV GXULQJ VSLQQLQJ LLf WKH SRO\PHU HDVLO\ ILEHUL]HG DQG VWUHWFKHG DQG LQf D ODUJHU DPRXQW RI ILEHUV ZDV FROOHFWHG

PAGE 324

EXW WKH DVVSXQ ILEHUV ZHUH VWXFN WRJHWKHU )LJXUH VKRZV 6(0 PLFURJUDSKV ILEHUV ZKLFK LOOXVWUDWH nQHFNLQJn EHWZHHQ WKH DVVSXQ ILEHUV 7KLV PD\ KDYH EHHQ FDXVHG E\ LQVXIILFLHQW VROYHQW UHPRYDO SULRU WR FROOHFWLRQ RI ILEHUV RQ WKH ZLQGLQJ GUXP 7KH ORZ IORZ WHVW WLPH LQGLFDWHV WKDW PRUH VROYHQW ZDV SUREDEO\ SUHVHQW LQ WKH VSLQQLQJ VROXWLRQ 7KLV FRXOG OHDG WR GLIILFXOWLHV LQ UHPRYLQJ HQRXJK VROYHQW WR fVROLGLI\f WKH ILEHUV SULRU WR FROOHFWLRQ RQ WKH ZLQGHUf 7KH QHFNLQJ PD\ DOVR KDYH EHHQ FDXVHG E\ IORZ RI D OLTXLG SRUWLRQ RI WKH 306 SRO\PHU LQ WKH VSLQ EDWFK /RZHU PROHFXODU ZHLJKW SRUWLRQV ZHUH OLTXLGV DW URRP WHPSHUDWXUHf +RZHYHU WKH ODWWHU H[SODQDWLRQ VHHPV OHVV OLNHO\ EHFDXVH DGKHVLRQ RI DVVSXQ ILEHUV ZHUH QRW REVHUYHG IRU VSLQ EDWFKHV ZKLFK KDG KLJKHU IORZ WHVW WLPHV )LEHUV IURP VRPH RI WKH VSLQ EDWFKHV LH 8)V DQG 8)Vf ZHUH IOH[LEOH DQG HDVLO\ VHSDUDEOH DIWHU VSLQQLQJ EXW EHFDPH EULWWOH DQG VWXFN WRJHWKHU DIWHU S\URO\VLV 7KLV ZDV SUREDEO\ FDXVHG E\ PHOWLQJ RI SRUWLRQV RI 306 SRO\PHUV )LJXUH VKRZV WKDW QHFNV IRUPHG DIWHU S\URO\VLV RI WKH 8)V ILEHUV %DWFKHV SUHSDUHG ZLWK D 3063&6 FRPSRVLWLRQ 8)V 8)V DQG 8) V LQ 7DEOH f GHYHORSHG VHYHUH SUREOHPV ZLWK DGKHVLRQ EHWZHHQ DVVSXQ ILEHUV DQG EHWZHHQ DVVSXQ ILEHUV DQG WKH ZLQGLQJ GUXP 7KLV PD\ KDYH EHHQ GXH WR IORZ RI WKH OLTXLG SRUWLRQ RI WKH 306 SRO\PHUV LQ WKH VSLQ EDWFKHV ,W LV DOVR SRVVLEOH WKDW WKH VROYHQW HYDSRUDWLRQ UDWH ZDV VORZHU LQ WKHVH EDWFKHV 7KLV ZRXOG UHVXOW LQ IORZ RI WKH ILEHUV GXH WR D KLJK UHVLGXDO OLTXLG FRQWHQWf 7DEOH VKRZV WKH ILEHU GLDPHWHUV DQG WHQVLOH VWUHQJWKV RI 6L& ILEHUV SUHSDUHG E\ VSLQQLQJ 3063&6 SRO\PHU EOHQGV QRQKHDW WUHDWHGf DQG S\URO\]LQJ WKH DVVSXQ ILEHUV XQGHU WKH FRQGLWLRQV LQGLFDWHG 7KH ILEHU WHQVLOH VWUHQJWKV GHFUHDVHG ZLWK LQFUHDVLQJ DPRXQW RI 306 LQ WKH VSLQ EDWFK )LEHU EDWFKHV SUHSDUHG ZLWK b 306 ZHUH WRR ZHDN DQG EULWWOH WR EH WHVWHG 7DEOH VKRZV WKDW ILEHU EDWFKHV SUHSDUHG ZLWK 3063&6 DQG S\URO\]HG DW r& KDG DQ DYHUDJH WHQVLOH VWUHQJWK RI

PAGE 325

)LJXUH 6(0 PLFURJUDSKV RI DVVSXQ ILEHUV EDWFK 8)Vf SUHSDUHG IURP 3063&6 EOHQGV QRQ KHDW WUHDWHGf VKRZLQJ QHFNLQJ

PAGE 326

)LJXUH 6(0 PLFURJUDSKV RI S\URO\]HG ILEHUV EDWFK 8)Vf SUHSDUHG IURP 3063&6 EOHQGV QRQKHDW WUHDWHGf VKRZLQJ QHFNLQJ

PAGE 327

7DEOH 7HQVLOH VWUHQJWKV RI 6L& ILEHUV VSXQ IURP DVSUHSDUHG 3063&6 SRO\PHU EOHQGV 'HVLJQDWLRQ 3063&6 UDWLR ZWbf +HDW WUHDWPHQW WHPSHUDWXUH r&f +HDW WUHDWPHQW DWPRVSKHUH RI ILEHUV WHVWHG )LEHU GLDPHWHU XUQf 7HQVLOH VWUHQTWK *3Df 8)V Q s s 8)V $U s s 8)V Q s s 8)6 Q s s 8)V Q s s 8)6 $U s s 8)6 Q s s 8)6 $U s s 8)6 Q s s

PAGE 328

*3D ZKHUHDV ILEHU EDWFKHV SUHSDUHG ZLWK 3063&6 UDWLR DQG DOVR S\URO\]HG DW r&f KDG DQ DYHUDJH WHQVLOH VWUHQJWK RI *3D 6RPH RI WKH ILEHU EDWFKHV ZLWK 3063&6 UDWLR VXFK DV 8)V DQG 8)V ZHUH WRR ZHDN WR EH WHVWHGf 7DEOH DOVR VKRZV WKDW ILEHUV KHDWWUHDWHG DW r& KDG ORZHU VWUHQJWKV WKDQ WKH FRUUHVSRQGLQJ ILEHUV KHDWWUHDWHG WR r& ,Q VXPPDU\ LW ZDV QRW SRVVLEOH WR SUHSDUH KLJK VWUHQJWK 6L& ILEHUV IURP DV SUHSDUHG 3063&6 SRO\PHU EOHQGV $ KLJKHU PROHFXODU ZHLJKW PRUH FURVVOLQNHGf LQIXVLEOH 306 SRO\PHU ZDV QHHGHG WR DYRLG DGKHVLRQ SUREOHPV EHWZHHQ DVVSXQ ILEHUV DQG PHOWLQJ RI ILEHUV GXULQJ S\URO\VLV 6SLQQLQJ RI KHDWWUHDWHG 306 SRO\PHUV DQG 3063&6 SRO\PHU EOHQGV 7DEOH VKRZV FRQGLWLRQV DQG VRPH TXDOLWDWLYH UHVXOWV IRU ILEHU VSLQQLQJ H[SHULPHQWV FDUULHG RXW XVLQJ KHDWWUHDWHG SRO\PHUV 3063&6 EOHQGV RI DQG ZHUH XVHG LQ PDNLQJ VSLQ GRSHV 7KH EOHQGV ZHUH SUHSDUHG E\ WZR PHWKRGV f 306 SRO\PHUV ZHUH KHDWWUHDWHG VHSDUDWHO\ DQG PL[HG ZLWK DV SUHSDUHG 3&6 LQ WKH GHVLUHG UDWLR DQG f $VSUHSDUHG 306 DQG 3&6 ZHUH PL[HG LQLWLDOO\ LQ WKH GHVLUHG SURSRUWLRQV DQG WKHQ WKH PL[WXUH ZDV KHDWWUHDWHG 7KUHH VSLQ GRSHV 8)V 8)V DQG 8)Vf ZHUH SUHSDUHG E\ PHWKRG XVLQJ D 3063&6 PL[WXUH 7KH UKHRORJLFDO IORZ EHKDYLRU RI WKHVH VSLQ GRSHV LV VKRZQ LQ )LJXUHV DQG $OO WKUHH EDWFKHV VSXQ ZHOO +RZHYHU WKH 8)V VSLQ GRSH ZKLFK KDG D VLJQLILFDQWO\ ORZHU YLVFRVLW\ 3D Vf FRPSDUHG WR WKH 8)V 3D Vf DQG 8)V 3D Vf VSLQ GRSHV SURGXFHG DVVSXQ ILEHUV ZKLFK ZHUH VWXFN WRJHWKHU ,Q FRQWUDVW ILEHUV IURP WKH RWKHU WZR VSLQ GRSHV ZHUH HDVLO\ VHSDUDWHG ,W LV LQWHUHVWLQJ WR QRWH 8)V KDG PXFK KLJKHU VROLGV ORDGLQJ ZWbf GHVSLWH WKH ORZHU YLVFRVLW\ FRPSDUHG WR WKH RWKHU WZR EDWFKHV ZKLFK KDG VROLGV ORDGLQJV RI DQG ZWb UHVSHFWLYHO\f 7KLV LV DWWULEXWHG WR D ORZHU PROHFXODU

PAGE 329

7DEOH &RQGLWLRQV DQG TXDOLWDWLYH UHVXOWV IRU ILEHUVSLQQLQJ H[SHULPHQWV IURP KHDWWUHDWHG 306 DQG 3063&6 EOHQGV %DWFK 306 XVHG 3&6 DGGHG %HIRUH KHDW $IWHU KHDW WUHDWPHQW WUHDWPHQW 306 3&6 UDWLR :Wb 36= DGGHG :Wb '% DGGHG %HIRUH KHDW $IWHU KHDW WUHDWPHQW WUHDWPHQW )LOWUDWLRQ EHKDYLRUr )LOWHU SPf WLPHPLQf )ORZ WHVW WLPHVf 6ROLGV ORDGLQJ bf 9LVFRVLW\ 3DVf 6SLQ VSHHG USPf 6SLQ SUHVVXUH SVLf 8)V 306 $+ r 3&6 6SXQ ZHOO DVVSXQ ILEHUV VWXFN WRJHWKHU 8)6 306 $+ r 3&6 6SXQ ZHOO DVVSXQ DQG S\URO\]HG IL EHUV VHSDUDEOH 8)V 306 $+ r 3&6 6SXQ ZHOO DVVSXQ DQG S\URO\]HG ILEHUV VHSDUDEOH 8)V 306 $+ r 3&6 r 6SXQ ZHOO DVVSXQ ILEHUV DQG S\URO\]HG ILEHUV VHSDUDEOH 8)6 306 $3+ 3&6 r 6SXQ ZHOO DVVSXQ ILEHUV VHSDUDEOH EXW S\URO\]HG ILEHUV VWXFN WRJHWKHU 8)V 306 $3+ 3&6 r VHWVf 6SXQ ZHOO DVVSXQ ILEHUV VHSDUDEOH EXW S\URO\]HG ILEHUV VWXFN WRJHWKHU 8)6 306 $3+ 3&6 r 6SXQ SRRUO\ DVVSXQ ILEHUV EXW S\URO\]HG ILEHUV ZHUH EULWWOH

PAGE 330

7DEOH &RQWfGf %DWFK 306 XVHG 3&6 DGGHG %HIRUH KHDW $IWHU KHDW WUHDWPHQW WUHDWPHQW 306 3&6 UDWLR :Wb 36= DGGHG :Wb '% DGGHG %HIRUH KHDW $IWHU KHDW WUHDWPHQW WUHDWPHQW )LOWUDWLRQ EHKDYLRU )LOWHU SPf WLPHPLQf )ORZ WHVW WLPHVf 6ROLGV ORDGLQJ bf 9LVFRVLW\ 3DVf 6SLQ VSHHG USPf 6SLQ SUHVVXUH SVLf 8)6 306 $3+ 3&6 r 6SXQ ZHOO DVVSXQ ILEHUV VHSDUDEOH EXW S\URO\]HG ILEHUV ZHUH EULWWOH 8)V 306 $3+ 3&6 r r 6SLQ GRSH JHOOHG GXULQJ VWRUDJH 8)6 306 $3+ 3&6 r r r r r 6SLQ GRSH JHOOHG GXULQJ VROXWLRQ SUHSDUDWLRQ 8)V 306 $3+ 3&6 r VHWVf 6SXQ ZHOO DVVSXQ DQG S\URO\]HG ILEHUV ZHUH VHSDUDEOH 8)6 306 $3+ 3&6 r r r r 6SLQ GRSH JHOOHG GXULQJ VROXWLRQ SUHSDUDWLRQ 8)6 306 $3'+ 3&6 r 6SXQ ZHOO DVVSXQ ILEHUV VHSDUDEOH EXW S\URO\]HG ILEHUV VWXFN WRJHWKHU 8)6 306 $3'D+ 3&6 r r 6SXQ SRRUO\ RQO\ IUDJPHQWV RI ILEHUV FROOHFWHG

PAGE 331

7DEOH FRQWnGf %DWFK 306 XVHG 3&6 DGGHG %HIRUH KHDW $IWHU KHDW WUHDWPHQW WUHDWPHQW 306 3&6 UDWLR :Wb 36= DGGHG :Wb '% DGGHG %HIRUH KHDW $IWHU KHDW WUHDWPHQW WUHDWPHQW )LOWUDWLRQ EHKDYLRU )LOWHU SPf WLPHPLQf )ORZ WHVW WLPHVf 6ROLGV ORDGLQJ bf 9LVFRVLW\ 3DVf 6SLQ VSHHG USPf 6SLQ SUHVVXUH SVLf 8)6 306 $3'+ 3&6 r VHWVf r 6SXQ SRRUO\ QR ILEHUV FROOHFWHG 8)6 306 $'+ r 3&6 6SXQ SRRUO\ DVVSXQ ILEHUV VHSDUDEOH EXW S\UR \]HG ILEHUV EULWWOH 8)6 306 $'+ r 3&6 r 1RW VSLQQD EOH 8)6 306 $+ r r 6SXQ SRRUO\ DVVSXQ ILEHUV VWXFN WRJHWKHU 8)6 306 $+ r r 6SXQ SRRUO\ DVVSXQ ILEHUV VWXFN WRJHWKHU 8)6 306 $+ r r &HQWULn IXJHG 6SXQ ZHOO DVVSXQ ILEHUV VWXFN WRJHWKHU 8)6 306 $'+ r r VHWVf r r r r r 6SLQ GRSH JHOOHG GXULQJ SURFHVVLQJ

PAGE 332

7DEOH &RQWfGf %DWFK 306 XVHG 3&6 DGGHG %HIRUH KHDW $IWHU KHDW WUHDWPHQW WUHDWPHQW 306 3&6 UDWLR :Wb 36= DGGHG :Wb '% DGGHG %HIRUH KHDW $IWHU KHDW WUHDWPHQW WUHDWPHQW )LOWUDWLRQ EHKDYLRU )LOWHU SPf WLPHPLQf )ORZ WHVW WLPHVf 6ROLGV ORDGLQJ bf 9LVFRVLW\ 3DVf 6SLQ VSHHG USPf 6SLQ SUHVVXUH SVLf 8)6 306 $'+ r VHWVf 6SXQ ZHOO DVVSXQ ILEHUV VHSDUDEOH EXW S\URO\]HG ILEHUV EULWWOH 8)6 306 $'+ r r VHWVf r 1RW VSLQQD EOH D 36= DGGHG EHIRUH KHDWWUHDWPHQW E 7LPH WDNHQ IRU ILOWUDWLRQ WKURXJK VSHFLILHG ILOWHU DW SVL QLWURJHQ SUHVVXUH F 7R FRQVHUYH PDWHULDO WKLV SDUWLFXODU KHDWWUHDWHG SRO\PHU VROXWLRQ ZDV FHQWULIXJHG DW USP IRU PLQ WR UHPRYH PLFURJHOV

PAGE 333

B 9f U A Q R R f 2 ,QFUHDVLQJ 6KHDU 5DWH ’ 'HFUHDVLQJ 6KHDU 5DWH f§4 7 D 7 7 %f 6KHDU 5DWH Vnf )LJXUH 3ORWV RI $f VKHDU VWHVV YV VKHDU UDWH DQG %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH

PAGE 334

9LVFRVLW\ 3D Vf VKHDU 6WUHVV 3D! $f 2 ,QFUHDVLQJ 6KHDU 5DWH Â’ 'HFUHDVLQJ 6KHDU 5DWH 2 Â’ 2 D R fL 6KHDU 5DWH Vnf %f )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH

PAGE 335

9LVFRVLW\ 3D Vf VKHDU 6WUHVV 3D! Â’ RQ R 2 ,QFUHDVLQJ 6KHDU 5DWH Â’ 'HFUHDVLQJ 6KHDU 5DWH Â’ 2 b f%f 6KHDU 5DWH Vnf )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH

PAGE 336

ZHLJKW IRU WKH 306 SRO\PHU )RU H[DPSOH DV GLVFXVVHG LQ VHFWLRQ 7DEOH f 306$+ XVHG LQ 8)Vf KDV ORZHU PROHFXODU ZHLJKW WKDQ 306$+ XVHG LQ 8)Vff 2QH VSLQ EDWFK 8)Vf ZDV SUHSDUHG E\ PHWKRG XVLQJ D 3063&6 FRPSRVLWLRQ ,W VSXQ ZHOO EXW KDG D UHODWLYHO\ ORZ VROLGV ORDGLQJ bf 7KLV LV SUHVXPDEO\ GXH WR WKH KLJK PROHFXODU ZHLJKW RI WKH VWDUWLQJ 306 306$+f VHH VHFWLRQ f 7KH *3& SORW LQ )LJXUH VKRZV WKH W\SLFDO ELPRGDO PROHFXODU ZHLJKW GLVWULEXWLRQ REVHUYHG LQ 306 SRO\PHUV ZKLFK KDYH EHHQ KHDWWUHDWHG WR HIIHFW VLJQLILFDQW LQFUHDVHV LQ DYHUDJH PROHFXODU ZHLJKW 7KH KLJK PROHFXODU ZHLJKW SRUWLRQ RI WKH SRO\PHU UHVXOWHG LQ GLIILFXOWLHV LQ ILOWHULQJ WKH VSLQ EDWFK 7KH VROXWLRQ FRXOG SDVV WKURXJK 72 SP ILOWHUV EXW QRW SP ILOWHUVf 7DEOH DOVR VKRZV FKDUDFWHULVWLFV RI VSLQ EDWFKHV SUHSDUHG E\ PHWKRG XVLQJ 3063&6 FRPSRVLWLRQV $V QRWHG SUHYLRXVO\ FRQFHQWUDWHG 306 VROXWLRQ WHQGV WR DJH LH LQFUHDVH LQ YLVFRVLW\ DQGRU JHOf XSRQ VWRUDJH +HQFH VHYHUDO RI WKH VSLQ GRSHV 8)V 8)V DQG 8)Vf JHOOHG GXULQJ VSLQ EDWFK SUHSDUDWLRQ RU GXULQJ VWRUDJH SULRU WR ILEHU VSLQQLQJ 7KH 306 XVHG LQ VSLQ EDWFKHV 8)V DQG 8)V YL] 306$3+ DQG 306$3+ KDG VLPLODU PROHFXODU ZHLJKW FKDUDFWHULVWLFV VHH WKH *3& SORWV )LJXUH 306$3+f DQG )LJXUH 306$3+f UHVSHFWLYHO\ LQ VHFWLRQ f 8)V KDG D KLJKHU VROLGV ORDGLQJ bf ,Q DGGLWLRQ LW ZDV PXFK PRUH GLIILFXOW WR ILOWHU WKH SRO\PHU VROXWLRQ 306$3+f WKURXJK SP ILOWHUV 7KH UHDVRQ IRU WKHVH REVHUYDWLRQV LV QRW FOHDU 8)V ZDV SUHSDUHG ZLWK D KLJKHU YLVFRVLW\ EXW LW LV XQOLNHO\ WKDW WKLV DORQH ZRXOG DFFRXQW IRU VXFK D ODUJH GLIIHUHQFH LQ VROLGV ORDGLQJ DQG ILOWUDWLRQ EHKDYLRUf %RWK 8)V DQG 8)V EDWFKHV VSXQ ZHOO 7KH DVVSXQ ILEHUV RI WKHVH EDWFKHV ZHUH VHSDUDEOH EXW WKH\ VWXFN WRJHWKHU DIWHU S\URO\VLV 7KLV LV OLNHO\ GXH WR WKH IDFW WKDW ORZ PROHFXODU ZHLJKW FRPSRQHQWV LQ WKH

PAGE 337

VWDUWLQJ 306 SRO\PHUV IRU ERWK 8)V DQG 8)Vf PHOWHG GXULQJ S\URO\VLV DQG FDXVHG WKH ILEHUV WR VWLFN WRJHWKHU 6SLQ EDWFK 8)V DOVR VSXQ ZHOO EXW WKH S\URO\]HG ILEHUV ZHUH EULWWOH DIWHU S\URO\VLV 7KLV LV DOVR SUHVXPDEO\ GXH WR PHOWLQJ RI ORZ PROHFXODU ZHLJKW FRPSRQHQWV LQ WKH SRO\PHU ,W PD\ EH UHFDOOHG IURP WKH GLVFXVVLRQ LQ VHFWLRQ WKDW HYHQ WKRXJK WKH DYHUDJH PROHFXODU ZHLJKW RI 306$3+ ZDV KLJK ArAf LW KDG D ELPRGDO PROHFXODU ZHLJKW GLVWULEXWLRQ +HQFH PHOWLQJ RI ORZ PROHFXODU ZHLJKW FRPSRQHQWV LQ WKH SRO\PHU FRXOG VWLOO KDYH RFFXUUHGf 6SLQ EDWFKHV 8)V DQG 8)V VSXQ SRRUO\ 7KH SRO\PHU XVHG LQ 8)V 306$3+f KDG D KLJK VWDUWLQJ PROHFXODU ZHLJKW 0r}f DQG WKH VSLQ GRSH ZDV DOVR QRW ILOWHUDEOH WKURXJK VXEPLFURQ ILOWHUV 7KH VROLGV ORDGLQJ ZDV DOVR UHODWLYHO\ ORZ bf IRU WKLV VSLQ GRSH ,Q WKH FDVH RI 8)V WKH VWDUWLQJ SRO\PHU XVHG 306 $'+f KDG D PROHFXODU ZHLJKW RI } LH ORZHU WKDQ WKH PROHFXODU ZHLJKW RI WKH SRO\PHU XVHG LQ 8)Vf DQG WKH VSLQ GRSH ILOWHUHG WKURXJK SP ILOWHU UHODWLYHO\ HDVLO\ +RZHYHU WKH VSLQ GRSH ZDV VKHDU WKLQQLQJ LH WKH YLVFRVLW\ GHFUHDVLQJ IURP a WR a 3D V DV VKHDU UDWH LQFUHDVHG IURP WR Vn UHVSHFWLYHO\f VHH )LJXUH f $OVR WKH VSLQ GRSH KDG D ORZ VROLGV ORDGLQJ bf 7KH ORZ VROLGV ORDGLQJ VXJJHVWV WKDW WKH SRO\PHU LV KLJKO\ FURVVOLQNHG $V LQGLFDWHG LQ 7DEOH WKH VWDUWLQJ SRO\PHU XVHG IRU WKLV VSLQ GRSH FRQWDLQHG ZWb '% ,W LV SRVVLEOH WKDW '% OHG WR WKH GHYHORSPHQW RI SRO\PHUV ZKLFK KDYH D KLJKO\ EUDQFKHG QHWZRUNW\SH VWUXFWXUH :HDNO\ DVVRFLDWHG SRO\PHUV LQ VXFK D VWUXFWXUH PD\ EUHDN DSDUW XQGHU VKHDU DQG KHQFH VKHDU WKLQQLQJ IORZ EHKDYLRU ZRXOG EH REVHUYHG LQ UKHRORJLFDO PHDVXUHPHQWV 7KH VWUXFWXUH LH QHWZRUN FKDUDFWHUf LQ WKHVH VROXWLRQV LPSDUWV D PRUH HODVWLF FKDUDFWHU ZKLFK LV DSSDUHQWO\ UHODWHG WR WKH SRRU VSLQQDELOLW\ 6LPLODU REVHUYDWLRQV LH GLIILFXOW\ LQ VSLQQLQJ

PAGE 338

$f )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH

PAGE 339

ILEHUV IURP VKHDU WKLQQLQJ DQG WKL[RWURSLF VROXWLRQVf KDYH EHHQ UHSRUWHG SUHYLRXVO\ >6DF@ 6SLQ EDWFK 8)V DOVR H[KLELWHG KLJKO\ VKHDU WKLQQLQJ UKHRORJLFDO IORZ EHKDYLRU )LJXUH f +RZHYHU XQOLNH 8)V WKLV EDWFK VSXQ ZHOO 7KH 8)V EDWFK ZDV SUHSDUHG ZLWK QR '% DQG WKH 306 SRO\PHU XVHG LQ WKH EDWFK KDG EHHQ SUHSDUHG ZLWK ZWb 36= GXULQJ KHDW WUHDWPHQW ,Q FRQWUDVW WKH 8)V EDWFK ZDV SUHSDUHG ZLWK ZWb '% DQG WKH 306 SRO\PHU XVHG LQ WKH EDWFK KDG ZWb 36= DQG ZWb '% GXULQJ KHDW WUHDWPHQW 7KH KLJKHU VROLGV ORDGLQJ LQ EDWFK 8)V VXJJHVWV WKDW WKH SRO\PHUV GHYHORS D OHVV FURVVOLQNHG VWUXFWXUH +RZHYHU LW LV QRW XQGHUVWRRG ZK\ WKH VROXWLRQ VWLOO VKRZV VXFK KLJKO\ VKHDU WKLQQLQJ EHKDYLRU 7KUHH VSLQ EDWFKHV 8)V 8)V DQG 8)Vf ZHUH SUHSDUHG ZLWK 3063&6 SRO\PHU EOHQGV 7KHVH VSLQ EDWFKHV HLWKHU VSXQ SRRUO\ RU FRXOG QRW EH VSXQ DW DOO 7KH VSLQ EDWFKHV KDG ORZ VROLGV ORDGLQJ DQG UKHRORJLFDO IORZ EHKDYLRU ZDV KLJKO\ VKHDU WKLQQLQJ W\SLFDO UKHRORJLFDO IORZ EHKDYLRU LV VKRZQ LQ )LJXUH IRU 8)Vf $V GLVFXVVHG HDUOLHU LQ WKH FDVH RI WKH 8)V VSLQ EDWFK WKH SRRU VSLQQLQJ EHKDYLRU PD\ KDYH EHHQ FDXVHG E\ KLJKO\ VKHDU WKLQQLQJ EHKDYLRU RI WKH VSLQ GRSHV 6L[ VSLQ EDWFKHV ZHUH SUHSDUHG ZLWK b KHDWWUHDWHG 306 SRO\PHU )LEHU EDWFKHV 8)V DQG 8)V VSXQ SRRUO\ 7KH VSLQ GRSHV XVHG IRU WKHVH EDWFKHV KDG ORZ YLVFRVLWLHV a 3D Vf DQG WKH DVVSXQ ILEHUV VWXFN WRJHWKHU )LEHU EDWFK 8)V VSXQ ZHOO EXW WKH DVVSXQ ILEHUV DOVR VWXFN WRJHWKHU 5KHRORJLFDO PHDVXUHPHQWV ZHUH QRW PDGH GXH WR OLPLWHG DPRXQW RI VSLQ GRSHf IRU WKLV VSLQ EDWFK EXW WKH ORZ IORZ WHVW WLPH LQGLFDWHG WKDW WKH YLVFRVLW\ ZDV SUREDEO\ WRR ORZ 6SLQ EDWFKHV 8)V 8)V DQG 8)6 ZHUH SUHSDUHG XVLQJ 306 SRO\PHUV ZKLFK ZHUH KHDWWUHDWHG ZLWK ZWb '% $V GLVFXVVHG LQ VHFWLRQ WKHVH SRO\PHUV KDG D WHQGHQF\ WRZDUGV JHODWLRQ +HQFH LW ZDV QRW VXUSULVLQJ WKDW LW ZDV GLIILFXOW WR SUHSDUH VWDEOH VSLQ GRSHV ZLWK WKHVH

PAGE 340

9LVFRVLW\ 3D Vf VKHDU 6WUHVV 3D! $f )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH

PAGE 341

)LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH

PAGE 342

SRO\PHUV 8)V JHOOHG GXULQJ VSLQ GRSH SUHSDUDWLRQ 7KH 8)V VSLQ GRSH ZDV VKHDU WKLQQLQJ VHH )LJXUH f DQG LW ZDV QRW VSLQQDEOH DW DOO 6SLQ EDWFK 8)V ZDV WKH RQO\ EDWFK LQ WKLV JURXS ZKLFK VSXQ ZHOO 7KH VSLQ GRSH KDG UHODWLYHO\ ORZ YLVFRVLW\ 3D Vf DQG WKH IORZ EHKDYLRU ZDV RQO\ VOLJKWO\ VKHDU WKLQQLQJ )LJXUH f 'HVSLWH WKH UHODWLYHO\ ORZ YLVFRVLW\ WKH ILEHUV UHPDLQHG VHSDUDEOH DIWHU VSLQQLQJ 7KLV PD\ EH UHODWHG WR WKH WHQGHQF\ IRU WKH EDWFKHV SUHSDUHG ZLWK '%FRQWDLQLQJ 306 WR JHO PRUH UHDGLO\ )OHQFH OHVV VROYHQW ZRXOG QHHG WR EH UHPRYHG GXULQJ VSLQQLQJ LQ RUGHU WR fVROLGLI\f WKH ILEHUVf 7DEOH JLYHV WKH WHQVLOH VWUHQJWKV IRU ILEHU EDWFKHV VSXQ IURP KHDWWUHDWHG SRO\PHUV 7DEOH VKRZV UHVXOWV REWDLQHG RQO\ IRU EDWFKHV SUHSDUHG ZLWK DQG 3063&6 FRPSRVLWLRQV )LEHU EDWFKHV SUHSDUHG ZLWK b KHDW WUHDWHG 306 SRO\PHU FRXOG QRW EH WHVWHG $V GLVFXVVHG SUHYLRXVO\ DOVR VHH 7DEOH f ILEHUV SUHSDUHG IURP b KHDWWUHDWHG 306 ZHUH JHQHUDOO\ VWXFN WRJHWKHU DIWHU VSLQQLQJ 8SRQ S\URO\VLV DW r& LQ QLWURJHQf DOO WKH EDWFKHV EHFDPH H[WUHPHO\ EULWWOH DQG WRR ZHDN WR WHVWf 7KH EDWFKHV SUHSDUHG ZLWK b 306 SRO\PHU HLWKHU FRXOG QRW EH VSXQ RU WKH VSLQQLQJ EHKDYLRU ZDV SRRU VHH 7DEOH f WKHUHIRUH QR ILEHUV ZLWK WKLV FRPSRVLWLRQ ZHUH S\URO\]HG DQG WKXV QR ILEHUV ZHUH DYDLODEOH IRU WHVWLQJf 0RVW RI WKH ILEHU EDWFKHV SUHSDUHG ZLWK b 306 SRO\PHU FRXOG QRW EH WHVWHG $V GLVFXVVHG SUHYLRXVO\ DOVR VHH 7DEOH f DVVSXQ ILEHUV ZHUH JHQHUDOO\ VHSDUDEOH EXW WKH ILEHUV EHFDPH VWXFN WRJHWKHU DIWHU S\URO\VLV DW r& LQ QLWURJHQf )OHQFH WKH ILEHUV EHFDPH EULWWOH DQG WRR ZHDN WR EH WHVWHG ,W ZDV SRVVLEOH WR VHSDUDWH DQG WHVW S\URO\]HG ILEHUV IURP RQH EDWFK 8)Vf EXW VWUHQJWKV ZHUH ORZ a *3Df 'HVSLWH WKH DELOLW\ WR VHSDUDWH WKH ILEHUV IRU WHVWLQJ 6(0 REVHUYDWLRQV LQ FRQMXQFWLRQ ZLWK ORZ WHQVLOH VWUHQJWKV VXJJHVWHG WKDW PDQ\ ILEHUV LQGHHG VWXFN WRJHWKHU GXULQJ S\URO\VLV )LJXUH VKRZV 6(0 PLFURJUDSKV RI WKH ERQGLQJ EHWZHHQ WZR S\URO\]HG ILEHUV LQ

PAGE 343

)LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH

PAGE 344

%f )LJXUH 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU 8)V VSLQ GRSH

PAGE 345

7DEOH 7HQVLOH VWUHQJWKV RI 6,& ILEHUV VSXQ IURP KHDWWUHDWHG 306 SRO\PHUV DQG 3063&6 SRO\PHU EOHQGV 'HVLTQDWLRQ 3063&6 UDWLR ZWbf +HDW WUHDWPHQW WHPSHUDWXUH r&f +HDW WUHDWPHQW DWPRVSKHUH RI ILEHUV WHVWHG )LEHU GLDPHWHU 0Pf 7HQVLOH VWUHQTWK *3Df 8)V Q s s 8)V $U s s 8)6 $U s s 8)V Q s s 8)6 Q s s 8)V Q s s

PAGE 346

SP )LJXUH 6(0 PLFURJUDSKV RI S\URO\]HG ILEHUV EDWFK Vf SUHSDUHG IURP KHDW WUHDWHG 3063&6 SRO\PHU EOHQGV VKRZLQJ QHFNLQJ EHWZHHQ ILEHUV

PAGE 347

WKLV EDWFK $V GLVFXVVHG HDUOLHU WKLV ERQGLQJ LV DWWULEXWHG WR PHOWLQJ RI ORZ PROHFXODU ZHLJKW SRUWLRQV RI WKH 306 SRO\PHU XVHG LQ WKH VSLQ EDWFK $ ILEHU EDWFK SUHSDUHG ZLWK b 306 8)Vf DOVR KDG ORZ VWUHQJWK 6(0 REVHUYDWLRQV ZHUH QRW FDUULHG RXW EXW LW LV SRVVLEOH WKDW ERQGLQJ EHWZHHQ S\URO\]HG ILEHUV ZDV DOVR D SUREOHP LQ WKLV EDWFK ,Q DGGLWLRQ WKH S\URO\]HG ILEHU GLDPHWHUV ZHUH YHU\ ODUJH DYHUDJH RI SPf ,W KDV EHHQ REVHUYHG WKDW ILEHU VWUHQJWKV XVXDOO\ GHFUHDVH ZLWK LQFUHDVLQJ GLDPHWHU >7RU%@f 7HQVLOH VWUHQJWKV RI a *3D DQG a *3D ZHUH PHDVXUHG IRU WZR S\URO\]HG ILEHU EDWFKHV 8)V DQG 8)V UHVSHFWLYHO\f SUHSDUHG ZLWK b 306 7KH VSLQ GRSHV XVHG LQ WKHVH EDWFKHV ERWK VKRZHG JRRG VSLQQLQJ EHKDYLRU DQG WKH DVVSXQ DQG S\URO\]HG ILEHUV DSSHDUHG VHSDUDEOH IRU ERWK EDWFKHV 7KH UHDVRQ IRU WKH ORZHU VWUHQJWK IRU 8)V LV QRW NQRZQ 7KH 8)V ILEHUV ZHUH KHDWWUHDWHG LQ DUJRQ DW r&PLQ WR r& DQG r& K KROGf 7KH ILEHU WHQVLOH VWUHQJWKV DIWHU KHDW WUHDWPHQW ZHUH *3D DQG *3D UHVSHFWLYHO\ 6(0 REVHUYDWLRQV ZHUH FDUULHG RXW RQ WKH r&KHDWWUHDWHG 8)V ILEHUV )LJXUH LQGLFDWHV WKDW ILEHU VXUIDFHV DUH UHODWLYHO\ VPRRWK DQG QR REYLRXV ILEHU GHJUDGDWLRQ RFFXUUHG DV D UHVXOW RI WKH KHDW WUHDWPHQW 7KH ILEHU FURVVVHFWLRQ )LJXUH &f DOVR VKRZHG QR ODUJH GHIHFWV 0RUH GHWDLOHG 6(0 REVHUYDWLRQV ZHUH PDGH RQ WKH IUDFWXUH VXUIDFHV RI ILEHU IUDJPHQWV FROOHFWHG GXULQJ WHQVLOH WHVWLQJ 0DQ\ RI WKH IUDFWXUH VXUIDFHV VKRZHG WKH SUHVHQFH RI VXEPLFURPHWHU SRUHV )LJXUHV $ )f 7KHVH SRUHV PD\ EH WKH UHDVRQ IRU WKH ORZ WHQVLOH VWUHQJWKV IRU WKHVH ILEHUV 7KHVH SRUHV PD\ KDYH GHYHORSHG DV D UHVXOW RI WKH SURFHVVLQJ FRQGLWLRQV XVHG LQ SUHSDUDWLRQ RI WKH VSLQ EDWFK $V LQGLFDWHG LQ 7DEOH D SP ILOWHU ZDV WKH VPDOOHVW VL]H XVHG LQ WKH ILOWUDWLRQ RSHUDWLRQ ,Q FRQWUDVW WKH VPDOOHVW ILOWHU XVHG LQ PRVW EDWFKHV ZDV SP DQG LQ VRPH FDVHV WKH VPDOOHVW ILOWHU ZDV SPf +HQFH LW ZRXOG EH H[SHFWHG

PAGE 348

)LJXUH 6(0 PLFURJUDSKV RI 8)V ILEHUV DIWHU KHDW WUHDWPHQW DW r& LQ DUJRQ

PAGE 349

)LJXUH &RQWfGf

PAGE 350

)LJXUH 6(0 PLFURJUDSKV RI IUDFWXUH VXUIDFHV RI 8)V ILEHUV DIWHU KHDW WUHDWPHQW DW r& LQ DUJRQ

PAGE 351

)LJXUH &RQWfGf

PAGE 352

)LJXUH &RQWfGf

PAGE 353

WKDW UHODWLYHO\ ODUJH SDUWLFXODWH GHIHFWV ZHUH LQWURGXFHG LQWR WKH 8)V VSLQ EDWFK +DUG LQRUJDQLF RU SUHFHUDPLF SDUWLFXODWHV PLJKW LQWHUIHUH ZLWK ILEHU VKULQNDJHGHQVLILFDWLRQ GXULQJ S\URO\VLV WKHUHE\ FUHDWLQJ fFUDFNOLNHf YRLGV 2UJDQLF SDUWLFXODWHV FRXOG SDUWLDOO\ RU IXOO\ fEXUQRXWf GXULQJ S\URO\VLV ZKLFK ZRXOG UHVXOW LQ SRUHV ZLWK VKDSHV DQG VL]HV VRPHZKDW FRPSDUDEOH WR WKH RULJLQDO SDUWLFXODWHVf 7DEOH VKRZV WKH UHVXOWV RI HOHPHQWDO DQDO\VHV 6L& DQG 2f RQ r& S\URO\]HG LQ QLWURJHQf 8)V 8)V DQG 8)V ILEHUV DV GHWHUPLQHG E\ (OHFWURQ 0LFURSUREH $QDO\VLV (0$f 8)V ILEHUV VSXQ XVLQJ b KHDWWUHDWHG 306 KDG D 6LULFK FRPSRVLWLRQ ZWb H[FHVV 6Lf 'HWDLOV RI FDOFXODWLRQ RI H[FHVV 6L DUH VKRZQ LQ $SSHQGL[ .f 5HFDOO IURP VHFWLRQ WKDW IUHH 6L ZDV GHWHFWHG DIWHU S\URO\VLV RI 306 DW r& LQ DUJRQ ;5' ZDV XVHG WR VKRZ WKH SUHVHQFH RI FU\VWDOOLQH 6L LQ WKH S\URO\VLV SURGXFW 8)V ILEHUV VSXQ XVLQJ D 3063&6 FRPSRVLWLRQ KDG ZWb H[FHVV FDUERQ 7KH GHWDLOV RI FDOFXODWLRQ RI H[FHVV & DUH VKRZQ LQ $SSHQGL[ .f 7KLV LV QRW VXUSULVLQJ VLQFH LW LV ZHOONQRZQ WKDW 3&6 S\URO\]HV WR D KLJKO\ FDUERQULFK FRPSRVLWLRQ 7KH DPRXQW RI H[FHVV FDUERQ LQFUHDVHG DV WKH 3063&6 UDWLR LQ WKH VSLQ GRSH GHFUHDVHG 6SLQQLQJ RI ILEHUV IURP IUDFWLRQDOO\SUHFLSLWDWHG 306 SRO\PHUV 7DEOH VKRZV FRQGLWLRQV IRU ILEHU VSLQQLQJ H[SHULPHQWV DQG VRPH TXDOLWDWLYH UHVXOWV XVLQJ IUDFWLRQDOO\SUHFLSLWDWHG 306 SRO\PHUV )LEHU EDWFK 8)V ZDV VSXQ IURP 306) 0Z}f SRO\PHU SUHFLSLWDWHG E\ DGGLQJ DOFRKROVf XVLQJ D SP KROH GLDPHWHU KROH VSLQQHUHW $OWKRXJK WKH ILEHUV VSXQ ZHOO EUHDNV SHU PLQXWH SHU KROHf WKH JUHHQ ILEHUV ZHUH VOLJKWO\ VWXFN WRJHWKHU DQG WKLV UHVXOWHG LQ EULWWOH ILEHUV DIWHU S\URO\VLV 7KH VWLFNLQJ EHWZHHQ JUHHQ ILEHUV ZDV PRVW OLNHO\ FDXVHG E\ LQDGHTXDWH 7KLV LV ORZ FRPSDUHG ZLWK WKH H[FHVV FDUERQ LH ZWbf IRXQG LQ 1LFDORQr1 ILEHUV

PAGE 354

7DEOH (OHPHQWDO DQDO\VLV E\ (OHFWURQ 0LFURSUREH IRU 6L& ILEHUV SUHSDUHG IURP KHDWWUHDWHG 3063&6 SRO\PHU EOHQGV )LEHU EDWFK 306L3&6 $GGLWLYHV XVHG &RPSRVLWLRQ UDWLR $VPHDVXUHG 6L b & b b 7RWDO b 1RUPDOL]HG WR bfE 6L b & b 2 b 8)6 ZWb 36= s s s s s 8)6 ZWb 36= s s s s s s s 8)6 ZWb 36= s s s s s s s 8)6 ZWb 36= ZWb '% s s s s s s s 1LWURJHQ DQG % ZHUH EHORZ WKH GHWHFWLRQ OLPLW RI WKH (OHFWURQ 0LFURSUREH $QDO\]HU XVHG E 1RUPDOL]HG 6L & DQG WR b WRWDO F $GGHG WR SRO\PHU VROXWLRQ SULRU WR KHDW WUHDWPHQW

PAGE 355

7DEOH &RQGLWLRQV DQG TXDOLWDWLYH UHVXOWV RI ILEHU VSLQQLQJ H[SHULPHQWV IRU IUDFWLRQDOO\SUHFLSLWDWHG 306 SRO\PHUV %DWFK $PRXQW RI 306 0Q 0Z 6SLQ DGGLWLYH ZWbf )LOWUDWLRQ FRQGLWLRQ )LOWHUSUHVVWLPH )ORZ WHVW WLPH Vf 6ROLGV ORDGLQJ bf 9LVFRVLW\ 3D Vf 6SLQ VSHHG USPf 3UHVVXUH SVLf 8)V J 306) b 36= SPSVL PLQ 6SXQ ZHOO JUHHQ ILEHUV ZHUH SDUWLDOO\ VWXFN WRJHWKHU HVSHFLDOO\ LQ WKH PLGGOH SRUWLRQ RI WKH EXQGOH 8)6 J 306) bf J 306) bf J 306) bf D D b 36= SPSVL PLQ VHWVf 1RW VSLQQDEOH DV WKH VSLQQHUHW JRW FORJJHG DV VRRQ DV WKH VSLQQLQJ VWDUWHG 8VHG SP KROH VSLQQHUHW 8)6 J 306) bf J 306) bf J 306) bf D D b 36= SPSVc PLQ 6SXQ ZHOO 8VHG SP KROH VSLQQHUHW )LEHUV VHSDUDEOH LQ JUHHQ VWDWH DQG DIWHU S\URO\VLV 8)6 J 306) bf J 306) bf J 306) bf D D b 36= b '% SPSVL PLQ 3RO\PHU VROXWLRQ JHOOHG GXULQJ SURFHVVLQJ 8)V J 306) bf J 306) bf J 306) bf J 306) bf D D b 362 b '% b 36= SPSVc PLQ 6SXQ ZHOO EXW WZR KROHV FORJJHG DQG RQO\ RQH VSXQ *UHHQ ILEHUV ZHUH VHSDUDEOH EXW QRW DV VHSDUDEOH DV 8)V 8VHG SPKROH VSLQQHUHW 8)6 J 306) bf J 306) bf J 306) bf J 306) bf D D b 362 b '% b 36= SPSVL PLQ 6SXQ ZHOO UHSHDW RI 8)V )LEHUV KLJKO\ VHSDUDEOH ERWK LQ JUHHQ DQG S\URO\]HG VWDWH 8VHG SP KROH VSLQQHUHW D &DOFXODWHG EDVHG RQ UXOH RI PL[WXUHV XVLQJ LQGLYLGXDO FRPSRQHQW PROHFXODU ZHLJKW LQIRUPDWLRQ

PAGE 356

VROYHQW UHPRYDO SULRU WR ZLQGLQJ RI WKH ILEHUV 7KH IUDFWLRQDWHG 306 SRO\PHUV DSSHDUHG WR EH VROLGV DW URRP WHPSHUDWXUH VR VWLFNLQJ LQ WKH JUHHQ VWDWH GLG QRW UHVXOW EHFDXVH RI IORZ RI WKH SRO\PHU ,Q DGGLWLRQ QR PHOWLQJ ZDV REVHUYHG IRU D VDPSOH RI 306) LQ D r&PHOW WHVWf 6RPH FKDQJHV LQ SURFHVVLQJ FRQGLWLRQV ZHUH PDGH LQ RUGHU WR DYRLG VWLFNLQJ RI WKH DVVSXQ ILEHUV )LUVW D VSLQQHUHW ZLWK VPDOOHU GLDPHWHU KROHV SP GLDPHWHU KROHVf ZDV XVHG LQ VXEVHTXHQW EDWFKHV 7KLV ZDV GRQH VR WKDW D JUHDWHU SURSRUWLRQ RI WKH VROYHQW ZRXOG EH HYDSRUDWHG E\ WKH WLPH WKH ILEHUV UHDFKHG WKH ZLQGLQJ GUXPf 6HFRQG VRPH RI WKH EDWFKHV ZHUH SUHSDUHG ZLWK D KLJKHU YLVFRVLW\ 7KLV ZDV GRQH VR WKDW OHVV OLTXLG UHPRYDO ZRXOG EH QHHGHG EHIRUH WKH ILEHUV ZRXOG fVROLGLI\ff 6SLQ EDWFK 8)V ZDV SUHSDUHG IURP D PL[WXUH RI SRO\PHU VROXWLRQV 306 ) Af 306) 0rrf DQG 306) 0Af LQ D ZWb SURSRUWLRQf ,W ZDV QRW VSLQQDEOH EHFDXVH WKH VSLQQHUHW KROHV EHFDPH FORJJHG DW WKH VWDUW RI ILEHU VSLQQLQJ 7KLV PD\ KDYH EHHQ DQ LQGLFDWLRQ WKDW WKH SRO\PHU VROXWLRQ ZDV FORVH WR WKH SRLQW RI JHODWLRQ 7KLV LV VXJJHVWHG EHFDXVH LW ZDV GLIILFXOW WR ILOWHU WKH VROXWLRQ SULRU WR FRQFHQWUDWLRQ VHH 7DEOH f 7ZR RI WKH SRO\PHUV XVHG LQ WKLV EDWFK 306) DQG 306)f KDG YHU\ KLJK PROHFXODU ZHLJKWV DQG PD\ KDYH FRQWDLQHG JHOOLNH IUDFWLRQV 8)V ILEHUV ZDV SUHSDUHG IURP SRO\PHU EDWFKHV 306) 0ZAf 306 ) AAf DQG 306) 0ZA f LQ D ZWb SURSRUWLRQ 7KHVH ILEHUV VSXQ ZHOO DQG ZHUH KLJKO\ VHSDUDEOH ERWK LQ WKH JUHHQ VWDWH DQG DIWHU S\URO\VLV 8)V VSLQ EDWFK ZDV SUHSDUHG IURP SRO\PHU EDWFKHV 306) 0Zmf 306) AAf DQG 306) 0Zmf LQ D ZWb SURSRUWLRQ 7KH VSLQ GRSH DOVR FRQWDLQHG ZWb '% 3UHYLRXV ZRUN >&KR@ KDV VKRZQ WKDW '% DQG

PAGE 357

36= UHDFW ZLWK HDFK RWKHU DQG DW VXIILFLHQWO\ KLJK FRQFHQWUDWLRQ VSLQQLQJ VROXWLRQV ZLWK WKHVH DGGLWLYHV HLWKHU XQGHUJR JHODWLRQ RU VRPH SUHFLSLWDWHV IRUP IURP WKH VROXWLRQV +HQFH LW LV QRW WRR VXUSULVLQJ WKDW WKH 8)V EDWFK XQGHUZHQW JHODWLRQ GXULQJ VSLQ GRSH SUHSDUDWLRQ )LEHU EDWFKHV 8)V DQG 8)V ZHUH SUHSDUHG IURP 306) AAf 306) 0Z f 306) Af DQG 306) 0mrf LQ SURSRUWLRQV RI E\ ZWb 7KH VSLQ EDWFK DGGLWLYHV ZHUH 36= ZWbf '% ZWbf DQG SRO\VLOR[DQH 362 ZWbf 362 KDV EHHQ UHSRUWHG WR EH DQ H[FHOOHQW VSLQQLQJ DLG LQ WKH VSLQQLQJ RI ILEHUV IURP 3&6 SRO\PHUV >6DF@f 8)V ILEHUV ZHUH VOLJKWO\ VWXFN WRJHWKHU LQ JUHHQ VWDWH ZKLOH WKH 8)V ILEHUV ZHUH KLJKO\ VHSDUDEOH ERWK DIWHU VSLQQLQJ DQG S\URO\VLV 7KH LPSURYHG VHSDUDELOLW\ RI WKH 8)V ILEHUV ZDV SUREDEO\ GXH WR WKH KLJKHU VSLQ EDWFK YLVFRVLW\ 3D V FRPSDUHG WR 3D V IRU 8)Vf 7KH 8)V ILEHUV KDG KLJK WHQVLOH VWUHQJWK *3Df DIWHU S\URO\VLV DW r& LQ QLWURJHQ 7DEOH f 7KH r&S\URO\]HG ILEHUV KDG D QHDUVWRLFKLRPHWULF FRPSRVLWLRQ RI ZWb 6L ZWb & DQG ZWb 2 DV GHWHUPLQHG E\ HOHFWURQ PLFURSUREH DQDO\VLV (0$f 7DEOH f 7KHVH ILEHUV VKRZHG XQH[SHFWHGO\ SRRU WKHUPDO VWDELOLW\ XSRQ IXUWKHU KHDW WUHDWPHQW 7KH ILEHUV KDG WRWDO ZHLJKW ORVVHV RI b ZWb DQG ZWb DIWHU KHDW WUHDWPHQWV RI r& IRU K LQ DUJRQf r& IRU K LQ DUJRQf DQG r& IRU K LQ DUJRQf UHVSHFWLYHO\ 7KH FRPSRVLWLRQ RI ILEHUV DIWHU r& K ZDV GHWHUPLQHG WR EH VRPHZKDW PRUH FDUERQULFK 6L ZWb & ZWb 2 ZWbf FRPSDUHG WR WKH r&S\URO\]HG ILEHUV 7KH S\URO\]HG r& 8)V ILEHUV KDG UHDVRQDEO\ JRRG WHQVLOH VWUHQJWK a *3D 7DEOH f EXW VKRZHG SRRU WKHUPDO VWDELOLW\ DW KLJKHU WHPSHUDWXUH 7KH ZHLJKW ORVV IRU WKHVH ILEHUV ZDV ab DIWHU KHDWWUHDWPHQW DW r& IRU K LQ DUJRQ

PAGE 358

7DEOH 7HQVLOH VWUHQJWKV RI 6,& ILEHUV VSXQ IURP IUDFWLRQDOO\SUHFLSLWDWHG 306 SRO\PHUV )LEHU EDWFK +HDW WUHDWPHQW WHPSHUDWXUH r&f +HDW WUHDWPHQW DWPRVSKHUH RI ILEHUV WHVWHG )LEHU GLDPHWHU SPf 7HQVLOH VWUHQJWK *3Df 8)V Q s s 8)V Q s s 7DEOH (OHPHQWDO DQDO\VLV E\ (OHFWURQ 0LFURSUREH IRU 6L& ILEHUV SUHSDUHG IURP IUDFWLRQDOO\SUHFLSLWDWHG 306 SRO\PHUV )LEHU EDWFK &RPSRVLWLRQ $VPHDVXUHG 6L b & b b 7RWDO b 1RUPDOL]HG WR bfE 6L b & b 2 b 8)V s s s s s s s 8)6 s s s s s 8)V s s s s s s s D 1LWURJHQ DQG % ZHUH EHORZ WKH GHWHFWLRQ OLPLW RI WKH (OHFWURQ 0LFURSUREH $QDO\]HU XVHG E 1RUPDOL]HG 6L & DQG 2 WR b WRWDO

PAGE 359

7KH HOHFWURQ PLFURSUREH DQDO\VLV RQ S\URO\]HG r&f 8)V ILEHUV UHYHDOHG D VLOLFRQULFK FRPSRVLWLRQ 6L ZWb & ZWb DQG ZWbf 7DEOH f 7KH UHDVRQVf IRU WKH KLJK R[\JHQ FRQWHQW LQ WKH ILEHUV DUH XQFOHDU 7KH 362 DGGLWLRQ ZRXOG UHVXOW LQ VRPH R[\JHQ LQ WKH S\URO\]HG ILEHU EXW QRW WR WKH OHYHO PHDVXUHG 7KH UHDVRQ IRU WKH REVHUYHG ODUJH ZHLJKW ORVVHV DW WKHVH WHPSHUDWXUHV LV QRW FOHDU ,W LV SRVVLEOH WKDW FDUERWKHUPDO UHGXFWLRQ UHDFWLRQV RFFXU ZKLFK UHVXOW LQ D PRUH FDUERQULFK ILEHU 7KH IROORZLQJ FDUERWKHUPDO UHGXFWLRQ UHDFWLRQV DUH SRVVLEOH >'DQ@ 6L& 6L 6L &2 f 6L& 6L2] 6L2 &2 f 6L & 6L2 &2 f 7KH ZHLJKW ORVVHV EDVHG RQ WKHVH UHDFWLRQV HTXDWLRQV f f DQG ff DQG VWRLFKLRPHWU\ FKDQJH FDQ EH GHWHUPLQHG IRU HDFK RI WKHVH UHDFWLRQV DV VKRZQ EHORZ &RQVLGHU 8)V ILEHUV 7KH LQLWLDO FRPSRVLWLRQ RI WKH r&S\URO\]HG ILEHU LV ZWb 6L ZWb & DQG ZWb 2 :H KDYH ZWb 6L& ZWb 6L DQG ZWb & %DVHG RQ UHDFWLRQ f ZH KDYH PROH RI 6L UHDFWLQJ ZLWK PROHV RI 6L& IRUPLQJ PROHV RI 6L DQG PROHV RI &2 ,W LV DVVXPHG WKDW 6L IRUPHG DV D UHVXOW RI WKLV UHDFWLRQ LV YRODWLOL]HG DW WKH KHDW WUHDWPHQW WHPSHUDWXUH r&f 7KH PHOWLQJ SRLQW RI 6L LV r&f 7KLV PHDQV WKDW IRU PROH RU Jf RI 6L WKH WRWDO DPRXQW RI YRODWLOH VSHFLHV IRUPHG 6L &2f ZRXOG EH J 7KXV WKH H[SHFWHG ZHLJKW ORVV LV b 7KH REVHUYHG ZHLJKW ORVV ZDV b DIWHU r& Kf 7KH FDOFXODWHG VWRLFKLRPHWU\ EDVHG RQ ORVV RI ZWb 6L& GXH WR UHDFWLRQ f LV ZWb 6L DQG

PAGE 360

ZWb & 7KH FRPSRVLWLRQ RI WKH ILEHU DIWHU r& K GHWHUPLQHG E\ (0$ LV ZWb 6L DQG ZWb &f %DVHG RQ UHDFWLRQ f ZH KDYH PROH RI 6L UHDFWLQJ ZLWK PROH RI 6L& WR SURGXFH PROHV RI 6L2 DQG PROH RI &2 7KLV PHDQV WKDW PROH RU Jf RI 6L UHDFWV ZLWK PROH RU Jf RI 6L& WR IRUP PROH RU Jf RI 6L2 DQG PROH RU Jf RI &2 7KH WRWDO DPRXQW RI YRODWLOH VSHFLHV 6L2 &2f LV J 7KXV WKH H[SHFWHG ZHLJKW ORVV LV b 7KH FDOFXODWHG VWRLFKLRPHWU\ IRU WKH ILEHU DIWHU KHDW WUHDWPHQW LV ZWb 6L DQG ZWb & %DVHG RQ UHDFWLRQ f ZH KDYH PROH RI 6L UHDFWLQJ ZLWK PROH RI & IRUPLQJ PROH RI 6L2 DQG PROH RI &2 RU JPROH RI 6L Jf UHDFWLQJ ZLWK JPROH RI & RU Jf IRUPLQJ J RI YRODWLOH VSHFLHV 6L2 DQG &2 7KXV WKH H[SHFWHG ZHLJKW ORVV LV b DV RSSRVHG WR WKH REVHUYHG ZHLJKW ORVV RI bf 7KH FDOFXODWHG VWRLFKLRPHWU\ EDVHG RQ ORVV RI J RI &f LV ZWb 6L DQG ZWb & 7KXV UHDFWLRQ f SUHGLFWV WKH ZHLJKW ORVV FORVHVW WR WKH REVHUYHG ZHLJKW ORVV IRU 8)V ILEHUV DIWHU r& K KHDW WUHDWPHQW +RZHYHU WKH ODUJH ZHLJKW ORVVHV RFFXUULQJ DIWHU r& K DQG r& K FDQQRW EH DGHTXDWHO\ H[SODLQHG E\ WKLV UHDFWLRQ 0RUH LQYHVWLJDWLRQV RQ WKHUPDO VWDELOLW\ RI WKHVH ILEHUV ZRXOG EH QHHGHG 7KH ODUJH ZHLJKW ORVV LQ 8)V ILEHUV DIWHU KHDW WUHDWPHQW DW r& K LV OLNHO\ GXH WR WKH FDUERWKHUPDO UHGXFWLRQ UHDFWLRQ VKRZQ E\ HTXDWLRQ f 7KH ZHLJKW ORVV EDVHG RQ WKLV UHDFWLRQ DQG VWRLFKLRPHWU\ FKDQJH FDQ EH GHWHUPLQHG DV IROORZV 7KH LQLWLDO FRPSRVLWLRQ RI WKH r&S\URO\]HG ILEHU LV ZWb 6L ZWb & DQG ZWb 2 $VVXPLQJ WKDW DOO LV WLHG WR 6L DV 6L ZH KDYH ZWb 6L& DQG ZWb 6L %DVHG RQ UHDFWLRQ f ZH KDYH PROH RI 6L UHDFWLQJ ZLWK PROH RI 6L& IRUPLQJ PROHV RI 6L DQG PROH RI &2 7KLV PHDQV WKDW IRU J RI 6L LQ WKH ILEHU RU JPROHf WKH WRWDO DPRXQW RI YRODWLOH VSHFLHV IRUPHG 6L2 &2f ZRXOG EH

PAGE 361

J 7KXV WKH H[SHFWHG ZHLJKW ORVV LV b 7KH REVHUYHG ZHLJKW ORVV ZDV b DIWHU r& Kf )LEHU H[WHQVLRQ H[SHULPHQWV RQ 306 SRO\PHU VSLQ GRSHV FRQWDLQLQJ 36= 7KH OHQJWKV WR ZKLFK ILEHUV FDQ EH VORZO\ KDQGGUDZQ EHIRUH WKH\ EUHDN ZHUH PHDVXUHG RQ fVSLQ GRSHVf SUHSDUHG XVLQJ 306 36= DQG 30636= PL[WXUHV 7KH WHFKQLTXH IRU KDQGGUDZLQJ ILEHUV LV GHVFULEHG LQ VHFWLRQ f 7KHVH fILEHU H[WHQVLRQ PHDVXUHPHQWVf ZHUH FRQVLGHUHG DQ LQGLFDWLRQ RI WKH VSLQQDELOLW\ RI WKH EDWFK LH WKH DELOLW\ WR VSLQ ILEHUV E\ H[WUXGLQJ XQGHU SUHVVXUHf D VSLQ GRSH WKURXJK D VSLQQHUHW KDYLQJ ILQHGLDPHWHU KROHV )LEHU H[WHQVLRQ PHDVXUHPHQWV ZHUH FDUULHG RXW RQ WZR 36= SRO\PHUV LH 36= $ ZLWK UHODWLYHO\ KLJK PROHFXODU ZHLJKW 0Qm f DQG 36= $ ZLWK UHODWLYHO\ ORZ PROHFXODU ZHLJKW 0Q} 0AO f %RWK 36=fV DUH OLTXLGV DW URRP WHPSHUDWXUH VR WKH LQLWLDO H[SHULPHQWV ZHUH FDUULHG RXW ZLWK QR VROYHQW DGGLWLRQV 7DEOH VKRZV WKDW WKH ILEHU H[WHQVLRQ ZDV DOPRVW WKUHH WLPHV JUHDWHU IRU WKH KLJK PROHFXODU ZHLJKW 36= LH H[WHQVLRQV ZHUH FP DQG FP IRU WKH $ DQG $ SRO\PHUV UHVSHFWLYHO\f ,W VKRXOG EH QRWHG WKDW 36= $ KDG PXFK KLJKHU YLVFRVLW\ WKDQ 36= $ VHH 7DEOH f 7KHUHIRUH LW ZDV QRW FOHDU IURP WKH LQLWLDO H[SHULPHQWV LI WKH JUHDWHU ILEHU H[WHQVLRQ ZDV GXH WR WKH KLJKHU PROHFXODU ZHLJKW RU WKH KLJKHU YLVFRVLW\ &RQVHTXHQWO\ D VROXWLRQ ZDV SUHSDUHG LQ ZKLFK WKH 36= $ ZDV GLOXWHG ZLWK WROXHQH LH ZWb 36= $ ZWb WROXHQHf LQ RUGHU WR REWDLQ DSSUR[LPDWHO\ WKH VDPH YLVFRVLW\ DV b 36= $ LH 3D Vf 7DEOH VKRZV WKDW WKH ILEHU H[WHQVLRQ RI WKH ZWb 36=$ VROXWLRQ ZDV VWLOO PXFK JUHDWHU WKDQ WKH 36= $ SRO\PHU 3OHQFH WKH KLJKHU PROHFXODU ZHLJKW ZDV WKH SULPDU\ IDFWRU UHVSRQVLEOH IRU JUHDWHU ILEHU H[WHQVLRQ

PAGE 362

7DEOH VKRZV ILEHU H[WHQVLRQ UHVXOWV IRU VROXWLRQV SUHSDUHG ZLWK IUDFWLRQDWHG 306 SRO\PHUV 306) DQG 306) 7KH 306) VROXWLRQV ZHUH SUHSDUHG DW D YLVFRVLW\ VLPLODU WR WKH b 36= $ SRO\PHU DQG WKH ZWb 36= $ ZWb WROXHQH VROXWLRQ 7KH 306) VROXWLRQV ZHUH SUHSDUHG ZLWK VLPLODU IORZ WHVW WLPHV DV WKH 306) VROXWLRQV 8QIRUWXQDWHO\ YLVFRVLW\ PHDVXUHPHQWV FRXOG QRW EH PDGH ZLWK 306) VROXWLRQV GXH WR WKH OLPLWHG DPRXQW RI PDWHULDO DYDLODEOHf 7KH ILEHU H[WHQVLRQ IRU 306) VROXWLRQ ZDV VOLJKWO\ JUHDWHU WKDQ IRU WKH 306) VROXWLRQ FP YV FPf 2QH SRVVLEOH UHDVRQ IRU WKLV REVHUYDWLRQ LV WKH KLJKHU PROHFXODU ZHLJKW IRU WKH IRUPHU SRO\PHU 7KH DYHUDJH PROHFXODU ZHLJKWV ZHUH 0Z D DQG 0Z m IRU WKH 306) DQG 306) SRO\PHUV UHVSHFWLYHO\r 7KH *3& PROHFXODU ZHLJKW GLVWULEXWLRQV IRU WKH DVSUHSDUHG 306 DQG IUDFWLRQDWHG 306) SRO\PHUV DQG WKH DVSUHSDUHG 306 DQG IUDFWLRQDWHG 306 ) SRO\PHUV DUH VKRZQ LQ )LJXUHV D DQG E DQG )LJXUH D DQG E UHVSHFWLYHO\f ,W VKRXOG EH QRWHG KRZHYHU WKDW WKH VPDOO GLIIHUHQFH LQ WKH ILEHU H[WHQVLRQ GLVWDQFHV PD\ DOVR EH GXH WR D GLIIHUHQFH LQ YLVFRVLW\ 7KH 306) VROXWLRQ KDG D VOLJKWO\ KLJKHU IORZ WLPH VR WKH YLVFRVLW\ PD\ KDYH EHHQ KLJKHU DOVR 7DEOH DOVR VKRZV ILEHU H[WHQVLRQ PHDVXUHPHQWV IRU VROXWLRQV SUHSDUHG ZLWK 30636= PL[WXUHV 7KH DGGLWLRQ RI ZWb 36= $ WR 306) FOHDUO\ UHVXOWHG LQ D GHFUHDVH LQ ILEHU H[WHQVLRQ FP IRU WKH PL[HG VROXWLRQ 306) YV FP IRU WKH 306) VROXWLRQ ZLWK QR 36=f 7KH PL[HG VROXWLRQ KDG HVVHQWLDOO\ LGHQWLFDO VROXWLRQ YLVFRVLW\ IORZ WHVW WLPH DQG VROLGV ORDGLQJ WR WKH VROXWLRQ ZLWK QR 36= r ,W LV LQWHUHVWLQJ WR QRWH WKDW VROLGV ORDGLQJ IRU WKH 306) VROXWLRQ ZDV VLJQLILFDQWO\ ORZHU FRPSDUHG WR WKH 306) VROXWLRQ LH ZWb YV ZWbf 7KLV ZDV VRPHZKDW VXUSULVLQJ VLQFH WKH IRUPHU SRO\PHU KDV D ORZHU PROHFXODU ZHLJKW 0Z D YV 0Z r IRU 306)f 7KHUH DUH DW OHDVW WZR SRVVLEOH UHDVRQV IRU WKLV REVHUYDWLRQ )LUVW WKH 306) VROXWLRQ PD\ DFWXDOO\ KDYH D KLJKHU YLVFRVLW\ $V VKRZQ LQ 7DEOH WKH IORZ WLPH LV VOLJKWO\ KLJKHUf ,Q WKDW FDVH WKH KLJKHU VROLGV ORDGLQJ ZRXOG EH OHVV VXUSULVLQJ 6HFRQG WKHUH PD\ EH GLIIHUHQFHV LQ WKH SRO\PHU DUFKLWHFWXUH

PAGE 363

7DEOH 5HVXOWV RI ILEHU H[WHQVLRQ H[SHULPHQWV IRU 306 SRO\PHUV FRQWDLQLQJ 36= 3RO\PHU 36= EDWFK $PRXQW RI 36= ZWbf 9LVFRVLW\ 3D Vf )ORZ WHVW WLPHVfI 6ROLGVORDGLQJ ZWbf )LEHU H[WHQVLRQ FPf 306) r s 306) $ r s 306) $ r s 306) $ r s 306) s 306) $ s 36= $ r s 36= $ s 36= $ s fn)ORZ WHVW WLPH LV WKH WLPH WDNHQ E\ WKH SRO\PHU VROXWLRQ WR WUDYHO FP DW r DQJOH 7KH PHDVXUHPHQW ZDV GRQH LQ D FDSSHG YLDO 7KH GHWDLOHG SURFHGXUH IRU WKH IORZ WHVW LV JLYHQ LQ VHFWLRQ f r 'DWD QRW DYDLODEOH

PAGE 364

GZWGORJ0f GZWGORJ0f )LJXUH *HO SHUPHDWLRQ FKURPDWRJUDPV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ

PAGE 365

7KH GHFUHDVHG ILEHU H[WHQVLRQ FDQ EH DWWULEXWHG WR WKH LQFRUSRUDWLRQ RI D 36= FRPSRQHQW LH WKH UHODWLYHO\ ORZ PROHFXODU ZHLJKW 36= $f ZKLFK LWVHOI KDV UHODWLYHO\ SRRU ILEHU H[WHQVLRQ ,Q FRQWUDVW WR WKH DERYH UHVXOWV WKH DGGLWLRQ RI ZWb 36= $ WR 306) UHVXOWHG LQ D VPDOO LQFUHDVH LQ ILEHU H[WHQVLRQ LH FP IRU WKH PL[HG VROXWLRQ 306 ) YV FP IRU WKH 306) VROXWLRQ ZLWK QR 36=f 7KH PL[HG VROXWLRQ KDG VLPLODU IORZ WHVW WLPH DQG VROLGV ORDGLQJ WR WKH VROXWLRQ ZLWK QR 36= 7KH LQFUHDVHG ILEHU H[WHQVLRQ FDQ EH DWWULEXWHG WR WKH LQFRUSRUDWLRQ RI D 36= FRPSRQHQW LH WKH UHODWLYHO\ KLJK PROHFXODU ZHLJKW 36= $f ZKLFK KDG EHWWHU ILEHU H[WHQVLRQ DV D SXUH FRPSRQHQW WKDQ WKH 306) VROXWLRQ $W KLJKHU FRQFHQWUDWLRQV RI 36= $ LH DQG ZWbf WKH WUHQG UHYHUVHG DQG WKH ILEHU H[WHQVLRQV GHFUHDVHG IRU PL[HG VROXWLRQV SUHSDUHG ZLWK 306) VHH 7DEOH DQG )LJXUH f 7KH GHFUHDVHV DUH SUREDEO\ QRW DVVRFLDWHG ZLWK GLIIHUHQFHV LQ YLVFRVLW\ VLQFH WKH IORZ WHVW WLPHV ZHUH PDLQWDLQHG DSSUR[LPDWHO\ FRQVWDQW IRU WKHVH VROXWLRQV ,W LV QRWHG KRZHYHU WKDW WKH VROLGV ORDGLQJ GHFUHDVHG ZLWK LQFUHDVLQJ 36= $ FRQWHQW LQ WKH PL[HG VROXWLRQV ,W LV QRW FOHDU LI WKLV LV UHODWHG WR WKH REVHUYHG GHFUHDVHV LQ ILEHU H[WHQVLRQ 7KH GHFUHDVHG VROLGV ORDGLQJ LV H[SHFWHG GXH WR WKH KLJK PROHFXODU ZHLJKW RI 36= &A26$r +RZHYHU WKHUH LV VRPH HYLGHQFH WKDW WKH GHFUHDVHG VROLGV ORDGLQJ PD\ DOVR KDYH EHHQ UHODWHG WR D UHDFWLRQ EHWZHHQ WKH 306 DQG 36= ,W ZDV REVHUYHG WKDW WKH LQLWLDOO\ FOHDU \HOORZ FRORUHG 306) VROXWLRQ EHFDPH LQFUHDVLQJO\ FORXGLHU ZLWK VXFFHVVLYH DGGLWLRQV RI 36= LH ZWb ZWb DQG ZWbf ,W ZDV QRW GHWHUPLQHG LI DQ\ LQFUHDVHV LQ PROHFXODU ZHLJKWV ZHUH DVVRFLDWHG ZLWK WKHVH FKDQJHV +RZHYHU LW ZDV REVHUYHG WKDW WKH WLPH UHTXLUHG IRU ILOWUDWLRQ LQFUHDVHG ZLWK LQFUHDVLQJ 36= FRQWHQW RI WKH VROXWLRQ I 5HFDOO WKDW WKLV 36= KDV UHODWLYHO\ KLJK YLVFRVLW\ LQ SXUH IRUP DQG WKDW LW PXVW EH GLOXWHG WR ZWb LQ WROXHQH WR KDYH D VLPLODU IORZ WHVW WLPH WR WKH PL[HG VROXWLRQV SUHSDUHG ZLWK 306)

PAGE 366

$02817 2) 36= :Wbf )LJXUH $YHUDJH H[WHQVLRQ IRU ILEHUV GUDZQ IURP 306EDVHG SRO\PHUV DV D IXQFWLRQ RI DPRXQW RI 36= $ DGGHG

PAGE 367

6ROXWLRQV a ZWb VROLGVf ZLWK DQG ZWb 36= UHTXLUHG DQG PLQ UHVSHFWLYHO\ IRU ILOWUDWLRQ WKURXJK SP ILOWHUV 7KH REVHUYDWLRQV RI LQFUHDVHG VROXWLRQ FORXGLQHVV DQG LQFUHDVHG ILOWUDWLRQ WLPH IRU WKH VROXWLRQV ZLWK KLJKHU 36= FRQWHQW VXJJHVW WKDW VRPH PLFURJHO PD\ KDYH EHHQ GHYHORSLQJ 7KLV LQ WXUQ ZRXOG KDYH DQ DGYHUVH HIIHFW RQ WKH DELOLW\ WR GUDZ ILEHUV LH GHFUHDVHG ILEHU H[WHQVLRQ ZRXOG EH H[SHFWHGf

PAGE 368

&+$37(5 6800$5< $1' &21&/86,216 6L& ILEHUV ZHUH SUHSDUHG E\ GU\ VSLQQLQJ RI SRO\FDUERVLODQH 3&6f VROXWLRQV 7KH HIIHFWV RI SRO\YLQ\OVLOD]DQH 36=f RQ VSLQQDELOLW\ RI 3&6 VROXWLRQV DQG PHFKDQLFDO SURSHUWLHV RI JUHHQ DQG KHDWWUHDWHG ILEHUV ZHUH LQYHVWLJDWHG ,W ZDV IRXQG WKDW WKH DGGLWLRQ RI 36= WR 3&6 JUHDWO\ LPSURYHG ILEHU VSLQQLQJ E\ UHGXFLQJ WKH QXPEHU RI ILEHU EUHDNV RFFXUULQJ GXULQJ VSLQQLQJ 7KLV DOVR DOORZHG D FRQVLGHUDEO\ JUHDWHU DPRXQW RI ILEHUV WR EH IRUPHG IURP WKH 3&6 VROXWLRQV FRQWDLQLQJ 36=f ,W ZDV DOVR REVHUYHG TXDOLWDWLYHO\ WKDW ILEHUV FRXOG EH VWUHWFKHG PRUH HDVLO\ LQ WKH FDVH RI 3&636= VROXWLRQV WKDQ 3&6 VROXWLRQV )LEHU H[WHQVLRQ H[SHULPHQWV FDUULHG RXW VHSDUDWHO\ FRQILUPHG WKLV REVHUYDWLRQ ,W ZDV GHWHUPLQHG WKDW 3&636= VROXWLRQ KDG DQ DYHUDJH ILEHU H[WHQVLRQ JUHDWHU WKDQ 3&6 VROXWLRQ E\ ab &RQWDFW DQJOH PHDVXUHPHQWV IRU 3&6 DQG 3&636= VROXWLRQV ZWb VROLGV ORDGLQJf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

PAGE 369

([SHULPHQWV ZHUH FDUULHG RXW RQ 3&6 DQG 3&636= VROXWLRQV WR DVVHVV FKDQJHV LQ UDWH RI VROYHQW HYDSRUDWLRQ DV D UHVXOW RI DGGLWLRQ RI 36= WR 3&6 &KDQJHV LQ VROYHQW HYDSRUDWLRQ UDWH LQIOXHQFH WKH GU\LQJ FKDUDFWHULVWLFV GXULQJ ILEHU VSLQQLQJf 7KH UDWH RI VROYHQW HYDSRUDWLRQ ZDV PRQLWRUHG IRU 3&6WROXHQH DQG 3&636=WROXHQH VROXWLRQV SUHSDUHG ZLWK ZWb SRO\PHU ,W ZDV IRXQG WKDW 3&636= VROXWLRQ H[KLELWHG ORZHU HYDSRUDWLRQ UDWH FRPSDUHG WR 3&6 VROXWLRQ LQ WKH HDUO\ VWDJHV RI HYDSRUDWLRQ 7KH HIIHFW RI 36= RQ WKH PHFKDQLFDO SURSHUWLHV RI ILEHUV SUHSDUHG IURP 3&6 DQG 3&636= VROXWLRQV ZDV LQYHVWLJDWHG ,W ZDV IRXQG WKDW DVVSXQ 3&6 DQG 3&636= ILEHUV GHYHORSHG VLPLODU WHQVLOH VWUHQJWKV DQG UXSWXUH VWUDLQV +RZHYHU DIWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ 3&636= ILEHUV VKRZHG KLJKHU WHQVLOH VWUHQJWK DQG UXSWXUH VWUDLQ FRPSDUHG WR 3&6 ILEHUV $LUKHDW WUHDWHG sr&f 3&6 DQG 3&636= ILEHUV DOVR VKRZHG FRQVLGHUDEO\ KLJKHU VWUHQJWKV DQG UXSWXUH VWUDLQV WKDQ DV VSXQ 3&6 DQG 3&636= ILEHUV $LUKHDW WUHDWHG 3&6 DQG 3&636= ILEHUV KDG KLJKHU WHQVLOH VWUHQJWKV DQG UXSWXUH VWUDLQV DIWHU KHDW WUHDWPHQW DW r& LQ QLWURJHQ FRPSDUHG WR DVVSXQ 3&6 DQG 3&636= ILEHUV JLYHQ RQO\ D r& KHDW WUHDWPHQW LQ QLWURJHQ ,W IROORZV IURP WKHVH UHVXOWV WKDW ERWK R[\JHQ DQG 36= DUH HIIHFWLYH FURVVOLQNLQJ DJHQWV IRU 3&6 7KH R[LGDWLYH FURVVOLQNLQJ RI 3&6 RFFXUV E\ R[LGDWLRQ RI 6L+ JURXSV WR IRUP 6L2+ JURXSV DQG VXEVHTXHQW FRQGHQVDWLRQ WR IRUP 6L26L DQG 6L2& QHWZRUNV 6LQFH 36= FRQWDLQV PDQ\ FDUERQFDUERQ GRXEOH ERQGV FURVVOLQNLQJ SUHVXPDEO\ RFFXUV E\ D PHFKDQLVP LQYROYLQJ IUHH UDGLFDOV )7,5 VSHFWUD RI DVVSXQ DQG DLUKHDW WUHDWHG 3&6 DQG 3&636= ILEHUV FROOHFWHG GXULQJ KHDW WUHDWPHQW WR r& LQ QLWURJHQ VXJJHVW WKDW 36= FURVVOLQNV 3&6 3&636= ILEHUV GHYHORSHG KLJKHU DYHUDJH WHQVLOH VWUHQJWKV FRPSDUHG WR 3&6 ILEHUV DIWHU KHDW WUHDWPHQWV LQ QLWURJHQ DW YDULRXV WHPSHUDWXUHV XS WR r&

PAGE 370

6L& ILEHUV ZHUH SUHSDUHG IURP SRO\PHWK\OVLODQH 306f SRO\PHUV DQG 3063&6 SRO\PHU EOHQGV 306 SRO\PHUV ZHUH V\QWKHVL]HG E\ :XUW]FRXSOLQJ SRO\PHUL]DWLRQ RI PHWK\OGLFKORURVLODQH 0'&6f DQG PHWK\OWULFKORURVLODQH 07&6f LQ ZWb SURSRUWLRQf ZLWK VRGLXP LQ UHIOX[LQJ VROYHQW PL[WXUHV ,Q RUGHU WR DGGUHVV SUREOHPV ZLWK ORZ SRO\PHU \LHOGV DVVRFLDWHG ZLWK :XUW] SRO\PHUL]DWLRQ UHDFWLRQVf SRODU VROYHQWV 7+) DQG GLR[DQH ZHUH DGGHG WR WROXHQH ,W ZDV IRXQG WKDW ERWK 7+) DQG GLR[DQH FDXVHG DQ LQFUHDVH LQ SRO\PHU \LHOG DQG PROHFXODU ZHLJKW RI WKH SRO\PHUV 2QH RI WKH PDMRU GUDZEDFNV RI 306 SRO\PHUV DUH WKDW WKH\ DUH OLTXLGV DW URRP WHPSHUDWXUH DQG KDYH ORZ PROHFXODU ZHLJKWV ,Q RUGHU WR IRUP ILEHUV IURP WKHVH SRO\PHUV DQ LQFUHDVHG PROHFXODU ZHLJKW DQG DQ LQFUHDVHG H[WHQW RI FURVVOLQNLQJ DUH QHHGHG VR WKDW WKH SRO\PHUV DUH VROLGV DW URRP WHPSHUDWXUH DQG UHPDLQ VROLGV GXULQJ S\URO\VLVf 7ZR DSSURDFKHV ZHUH XVHG WR UDLVH WKH PROHFXODU ZHLJKWFURVVOLQNLQJ RI WKH SRO\PHUV f SRO\PHUL]DWLRQ DQG FURVVOLQNLQJ E\ KHDW WUHDWPHQW RI VROXWLRQV ZLWK DQG ZLWKRXW DGGLWLYHV DQG f IUDFWLRQDO SUHFLSLWDWLRQ RI KLJKHU PROHFXODU ZHLJKW IUDFWLRQV E\ DGGLWLRQ RI QRQVROYHQWV 7KH DGGLWLYHV IRU KHDW WUHDWPHQW FRQVLVWHG RI SRO\YLQ\OVLOD]DQH 36=f GLFXP\O SHUR[LGH '&3f DQG GHFDERUDQH '%f ,W ZDV IRXQG WKDW KHDW WUHDWPHQW DSSURDFK ZDV HIIHFWLYH LQ LQFUHDVLQJ WKH PROHFXODU ZHLJKW EXW LW ZDV QRW SRVVLEOH WR DFKLHYH WKHVH LQFUHDVHV UHSURGXFLEO\ )XUWKHUPRUH WKH KHDWWUHDWHG SRO\PHUV WHQGHG WR KDYH ELPRGDO PROHFXODU ZHLJKW GLVWULEXWLRQV ZKLFK LV XQGHVLUDEOH 7KH ORZ PROHFXODU ZHLJKW SRUWLRQ UHPDLQV DV D OLTXLGf +HQFH WKHVH SRO\PHUV DUH QRW SDUWLFXODUO\ VXLWDEOH IRU ILEHU IRUPDWLRQ )UDFWLRQDO SUHFLSLWDWLRQ RI KLJKHU PROHFXODU ZHLJKW IUDFWLRQV ZDV DQ HIIHFWLYH PHWKRG RI SURGXFLQJ VROLG SRO\PHUV 8VH RI DOFRKROV DV QRQVROYHQWV IRU IUDFWLRQDO SUHFLSLWDWLRQ ZDV XQGHVLUDEOH VLQFH LW LQFRUSRUDWHG D ODUJH DPRXQW RI R[\JHQ LQ WKH SRO\PHU 7KLV ZDV LQGLFDWHG E\ DQDO\VHV FDUULHG RXW RQ S\URO\]HG VDPSOHV ZKLFK

PAGE 371

VKRZHG R[\JHQ FRQWHQWV XS WR ZWbf 7KLV R[\JHQ LQFRUSRUDWLRQ LV SULPDULO\ DWWULEXWHG WR UHDFWLRQ RI WKH SRO\PHU ZLWK DOFRKROV LH K\GURO\VLVf 7KLV ZDV QRW D SUREOHP LQ WKH FDVH RI SRO\PHUV SUHFLSLWDWHG ZLWK DFHWRQH DV QRQVROYHQW ,W ZDV SRVVLEOH WR SUHSDUH KLJK VWUHQJWK S\URO\]HG 6L&EDVHG ILEHUV IURP IUDFWLRQDOO\SUHFLSLWDWHG SRO\PHUV 6RPH FKDQJHV LQ SURFHVVLQJ FRQGLWLRQV ZHUH QHFHVVDU\ LQ RUGHU WR DYRLG VWLFNLQJ RI DVVSXQ ILEHUV )LUVW D VSLQQHUHW ZLWK VPDOOHU GLDPHWHU KROHV SP GLDPHWHU KROHVf ZDV QHHGHG WR VSLQ ILEHUV 7KLV ZDV GRQH VR WKDW D JUHDWHU SRUWLRQ RI WKH VROYHQW ZRXOG EH HYDSRUDWHG E\ WKH WLPH WKH ILEHUV UHDFKHG WKH ZLQGLQJ GUXPf 6HFRQG VRPH RI WKH ILEHU EDWFKHV ZHUH SUHSDUHG ZLWK KLJKHU YLVFRVLW\ 7KLV ZDV GRQH VR WKDW OHVV OLTXLG UHPRYDO ZRXOG EH QHHGHG EHIRUH WKH ILEHUV ZRXOG nfVROLGLI\fff 7KH ILEHUV KDG KLJK WHQVLOH VWUHQJWK a *3Df DQG D QHDU VWRLFKLRPHWULF FRPSRVLWLRQ ZWb 6L ZWb & DQG ZWb 2f DIWHU S\URO\VLV DW r& 7KH ILEHUV KRZHYHU VKRZHG SRRU WKHUPDO VWDELOLW\ XSRQ IXUWKHU KHDW WUHDWPHQW ,W ZDV REVHUYHG WKDW 306 SRO\PHUV ZHUH H[WUHPHO\ VHQVLWLYH WRZDUGV DLUPRLVWXUH 7KLV LV GXH WR WKH SUHVHQFH RI D ODUJH QXPEHU RI 6L+ JURXSV LQ WKH 7KHUHIRUH IRU PDQ\ SUDFWLFDO DSSOLFDWLRQV LQYROYLQJ 306 SRO\PHUV H[FHSW IRU H[DPSOH LQ DSSOLFDWLRQV LQYROYLQJ XVH DV SKRWRUHVLVWV LQ PLFUROLWKRJUDSK\ ZKHUH VHQVLWLYLW\ RI 306 SRO\PHUV WRZDUGV R[\JHQ LV H[SORLWHGf LW ZRXOG EH QHFHVVDU\ WR WDNH H[WHQVLYH SUHFDXWLRQV GXULQJ KDQGOLQJ WR H[FOXGH R[\JHQ DQG ZDWHU YDSRU

PAGE 372

$33(1',; $ 5+(2/2*,&$/ &+$5$&7(5,=$7,21 2) 3&6 $1' 3&636= 63,1 '23(6

PAGE 373

Z UH D r I R R f6 2 ,QFUHDVLQJ 6KHDU 5DWH ’ 'HFUHDVLQJ 6KHDU 5DWH f§k t %f , , 6KHDU 5DWH Vnf )LJXUH $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU EDWFK V VSLQ GRSH 3&6f VROLGV FRQFHQWUDWLRQ a ZWbf

PAGE 374

m UH er $ R R 2 ,QFUHDVLQJ 6KHDU 5DWH ’ 'HFUHDVLQJ 6KHDU 5DWH ‘k %f 7 6KHDU 5DWH Vnf )LJXUH $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU EDWFK V VSLQ GRSH 3&6f VROLGV FRQFHQWUDWLRQ a ZWbf

PAGE 375

$ f UH &/ $ 2 2 $ 2 ,QFUHDVLQJ 6KHDU 5DWH Â’ 'HFUHDVLQJ 6KHDU 5DWH Ri i k Rr 4 7 %f 6KHDU 5DWH Vnf )LJXUH $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU EDWFK V VSLQ GRSH 3&6f VROLGV FRQFHQWUDWLRQ a ZWbf

PAGE 376

a F! &/ er R B R &2 2 ,QFUHDVLQJ 6KHDU 5DWH Â’ 'HFUHDVLQJ 6KHDU 5DWH A i r 2 4 %f 6KHDU 5DWH Vnf )LJXUH $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU EDWFK V VSLQ GRSH 3&636=f VROLGV FRQFHQWUDWLRQ a ZWbf

PAGE 377

e! UH t 9f R R f 2 ,QFUHDVLQJ 6KHDU 5DWH Â’ 'HFUHDVLQJ 6KHDU 5DWH # i 4 %f 7 7 7 6KHDU 5DWH Vnf )LJXUH $ 3ORWV RI $f VKHDU VWUHVV YV VKHDU UDWH %f YLVFRVLW\ YV VKHDU UDWH IRU EDWFK V VSLQ GRSH 3&636=f VROLGV FRQFHQWUDWLRQ a ZWbf

PAGE 378

$33(1',; % ),%(5 63,11,1* &+$5$&7(5,67,&6 )25 3&6 $1' 3&636= 63,1 '23(6

PAGE 379

)LEHU VSLQQLQJ FKDUDFWHULVWLFV IRU 3&6 DQG 3&636= VSLQ EDWFKHV 8)6 3&6f W PLQ 1XPEHU RI KROHV VSXQ 1XPEHU RI ILEHU EUHDNV 7RWDO QXPEHU RI ILEHU EUHDNV 1XPEHU RI EUHDNV SHU PLQXWH SHU VSLQQHUHW KROH 8)V 3&6f W PLQ 1XPEHU RI KROHV VSXQ 1XPEHU RI ILEHU EUHDNV 7RWDO QXPEHU RI EUHDNV 1XPEHU RI EUHDNV SHU PLQXWH SHU VSLQQHUHW KROH

PAGE 380

8)6 3&6f W PLQ 1XPEHU RI KROHV VSXQ 1XPEHU RI ILEHU EUHDNV 7R WDO QXPEHU RI EUHDNV 1XPEHU RI EUHDNV SHU PLQXWH SHU VSLQQHUHW KROH 8)6 3&6f W PLQ 1XPEHU RI KROHV VSXQ 1XPEHU RI ILEHU EUHDNV 7R WDO QXPEHU RI EUHDNV 1XPEHU RI EUHDNV SHU PLQXWH SHU VSLQQHUHW KROH

PAGE 381

8)6 3&636=f W PLQ 1XPEHU RI KROHV VSXQ 1XPEHU RI ILEHU EUHDNV 7RWDO QXPEHU RI EUHDNV 1XPEHU RI EUHDNV SHU PLQXWH SHU KROH 8)V 3&636= W PLQ 1XPEHU RI KROHV VSXQ 1XPEHU RI ILEHU EUHDNV RWDO QXPEHU RI EUHDNV 1XPEHU RI EUHDNV SHU PLQXWH SHU VSLQQHUHW KROH

PAGE 382

8)6 3&636=f W PLQ 1XPEHU RI KROHV VSXQ 1XPEHU RI ILEHU EUHDNV 7RWDO QXPEHU RI EUHDNV 1XPEHU RI EUHDNV SHU PLQXWH SHU VSLQQHUHW KROH

PAGE 383

$33(1',; & ),%(5 (;7(16,21 ',67$1&(6 )25 3&6 $1' 3&636= 63,1 '23(6

PAGE 384

(;7(16,21 FPf (;7(16,21 FPf 75,$/ 180%(5 75,$/ 180%(5 )LJXUH & )LEHU H[WHQVLRQ GLVWDQFHV IRU 3&6 VSLQ GRSHV

PAGE 385

(;7(16,21 FPf (;7(16,21 FPf 75,$/ 180%(5 ([SHULPHQW 3&636= VSLQ GRSH %f $YHUDJH s FP 75,$/ 180%(5 )LJXUH & )LEHU H[WHQVLRQ GLVWDQFHV IRU 3&636= VSLQ GRSHV

PAGE 386

$33(1',; ,175,16,& 9,6&26,7< &$/&8/$7,216 )25 3&6 3&636= 36= $1' 306 32/<0(56

PAGE 387

7DEOH ,QWULQVLF YLVFRVLW\ FDOFXODWLRQV IRU 3&6 DQG 3&636= VROXWLRQV LQ WROXHQH 8EKHOORGH YLVFRPHWHU W\SH 2&f 3&6 VROXWLRQ 6HW &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf s s s s 6HW &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf s s s 7ROXHQH &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf \ $YH HIIOX[ WLPH Vf s &DOFXODWLRQV +UHI WWJ 7@6Sf§ ULUH_ F JGOf WDYHf 7LUHf +VS 9F GOJf )URP D SORW RI UVSF YV F >Q@ GOJ s [ n

PAGE 388

7DEOH &RQWfGf 3&6 36= VROXWLRQ 6HW &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf s s s s 6HW &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf s s s 7ROXHQH &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf WRf $YH HIIOX[ WLPH Vf s &DOFXODWLRQV 7OUHOfAAR L +VS f§ +UHI F JGOf WDYHf 7OUHO QVS +VSF GOJf )URP D SORW RI QSF YV F >Q@ GOJ s [

PAGE 389

7DEOH &RQWfGf 36= VROXWLRQ EDWFK $f 6HW &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf s s s s 6HW &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf s s s 7ROXHQH &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf WRf $YH HIIOX[ WLPH Vf s &DOFXODWLRQV r@UHOf§W 7OVS + UHLn F JGOf WDYHf A,UHO rOVS 9F GOJf )URP D SORW RI 9F YV F >U_@ GOJ s [

PAGE 390

7DEOH ,QWULQVLF YLVFRVLW\ FDOFXODWLRQV IRU 306 SRO\PHU LQ WROXHQH 8EKHOORGH YLVFRPHWHU W\SH 2%f &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf s s s s 7ROXHQH &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf f s &DOFXODWLRQV UfUHLf§WAWR UMVSf UfUHLa F JGOf WDYHf A UHO +VS ULVSF GOJf )URP D SORW RI UAF YV F >Q@ GOJ s [ 5

PAGE 391

7DEOH ,QWULQVLF YLVFRVLW\ FDOFXODWLRQV IRU 306 SRO\PHU LQ WROXHQH GLR[DQH PL[WXUH E\ YROXPHf 8EKHOORGH YLVFRPHWHU W\SH 2%f &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf s s s s 7ROXHQH GLR[DQH PL[WXUH 9RObf &RQFHQWUDWLRQ JGOf (IIOX[ WLPHV Vf $YH HIIOX[ WLPH Vf s &DOFXODWLRQV +UHI WWS 7@6S U_UH_ F JGOf WDYHf AOUHL +VS :F GLJf )URP D SORW RI WL3F YV F >U_@ GOJ s [ V 5

PAGE 392

$33(1',; ( 5(68/76 2) 685)$&( 7(16,21 0($685(0(176

PAGE 393

7DEOH ( 5HVXOWV RI VXUIDFH WHQVLRQ PHDVXUHPHQWV DW r&f :DWHU YLVFRVLW\ P3D V DW r& SXEOLVKHG VXUIDFH WHQVLRQ 1P DW r&f >'HD@ )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH VXUIDFH WHQVLRQ s >'HYLDWLRQ IURP SXEOLVKHG YDOXH b@ $FHWRQH YLVFRVLW\ P3D V DW r& SXEOLVKHG VXUIDFH WHQVLRQ 1P DW r&f >'HD@ )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH VXUIDFH WHQVLRQ s >'HYLDWLRQ IURP SXEOLVKHG YDOXH b@ *O\FHURO YLVFRVLW\ a 3D V DW r& SXEOLVKHG VXUIDFH WHQVLRQ 1P DW r&f )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH VXUIDFH WHQVLRQ s >'HYLDWLRQ IURP SXEOLVKHG YDOXH b@

PAGE 394

7DEOH ( &RQWfGf 3RO\GLPHWK\OVLOR[DQH YLVFRVLW\ 3D V PROHFXODU ZHLJKWf DW r& SXEOLVKHG VXUIDFH WHQVLRQ 1Pf )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH VXUIDFH WHQVLRQ s >'HYLDWLRQ IURP SXEOLVKHG YDOXH b@ 7ROXHQH YLVFRVLW\ P3DV DW r& 3XEOLVKHG YDOXH RI VXUIDFH WHQVLRQ 1P DW r&f >'HD@ )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH VXUIDFH WHQVLRQ s >'HYLDWLRQ IURP SXEOVLKHG YDOXH b@ 3&6 6ROXWLRQ ZWbf )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH VXUIDFH WHQVLRQ s

PAGE 395

7DEOH ( &RQWfGf 3&6 6ROXWLRQ ZWbf )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH s 3&6 6ROXWLRQ ZWbf )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH s 3&636= 6ROXWLRQ ZWbf )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH s

PAGE 396

7DEOH ( &RQWfGf 3&636= 6ROXWLRQ ZWbf )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH s 3&636= 6ROXWLRQ ZWbf )RUFH PTf 6XUIDFH WHQVLRQ 1Pf $YHUDJH s

PAGE 397

$33(1',; ) 7(03(5$785( $1' :(,*+7 *$,16 )25 +($7 75($70(17 2) 3&6 $1' 3&636= ),%(56 ,1 $,5

PAGE 398

7DEOH ) $LUKHDW WUHDWPHQW WHPSHUDWXUHV DQG ZHLJKW JDLQV IRU 3&6 DQG 3&636= ILEHUV )LEHU EDWFK 3&6 RU 3&636= $PRXQW RI VDPSOH PJf 7HPSHUDWXUH r&f :HLJKW JDLQ bf 8)V$/ Kf 3&6 8)V $/Kf 3&6 8)V$/Kf 3&6 8)V$/Kf 3&6 8)V$/ Kf 3&636= 8)V$/Kf 3&636=

PAGE 399

$33(1',; :(,*+7 /266 '$7$ )25 3&6 3&636= ),%(56 $,5+($7 75($7(' $1' 121 $,5 +($7 75($7('f $)7(5 3<52/<6,6 $7 r& ,1 1,752*(1

PAGE 400

7DEOH :HLJKW ORVV GDWD IRU DLUKHDW WUHDWHG DQG QRQDLU KHDW WUHDWHG 3&6 DQG 3&636= ILEHUV DIWHU S\URO\VLV DW r& LQ QLWURJHQ %DWFK 1XPEHU RI EDWFKHV :HLTKW ORVV bf 6WDQGDUG GHYLDWLRQ 3&6 3&636= 3&6 DLUKHDW WUHDWHGf 3&636= DLUKHDW WUHDWHGf

PAGE 401

$33(1',; + 7(16,/( 675(1*7+ '$7$ )25 3<52/<=(' 3&6 $1' 3&636= ),%(56

PAGE 402

7DEOH + 8)V r& K1f 3&6f %DWFK GLQPf G]8LPf GODYJM $YHUDJH 6WG 'HY %DWFK GLSPf GSPf GLDYTf $YHUDJH 6WG 'HY /RDGTf 6WUDLQ 76L*3DL (0I*3DO /RDGTf 6WUDLQ 76L*3DL (0L*3Df

PAGE 403

7DEOH + 8)V r& K1f 3&6f %DWFK GMO\Pf G£XQ GMDYJM $YHUDJH 6WG 'HY %DWFK GLQPf GE£XPf GLDYDf $YHUDJH 6WG 'HY /RDGJf 6WUDLQ 76*3Df (0I*3DO /RDGJf 6WUDLQ 76*3Df (0L*3DO

PAGE 404

7DEOH + &RQWnF8 %DWFK F0_MPO GAP GDYDf /RDGLDO 6WUDLQ 76I*3DL (0W*3DO $YHUDJH 6WG 'HY %DWFK $YHUDJH 6WG 'HY GLSPf £D+Pf GDYJf /RDGIDO 6WUDLQ 76I*3DO (0I*3DO

PAGE 405

7DEOH + &RQWnGf %DWFK GLSPf GLO\Pf GDYJf /RDGJf 6WUDLQ 76I*3DO (0I*3DO $YHUDJH 6WG 'HY

PAGE 406

7DEOH + /f)V r& K1f 3&6f %DWFK GLSPf G\Pf GLDYDO $YHUDJH 6WG 'HY %DWFK GM\Pf GDWXPf GMD\Jf $YHUDJH 6WG 'HY /RDGLDO 6WUDLQ 76L*3DL (0I*3DO /RDGTf 6WUDLQ 76W*3DO (0I*3Df

PAGE 407

7DEOH + &RQWnF0 %DWFK GLSPf GLWPf GDYJf $YHUDJH 6WG 'HY %DWFK GLQPf GSPf GDYJf $YHUDJH 6WG 'HY /RDGTf 6WUDLQ 76I*3DO (0I*3DO /RDGLDO 6WUDLQ 76I*3DO (0I*3DL

PAGE 408

7DEOH + &RQWnGf %DWFK GWWLPf G£XPf GDYJf /RDGDf 6WUDLQ 76I*3DO (0L*3DO $YHUDJH 6WG 'HY

PAGE 409

7DEOH + 8)V r& K1f 3&6f %DWFK GLSPf GSPf GLDYD $YHUDJH 6WG 'HY %DWFK GL4MUQf GLOXPf GLDYD $YHUDJH 6WG 'HY /RDGTf 6WUDLQ 76*3Df (0I*3DO /RDGTf 6WUDLQ 76I*3DL (0*3Df

PAGE 410

7DEOH + &RQWnGf %DWFK GLSPf GZPf GDYJf $YHUDJH 6WG 'HY %DWFK GLSPf GLLXPf GDYJf $YHUDJH 6WG 'HY /RDGJf 6WUDLQ 76L*3DO (0L*3DO /RDGJf 6WUDLQ 76L*3DO (0*3Df

PAGE 411

7DEOH + &RQWnF %DWFK GWQPf G"^SPf GDYDf $YHUDJH 6WG 'HY %DWFK GMLXPf GL-Pf GDYJf $YHUDJH 6WG 'HY /RDGJf 6WUDLQ 76*3Df (0I*3DO /RDGLDO 6WUDLQ 76L*3DO (0I*3DO

PAGE 412

7DEOH + 8)6 r& K1f 3&636=f %DWFK GLWLPf GDL\Pf GLDYDO $YHUDJH 6WG 'HY %DWFK GAMPf GDWPf GDYJf $YHUDJH 6WG 'HY /RDGJf 6WUDLQ 76L*3DO (0L*3DO /RDGDf 6WUDLQ 76*3Df (0*3Df

PAGE 413

7DEOH + &RQWfGf %DWFK G-APL GSPf GIDYJf /RDGJf 6WUDLQ 76L*3DO (0*3Df $YHUDJH 6WG 'HY %DWFK $YHUDJH 6WG 'HY GLSPf GSPf GLDYDf /RDGJf 6WUDLQ 76L*3DL (0I*3DL

PAGE 414

7DEOH + &RQWnGf %DWFK GWSPf GQPf GLDYD $YHUDJH 6WG 'HY %DWFK GL8O4 GMLXPf GLDYDO $YHUDJH 6WG 'HY /RDGTf 6WUDLQ 76I*3DO (0L*3DO /RDGJf 6WUDLQ 76L*3DO (0L*3DO

PAGE 415

7DEOH + &RQWnG7 %DWFK GL0Pf GL\QLf GDYJf /RDGJf 6WUDLQ 76W*3DO (0*3Df $YHUDJH 6WG 'HY

PAGE 416

$YHUDJH 6WG 'HY 1f &2 UR e .&2 &2 .f .! 8 E R E R E R FQ R UR e 1f UR I2 UR e FQ FQ R FQ R FQ R FQ R E R FQ R N N W N N BN N N N UR &2 UR X 8 .f &2 &2 UR UR $ nFQ 0 FQ Nf FQ Nf FQ Nf FQ UR FQ NM FQ FQ R LR FQ NM FQ UR e &2 UR FQ &2 IH S FQ FQ &2 &2 &2 &2 &2 UR &-f R FQ R FQ &2 UR E R /N &' E &' E &2 E E FQ ER aR UR IF &2 &' &2 UR R &2 &2 &' &' R R 2 R R R R R R R R R R R E E E R E E E E E E E E R R UR UR UR &' FQ R RR R FQ nM R nVL FQ &2 &2 &' FQ IF nM &' R FQ 2f nVL R R UR UR UR }‘ &2 &2 UR UR &2 &2 UR &2 UR E UR &' FQ n, E &2 E UR &2 R NM UR RR &2 E &' t FQ 22 FQ nmL FQ FQ FQ FQ FQ 8 R R 2f UR &' UR UR f§r R FQ FQ UR FQ t &' NM FQ &' NM &2 E &2 ‘Wr N_ UR E &' ! SI R UR GAQPf GAPO GIDYTf /RDGTf 6WUDLQ 76L*3DO (0I*3DO 2 DL 9 2 Y &2 f f RL nFQ FQ nFQ FQ FQ E FQ nR E nR nFQ nR R nR R nR nR R ZZRRRRRRRRRRRRRRRRRR p /r FQEEEE ERR E E EREE R FQ E R frr }‘ 1f A A UR r r UR UR UR R rf r‘ r r‘ r r‘ f§}‘ UR UR FR E NO E UR N_ E NJ .M NM nVL E E E UR UR FQ UR R FQ R FQ FQ R FQ FQ FQ FQ R R R FQ FQ R &2 FQ W &2 &2 &2 &2 FQ nVL UR &' &2 &2 UR &' &2 &2 UR &' UR &' UR FQ &2 R &2 $ &2 &' R f X &2 E ER ER &2 E E &' &2 UR E E FQ ‘IF E E 4 2L A FQ UR RR &' FQ FQ &' FQ UR &2 UR UR FQ 4 RRRRRRRRRRRRRRRRRR 3EEEEREEEEEEEEEEEER 1&22f8fW'&-fAefIDL8f&Q2f'2fA &2 &2 &2 &2 &2 &2 &2 &2 &2 UR &2 UR &2 UR UR FR &2 8FR /[ E E E .M $ E E R NM NM E O FQ ‘Wr RR &2 &' &2 FQ FQ FQ &' FQ r f§r 1f &' &' r‘ FG FQ nVL UFRFQFRRFRRSFR UR BN UR BN BN BN BN UR aYO R FQ &' FQ &' FQ &2 FQ E BN E E /N UR E E E /N UR f8 FQ &2 FR FQ &' UR &2 &' 7DEOH + 8)V r& K1f 3&636=f

PAGE 417

7DEOH + &RQWnF+ %DWFK GLSPf GDWXPf GDYJf $YHUDJH 6WG 'HY %DWFK GDWXPf G8Pf GDYJf $YHUDJH 6WG 'HY /RDGJf 6WUDLQ 76*3Df (0L*3Df /RDGTf 6WUDLQ 76L*3DO (0*3Df

PAGE 418

7DEOH + &RQWnGO %DWFK GLSPf GSPf GDYDf /RDGJf 6WUDLQ 76*3Df (0*3Df $YHUDJH 6WG 'HY

PAGE 419

7DEOH + 8)V r& K1f 3&636=f %DWFK GWLXPf GDWXPf GWDYJf $YHUDJH 6WG 'HY %DWFK GLSPf GDWXPf GDYJf $YHUDJH 6WG 'HY /RDGJf 6WUDLQ 76L*3DO (0L*3DO /RDGJf 6WUDLQ 76I*3DO (0L*3DO

PAGE 420

7DEOH + L&RQWnG7 %DWFK GLSPf G8Pf GDYJf $YHUDJH 6WG 'HY %DWFK GL_MPf GSPf GDYJf $YHUDJH 6WG 'HY /RDGJf 6WUDLQ 76*3Df (0*3Df /RDGTf 6WUDLQ 76L*3DL (0I*3DO

PAGE 421

$33(1',; *3& 02/(&8/$5 :(,*+7 ',675,%87,216 )25 306 32/<0(56 )5$&7,21$//< 35(&,3,7$7(' %< $'',7,21 2) $/&2+2/6

PAGE 422

GZWGORJ0f GZWGORJ0f ORJ 0: )LJXUH *3& GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DOFRKROV

PAGE 423

GZWGORJ0f GZWGORJ0f $f %f ORJ 0: )LJXUH *3& GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFRKROV

PAGE 424

$33(1',; *3& 02/(&8/$5 :(,*+7 ',675,%87,216 )25 306 32/<0(56 )5$&7,21$//<35(&,3,7$7(' %< $'',7,21 2) $&(721(

PAGE 425

GZWGORJ0f GZWGORJ0f GZWGORJ0f 306 0Q 0Z 3' 7 306) 0Q 0Z 3', 7 306) 0Q 0Z 3', $f %f &f )LJXUH -*3& GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DQG &f DIWHU WZR IUDFWLRQDO SUHFLSLWDWLRQV ZLWK DFHWRQH

PAGE 426

GZWGORJ0f GZWGORJ0f ORJ 0: )LJXUH *3& GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH

PAGE 427

GZWGORJ0f GZWGORJ0f ORJ 0: )LJXUH *3& GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH

PAGE 428

GZWGORJ0f GZWGORJ0f )LJXUH *3& GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH

PAGE 429

GZWGORJ0f GZWGORJ0f )LJXUH *3& GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH

PAGE 430

GZWGORJ0f GZWGORJ0f

PAGE 431

GZWGORJ0f GZWGORJ0f $f )LJXUH *3& GLVWULEXWLRQ RI 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH

PAGE 432

GZWGORJ0f GZWGORJ0f )LJXUH *3& GLVWULEXWLRQV IRU 306 SRO\PHU $f EHIRUH DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH

PAGE 433

GZWGORJ0f GZWGORJ0f )LJXUH *3& GLVWULEXWLRQV IRU 306 SRO\PHU EHIRUH$f DQG %f DIWHU IUDFWLRQDO SUHFLSLWDWLRQ ZLWK DFHWRQH

PAGE 434

$33(1',; &$/&8/$7,216 )25 (;&(66 6,/,&21 $1' &$5%21 ,1 6,& ),%(56

PAGE 435

([FHVV 6L &DOFXODWLRQV &RQVLGHU WKH FRPSRVLWLRQ RI D r&S\URO\]HG 306 SRO\PHU 7KH HOHPHQWDO FRPSRVLWLRQ GHWHUPLQHG E\ (OHFWURQ 0LFURSUREH $QDO\VLV (0$f LV ZWb 6L ZWb & DQG ZWb $VVXPLQJ WKDW DOO LV WLHG WR 6L DV 6L ZH KDYH ZWb 2 WLHG WR ZWb 6L WRWDO RI ZWb 6Lf :H WKHQ KDYH ZWb 6L IRU FRPELQDWLRQ ZLWK & 1RZ WKH VWRLFKLRPHWULF FRPSRVLWLRQ RI 6L& LV ZWb 6L DQG ZWb & LH ZWb & UHTXLUHV ZWb 6L WR IRUP 6L&f 7KHUHIRUH ZWb & UHTXLUHV ZWb 6L WR IRUP 6L& 7KH H[FHVV 6L LQ WKH S\URO\]HG 306 SRO\PHU LV ZWb ([FHVV & FDOFXODWLRQV LQ 3&6EDVHG ILEHUV &RQVLGHU WKH HOHPHQWDO FRPSRVLWLRQ RI 1LFDORQr1 6L& ILEHU ZWb 6L ZWb & DQG ZWb 2 >7RU%@ $VVXPLQJ WKDW DOO LV WLHG WR 6L DV 6L ZH KDYH ZWb WLHG WR ZWb 6L DV 6L WRWDO RI ZWb 6Lf :H WKHQ KDYH ZWb 6L DYDLODEOH IRU FRPELQDWLRQ ZLWK & ZWb RI 6L UHTXLUHV ZWb RI & WR IRUP VWRLFKLRPHWULF 6L& 7KH H[FHVV & LQ WKH 1LFDORQr1 6L& ILEHU LV WKHQ ZWb

PAGE 436

$33(1',; / &+$5$&7(5,67,&6 2) 306 32/<0(56 6<17+(6,=(' )520 0'&6 02120(5

PAGE 437

7DEOH / 5HVXOWV RI FKDUDFWHUL]DWLRQ RI 306 SRO\PHUV V\QWKHVL]HG IURP PHWK\OGLFKORURVLODQH PRQRPHU %DWFK 'HVLJQDWLRQ 6ROYHQWVf 3RO\PHU
PAGE 438

$33(1',; 0 &+$5$&7(5,67,&6 2) 306 32/<0(56 6<17+(6,=(' )520 0'&6 $1' 07&6 02120(5 0,;785(

PAGE 439

7DEOH 0 5HVXOWV RI FKDUDFWHUL]DWLRQ RI 306 SRO\PHUV V\QWKHVL]HG IURP 0'&607&6 PRQRPHUV ZWbf %DWFK 'HVLJQDWLRQ 6ROYHQWVf 3RO\PHU
PAGE 440

7DEOH 0 &RQWfGf %DWFK 'HVLJQDWLRQ 6ROYHQWVf 3RO\PHU
PAGE 441

7DEOH 0 &RQWfGf %DWFK 'HVLJQDWLRQ 6ROYHQWVf 3RO\PHU
PAGE 442

7DEOH 0 &RQWfGf %DWFK 'HVLJQDWLRQ 6ROYHQWVf 3RO\PHU
PAGE 443

7DEOH 0 &RQWfGf %DWFK 'HVLJQDWLRQ 6ROYHQWVf 3RO\PHU
PAGE 444

$33(1',; 1 &+(0,&$/ )2508/$6 2) 02120(56 86(' ,1 :857=&283/,1* 32/<0(5,=$7,21

PAGE 445

&KHPLFDO IRUPXODV RI PRQRPHUV XVHG LQ :XUW]FRXSOLQT SRO\PHUL]DWLRQ 'LPHWK\OGLFKORURVLODQH &+R L &O f§ 6L f§ &O FK 0HWK\OGLFKORURVLODQH &+R &O 6L f§ &O + 0HWK\OWULFKORURVLODQH &+R &O6L&, &O FK &O6L&, FK 3KHQ\OPHWK\OGLFKORURVLODQH

PAGE 446

+H[\OPHWK\OGLFKORURVLODQH +H[\OGcQGcFKORURVcODQH 'RGHF\OPHWK\OGLFKORURVLODQH &+ &O f§ 6L f§ &O FK _K &O f§ 6L f§&O FK MO+ &O f§ 6L &O FK _+ &O f§6L &O FK 'RGHF\OGLQGLFKORURVLODQH

PAGE 447

5()(5(1&(6 >$EX@ 0$ $EX(LG 5% .LQJ DQG $0 .RWOLDU f6\QWKHVLV RI 3RO\VLODQH 3UHFXUVRUV DQG 7KHLU 3\URO\VLV WR 6LOLFRQ &DUELGHVf (XU 3RO\P >@ f >$LW@ & $LWNHQ -) +DUURG DQG ( 6DPXHO f3RO\PHUL]DWLRQ RI 3ULPDU\ 6LODQHV WR /LQHDU 3RO\VLODQHV &DWDO\]HG E\ 7LWDQRFHQH 'HULYDWLYHVf 2UJDQRPHW &KHP && f >$LW@ & $LWNHQ -) +DUURG DQG 86 *LOO f6WUXFWXUDO 6WXGLHV RI 2OLJRVLODQHV 3URGXFHG E\ &DWDO\WLF 'HK\GURJHQDWLYH &RXSOLQJ RI 3ULPDU\ 2UJDQRVLODQHV &DQ &KHP f >$LW@ & $LWNHQ -3 %DUU\ ) *DXYLQ -) +DUURG $ 0DOHN DQG 5RXVVHDX f$ 6XUYH\ RI &DWDO\WLF $FWLYLW\ RI UL&\FORSHQWDGLHQ\O &RPSOH[HV RI *URXSV DQG 8UDQLXP DQG 7KRULXP IRU WKH 'HK\GURFRXSOLQJ RI 3KHQ\OVLODQHf 2UJDQRPHWDOOLFV f >$QG@ 5 $QGHUVRQ */ /DUVRQ DQG & 6PLWK (GVf 6LOLFRQ &RPSRXQGV 5HJLVWHU DQG 5HYLHZ A HGf +XOV $PHULFD 3LVFDWDZD\ 1f >$67$670 'HVLJQDWLRQ D f6WDQGDUG 6SHFLILFDWLRQV DQG 2SHUDWLQJ ,QVWUXFWLRQV IRU *ODVV &DSLOODU\ .LQHPDWLF 9LVFRPHWHUVf $QQXDO %RRN RI $670 6WDQGDUGV 9RO $670 3KLODGHOSKLD 3$ f >$WW@ $WWRQ 6$ %RQH DQG ,07 'DYLGVRQ f&KORULQHDEVWUDFWLRQ DQG &KORULQH 0LJUDWLRQ 5HDFWLRQ RI 6LO\O 5DGLFDOVf 2UJDQRPHW &KHP & f >%DQ@ 5+ %DQH\ f+LJK %DQ@ 5+ %DQH\ -+ *DXO -U DQG 7. +LOW\ f0HWK\OFKORURSRO\VLODQHV DQG 'HULYDWLYHV 3UHSDUHG IURP WKH 5HGLVWULEXWLRQ RI 0HWK\OFKORURGLVLODQHV 2UJDQRPHWDOOLFV >@ f >%DQ@ 5+ %DQH\ f0HWKRG RI 3UHSDULQJ 6LOLFRQ &DUELGHf 86 3DW 1R f >%HQ@ 5( %HQILHOG 5+ &UDJJ 5* -RQHV DQG $& 6ZDLQ f$LU6WDEOH $ONDOL 0HWDO &ROORLGV DQG WKH %OXH &RORU LQ :XUW] 6\QWKHVLVf 1DWXUH >@ f

PAGE 448

>%HU@ %& %HUULV f0HWKRG RI 3URGXFLQJ 3RO\VLODQH &RPSRXQGVf 86 3DW 1R f >%LO@ ) %LOOPH\HU $ 7H[WERRN RI 3RO\PHU 6FLHQFH :LOH\(DVWHUQ 3XEOLFDWLRQV 1HZ %RX@ ( %RXLOORQ ) /DQJODLV 5 3DLOOHU 5 1DVODLQ ) &UXHJH -& 6DUWKRX $ 'HOSXHFK & /DIIRQ 3 /DJDUGH 0 0RQWKLRX[ $ 2EHUOLQ f&RQYHUVLRQ 0HFKDQLVPV RI D 3RO\FDUERVLODQH 3UHFXUVRU LQWR DQ 6L&EDVHG &HUDPLF 0DWHULDOf 0DWHU 6FL f >%UR@ .$ %URZQ:HQVOH\ DQG 5$ 6LQFODLU f3RO\K\GULGRVLODQHV DQG 7KHLU &RQYHUVLRQ WR 3\URSRO\PHUVf 86 3DW 1R f >%UR@ .$ %URZQ:HQVOH\ f)RUPDWLRQ RI 6L6L ERQGV IURP 6L+ %RQGV LQ WKH 3UHVHQFH RI +\GURVLODWLRQ &DWDO\VWVf 2UJDQRPHWDOOLFV f >%XM@ '5 %XMDOVNL f3RO\VLODQH 3UHFHUDPLF 3RO\PHUVf 86 3DW 1R f >%XU@ & %XUNKDUG f3RO\GLPHWK\OVLODQHVf $P &KHP 6RF f >%XU@ *7 %XUQV f3UHFHUDPLF 0HWK\OSRO\VLODQHVf 86 3DW 1R f >&DP@ :+ &DPSEHOO DQG 7. +LOW\ f'LPHWK\O]LUFRQRFHQH&DWDO\]HG 3RO\PHUL]DWLRQ RI $ON\OVLODQHVf 2UJDQRPHWDOOLFV f >&DU@ '&DUOVVRQ -' &RRQH\ 6 *DXWKLHU DQG ':RUVIROG f3\URO\VLV RI 6LOLFRQ%DFNERQH 3RO\PHUV WR 6LOLFRQ &DUELGHf $P &HUDP 6RF >@ f >&KR@ *&KRL 3K' 'LVVHUWDWLRQ 8QLYHUVLW\ RI )ORULGD >&OD@ 7&ODUN 50 $URQV -% 6WDPDWRII DQG 5DEH f7KHUPDO 'HJUDGDWLRQ RI 1LFDORQ 6L& )LEHUf &HUDP (QJ 6FL 3URF >@ f >&RO@ 1 &ROWKXS /+ 'DO\ DQG 6( :LOEHUO\ LQ ,QWURGXFWLRQ WR ,QIUDUHG DQG 5DPDQ 6SHFWURVFRS\ $FDGHPLF 3UHVV 1HZ &RU@ -< &RUH\ ;+ =KX 7& %HGDUG DQG /' /DQJH f&DWDO\WLF 'HK\GURJHQDWLYH &RXSOLQJ RI 6HFRQGDU\ 6LODQHV ZLWK &S0&,Q%X/Lf 2UJDQRPHWDOOLFV f >&5&@ +DQGERRN RI 3K\VLFV DQG &KHPLVWU\ &5& 3XEOLFDWLRQV 1HZ 'DQ@ ) 'DQHV ( 6DLQW$PDQ DQG / &RXGXULHU f7KH 6L& 6\VWHP 3DUW 5HSUHVHQWDWLRQ RI 3KDVH (TXLOLEULD 0DWHU 6FL f

PAGE 449

>)HQ@ =& )HQJ && 7LQ .7 *DX@ 6 *DXWKLHU DQG ':RUVIROG f7KH (IIHFW RI 3KDVH7UDQVIHU &DWDO\VWV RQ 3RO\VLODQH )RUPDWLRQf 0DFURPROHFXOHV B f >*DX@ 6 *DXWKLHU DQG ':RUVIROG f0HFKDQLVWLF 6WXGLHV RI 3RO\VLODQH 3RO\PHUL]DWLRQf LQ 6LOLFRQ%DVHG 3RO\PHU 6FLHQFH$ &RPSUHKHQVLYH 5HVRXUFH SS (GV -0 =HLJOHU DQG ):* )HDURQ $PHULFDQ &KHPLFDO 6RFLHW\ :DVKLQJWRQ '& f >*UH@ 11 *UHHQZRRG (-) 5RVV DQG %3 6WUDXJKDQ LQ ,QGH[ RI 9LEUDWLRQDO 6SHFWUD RI ,QRUJDQLF DQG 2UJDQRPHWDOOLF &RPSRXQGV 9RO &5& 3UHVV &OHYHODQG 2+ f >+DQ@ : +DQ 6 )DQ 4 /L : /LDQJ % *X DQG +DU@ -) +DUURG f3RO\PHUL]DWLRQ RI *URXS +\GULGHV E\ 'HK\GURJHQDWLYH &RXSOLQJf LQ ,QRUJDQLF DQG 2UJDQRPHWDOOLF 3RO\PHUV SS (GV 0 =HOGLQ .:\QQH DQG +5 $OOFRFN $PHULFDQ &KHPLFDO 6RFLHW\ :DVKLQJWRQ '& f >+DV$@ < +DVHJDZD DQG 2NDPXUD f6\QWKHVLV RI &RQWLQXRXV 6LOLFRQ &DUELGH )LEUH3DUW 3\URO\VLV RI 3RO\FDUERVLODQH DQG 6WUXFWXUH RI 3URGXFWVf 0DWHU 6FL f >+DV%@ < +DVHJDZD 0 ,OPXUD DQG 6 +DV@ < +DVHJDZD DQG 2NDPXUD f6\QWKHVLV RI &RQWLQXRXV 6LOLFRQ &DUELGH )LEUH3DUW 7KH 6WUXFWXUH RI 3RO\FDUERVLODQH DV WKH 3UHFXUVRUf 0DWHU 6FL f >+DV@ < +DVHJDZD f6\QWKHVLV RI &RQWLQXRXV 6LOLFRQ &DUELGH )LEUH 3DUW 3\URO\VLV 3URFHVV RI &XUHG 3RO\FDUERVLODQH )LEUH DQG 6WUXFWXUH RI 6L& )LEUHf 0DWHU 6FL f >+DV@ < +DVHJDZD f6L& )LEUH 3UHSDUHG IURP 3RO\FDUERVLODQH &XUHG :LWKRXW 2[\JHQf ,QRUJ 2UJDQRPHW 3RO\P f >+DV@ < +DVHJDZD f1HZ &XULQJ 0HWKRG IRU 3RO\FDUERVLODQH ZLWK 8QVDWXUDWHG +\GURFUDERQV DQG $SSOLFDWLRQ WR 7KHUPDOO\ 6WDEOH 6L& )LEUHf &RPSRVLWHV 6FL 7HFKQRO f

PAGE 450

>+HU@ :+HU]EHUJ DQG -( 0DULDQ f5HODWLRQVKLS %HWZHHQ &RQWDFW $QJOH DQG 'URS 6L]H RI &ROORLG DQG ,QWHUIDFH 6FL >@ f >,FK@ + ,FKLNDZD ) 0DFKLQR 6 0LWVXQR 7 ,VKLNDZD 2NDPXUD DQG < +DVHJDZD f6\QWKHVLV RI &RQWLQXRXV 6LOLFRQ &DUELGH )LEUH 3DUW )DFWRUV $IIHFWLQJ 6WDELOLW\ RI 3RO\FDUERVLODQH WR 2[LGDWLRQf 0DWHU 6FL f >,FK@ + ,FKLNDZD ) 0DFKLQR + 7HUDQLVKL DQG 7 ,VKLNDZD f2[LGDWLRQ 5HDFWLRQ RI 3RO\FDUERVLODQHf LQ 6LOLFRQ%DVHG 3RO\PHU 6FLHQFH$ FRPSUHKHQVLYH 5HVRXUFH SS (GV 0 =HLJOHU DQG ):* )HDURQ $PHULFDQ &KHPLFDO 6RFLHW\ :DVKLQJWRQ '& f >,VK@ 7 ,VKLNDZD f5HFHQW 'HYHORSPHQWV RI WKH 6L& )LEHU 1LFDORQ DQG LWV &RPSRVLWHV ,QFOXGLQJ 3URSHUWLHV RI WKH 6L& )LEHU +L1LFDORQ IRU 8OWUD+LJK 7HPSHUDWXUHf &RPSRVLWHV 6FL 7HFKQRO f >-RQ@ 5* -RQHV 5( %HQILHOG 5+ &UDJJ 3(YDQV DQG $& 6ZDLQ f7KH )RUPDWLRQ RI 3RO\VLODQHV IURP +RPRJHQHRXV 5HDJHQWV LQ 7HWUDK\GURIXUDQ 6ROXWLRQ DW /RZ 7HPSHUDWXUHVf 3RO\PHU >@ f >.LP@ +. .LP DQG 0DW\MDV]HZVNL f3UHSDUDWLRQ RI 3RO\VLODQHV LQ WKH 3UHVHQFH RI 8OWUDVRXQGf $P &KHP 6RF f >.LS @ )6 .LSSLQJ DQG -( 6DQGV f2UJDQLF 'HULYDWLYHV RI 6LOLFRQ 3DUW ;;9 6DWXUDWHG DQG 8QVDWXUDWHG 6LOLFRK\GURFDUERQV 6L 3K f &KHP 6RF f >/LS@ /LSRZLW] /H*URZ 7 /LP DQG 1 /DQJOH\ f6LOLFRQ &DUELGH )LEHUV IURP 0HWK\OSRO\VLODQH 3RO\PHUVf LQ &HUDPLF 7UDQVDFWLRQV9ROXPH 6LOLFRQ &DUELGH f (GV -' &DZOH\ DQG &( 6HPOHU 7KH $PHULFDQ &HUDPLF 6RFLHW\ :HVWHUYLOOH 2+ f >/LS$@ /LSRZLW] -$ 5DEH DQG *$ =DQN f3RO\FU\VWDOOLQH 6L& )LEHUV IURP 2UJDQRVLOLFRQ 3RO\PHUVf &HUDP (QJ 6FL 3URF >@ f >/LS %@ /LSRZLW] f6WUXFWXUH DQG 3URSHUWLHV RI &HUDPLF )LEHUV 3UHSDUHG IURP 2UJDQRVLOLFRQ 3RO\PHUVf ,QRUJ 2UJDQRPHW 3RO\P >@ f >/LS$@ /LSRZLW] 7 %DUQDUG %XMDOVNL -$ 5DEH *$ =DQN < ;X DQG $ =DQJYLO f)LQH'LDPHWHU 3RO\FU\VWDOOLQH 6L& )LEHUV &RPSRVLWHV 6FL 7HFKQRO f >/LS%@ /LSRZLW] DQG -$ 5DEH f3RO\FU\VWDOOLQH 6LOLFRQ &DUELGH )LEHUV 86 3DW 1R f

PAGE 451

>/LS@ /LSRZLW] $ 5DEH .7 1JX\HQ /' 2UU DQG 55 $QGURO 6WUXFWXUH DQG 3URSHUWLHV RI 3RO\PHUGHULYHG 6WRLFKLRPHWULF 6L& )LEHUf &HUDP (QJ 6FL 3URF >@ f >0DK@ 7 0DK 1/ +HFKW '( 0F&XOOXP -5 +RHQLJQPDQ +0 .LP $3 .DW] DQG +3 /LSVLWW f7KHUPDO 6WDELOLW\ RI 1LFDORQ )LEHUVf 0DWHU 6FL >@ f >0DU@ -( 0DUN +5 $OOFRFN DQG 5 :HVW f3RO\VLODQHV DQG 5HODWHG 3RO\PHUV LQ ,QRUJDQLF 3RO\PHUV SS 3UHQWLFH +DOO (QJOHZRRG &OLIIV 1HZ -HUVH\ f >0DW@ 0DW\MDV]HZVNL 0DW@ 0DW\MDV]HZVNL 0 &\SU\N + )UH\ +UNDFK +. .LP 0 0RHOOHU 5XHKO DQG 0 :KLWH f6\QWKHVLV DQG &KDUDFWHUL]DWLRQ 3RO\VLODQHVf 0DFURPRO 6FL &KHP $ > t @ f >0DW@ 5% 0DWKXU 23 %DKO DQG 0LWWDO f$ 1HZ $SSURDFK WR 7KHUPDO 6WDELOL]DWLRQ RI 3$1 )LEHUVf &DUERQ >@ f >0c,@ 5' 0LOOHU -) 5DEROW 5 6RRUL\DNXPDUDQ : )OHPLQJ *1 )LFNHV %/ )DUPHU DQG + .X]PDQ\ f6ROXEOH 3RO\VLODQH 'HULYDWLYHV &KHPLVWU\ DQG 6SHFWURVFRS\f LQ ,QRUJDQLF DQG 2UJDQRPHWDOOLF 3RO\PHUV SS (GV 0 =HOGLQ .:\QQH DQG +5 $OOFRFN $PHULFDQ &KHPLFDO 6RFLHW\ :DVKLQJWRQ '& f >0,@ 5' 0LOOHU DQG 0LFKO f3RO\VLODQH +LJK 3RO\PHUVf &KHP 5HY f >0,@ 5' 0LOOHU f5DGLDWLRQ 6HQVLWLYLW\ RI 6ROXEOH 3RO\VLODQH 'HULYDWLYHVf LQ 6LOLFRQ%DVHG 3RO\PHU 6FLHQFH $ &RPSUHKHQVLYH 5HVRXUFH SS (GV -0 =HLJOHU DQG ):* )HDURQ $PHULFDQ &KHPLFDO 6RFLHW\ :DVKLQJWRQ '& f >0,@ 5' 0LOOHU 7KRPSVRQ 5 6RRUL\DNXPDUDQ DQG *1 )LFNHV f6\QWKHVLV RI 6ROXEOH 6XEVWLWXWHG 6LODQH +LJK 3RO\PHUV E\ :XUW] &RXSOLQJ 7HFKQLTXHVf 3RO\P 6FL 3DUW $ 3RO\P &KHP f >0,@ 5' 0LOOHU (*LQVEXUJ DQG 7KRPSVRQ f/RZ 7HPSHUDWXUH :XUW] 7\SH 3RO\PHUL]DWLRQ RI 6XEVWLWXWHG 'LFKORURVLODQHV 3RO\P >@ f

PAGE 452

>0RF@ 0RFDHU 5 3DLOOHU 5 1DVODLQ & 5LFKDUG -3 3LOORW 'XQRJXHV & *HUDUGLQ DQG ) 7DXOHOOH f6L&1 &HUDPLFV ZLWK D +LJK 0LFURVWUXFWXUDO (ODERUDWHG IURP WKH 3\URO\VLV RI 1HZ 3RO\FDUERVLOD]DQH 3UHFXUVRUV 3DUW 7KH 2UJDQLF,QRUJDQLF 7UDQVLWLRQ 0DWHU 6FL f >0X$@ < 0X DQG -) +DUURG f6\QWKHVLV RI 3RO\PHWK\OVLO\OHQHf E\ &DWDO\WLF 'HK\GURFRXSOLQJ ZLWK &S00H 0 7L =Uf &DWDO\VWVf LQ ,QRUJDQLF DQG 2UJDQRPHWDOOLF 2OLJRPHUV DQG 3RO\PHUV SS (GV -) +DUURG DQG 50 /DLQH .OXZHU $FDGHPLF 3XEOLVKHUV 'RUGUHFKW 7KH 1HWKHUODQGVf f >0X%@ < 0X & $LWNHQ % &RWH DQG -) +DUURG f5HDFWLRQV RI 6LODQHV ZLWK ELVF\FORSHQWDGLHQ\Of 'LDON\O]LUFRQLXP &RPSOH[HV &DQ &KHP f >2ND@ 2NDPXUD f&HUDPLF )LEHUV IURP 3RO\PHU 3UHFXUVRUVf &RPSRVLWHV >@ f >3UL@ *3ULFH $ 0 3DWHO DQG 3:HVW f3RO\PHU 6\QWKHVLV 8VLQJ +LJK ,QWHQVLW\ 8OWUDVRXQGf 0DFURPRO 5HSRUWV $ 6XSSOV t f f >4LX$@ +4LX DQG = 'X f2UJDQRVLODQH 3RO\PHUV )RUPDEOH 3RO\PHUV &RQWDLQLQJ 0HWK\O 6LO\OHQH 8QLWVf 3RO\P 6FL 3DUW $ 3RO\P &KHP f >4LX%@ + 4LX DQG = 'X f2UJDQRVLODQH 3RO\PHUV )RUPDEOH 3RO\PHUV &RQWDLQLQJ 5HDFWLYH 6LGH *URXSVf 3RO\P 6FL 3DUW $ 3RO\P &KHP f >5HH@ 7 5HH DQG + (\ULQJ f5HOD[DWLRQ 7KHRU\ RI 7UDQVSRUW 3KHQRPHQDf LQ 5KHRORJ\ 7KHRU\ DQG $SSOLFDWLRQV (G (LULFK 9RO ,, $FDGHPLF 3UHVV 1HZ 5HL@ ( 5HLFKPDQLV $( 1RYHPEUH 5& 7DUDVFQ $ 6KXJDUG DQG /) 7KRPSVRQ f2UJDQRVLOLFRQ 3RO\PHUV IRU 0LFUROLWKRJUDSKLF $SSOLFDWLRQV LQ 6LOLFRQ%DVHG 3RO\PHU 6FLHQFH $ &RPSUHKHQVLYH 5HVRXUFH SS (GV -0 =HLJOHU DQG ):* )HDURQ $PHULFDQ &KHPLFDO 6RFLHW\ :DVKLQJWRQ '& f >6DF@ 0' 6DFNV f5KHRORJ\ RI 6XVSHQVLRQVf LQ 6FLHQFH RI &HUDPLF 3URFHVVLQJ SS (GV // +HQFK DQG '5 8OULFK -RKQ :LOH\ t 6RQV 1HZ 6DF$@ 0' 6DFNV *: 6FKHLIIHOH 06DOHHP *$ 6WDDE $$ 0RUURQH DQG 7:LOOLDPV f3RO\PHU'HULYHG )LEHUV ZLWK 1HDU6WRLFKLRPHWULF &RPSRVLWLRQ DQG /RZ 2[\JHQ &RQWHQWf LQ 0DW 5HV 6RF 6\PS 3URF &HUDPLF 0DWUL[ &RPSRVLWHV 0DWHULDOV 5HVHDUFK 6RFLHW\ 3LWWVEXUJK 3$ f

PAGE 453

>6DF%@ 0' 6DFNV $$ 0RUURQH *: 6FKHLIIHOH DQG 06DOHHP f&KDUDFWHUL]DWLRQ RI 3RO\PHU'HULYHG 6L& )LEHUV ZLWK /RZ 2[\JHQ &RQWHQW 1HDU6WRLFKLRPHWULF &RPSRVLWLRQ DQG ,PSURYHG 7KHUPRPHFKDQLFDO 6WDELOLW\ &HUDP (QJ 6FL 3URF >@ f >6DN@ 7 6DNDNXUD +/DXWHQVFKODJHU 0 1DNDMLPD DQG 0 7DQDND f'HK\GURJHQDWLYH &RQGHQVDWLRQ RI +\GURVLODQHV &DWDO\]HG E\ DQ 2UJDQRQHRG\PLXP &RPSOH[f &KHP /HWW f >6DN@ 7 6DNDNXUD 0 7DQDND DQG 7 .RED\DVKL f0HWKRG IRU 3URGXFLQJ 3RO\VLODQHVf 86 3DW 1R f >6DO@ 0 6DOHHP XQSXEOLVKHG ZRUN >6DO@ 0 6DOHHP DQG 0' 6DFNV XQSXEOLVKHG ZRUN >6FK@ &/ 6FKLOOLQJ -U DQG 7& :LOOLDPV f3RO\PHULF 5RXWHV WR 6LOLFRQ &DUELGH 3RO\FDUERVLODQHV 3RO\VLODK\GURFDUERQV DQG 9LQ\OLF 3RO\VLODQHV 3RO\P 3UHSU f >6FK@ &/ 6FKLOOLQJ -U DQG % .DQQHU f3RO\VLODQH 3UHFXUVRUV &RQWDLQLQJ 2OHILQLF *URXSV IRU 6LOLFRQ &DUELGHf 86 3DW 1R f >6FK@ :5 6FKPLGW /9 ,QWHUQDQWH 5+ 'RUHPXV 7 7URXW 36 0DUFKHWWL DQG *( 0DFLHO f3\URO\VLV &KHPLVWU\ RI DQ 2UJDQRPHWDOOLF 3UHFXUVRU WR 6LOLFRQ &DUELGH &KHP 0DWHU f >6H\@ 6H\IHUWK *+ :LVHPDQ <) 6H\@ 6H\IHUWK f6\QWKHVLV RI 6RPH 2UJDQRVLOLFRQ 3RO\PHUV DQG 7KHLU 3\URO\WLF &RQYHUVLRQ WR &HUDPLFVf LQ 6LOLFRQ%DVHG 3RO\PHU 6FLHQFH $ &RPSUHKHQVLYH 5HVRXUFH SS (GV -0 =HLJOHU DQG ):* )HDURQ $PHULFDQ &KHPLFDO 6RFLHW\ :DVKLQJWRQ '& f >6H\@ 6H\IHUWK 7* :RRG +7UDF\ DQG -/ 5RELVRQ f1HDU6WRLFKLRPHWULF 6LOLFRQ &DUELGH IURP DQ (FRQRPLFDO 3RO\VLODQH 3UHFXUVRU $P &HUDP 6RF >@ f >6H\@ 6H\IHUWK +7UDF\ DQG -/ 5RELVRQ f3UHSDUDWLRQ RI 6LOLFRQ &DUELGH &HUDPLFV IURP WKH 0RGLILFDWLRQ RI DQ 6L+ &RQWDLQLQJ 3RO\VLODQH 86 3DW 1R f >6KL@ 6KLQD DQG 0 .XPDGD f7KHUPDO 5HDUUDQJHPHQW RI +H[DPHWK\OGLVLODQH WR 7ULPHWK\OGLPHWK\OVLO\OPHWK\Of 6LODQHf 2UJ &KHP f

PAGE 454

>6cP@ 6LPRQ DQG $5 %XQVHOO f0HFKDQLFDO DQG 6WUXFWXUDO &KDUDFWHUL]DWLRQ RI WKH 1LFDORQ 6LOLFRQ &DUELGH )LEHUf 0DWHU 6FL >@ f >7DN@ 0 7DNHGD < ,PDL + ,FKLNDZD DQG 7 ,VKLNDZD f3URSHUWLHV RI WKH /RZ 2[\JHQ &RQWHQW 6L& )LEHU RQ +LJK 7HPSHUDWXUH +HDW7UHDWPHQW &HUDP (QJ 6FL 3URF >@ f >7DN@ 0 7DNHGD < ,PDL + ,FKLNDZD 7 ,VKLNDZD 1 .DVDL 7 6XJXFKL DQG 2NDPXUD f7KHUPDO 6WDELOLW\ RI WKH /RZ 2[\JHQ &RQWHQW 6LOLFRQ &DUELGH )LEHUV 'HULYHG IURP 3RO\FDUERVLODQH &HUDP (QJ 6FL 3URF >@ f >7DN@ 0 7DNHGD 6DNDPRWR < ,PDL + ,FKLNDZD DQG 7 ,VKLNDZD f3URSHUWLHV RI 6WRLFKLRPHWULF 6LOLFRQ &DUELGH )LEHU 'HULYHG IURP 3RO\FDUERVLODQHf &HUDP (QJ 6FL 3URF f >7DN@ 0 7DNHGD 6DNDPRWR $ 6DFNL < ,PDL DQG + ,FKLNDZD f+LJK 3HUIRUPDQFH 6LOLFRQ &DUELGH )LEHU +L1LFDORQ IRU &HUDPLF 0DWUL[ &RPSRVLWHVf &HUDP (QJ 6FL 3URF f >70 @ 7' 7LOOH\ DQG +* :RR f&DWDO\WLF 'HK\GURJHQDWLYH 3RO\PHUL]DWLRQ RI 6LODQHV WR 3RO\VLODQHV E\ =LUFRQRFHQH DQG +DIQRFHQH &DWDO\VWV $ 1HZ 3RO\PHUL]DWLRQ 0HFKDQLVPf LQ ,QRUJDQLF DQG 2UJDQRPHWDOOLF 2OLJRPHUV DQG 3RO\PHUV SS (GV -) +DUURG DQG 50 /DLQH .OXZHU $FDGHPLF 3XEOLVKHUV 'RUGUHFKW 7KH 1HWKHUODQGV f >7L@ 7' 7LOOH\ f+LJK0ROHFXODU :HLJKW 6LOLFRQ&RQWDLQLQJ 3RO\PHUV DQG 0HWKRGV IRU WKH 3UHSDUDWLRQ DQG 8VH WKHUHRIf 86 3DW 1R f >7RU@ : 7RUHNL 1$ &UHHG DQG &' %DWLFK f6LOLFRQ&RQWDLQLQJ 9LQ\O 3RO\PHUV DV 3UHFXUVRUV WR &HUDPLF 0DWHULDOVf 3RO\PHU 3UHSULQWV >@ f >7RU$@ : 7RUHNL *&KRL &' %DWLFK 0' 6DFNV DQG 0 6DOHHP f3RO\PHU 'HULYHG 6LOLFRQ &DUELGH )LEHUV ZLWK /RZ 2[\JHQ &RQWHQWf &HUDP (QJ 6FL 3URF >@ f >7RU%@ : 7RUHNL &' %DWLFK 0' 6DFNV 0 6DOHHP DQG *&KRL f3RO\PHU 'HULYHG 6LOLFRQ &DUELGH )LEHUV ZLWK ,PSURYHG 7KHUPRPHFKDQLFDO 6WDELOLW\f 0DW 5HV 6RF 6\PS f >7RU@ : 7RUHNL &' %DWLFK 0' 6DFNV 0 6DOHHP *&KRL DQG $$ 0RUURQH f3RO\PHU'HULYHG 6LOLFRQ &DUELGH )LEHUV ZLWK /RZ 2[\JHQ &RQWHQW DQG ,PSURYHG 7KHUPRPHFKDQLFDO 6WDELOLW\f &RPSRVLWHV 6F 7HFKQRO f

PAGE 455

>7UHM 3 7UHIRQDV ,,, 5 :HVW DQG 5' 0LOOHU f3RO\VLODQH +LJK 3RO\PHUV 0HFKDQLVP RI 3KRWRGHJUDGDWLRQf $P &KHP 6RF f >:HV@ 5 :HVW /' 'DYLG 3O 'MXURYLFK ./ 6WHDUOH\ .69 6ULQLYDVDQ DQG + :HV$@ 5 :HVW f7KH 3RO\VLODQH +LJK 3RO\PHUVf 2UJDQRPHW &KHP f >:HV%@ 5 :HVW ;+ =KDQJ 3O 'MXURYLFK DQG + 6WXJHU f&URVVOLQNLQJ RI 3RO\VLODQHV DV 6LOLFRQ &DUELGH 3UHFXUVRUVf LQ 6FLHQFH RI &HUDPLF 3URFHVVLQJ SS (GV // +HQFK DQG '5 8OULFK -RKQ :LOH\ t 6RQV 1HZ :HV@ 5 :HVW DQG 0D[ND f3RO\VLODQH +LJK 3RO\PHUV $Q 2YHUYLHZf LQ ,QRUJDQLF DQG 2UJDQRPHWDOOLF 3RO\PHUV SS (GV 0 =HOGLQ .:\QQH DQG +5 $OOFRFN $PHULFDQ &KHPLFDO 6RFLHW\ :DVKLQJWRQ '& f >:H\@ '5 :H\HQEHUJ /* 0DKRQH DQG :+ $WZHOO f5HGLVWULEXWLRQ 5HDFWLRQV LQ WKH &KHPLVWU\ RI 6LOLFRQf $QQ 1< $FDG 6FL >@ f >:,@ $5 :ROII 1R]XH 0D[ND DQG 5 :HVW f6, 105 RI 'LPHWK\O DQG 3KHQ\OPHWK\O &RQWDLQLQJ 3RO\VLODQHV 3RO\P 6FL 3DUW $ 3RO\P &KHP >@ f >:RR@ 7* :RRG f, 3KRVSKLGR%ULGJHG 'LLURQ +H[DFDUERQ\O &RPSOH[HV DQG ,, 3RO\PHULF 3UHFXUVRUV WR 6LOLFRQ &DUELGHf 3K' 'LVVHUWDWLRQ 0DVVDFKXVHWWV ,QVWLWXWH RI 7HFKQRORJ\ &DPEULGJH 0$ f >:RU@ ':RUVIROG f3RO\VLO\OHQH 3UHSDUDWLRQVf LQ ,QRUJDQLF DQG 2UJDQRPHWDOOLF 3RO\PHUV SS (GV 0 =HOGLQ .:\QQH DQG +5 $OOFRFN $PHULFDQ &KHPLFDO 6RFLHW\ :DVKLQJWRQ '& f >:X@ 6 :X 3RO\PHU ,QWHUIDFH DQG $GKHVLRQ 0DUFHO 'HNNHU 1HZ :\Q@ .:\QQH DQG 5: 5LFH f&HUDPLFV YLD 3RO\PHU 3\URO\VLVf $QQ 5HY 0DWHU 6FL f >;X@ < ;X $ =DQJYLO /LSRZLW] -$ 5DEH DQG *$ =DQN f0LFURVWUXFWXUH DQG 0LFURFKHPLVWU\ RI 3RO\PHU'HULYHG &U\VWDOOLQH 6L& )LEHUVf $P &HUDP 6RF >@ f >
PAGE 456

>@ f >=HL$@ -0 =HLJOHU f0HFKDQLVWLF 6WXGLHV RI 3RO\VLODQH 6\QWKHVLV E\ 5HGXFWLYH &RXSOLQJ RI 'LFKORURVLODQHVf 3RO\P 3UHSU f >=HL%@ -0 =HLJOHU f0HWKRGV IRU 6\QWKHVLV RI 3RO\VLODQHVf 86 3DW 1R f >=HL@ -0 =HLJOHU /$ +DUUDK DQG $: -RKQVRQ f6\QWKHVLV 3KRWRSK\VLFV DQG 3KRWRFKHPLVWU\ RI 2UJDQR DQG 6LO\OVXEVWLWXWHG 3RO\VLODQH 5HVLVW 0DWHULDOVf 3RO\P 3UHSU f >=KD$@ =) =KDQJ ) %DERQQHDX 50 /DLQH < 0X -) +DUURG DQG -$ 5DKQ f3RO\PHWK\OVLODQHf $ +LJK &HUDPLFV @ f >=KD%@ =) =KDQJ < 0X ) %DERQQHDX 50 /DLQH -) +DUURG DQG -$ 5DKQ f3RO\PHWK\OVLODQH DV D 3UHFXUVRU WR +LJK 3XULW\ 6LOLFRQ &DUELGHf LQ ,QRUJDQLF DQG 2UJDQRPHWDOOLF 2OLJRPHUV DQG 3RO\PHUV SS (GV -) +DUURG DQG 50 /DLQH .OXZHU $FDGHPLF 3XEOLVKHUV 'RUGUHFKW 7KH 1HWKHUODQGVf f >=KD$@ =) =KDQJ &6 6FRWWR DQG 50 /DLQH f3URFHVVLQJ RI 6LOLFRQ &DUELGH )LEHU ZLWK &RQWUROOHG 6WRLFKLRPHWU\ XVLQJ 3RO\PHWK\OVLODQH >0H6L+@[f LQ &RYDOHQW &HUDPLFV ,, 1RQ2[LGHV 0DWHU 5HV 6RF 6\PS 3URF 9 SS 0DWHULDOV 5HVHDUFK 6RFLHW\ 3LWWVEXUJK 3$ f >=KD%@ =) =KDQJ &6 6FRWWR DQG 50 /DLQH f3XUH 6LOLFRQ FDUELGH )LEHUV IURP 3RO\PHWK\OVLODQHf &HUDP (QJ 6FL 3URF f

PAGE 457

%,2*5$3+,&$/ 6.(7&+ 7KH DXWKRU ZDV ERUQ LQ .HUDOD ,QGLD RQ 0D\ WK +H JUDGXDWHG ZLWK D %DFKHORU RI 7HFKQRORJ\ %7HFKf GHJUHH LQ FKHPLFDO HQJLQHHULQJ IURP 5HJLRQDO (QJLQHHULQJ &ROOHJH 7ULFK\ ,QGLD LQ $IWHU ZRUNLQJ IRU \HDU DW 7DPLO 1DGX 3HWURSURGXFWV /WG 0DGUDV ,QGLD DV D GHSXW\ PDQDJHU KH FDPH WR WKH 86 LQ WR SXUVXH WKH 0DVWHU RI 6FLHQFH GHJUHH LQ FKHPLFDO HQJLQHHULQJ DW 7XIWV 8QLYHUVLW\ 0HGIRUG 0DVVDFKXVHWWV $IWHU FRPSOHWLQJ WKH 06 GHJUHH LQ WKH )DOO RI KH PRYHG WR WKH 8QLYHUVLW\ RI )ORULGD LQ 6SULQJ WR SXUVXH WKH 3K' GHJUHH LQ PDWHULDOV VFLHQFH DQG HQJLQHHULQJ +H LV SUHVHQWO\ HPSOR\HG DV D WHFKQRORJ\ GHYHORSPHQW HQJLQHHU DW 8OWUD &OHDQ 7HFKQRORJ\ D VHPLFRQGXFWRU HTXLSPHQW PDQXIDFWXULQJ FRPSDQ\ LQ 0HQOR 3DUN &DOLIRUQLD

PAGE 458

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

PAGE 459

, FHUWLI\ WKDW KDYH UHDG WKLV VWXG\ DQG WKDW LQ P\ RSLQLRQ LW FRQIRUPV WR DFFHSWDEOH VWDQGDUGV RI VFKRODUO\ SUHVHQWDWLRQ DQG LV IXOO\ DGHTXDWH LQ VFRSH DQG TXDOLW\ DV D GLVVHUWDWLRQ IRU WKH GHJUHH RI 'RFWRU RI 3KLORVRSK\ -" 'DQLHO 5 7DOKDP $VVRFLDWH 3URIHVVRU RI &KHPLVWU\ 7KLV GLVVHUWDWLRQ ZDV VXEPLWWHG WR WKH *UDGXDWH )DFXOW\ RI WKH &ROOHJH RI (QJLQHHULQJ DQG WR WKH *UDGXDWH 6FKRRO DQG ZDV DFFHSWHG DV SDUWLDO IXOILOOPHQW RI WKH UHTXLUHPHQWV IRU WKH GHJUHH RI 'RFWRU RI 3KLORVRSK\ $XJXVW :LQIUHG 0 3KLOOLSV 'HDQ &ROOHJH RI (QJLQHHULQJ .DUHQ $ +ROEURRN 'HDQ *UDGXDWH 6FKRRO

PAGE 460

/' PR r 6 ? F :rP6c+e/ (-/25,'$


326
Figure 4.115. SEM micrographs of UF-35s fibers after heat treatment at 1700C in
argon.


CHAPTER 2
LITERATURE REVIEW
2.1 Background
There has been much interest in recent years in the preparation of ceramic
materials by pyrolysis of organometallic polymers. A wide range of ceramic materials
can be produced by this method, such as SiC, Si3N4, B4C, BN, Si02, Al203 and AIN. In
this review, only silicon-based preceramic polymers, viz., polysilanes are discussed.
Polysilanes are a class of polymers with Si-Si backbone in their main chain. The interest
in polysilanes stems from a number of commercially attractive applications such as
precursors to p-SiC fibers, photoresists in multilayer microlithography and photoinitiators
in radical polymerization. Despite the commercial significance of these polymers,
polysilane technology suffers from the lack of well-controlled and reproducible methods
for synthesis of polysilanes with high yields, high molecular weight, and narrow
polydispersity.
A number of factors need to be considered when selecting a polysilane polymer
for a specific application: (1) nature of the ceramic material (chemical composition and
crystal structure) produced after further processing (e.g., heat treatment), (2) elemental
composition of the starting polymer (which influences the final stoichiometry of the
ceramic produced), (3) molecular architecture of the polymer (linear vs. cross-linked
polymer, which strongly influences the ceramic yield), (4) sensitivity to air (i.e., oxygen
and water vapor) of the polymer, (5) starting molecular weight, (6) capacity of the
5


Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy
PREPARATION OF SIC-BASED FIBERS FROM ORGANOSILICON POLYMERS:
(I) EFFECTS OF POLYVINYLSILAZANE ON THE CHARACTERISTICS AND
PROCESSING BEHAVIOR OF POLYCARBOSILANE-BASED SOLUTIONS AND
(II) SYNTHESIS, CHARACTERIZATION, AND PROCESSING OF
POLYMETHYLSILANES
By
Mohamed Saleem
August 1998
Chairman: Dr. Michael D. Sacks
Major Department: Materials Science and Engineering
The effect of the addition of polyvinylsilazane (PSZ) on the characteristics (i.e.,
spinnability, rheological behavior, wetting behavior, evaporation behavior, etc.) of
polycarbosilane (PCS) solutions was investigated. Spinnability of PCS solution was
characterized by number of breaks occurring during spinning and amount of fibers
formed after spinning. PCS and PCS+PSZ solutions were characterized by measuring
surface tension, contact angles and rate of solvent evaporation. Effect of PSZ on
mechanical properties of SiC fibers prepared from PCS and PCS+PSZ solutions was
also investigated. Chemical changes taking place in PCS and PCS+PSZ fibers during
heat treatment from 40-600C in nitrogen were studied by Fourier transform infrared
spectroscopy (FTIR).
Addition of PSZ to PCS greatly improved spinnability of PCS solutions.
Significant differences in wetting characteristics were observed for PCS solutions and
XXI


9
Polymer yields and molecular weight distributions are quite sensitive to
substituents (pendant groups) in the monomers, order of reagent addition, solvent
composition, reaction temperatures, etc. The reaction is usually carried out at
elevated temperatures (~100C) using a suitable alkali metal dispersion. Sodium,
potassium or lithium could be chosen as alkali metals but sodium is usually preferred
because potassium and lithium are relatively more flammable and hazardous. In the
Wurtz-coupling reaction, sodium is normally employed as a dispersion in an appropriate
solvent such as toluene, xylene, THF, etc. As discussed in section 2.2.1.4, the choice of
solvents plays an important role in determining the polymer molecular weight
distribution and polymer yields.
Equation (2.1) is indicative of the fact the polymerization reaction proceeds by
condensation type mechanism. However, Worsfold [Wor88] and Miller et al. [MI91]
reported, based on the characteristics of the polymers produced during the reaction, that
it proceeds by an addition type mechanism. In an addition type polymerization reaction,
high molecular weight polymer fractions form very early in the reaction and the formation
of high molecular weight polymer is not affected by the stoichiometry of the reagents
(i.e., high molecular weight polymer forms even when one of the reagents is in excess).
Worsfold demonstrated these characteristics for Wurtz-coupling polymerization of
hexylmethyldichlorosilane (carried out in the normal mode (see section 2.2.1.2) in
which monomers are added to molten sodium) by isolating high molecular weight
polymer (~105) in the early stages of reaction. The rate determining step in Wurtz-
coupling polymerization is the reaction between silyl radical and monomer, as shown by
equation (2.3) in Figure 2.1. The reaction between chlorine-ended chain and sodium
takes place rapidly (equation (2.4) in Figure 2.1). Weyenberg [Wey69] et al. have


Table 4.13. Properties of SiC fibers spun from PCS11.
Fiber batch
# of fibers tested
Diameter (pm)
Tensile strength (GPa)
63s
35
11.81 1.32
2.26 0.56
64s
87
9.45 0.66
2.38 1.02
65s
92
11.89 1.19
2.08 0.82
69s
110 .
12.44 1.16
2.70 0.80
Table 4.14. Properties of SiC fibers spun from PCS + PSZ11.
Fiber batch
# of fibers tested
Diameter (pm)
Tensile strength (GPa)
67s
121
10.62 0.70
2.81 0.80
68s
90
12.49 0.84
2.97 0.63
69s
72
12.74 0.98
3.25 0.97
1 Pyrolysis conditions: 1150X, nitrogen atmosphere


93
in the sample.) The dried polymer solution was quickly (<1 min) transferred to a TGA
sample holder to minimize exposure to air. In some cases, the ceramic yield was
determined by pyrolyzing polymers in a tube furnace to 1000C in nitrogen at 10C/min.
(The ceramic yield was determined by measuring the weights before and after
pyrolysis.)
In the case of polymers fractionally-precipitated by nonsolvents, a portion of the
dried polymer was subjected to pyrolysis to determine if the polymer melted during
pyrolysis (melt test) as well as to evaluate ceramic yield. The dried polymer was
crushed into coarse powder, weighed and transferred into a tube furnace quickly (<2
min). The pyrolysis schedule used for the melt test was: 5C/min to 1000C in nitrogen
with no hold at temperature. The polymer was considered to have undergone no melting
if the pyrolyzed polymer retained sharp corners and edges. It was considered partially
melted if some rounding of edges and corners occurred and if the pyrolyzed chunks
were stuck to the alumina boat used for pyrolysis.
Phase analyses of the pyrolyzed samples was carried out by X-ray diffraction
(XRD)§§. All the samples forXRD were heat-treated in argon at 10C/min to 1350C (no
hold time). The pyrolyzed residues were slightly ground with a mortar and pestle and
subsequently mixed with collodian/amyl acetate (1:7 volume ratio). The mixture was
deposited on a glass slide and dried at room temperature prior to analysis.
The crystallite sizes for the Si and SiC phases were determined by the XRD line
broadening method using Schemers formula:
t = 0.9 XI (B Cos0) (3.5)
where t = crystallite size in A
5§ Model APD 3720, Phillips Instruments Company, Mt. Vernon, NY.


315
starting PMS polymers (for both UF-31s and UF-32s) melted during pyrolysis and
caused the fibers to stick together. Spin batch UF-37s also spun well, but the pyrolyzed
fibers were brittle after pyrolysis. This is also presumably due to melting of low
molecular weight components in the polymer. (It may be recalled from the discussion in
section 4.3.1.1 that even though the average molecular weight of PMS-218-AP-H was
high (1^*^23,000), it had a bimodal molecular weight distribution. Hence, melting of low
molecular weight components in the polymer could still have occurred.)
Spin batches UF-34s and UF-45s spun poorly. The polymer used in UF-34s
(PMS-217-AP2-H) had a high starting molecular weight (M*16,200), and the spin dope
was also not filterable through sub-micron filters. The solids loading was also relatively
low (69%) for this spin dope. In the case of UF-45s, the starting polymer used (PMS-
222-AD-H) had a molecular weight of 12,800 (i.e., lower than the molecular weight of
the polymer used in UF-34s) and the spin dope filtered through 0.45 pm filter relatively
easily. However, the spin dope was shear thinning (i.e., the viscosity decreasing from
~52 to ~20 Pa s as shear rate increased from 1 to 40 s'1, respectively) (see Figure
4.109). Also, the spin dope had a low solids loading (62.3%). The low solids loading
suggests that the polymer is highly cross-linked. As indicated in Table 4.23, the starting
polymer used for this spin dope contained 3 wt% DB. It is possible that DB led to the
development of polymers which have a highly branched, network-type structure. Weakly
associated polymers in such a structure may break apart under shear and, hence, shear
thinning flow behavior would be observed in rheological measurements. The structure
(i.e., network character) in these solutions imparts a more elastic character which is
apparently related to the poor spinnability. Similar observations (i.e., difficulty in spinning


345
Solutions (~33 wt% solids) with 0, 4, 8, and 14.5 wt% PSZ required 3, 5, 9, and 12 min,
respectively, for filtration through 0.45 pm filters. The observations of increased solution
cloudiness and increased filtration time for the solutions with higher PSZ content
suggest that some microgel may have been developing. This, in turn, would have an
adverse effect on the ability to draw fibers (i.e., decreased fiber extension would be
expected).


111
PCS+PSZ solutions are similar5. This is somewhat surprising because PSZ has a larger
fraction of higher molecular weight molecules compared to PCS. If other factors were
constant, this should result in a higher intrinsic viscosity. However, the intrinsic viscosity
also depends on the polymer/solvent interactions, the polymer molecular shape (e.g.,
linear vs. equiaxed), and the polymer chain flexibility.
4.1.2.2 Studies on rates of evaporation of solvents from PCS and PCS+PSZ solutions
Experiments were carried out on PCS and PCS+PSZ solutions to assess
changes in rate of solvent evaporation as a result of addition of PSZ to PCS. Changes in
solvent evaporation rate would have an influence on the drying characteristics of the
polymer spin dope near the spinneret surface and extension of fibers from spin dope
and consequently, could influence the process of fiber spinning. The rate of solvent
evaporation was monitored for PCS/toluene and PCS+PSZ/toluene solutions prepared
with 68 wt% polymer. Figures 4.6a and 4.6b show the percentage weight change vs.
time and absolute weight change vs. time, respectively, for both polymer solutions. It is
evident that the toluene evaporation rate was much slower for the PCS+PSZ solution.
This suggests that rate of evaporation of solvent near the spinneret face will be lower for
PCS+PSZ spin dope compared to PCS (and, hence, drying effects at the spinneret face
will be minimized also). When the polymer spin dope dries rapidly on the spinneret face,
it may form drier material which could obstruct the spinneret holes and interfere with
fiber formation and spinning. In addition, a faster drying rate may have an adverse effect
on filament extension and winding. It was shown in section 4.1.1 that fiber extensions
were lower for PCS polymer solution compared to PCS+PSZ solution (see Table 4.2).
This might be caused by a faster drying rate of the filament pulled from the polymer
5 The regression coefficient in the intrinsic viscosity calculations for PSZ was considerably lower than the
values obtained for the PCS and PCS+PSZ solutions.


327
Figure 4.115. (Contd.)


387
Table H-4. UF-69s-1150: (1150C/1 h/N2) (PCS)
Batch 1
di(pm)
d2(pm)
diava.1
12.00
12.00
12.00
10.00
11.00
10.50
9.50
10.00
9.75
10.00
10.50
10.25
12.50
14.00
13.25
9.00
10.50
9.75
11.00
11.50
11.25
10.00
10.00
10.00
12.50
12.50
12.50
10.00
11.50
10.75
11.00
11.00
11.00
11.00
11.50
11.25
10.50
11.50
11.00
11.50
12.50
12.00
10.50
11.00
10.75
12.00
13.00
12.50
10.00
11.50
10.75
Average
10.76
11.50
11.13
Std. Dev
1.05
1.06
1.02
Batch 2
diQjrn)
dilum)
diava.1
12.50
12.50
12.50
11.50
12.00
11.75
13.00
13.00
13.00
11.50
12.00
11.75
12.50
12.50
12.50
13.50
13.50
13.50
13.00
13.50
13.25
11.50
11.50
11.50
12.50
12.50
12.50
13.50
14.00
13.75
13.50
13.50
13.50
13.50
13.50
13.50
13.00
13.50
13.25
13.50
13.50
13.50
12.00
12.50
12.25
11.50
11.50
11.50
12.50
12.50
12.50
11.50
12.00
11.75
Average
12.56
12.75
12.65
Std. Dev
0.80
0.77
0.78
Load(q)
Strain
TS(GPa)
EMfGPal
28.58
0.0116
2.48
212.98
14.80
0.0090
1.68
186.34
12.59
0.0078
1.65
213.14
14.61
0.0086
1.74
201.27
18.95
0.0076
1.35
176.94
17.89
0.0096
2.36
244.94
29.98
0.0131
2.96
225.34
27.71
0.0148
3.46
234.26
30.51
0.0130
2.44
188.04
28.63
0.0121
3.11
256.53
32.96
0.0156
3.40
217.28
11.63
0.0051
1.15
225.51
9.70
0.0060
1.00
166.20
27.81
0.0123
2.41
196.64
28.00
0.0122
3.03
248.57
21.64
0.0095
1.73
182.14
3263
0.0161
3.54
224.12
22.86
0.0108
2.32
211.78
8.01
0.0033
0.83
26.50
Load(q)
Strain
TSfGPai
EM(GPa)
39.07
0.0143
3.12
235.42
4.80
0.0020
0.43
222.13
27.57
0.0109
2.04
186 00
24.79
0.0109
2.24
205.89
20.01
0.0066
1.60
242.41
25.91
0.0083
1.77
212.94
48.05
0.0166
3.42
205.76
32.54
0.0139
3.07
221.00
33.76
0.0128
2.70
210.53
44.58
0.0140
2.94
217.62
29.96
0.0095
2.05
225.47
15.96
0.0053
1.09
207.98
24.11
0.0075
1.71
228.10
40.29
0.0130
2.76
220.54
29.27
0.0110
2.44
221.51
23.37
0.0095
2.21
231.94
36.00
0.0133
2.88
215.40
43.37
0.0190
3.92
217.03
30.19
0.0110
2.35
218.20
10.91
0.0042
0.85
12.85


51
Figure 2.13. TGA plots for polymethylsilane polymer prepared by Zhang et al. [Zha94]


FINAL M
296
Figure 4.102. Plot of non-solvent to polymer ratio vs. final Mw for polymers
precipitated using acetone as non-solvent.


Table M-1. (Contd.)
Batch
Designation
Solvent(s)
Polymer Yield
(%)
GPC MW distribution
Mn Mw PDI
Ceramic Yield (%)
by pyrolysis by TGA b
XRD
Results
(1350C/Ar)
PMS-226
Toluene, THF
(95:5)
37.9
PMS-227
Toluene, THF
(95:5)
40.7
PMS-228
Toluene, THF
(95:5)
40.2
894
1674
1.87
52.1
PMS-229
Toluene, THF
(95:5)
34.4
PMS-230
Toluene, THF
(95:5)
27.6
PMS-231
Toluene, THF
(95:5)
29.6
1352
2747
2.03
73.8
No Si peaks
PMS-232
Toluene, THF
(95:5)
37.2
1001
1756
1.75
64.1
No Si peaks
PMS-233
Toluene, THF
(95:5)
31.7
66.3
No Si peaks
PMS-234
Toluene, THF
(95:5)
18.6
1120
2292
2.05
66.2
No Si peaks
PMS-235
Toluene, THF
(95:5)
20.0
863
1531
1.77
PMS-236
Toluene, THF
(95:5)
32.7
967
1149
1.23


90
18.70 g. The polymer yield is calculated as a percentage of theoretical yield by dividing
the actual polymer yield by the theoretical yield (and then multiplying by 100).
3.2.4 General procedure for heat treatment of PMS-based polymer solutions
PMS polymer solution (33 wt% in toluene) was mixed with PCS (where
applicable in ratios of 90:10, 70:30, etc.) and the solution was filtered through a 0.1 pm
filter. (The concentration of polymer solution was kept at 33 wt% after mixing with PCS
by adding the necessary amount of toluene.) The additives polyvinylsilazane (PSZ)
(amounts in the range of 0.25-14.5 wt%), dicumyl peroxide (DCP) (amounts in the range
of 0.5-1.5 wt%), and decaborane (DB) (amounts in the range of 1-6 wt%) were dissolved
in toluene at 25 wt% solids loading, and separately added (where applicable) to the
polymer solutions after filtering through 0.1 pm filter. The polymer solution was then
transferred to a teflon container (20 ml size) and encased in a stainless steel pressure
bomb5 The teflon container was backfilled with N2 before encasing in the pressure
bomb. The polymer solution (approximately 10-15 g) was heat-treated at
temperatures in the range of 50-150C in a convection oven and were sometimes given
multiple treatments at successively increasing temperatures in this range. The effects of
these heat treatments on the polymer solution viscosity and/or the polymer molecular
weight (determined by GPC) were determined in some cases. Polymer solutions
showed increases in viscosity after heat treatments and this was taken as a measure of
increase in branching/molecular weight of the polymer. The viscosity of the polymer
solution was measured using a cone-plate viscometer1. Heat treatments of polymer
solutions were usually stopped when increases in viscosity of at least ~250% were
obtained (e.g., increases from 2 mPa-s to 7 mPa-s). After heat treatments, polymer
5 Model 243AC, Parr Instrument Company, Moline, IL.
1 Model LVT, Brookfield Engineering Labortaories, Stoughton, MA.


dwt/d(logM) dwt/d(logM)
410
Figure J-8. GPC distributions for PMS-253 polymer: (A) before and
(B) after fractional precipitation with acetone.


129
(f
to
Cl
E
(/)
o
o
w
40
30 -
^20-
10
O Increasing Shear Rate
PCS (33 wt%)
Decreasing Shear Rate
~ Q
DID Q w
fcj
50
100
150
(B)
200
250
300
Shear Rate (s'1)
Figure 4.16. Plots of: (A) shear stress vs. shear rate and (B) viscosity vs. shear rate
for a 33 wt% PCS solution used in surface tension measurement.


374
Table E-1. (Contd.)
PCS+PSZ Solution (50 wt%)
Force (mq)
Surface tension ( N/m)
163.00
0.03195
163.20
0.03199
164.60
0.03226
164.00
0.03214
163.60
0.03203
Average: 0.03207 0.00013
PCS+PSZ Solution (66 wt%)
Force (mq)
Surface tension ( N/m)
178.00
0.03489
178.40
0.03497
178.20
0.03493
179.60
0.03520
178.00
0.03489
Average: 0.03497 0.00013


Table M-1. Results of characterization of PMS polymers synthesized from MDCS:MTCS monomers (70:30 wt%)
Batch
Designation
Solvent(s)
Polymer Yield
(%)
GPC MW distribution
Mn Mw PDi
Ceramic Yield (%)
by pyrolysis by TGA b
XRD Results
(1350C/Ar)
PMS-208a
Toluene, THF
(95:5)
36.3
71.0
Strong Si peaks; Si
cryst. size; 17.5 nm
PMS-209 a
Toluene, THF
(95:5)
43.6
61.0
Weak Si peaks
PMS-216
Toluene, THF
(95:5)
38.4
44.0
Strong Si; 17.5 nm
PMS-218
Toluene, THF
(95:5)
32.4
41.0
Strong Si; 20.2 nm
PMS-219
Toluene, THF
(95:5)
41.0
47.0
Strong Si; 23.8 nm
PMS-220
Toluene, THF
(95:5)
32.9
47.0
Strong Si; 21.8 nm
PMS-221
Toluene, THF
(95:5)
37.2
871
1566
1.80
48.0
51.3
Strong Si; 13.8 nm
PMS-222
Toluene, THF
(95:5)
38.2
953
1725
1.81
45.0
53.3
Strong Si; 13.8 nm
PMS-223
Toluene, THF
(95:5)
30.7
PMS-224
Toluene, THF
(95:5)
31.1
PMS-225
Toluene, THF
(95:5)
37.6


Table 4.29. (Contd.)
Batch
PMS used
PCS added
Before heat- After heat-
treatment treatment
PMS:
PCS ratio
Wt%
PSZ
added3
Wt% DB added
Before heat After heat
treatment treatment
Filtration
behavior6
Filter (pm)/
time(min)
Flow
test
time(s)
Solids
loading
(%)
Viscosity
(Pas)
Spin
speed
(rpm)
Spin
pressure
(psi)
UF-37S
PMS-218-
AP-H
PCS 145
*
70:30
10
0
0
0.45/10
32
69.7
57-45
28
350-375
Spun well; as-spun fibers separable but pyrolyzed fibers were brittle.
UF-40s
PMS-220-
AP-H
PCS 145
*
70:30
14.5
0
0
0.45/40
24
87.0
38

*
Spin dope gelled during storage
UF-41S
PMS-219-
AP-H
PCS 145
*
70:30
14.5
0
0
1.0/10
*

*
*
*
Spin dope gelled during solution preparation
UF-42s
PMS-220-
AP2-H
PCS 145
*
70:30
14.5
0
0
0.45/180
(3 sets)
30
70.0
125-50
194
200
Spun well; as-spun and pyrolyzed fibers were separable.
UF-43S
PMS-221-
AP2-H
PCS 144
*
70:30
14.5
0
0
0.45/35

*

*
*
Spin dope gelled during solution preparation.
UF-44S
PMS-222-
APD-H
PCS 144
*
70:30
1
0
1
0.45/20
34
77.4
23-19.5
69-84
350
Spun well; as-spun fibers separable but pyrolyzed fibers stuck together.
UF-45S
PMS-222-
APD-a-H
PCS 144
*
70:30
0.5
3
3
0.45/8
31
62.3
52-20
*
300-450
Spun poorly; only fragments of fibers collected.
308


Viscosity (Pa s) shear Stress
313
100
90 -
80 -
70 -

60 -
on
o
50 -
40 -
30 -
20
O Increasing Shear Rate
Decreasing Shear Rate

O
%
10
J
20
(B)
30
Shear Rate (s'1)
Figure 4.108. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for UF-36s spin dope.


46
FIRING TEMPERATURE (C>
O
UJ
>
LU
>
H-
<
UJ
cc
Figure 2.12. Change in intensities of pendant groups based on IR spectra for polysilane
polymer (Vllb in Table 2.6) [Car90] : o: p(CH3) from Si-CH3; 0: 5 (CH2) of
Si-C6H5; : 5 (CH) of Si-C6H13; +: 6 (CH2) of Si-(CH2)n-Si; A:v (Si-H); V: v
(Si-C)


52
The pyrolyzed ceramic residue had an elemental composition of 69 wt% Si/ 31wt% C
(i.e., close to stoichiometric composition). The bulk of the weight loss is shown to occur
between 200C and 600C in a gradual manner. This weight loss behavior is
different from that of Wood's polymethylsilane polymers (prepared by Wurtz coupling
reaction), where weight loss is reported to occur between 130C and 410C. (The
heating rates were comparable, i.e., 10C/min to 1000C.) Zhang et al. also studied the
chemical evolution of the polymethyslilane polymer during pyrolysis to 1100C using
diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Figure 2.14
shows DRIFT spectra of polymethylsilane polymer heated to selected temperatures
at 1C/min in nitrogen and held at temperature for 0.5 h. The 400C spectra shows
the appearance of a strong peak at ~1350 cm'1 attributed to the bending
vibration of Si-CH2-Si group. (This is analogous to the thermal rearrangement taking
place during the conversion of polydimethylsilane to polycarbosilane.) Schmidt et al.
[Sch91] have reported similar observations. At 600C, the polymer is shown to lose well-
defined molecular structure with the only peaks remaining attributed to v (C-H) of CF)3
(2896 cm'1), v (Si-H) (~2068 cm'1), and 5 (CH2) of Si-CH2-Si (at 1354 cm'1). These peaks
disappeared at temperatures >800C, and the spectra showed absorptions in the
region of 400 cm'1 to 1000 cm'1 corresponding to (3-SiC.
Recall that linear polysilanes prepared by the Wurtz-coupling reaction of dialkyl
or monoalkyl chlorosilanes have ceramic yields of only up to < 25% [Bur49; Qiu89;
Woo84], Schilling and Kanner [Sch88] reported that when olefinic halosilanes are
used as monomers in the Wurtz-coupling reaction with sodium, the resultant polysilanes
contain olefinic groups which act as backbone branching sites and cause in-situ cross-
linking. This resulted in relatively higher ceramic yields (38-50%) for these polymers.


395
Table H-6. (Cont'cH
Batch 3
di(pm)
datum)
d(avg.)
13.00
13.00
13.00
12.50
13.50
13.00
12.50
13.50
13.00
11.50
12.50
12.00
12.50
14.00
13.25
12.50
13.00
12.75
13.50
13.50
13.50
13.00
13.50
13.25
13.50
13.50
13.50
12.50
13.50
13.00
12.50
13.00
12.75
13.00
13.00
13.00
13.50
13.50
13.50
12 00
12.00
12.00
12.50
13.00
12.75
13.00
13.50
13.25
13.00
13.50
13.25
12.50
14.00
13.25
Average
12.72
13.28
13.00
Std. Dev
0.52
0.49
0.44
Batch 4
datum)
d;(Um)
d(avg.)
12.50
13.00
12.75
13.00
13.00
13.00
11.50
12.00
11.75
11.00
11.50
11.25
13.00
13.50
13.25
11.00
11.50
11.25
12.00
12.50
12.25
11.00
12.00
11.50
13.00
13.00
13.00
12.50
13.00
12.75
12.50
13.00
12.75
11.50
12.00
11.75
11.50
11.50
11.50
11.50
11.50
11.50
13.50
13.50
13.50
11.50
11.50
11.50
13.50
14.00
13.75
12.50
13.00
12.75
Average
12.14
12.50
12.32
Std. Dev
0.85
0.82
0.83
Load(g)
Strain
TS(GPa)
EMiGPa)
37.38
0.0173
2.76
177.79
38.11
0.0170
2.82
174.01
42.81
0.0198
3.17
168.06
43.30
0.0192
3.76
211.22
45.43
0.0192
3.24
169.04
48.54
0.0202
3.73
184.58
29.91
0.0130
2.05
170.48
35.93
0.0167
2.55
152.64
43.93
0.0188
3.01
175.43
38.93
0.0176
2.88
174.78
46.26
0.0194
3.55
183.06
33.60
0.0149
2.48
165.97
42.96
0.0195
2.94
171.32
44.61
0.0194
3.87
208.55
36.51
0.0166
2.80
182.96
34.13
0.0152
2.43
159.18
47.33
0.0192
3.37
175.06
47.28
0.0202
3.37
166.86
40.94
0.02
3.04
176.17
5.50
0.00
0.50
14.67
Load(q)
Strain
TSiGPal
EM(GPa)
35.21
0.0134
2.70
201.15
42.75
0.0166
3.16
190.31
37.67
0.0169
3.41
201.89
32.31
0.0143
3.19
222.77
51.11
0.0194
3.63
203.35
38.21
0.0166
3.77
231.56
35.64
0.0137
297
223.51
24.04
0.0108
2.27
210.12
32.31
0.0121
2.39
197.47
29.89
0.0111
2.30
206.33
18.92
0.0070
1.45
208.31
38.83
0.0173
3.51
205.27
19.79
0.0092
1.87
202.45
35.64
0.0154
3.36
217.74
24.82
0.0082
1.70
207.41
19.45
0.0081
1.84
226.07
39.08
0.0128
2.58
204.46
51.21
0.0200
3.93
205.91
33.72
0.01
2.78
209.23
9.70
0.00
0.77
10.85


228
Polymerization in toluene
Polymerization in a 50:50 mixture
(by volume) of toluene and 1,4-dioxane
(a)
(b)
Figure 4.71. Schematic illustration for solvent effects for polymerization of MDCS (a) in
toluene and (b) in a 50:50 mixture of toluene:1,4-dioxane.


367
Table D-1. (Contd.)
PSZ solution (batch 0831A):
Set #1:
Concentration (g/dl)
Efflux times (s)
Ave. efflux time (s)
4.3762
267.50
267.15
267.10
267.19
267.24 0.18
3.1827
257.38
257.37
257.59
257.28
257.41 0.13
2.6930
252.87
253.35
253.18
253.22
253.16 0.20
2.3334
249.85
249.75
250.28
250.03
249.98 0.23
Set #2:-
Concentration (g/dl)
Efflux times (s)
Ave. efflux time (s)
3.4937
259.85
260.01
260.05
259.70
259.90 0.16
2.7949
254.09
253.90
253.98
253.97
253.99 0.08
2.1499
248.60
248.42
248.39
248.65
248.52 0.13
Toluene:
Concentration (g/dl)
Efflux times (s)
(to)
Ave. efflux time (s)
231.13
231.25
231.16
231.25
231.20 0.06
Calculations:
*]relt Tlsp- H rei' 1
c (g/dl)
t(ave)
^Irel
*lsp
Vc (dl/g)
4.3762
267.24
1.1559
0.1559
0.03562
3.4937
259.90
1.1241
0.1241
0.03553
3.1827
257.41
1.1134
0.1134
0.03562
2.7949
253.99
1.0986
0.0986
0.03527
2.6930
253.16
1.0950
0.0950
0.03527
2.3334
249.98
1.0812
0.0812
0.03481
2.1499
248.52
1.0749
0.0749
0.03485
From a plot of Vc vs. c, [r|] = 0.0342 dl/g 2.00 x 10"


294
Although fractional precipitation with the alcohol mixture allowed the preparation
of PMS polymers with sufficiently high molecular weight for fiber processing, the method
turned out to be unsatisfactory because it resulted in large amounts of oxygen
contamination in the polymers. This was determined from EMA results that were
obtained on a sample prepared by pyrolysis (1150C in nitrogen) of PMS-243-F. Table
4.26 shows that the pyrolyzed sample contained ~30 wt% oxygen. It is presumed that
this high oxygen content resulted from reactions that occurred between the alcohols and
the PMS during the fractionation process. (Such reactions would incorporate hydroxyl
groups (i.e., in the form of Si-OH groups) in the polymer. It is expected that the silanol
groups would condense upon heat treatment to form siloxane bonds.)
The oxygen contents of the different polymers prepared by fractional
precipitation with the alcohol mixture were not determined. However, it is speculated the
oxygen content may be a factor that affects the melting behavior. The formation of
siloxane bonds during the early stages of heat treatment would presumably result in a
more highly cross-linked polymer which, in turn, would make the polymer less likely to
melt upon pyrolysis. It is possible that the oxygen content of the precipitated polymers
might vary due to differences in the starting PMS polymers (e.g., differences in the
reactive Si-H groups) and/or the amount of alcohol (e.g., the alcohol/polymer ratio) used
in the precipitation process.
Fractional precipitation was carried out using acetone because of the large
amount of oxygen contamination that occurred when the alcohol mixture was used.
Table 4.25 shows that the polymer yields obtained using acetone were in the range of 7-
29%, i.e., less (in most cases) than yields obtained by using the alcohol mixture.
However, the method was successful in producing PMS polymers with increased
molecular weight. Figure 4.102 shows a plot of the average molecular weight after


369
Table D-3. Intrinsic viscosity calculations for PMS polymer in toluene-1,4 dioxane
mixture (50:50 by volume) (Ubhellode viscometer type OB)
Concentration (g/dl)
Efflux times (s)
Ave. efflux time (s)
7.1640
180.72
180.92
180.62
180.78
180.85
180.78 0.11
5.7312
174.50
174.16
174.28
174.47
174.18
174.32 0.16
4.7760
170.25
170.19
170.22
170.16
170.25
170.21 0.04
4.0937
167.50
167.38
167.47
167.47
167.25
167.41 0.10
Toluene-1,4 dioxane mixture (50:50 Vol%):
Concentration (g/dl)
Efflux times (s)
Ave. efflux time (s)
-
152.44
152.50
152.62
152.75
152.62
152.59 0.12
Calculations:
Href t/tp, T]Sp- r|re|-1
c (g/dl)
t(ave)
^lrei
Hsp
Wc (di/g)
7.1640
180.78
1.1847
0.1847
0.02578
5.7312
174.32
1.1424
0.1424
0.02485
4.7760
170.21
1.1155
0.1155
0.02417
4.0930
167.41
1.0971
0.0971
0.02372
From a plot of ti5P/c vs c, [r|] = 0.020968 dl/g 3.6 x 10 s; R2 = 0.9998


dwt/d(logM) dwt/d(logM)
406
Figure J-4. GPC distributions for PMS-248 polymer: (A) before and
(B) after fractional precipitation with acetone.


INTENSITY (arbitrary units)
WAVENUMBER (cm1)
Figure 4.47. Subtraction spectra for PCS+PSZ (batch 70s) and PCS (batch 69s) fibers at 600C.
400
182


APPENDIX D
INTRINSIC VISCOSITY CALCULATIONS FOR PCS, PCS+PSZ, PSZ, AND PMS
POLYMERS


95
This polishing step was typically carried out for 1-3 days. After polishing, samples were
cleaned in an ultrasonic cleaner with de-ionized water.
FTIR* spectra of polymer samples were collected in the region 600-4000 cm'1.
The spectra were collected in the diffuse reflectance mode. Sample preparation for
obtaining FTIR spectra for the polymers involved mixing 0.15 g of 10-15 wt% polymer
solution with diamond powder, heating the mixture on a hot-stage¥ to 45C for 3 h in
nitrogen (to remove toluene), and then cooling back to room temperature. Pyrolysis
behavior of the polymers in the FTIR mode was studied by using the hot stage to heat
treat the samples from 30C to 600C in N2 at 1C/min and collecting spectra in-situ at
regular intervals of temperature (i.e., every 80C). FTIR spectra of samples pyrolyzed to
750, 900, 1050 and 1150C (5C/min to temperature in nitrogen with no hold time) were
collected separately.
The intrinsic viscosities of polymer solutions were determined according to
ASTM D-446 procedure by employing a Ubellohde Viscometer (type 0B), as described
in section 3.1.2. The concentrations of polymer solutions used were in the range of 1 to
8 wt%.
3.3 Spinning and Characterization of Fibers Prepared from PMS-based Polymers
3.3.1 Spin dope preparation, fiber spinning, and fiber heat treatment
The as-prepared or fractionally-precipitated PMS polymer solutions were
generally filtered through 0.1 pm PTFE filter. (However, some polymer solutions were
filterable only through 0.45 pm or 1.0 pm filters.) It is important to filter the polymer
Nicolet 60SX Spectrometer, Nicolet Instruments Company, Madison, Wl.
Â¥ Harrick Corporation, Ossining, NY.


Table H-4. (Cont'd.)
Batch 3
di(pm)
d2(wm)
d(avg.)
13.00
15.00
14.00
13.00
13.00
13.00
12.50
15.00
13.75
11.50
15.50
13.50
11.00
12.50
11.75
15.50
16.00
15.75
10.50
11.50
11.00
13.00
14.50
13.75
14.00
14.50
14.25
12.00
15.00
13.50
12.00
12.50
12.25
11.50
14.50
13.00
14.00
15.50
14.75
13.00
15.50
14.25
10.50
11.50
11.00
15.00
15.50
15.25
11.50
13.00
12.25
12.50
14.50
13.50
Average
12.56
14.17
13.36
Std. Dev
1.42
1.45
1.33
Batch 4
di(pm)
diium)
d(avg.)
12.00
13.50
12.75
11.50
14.00
12.75
13.00
13.50
13.25
12.00
12.50
12.25
11.50
14.00
12.75
11.50
14.00
12.75
12.50
13.50
13.00
13.00
14.00
13.50
12.00
13.50
12.75
11.00
13.50
12.25
11.50
13.50
12.50
12.00
14.00
13.00
12.00
13.00
12.50
11.50
13.00
12.25
13.00
13.00
13.00
11.50
14.00
12.75
11.50
13.00
12.25
Average
11.94
13.50
12.72
Std. Dev
0.61
0.47
0.36
-Load(g)
Strain
TSiGPal
EMiGPal
52.70
0.0168
3.37
201.15
37.07
0.0163
2.74
167.49
53.95
0.0180
3.59
199.82
25.00
0.0086
1.75
204.65
36.40
0.0154
3.30
214.65
52.46
0.0192
2.64
141.62
39.09
0.0163
4.04
247.65
36.59
0.0129
2.42
187.62
38.56
0.0155
2.37
153.07
31.16
0.0117
2.16
184.05
38.47
0.0164
3.20
195.59
55.49
0.0187
4.15
221.73
40.05
0.0130
2.30
176.82
42.31
0.0162
2.62
162.23
20.00
0.0094
2.07
219.71
45.82
0.0152
2.46
161.74
37.46
0.0158
3.13
197.37
32.79
0.0112
2.26
201.27
39.74
0.0148
2.81
191.01
9.67
0.0030
0.68
27.06
Load(g)
Strain
TSiGPal
EM(GPa)
41.51
0.0173
3.20
184.40
29.72
0.0126
2.30
182.24
39.57
0.0160
2.81
184.65
51.99
0.0212
4.33
211.66
39.48
0.0166
3.06
196.23
36.43
0.0163
2.82
173.53
58.03
0.0236
4.29
181.73
34.35
0.0134
2.36
187.98
35.22
0.0149
2.71
181.78
33.63
0.0123
2.83
244.32
38.32
0.0163
3.08
189.33
59.19
0.0232
4.40
189.25
42.09
0.0175
3.37
192.71
41.75
0.0177
3.48
205.79
49.09
0.0190
3.63
209.43
40.88
0.0173
3.17
182.94
49.77
0.0205
4.15
203.05
42.41
0.0174
3.29
194.18
8.45
0.0033
0.67
16.86


10
demonstrated by gas chromatography that molecules containing sequences of Si atoms
react faster than molecules containing single atoms.
2.2.1.2 Mode of addition of reagents
At the beginning of the reaction, molten sodium (melting point of sodium =
98.5C) can be added to dichlorosilanes dissolved in a suitable solvent at the reflux
temperature of the solvent (inverse mode of addition) or dichlorosilanes dissolved in a
small amount of solvent could be added to the molten sodium dispersed in the inert
solvent ('normal' mode of addition). The inverse mode of addition usually leads to higher
molecular weight polymers with lower polymer yields compared to the normal mode of
addition. The former method is also more hazardous (i.e., due to handling of sodium)
and difficult to control.
Zeigler [Zei86A; Zei87] investigated the effect of rate of monomer addition (in the
normal mode) and sodium addition (in the inverse mode) on the polymodality of the
molecular weight distribution in the synthesis of polymethylphenylsilane. Zeigler
concluded that the rate of reagent addition (monomer or sodium) and the mode of
addition had an important role in determining the molecular weight distribution because
of its influence in controlling the rate of diffusion of reactive species to and from the
sodium surface When the rates of addition of Na or monomer were kept constant (for a
range of addition rates 80-640 meq/min (i.e., moles equivalent per min)), the molecular
weight distributions were nearly monomodal and the average molecular weights
remained approximately constant at 600,000 for inverse mode of addition and 4000 for
normal mode of addition. However, when the addition rate was varied, there was a
tendency to form a bimodal molecular weight distribution. Figure 2.2 shows the effect of
the rate of Na addition (inverse mode) on the (PhMeSi)n molecular weight distribution.


266
the polymer solution to remove any microgels present, low concentration of polymer
in the spin dope which necessitates greater removal of solvent in forming the fiber).
(iv) Viscosity. The spin dope should have optimum viscosity for preparation of useful
fibers. For example, if the viscosity is too high, it will be difficult to extrude spin dope
through the spinneret. This tends to result in discontinuous brittle fibers with rough
surfaces. If the viscosity is too low, fibers will not maintain their shape after exiting
the spinneret and fibers may also stick together. (At greater extremes in viscosity, it
will not even be possible to form fibers.)
(v) Solvent evaporation/ fiber solidification. In dry spinning, the rate of solvent
evaporation from fibers exiting from spinneret must be high enough so that fibers
remain separable (i.e., they do not stick together) when they are collected on a
winding drum. The rate of evaporation during fiber spinning depends on many
factors such as the vapor pressure of the solvent, temperature of the spin dope,
temperature in the spinning column, spinneret geometry, extrusion pressure, winding
pressure, etc. Conditions which promote the formation of fine-diameter fibers are
helpful in allowing fibers to solidify quickly (i.e., prior to the fibers reaching the
winding drum). This is because a smaller quantity of solvent needs to be removed
during spinning, i.e., assuming other factors (such as the number of fibers spun)
remains consistent. (In addition, finer fibers will have a greater specific surface area
available for evaporation, so the evaporation rate may be higher.) Process variables
which lead to finer-diameter fibers include smaller hole diameter in the spinneret and
higher winding speed.
(vi) Stability. The polymer should be stable at room temperature or at the temperature of
storage. The polymer should not show latent reactivity to form gel-like particles or
react with the environment. In some cases, such problems can be avoided by storing


Intensity (Kubelka-Munk Units)
i 1 I T I T I 1 l 1 i 1 [ 1 | 1 i
4000 3600 3200 2800 2400 2000 1600 1200 800
Wavenumber (cm'1)
Figure 4.32. Comparison of FTIR spectra of PCS fibers at 40C before and after heat treatment in air.
40C, before heat treatment in air (green fibers) (batch 69s)
40C, after heat treatment in air at 187C (batch 65s)
400
156


269
aids for the PMS polymers. The polymer solution viscosity was generally monitored
before and after heat treatment. Increases in viscosity indicated that polymer molecular
weight increased. In most cases, the molecular weight was also directly determined (by
GPC) before and after heat treatment.
Table 4.21 shows the heat treatment conditions for different PMS polymer
batches (with and without additives) and the resulting effects on viscosity and molecular
weight. The nomenclature of the PMS polymers used in this study is shown in Table
4.22. The main problems in the heat treatment approach to raising molecular weight of
PMS polymers were poor control over the molecular weight increases and lack of
reproducibility (i.e., the increase in molecular weight was not uniform from batch to
batch). The poor control over the molecular weight increases meant that it was difficult
to avoid microgel formation and, in some cases, complete gelation of the solution.
(Microgel formation is highly undesirable because it causes difficulty in filtering solutions
and results in lower solids loading in the solutions (or higher viscosities for a fixed solids
loading).) The lack of reproducibility may have been due to the variation in the
characteristics of as-prepared polymers from batch to batch. The monomers used in the
polymer synthesis (MDCS and MTCS) are highly reactive (e.g., they are highly sensitive
towards moisture) and may age with time, even though samples were stored after
backfilling with nitrogen and all handling operations were carried out under argon in a
glove bag. In addition, it is speculated that the polymers may age (i.e., undergo
increases in molecular weight with time) due to latent reactivity of Si-H groups.
The lack of reproducibility in the polymer syntheses is indicated by the initial
characteristics of polymer PMS-231, PMS-235, and PMS-236 in Table 4.21. Although
synthesized under identical conditions, PMS-231 showed a much higher initial molecular
weight compared to PMS-235 and PMS-236. Also, the changes in viscosity and


373
Table E-1. (Contd.)
PCS Solution (50 wt%)
Force (mq)
Surface tension ( N/m)
172.60
0.03383
173.00
0.03391
174.00
0.03410
173.40
0.03399
173.00
0.03391
Average : 0.03395 0.00010
PCS Solution (66 wt%)
Force (mq)
Surface tension ( N/m)
199.20
0.03728
191.40
0.03751
193.60
0 03795
194.20
0.03806
192.80
0.03770
Average: 0.03772 0.00032
PCS+PSZ Solution (33 wt%)
Force (mq)
Surface tension ( N/m)
140.00
0.02744
140.40
0.02752
140.80
0.02760
140.00
0.02744
140.40
0.02752
Average: 0.02750 0.00007


Table 4.25. (contd.)
Polymer
designation
Polymer, non
solvents proportion
Non-solvent/
polymer
ratio (ml/g)
THF /
polymer
ratio (ml/g)
Non-solvent/
THF ratio
(ml/g)
Initial
Mn
Initial
Mw
Initial
PDI
Final
Mn
Final
Mw
Final
PDI
Yield
%
Melted
Yes /
No
PMS-249-F-
1
PMS-249 (8.91 g)
Acetone (205ml)
23.0
6.4
3.6
977
2329
2.38
3635
6197
1.70
18.4
Yes
(slight)
PMS-249-F-
2*
PMS-249 (8.28g)
Acetone (166ml)
20.0
6.1
3.3
5700
10800
1.89
17.9
No
PMS-250-F
PMS-250 (9.00)
Acetone (216ml)
24.0
4.5
5.3
1207
1919
1.59
2990
6173
2.06
19.2
No
PMS-251-F
PMS-251 (8.25g)
Acetone (234ml)
28.4
4.5
6.3
1174
1981
2.01
2736
5513
2.01
27.7
No
PMS-252-F
PMS-252 (9.00g)
Acetone (234ml)
26.0
4.5
5.7
1133
2118
1.87
2579
4488
1.74
27.1
No
PMS-253-F
PMS-253 (8.00g)
Acetone (208ml)
26.0
4.5
5.8
975
1725
1.77
2691
7796
2.90
15.5
No
PMS-254-F
PMS-254 (8.00g)
Acetone (208ml)
26.0
4.5
5.8
887
1857
2.09
2366
5270
2.23
21.8
No
PMS-255-F
PMS-255 (8.00g)
Acetone (208ml)
26.0
4.5
5.8
971
2017
2.08
2280
5892
2.58
28.7
No
* PMS-249-F-1 was redissolved and fractional precipitation was attempted again.
ro
co


AVERAGE TENSILE STRENGTH (MPa) AVERAGE TENSILE STRENGTH (MPa)
208
Figure 4.61. Average tensile strength vs. temperature for: (A) PCS fibers (batch 69s),
and (B) PCS+PSZ fibers (batch 70s).


15
Figure 2.4.
UV-Vis Diffuse Reflectance spectrum of purple solid isolated during Wurtz
polymerization [Ben91].


155
spectra (at 40C) of fibers before and after air-heat treatment. Figure 4.32 shows a
comparison of spectra at 40C before and after air-heat treatment. It can be seen that all
the original absorption bands, except 5as(CH3) from Si-CH3 at 1407 cm'1, decreased in
intensity after air-heat treatment. The spectrum for the air-heat treated fibers also shows
the formation of v(C=0) groups (at 1722 cm'1) due to oxidation of methyl groups and
v(OH) groups due to oxidation of Si-H groups.
4.1.3.1.3 FTIR spectra of air-heat treated PCS fibers during heat treatment in N,
Figure 4.33 shows FTIR spectra of oxidized PCS fibers (batch UF-65s) during
heat treatment to 600C in nitrogen atmosphere. Figure 4.34 shows the changes in
intensities of specific absorption bands as a function of temperature. In the range ~300-
600C, the intensities associated with the Si-OH and Si-H absorptions decreased
significantly and that associated with the Si-O-Si absorptions increased significantly.
This suggests that Si-OH and Si-H groups are involved in condensation reactions to
form -Si-O-Si- linkages as indicated below:
\ / \ /
SiOH + HOSi Si-O Si + HpO (4.2)
\ / \ /
SiOH + HSi SiOSi + Ho (4.3)
/ \ / \
Ichikawa et al. [Ich90] have also observed a rapid decrease in intensity of Si-OH
groups during heat treatment of air-heat treated PCS5 (low molecular weight) in nitrogen
to 500C. Figure 4.35 shows Ichikawa et al.s FTIR spectra of air-heat treated PCS
polymer as a function of heat treatment temperature. They report that the absorption
5 Nippon Carbon Company, Japan.


12
11
10
9
8
7
6
5
4
3
2
1
0
Green, no PSZ
400*C (Nj). no PSZ
|-#£ l 180'C 10*C (Air), no PSZ
¡lli 180"C 10"C (Air), 400C (N2), no PSZ
| | Green, PSZ
Hill 400*C (N2), PSZ
180*C 10*C (Air), PSZ
HH) 180C 10*C (Air), 400C (N2), PSZ
O
o
o

CO
to
c
Q)
O
s
o
0
O
o
(/)

in
to
63s, 64s, 65s, 69s: PCS fibers
67s, 68s, 70s: PCS + PSZ fibers
c
<1>
O)

to
<
O
o
O
H
o
00
l/>
o
r*
BATCH DESIGNATION
Figure 4.56. Average rupture strains for PCS, PCS+PSZ fibers, as-spun and after heat treatment in (i)nitrogen at 400C, ->
(ii) air at 180 10C, and (iii) air at 180 10C, followed by N2 at 400C. S


REFERENCES
[Abu92], M.A. Abu-Eid, R.B. King, and A.M. Kotliar, Synthesis of Polysilane
Precursors and Their Pyrolysis to Silicon Carbides, Eur. Polym. J., 28 [3]
315-320 (1992).
[Ait85], C. Aitken, J.F. Harrod, and E. Samuel, Polymerization of Primary Silanes to
Linear Polysilanes Catalyzed by Titanocene Derivatives, J. Organomet.
Chem., 279 C11-C13 (1985).
[Ait87], C. Aitken, J.F. Harrod, and U.S. Gill, Structural Studies of Oligosilanes
Produced by Catalytic Dehydrogenative Coupling of Primary Organosilanes,"
Can. J. Chem., 65 1804-1809 (1987).
[Ait89], C. Aitken, J.-P. Barry, F. Gauvin, J.F. Harrod, A. Malek, and D. Rousseau, A
Survey of Catalytic Activity of ri5-Cyclopentadienyl Complexes of Groups 4-6
and Uranium and Thorium for the Dehydrocoupling of Phenylsilane,
Organometallics, 8 1732-1736 (1989).
[And91], R. Anderson, G.L. Larson, and C. Smith (Eds.), Silicon Compounds: Register
and Review (5^ ed.), Huls America, Piscataway, NJ (1991).
[AST88J. ASTM Designation D 446-85a, Standard Specifications and Operating
Instructions for Glass Capillary Kinematic Viscometers, Annual Book of
ASTM Standards, Vol. 5.01, ASTM, Philadelphia, PA (1988).
[Att72], D. Atton, S.A. Bone, and I.M.T. Davidson, Chlorine-abstraction and Chlorine
Migration Reaction of Silyl Radicals, J. Organomet. Chem, 39 C47 (1972).
[Ban82], R.H. Baney, High Yield Silicon Carbide Pre-ceramic Polymers," U.S.
Pat. No. 4 310 482 (1982).
[Ban83], R.H. Baney, J.H. Gaul, Jr., and T.K. Hilty, Methylchloropolysilanes and
Derivatives Prepared from the Redistribution of Methylchlorodisilanes,"
Organometallics, 2 [7] 859-863 (1983).
[Ban85], R.H. Baney, Method of Preparing Silicon Carbide, U.S. Pat. No. 4 534 948
(1985).
[Ben91], R.E. Benfield, R.H. Cragg, R.G. Jones, and A.C. Swain, Air-Stable Alkali
Metal Colloids and the Blue Color in Wurtz Synthesis, Nature, 353 [26]
340-341 (1991).
425


2.17. FTIR spectrum of polymethylsilane polymer, prepared by Abu-Eid et al. ... 61
2.18. Scheme for photo cross-linking reactions of polysilane polymers 64
2.19. Comparison of single layer photoresist process vs. multilayer photoresist
process 71
3.1. Structure of 1,3,5-trimethyl-1,3,5-trivinylcyclotrisilazane 72
3.2. Schematic of reaction assembly for PSZ synthesis 73
3.3. Definition of terms in Young's equation and schematic illustration of the
geometry for determination of the contact angle by the sessile drop
method 79
3.4. Schematic of reaction assembly for synthesis of polymethylsilane 87
4.1. Plots of (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
PCS spin dope (solids concentration ~68 wt%) 101
4.2. Plots of (A) shear stress vs. shear rate (B) viscosity vs. shear rate for a
PCS+PSZ spin dope (solids concentration ~70 wt%) 102
4.3. Schematic illustration of globule formation during spinning of fibers from
PCS spin dope 106
4.4. GPC molecular weight distributions: (A) PCS (B) PSZ 109
4.5 Plots of rjsp/c vs. c for (A) PCS (B) PCS+PSZ (C) PSZ 110
4.6. (a) Percentage change in weight of PCS and PCS+PSZ spin dope as a
function of time due to evaporation of toluene, and (b) Absolute weight
change of PCS and PCS+PSZ spin dopes as a function of time due to
evaporation of toluene 112
4.7. Advancing and receding contact angles for water on: (A) teflon substrate
(B) stainless steel substrate as a function of cumulative drop volume 115
4.8. Advancing and receding contact angles for toluene on teflon substrate
as a function of cumulative drop volume 117
4.9. Advancing and receding contact angles for toluene on stainless steel
substrate as a function of cumulative drop volume 118
4.10. Advancing and receding contact angles for PCS (33 wt%)/toluene solution
on stainless steel substrate as a function of cumulative drop volume 119
xii


199
low- molecular-weight PCS fibers which were first heat-treated in air (at ~200C) and
then heat-treated at 400C in nitrogen.
The observation of increased tensile strength and rupture strain is not generally
observed for organic polymeric materials which undergo cross-linking. An increase in
tensile strength almost always results in decreased rupture strain. For example,
unvulcanized elastomers exhibit low tensile strengths and large strain (~1200%). After
vulcanizing (cross-linking) these elastomers with sulfur, the tensile strength increases
many times, but a decrease in strain (to ~700-800%) is observed [BI83]. Mathur et al.
[Mat92] measured the tensile strength and rupture strain of polyacrylonitrile (PAN) fibers
(a precursor for carbon fibers) upon heat treatment in air (i.e., in order to achieve
oxidative cross-linking). Figure 4.57 shows that the rupture strain initially increased, but
the tensile strength decreased upon heat treatment to ~220C.
It is not clear what mechanism(s) are responsible for the simultaneous increases
in tensile strength and rupture strain which were observed in this study for the various
PCS and PCS+PSZ fibers. The original structure of the PCS consists mostly of relatively
low-molecular-weight polymer chains which are cross-linked to a minimal extent. This
results in green fibers with relatively low initial tensile strength and rupture strain. It is
speculated that the increases in tensile strength upon heat treatment arise primarily
from increases in the extent of cross-linking between the polymer chains. It is also
speculated that the increases in rupture strain upon heat treatment arise primarily from
increases in molecular weight that are associated with linear extension of the individual
polymer chains (in contrast to increases in molecular weight arising from branching and
cross-linking of the polymer chains).
On this basis, it is suggested that heat treatment in nitrogen alone (to 400C)
leads to only a limited increase in molecular weight, including some branching and


63
nm in nitrogen or vacuum, cross-linking of the polymer occurred with the formation of
insoluble material. One of the disadvantages of photo-cross linking is that some
degradation of polymer molecular weight (due to photo-scission) always accompanies
photo-cross linking (as shown by equations (2.11), (2.12), and (2.13)). However, West et
al. [Wes86B] observed that when a cross-linking agent containing C=C double bonds
(e.g., tetravinylsilane) was mixed with the polymer and then irradiated with UV light, no
degradation in molecular weight occurred and all of the polymer converted to an
insoluble material. The photo cross-linking takes place by cleavage of polysilane chains
to form radicals and addition of these radicals to C=C double bonds of vinylic silanes
(polyunsaturated additives), causing formation of cross-links and generation of new
carbon radicals. These new carbon radicals sustain further cross-linking reactions
(equation (2.14)). The reactions can be represented as given in Figure 2.18.
2.5. Applications of Polysilane Polymers
There are three main technological applications of polysilane polymers: (i)
precursors for (3-SiC, (ii) photoinitiators for radical polymerization reactions, and (iii)
photoresists in microelectronics.
2.5.1 Precursor for B-SiC
Yajima and Hasegawa [Yaj78A; Yaj78B; Has83A; Has83B; Has86; Ich86;
Has89] pioneered research in the preparation of (3-SiC from polysilane-based
preceramic polymers. They first synthesized polydimethylsilane (PDMS) by Wurtz-
coupling of dimethyldichlorosilane with sodium in xylene at 135C and then converted
the insoluble PDMS to a soluble polycarbosilane by pressure pyrolysis at ~450C. The


ch3
Cl Si Cl
H
Methyldichlorosilane
((functionality, f=2)
Figure 4.65. Schematic
ch3
Na,Solvent,Reflux
O Si a
-NaCI
H
Methyldichlorosilane
(functionality, f=2)
(a)
ch3
CHc
Na,Solvent,Reflux
Cl Si Cl
-NaCI
a
Methyltrichlorosilane
(functionality, f=3)
(b)
ch3 ch3 ch3
H CHoSiH H
ch3 ch3 ch3
Si Si Si Si Si Si
n H CH3SiH H
ch3
ch3
--Si
Si Si
H CH3
for Wurtz polymerization of (a) methyldichlorosilane and (b) methyldichlorosilane/methyltrichlorosilane mixture
217


Table H-7. iCont'dT
Batch 3:
di(pm)
d2(Um)
d(avg.)
12.00
12.50
12.25
12.00
12.50
12.25
14.00
14.00
14.00
12.00
12.50
12.25
12.00
12.50
12.25
11.50
12.50
12.00
12.50
12.50
12.50
13.50
14.00
13.75
13.50
14.00
13.75
14.00
14.00
14.00
13.00
14.00
13.50
14.00
14.00
14.00
14.00
14.00
14.00
13.50
14.00
13.75
14.00
14.00
14.00
12.50
12.50
12.50
14.00
14.00
14.00
13.00
14.00
13.50
Average
13.06
13.42
13.24
Std. Dev
0.89
0.75
0.80
Batch 4:
di(|jm)
d2(pm)
d(avg.)
13.00
13.50
13.25
12.50
13.50
13.00
10.50
12.00
11.25
13.50
15.00
14.25
10.50
12.50
11.50
13.50
13.50
13.50
10.50
12.00
11.25
14.50
15.00
14.75
12.50
14.00
13.25
11.00
11.50
11.25
11.00
12.50
11.75
12.00
14.50
13.25
10.50
12.00
11.25
11.00
12.00
11.50
11.50
13.00
12.25
10.50
11.50
11.00
12.50
13.00
12.75
14.00
14.50
14.25
Average
11.94
13.08
12.51
Std. Dev
1.35
1.17
1.22
Load(g)
Strain
TS(GPa)
EM(GPa)
34.37
0.0146
2.86
200.67
41.59
0.0140
3.46
247.10
59.19
0.0202
3.77
197.32
38.58
0.0159
3.21
204.96
43.87
0.0177
3.65
213.30
10.47
0.0041
0.91
224.28
27.72
0.0104
2.21
212.03
34.95
0.0113
2.31
203.46
13.52
0.0042
0.89
211.82
32.57
0.0097
2.07
213.92
26.27
0.0083
1.80
217.48
24.77
0.0079
1.58
199.47
27.05
0.0090
1.72
191.63
23.31
0.0075
1.54
204.58
41.64
0.0135
2.65
195.73
38.24
0.0153
3.05
199.50
28.11
0.0088
1.79
204.48
38.34
0.0124
2.63
211.74
32.48
0.0114
2.34
208.53
11.43
0.0044
0.88
12.77
Load(q)
Strain
TSiGPai
EMfGPal
49.70
0.0175
3.53
209.46
58.72
0.0202
4.34
229.33
30.83
0.0137
3.05
222.84
66.92
0.0240
4.12
183.52
31.84
0.0140
3.03
216.34
50.18
0.0181
3.44
205.85
40.92
0.0178
4.05
237.01
53.89
0.0182
3.09
176.30
35.80
0.0121
2.55
210.38
39.95
0.0170
3.94
231.21
31.12
0.0139
2.82
203.87
68.37
0.0255
4.90
209.07
19.06
0.0086
1.89
218.36
39.08
0.0178
3.69
211.08
38.31
0.0168
3.20
195.29
35.80
0.0150
3.70
251.84
25.57
0.0114
1.96
171.85
44.97
0.0169
2.76
173.23
42.28
0.0166
3.34
208.71
13.54
0.0041
0.79
22.32


21
new initiation reactions can occur readily. This tends to result in high polymer yield
(because monomer is consumed readily) and low average molecular weight. (Because
there are a large number of chains, the amount of chain extension is limited since the
supply of monomer is fixed.) In a poor solvent on the other hand, polymer coils are
contracted and there is a much greater tendency for the polymer chains to absorb on
the sodium particle surfaces. Since the direct path of monomer to the sodium surface
(through the solvents) is impeded now, the monomer is forced to diffuse through
polymer chains. This tends to promote propagation reactions (at the reactive chain
ends) (i.e., causes formation of longer chain polymers) and leads to lower polymer yield
and higher overall polymer molecular weight. In the extreme case when the solvent is
'too poor, the polymer would tend to precipitate out of solution, which is not desirable.
Thus, Zeigler et al model suggests that there is an optimum A8 for a given polysilane
polymer-solvent system which would dictate the yield and overall molecular weight of
the polymer.
Gauthier and Worsfold [Gau89] investigated the influence of cosolvent 15-crown-
5 ether (phase-transfer catalyst) on the Wurtz-coupling polymerization of n-
hexylmethyldichlorosilane (Figure 2.5 shows structure of 15-crown-5 ether). The primary
solvent used was toluene and the amount of 15-crown-5 ether used was in the range of
0.25-4 mol% (of hexylmethyldichlorosilane). They also found that in the presence of the
cosolvent, the polymer yield becomes high, the overall molecular weight of the polymer
decreases, and the molecular weight distribution changes from bimodal to monomodal.
Figure 2.7 shows the amount of monomer consumed as a function of time in the
study by Gauthier and Worsfold. They suggested that silyl anionic intermediates (shown


71
Wet Development (single layer)
Dry Development (multilayer)
Resist
Substrate
Coat
Resist
Planarizing Layer
Substrate
Mask
Expose
Develop
Dry Etch
02-Plasma
Strip
Etch
Strip
Figure 2.19: Comparison of single layer photoresist process vs. multilayer photoresist
process [MN88],


Intensity (Kubelka-Munk Units)
146
0 100 200 300 400 500 600 700
Temperature (C)
Figure 4.27. (Cont'd.)


196
Table 4.10. Average tensile strengths and rupture strains for PCS and PCS+PSZ fibers
(green, heat treatment in air at 180 10C, heat treatment in nitrogen at 400C, and heat
treatment in air at 180 10C followed by heat treatment in nitrogen at 400C).
PCS fibers
PCS+PSZ fibers
Fiber batch
Tensile
Rupture
Fiber batch
Tensile
Rupture
strength (GPa)
strain (%)
strength (GPa)
strain (%)
Green
63s
0.020 0.007
0.87 0.31
67s
0.018 0.008
0.83 0.42
64s-A
0.014 0.008
0.63 0.34
68s
0.016 0.007
0.76 0.37
64s-B
0.022 0.006
1.02 0.38
70s
0.016 0.005
0.63 0.23
(.Average for 64s)
0.018 0.007
0.83 0.36
65s
0.018 0.008
0.81 0.37
69s
0.018 0.007
0.80 0.36
180C 10C/Air
65s
0.051 0.009
3.23 1.31
70s
0.058 0.013
4.33 1.27
69s
0.050 0.008
2.92 0.70
400C/Nitroqen
63s
0.019 0.010
0.88 0.52
67s
0.055 0.011
5.64 1.52
64s-A
0.026 0.009
1.25 0.44
68s
0.061 0.008
6.50 1.19
64s-B
0.015 0.006
0.62 0.28
70s
0.058 0.007
5.99 1.19
(Average for 64s)
0.021 0.008
0.95 0.36
65s-A
0.029 0.010
1.35 0.51
65s-B
0.020 0.006
0.83 0.26
65s-C
0.044 0.006
2.16 0.32
(Average for 65s)
0.031 0.007
1.45 0.36
69s
0.043 0.003
2.12 0.20
180C 10C/Air +
i00C/Nitroqen
69s
0.11 0.014
5.01 0.97
70s
0.105 0.014
7.38 1.49


368
Table D-2. Intrinsic viscosity calculations for PMS polymer in toluene (Ubhellode
viscometer type OB)
Concentration (g/dl)
Efflux times (s)
Ave. efflux time (s)
7.8005
143.81
143.88
144.01
143.98
143.82
143.90 0.09
5.6731
136.56
136.36
136.41
136.39
136.28
136.40 0.10
4.8003
133.28
133.41
133.48
133.36
133.22
133.35 0.10
4.1603
131.40
131.21
131.17
131.11
131.21
131.22 0.11
Toluene:
Concentration (g/dl)
Efflux times (s)
Ave. efflux time (s)

118.06
118.10
118.13
118.13
118.13
118.11 0.03
Calculations:
r)reit^to. rjsp r)rei~1
c (g/dl)
t(ave)
^1 rel
Hsp
risp/c (dl/g)
7.8005
143.90
1.21835
0.21835
0.02799
5.6731
136.40
1.15485
0.15485
0.02729
4.8003
133.35
1.12903
0.12903
0.02688
4.1603
131.22
1.11099
0.11099
0.02668
From a plot of r^c vs c, [n] = 0.02516 dl/g 1.1 x 10-4; R2 = 0.9946


272
molecular weight with heat treatment were much different among these polymers. PMS-
235 showed a relatively small increase in molecular weight after holding for 168 h at
130C. Despite an initial molecular weight similar to PMS-235, PMS-236 showed a
much larger increase in molecular weight after heat treatment. (PMS-231 showed an
even larger increase in molecular weight with heat treatment, but this is not surprising
considering the high initial molecular weight.)
The occurrence of aging in the polymers is shown by the observation that the
molecular weight of PMS polymer (PMS-231) increased significantly upon storage at
room temperature (under nitrogen) for 260 days. Mn increased from 1350 to 3,000 and
Mw from 3,000 to 21,000 (see Figure 4.88).
Table 4.21 shows conditions for heat treatment of PMS polymers containing both
PSZ and DCP additives (first six entries). Heat treatment was carried out at
temperatures in the range of 50-150C in a teflon container encased in a pressure
bomb, as described in section 3.2.4. Increases in molecular weight were obtained, but
there were also increases in polydispersity. This was true for almost all heat treatments
which resulted in significant increases in molecular weight. (An exception was for the
heat treatment of PMS-235, as shown in Table 4.21.) Although data is limited, the
increases in the molecular weight and polydispersity after heat treatment appeared to be
greater when the PSZ (5-14.5 wt%)/DCP (0.5-1.5 wt%) additives were used. Figure 4.89
shows a plot of polydispersity index vs. weight average molecular weight for these
polymers before and after heat treatment. Figures 4.90a and 4.90b show GPC
molecular weight distributions of polymer PMS-214-A and PMS-214-A-H (before and
after heat treatment, respectively). The heat-treated polymer shows a bimodal
distribution. The modes for the low molecular weight portions of the polymers remain in
nearly the same position before and after heat treatment. It is clear from these


246
dehydrocoupling of methylsilane) to silicon carbide at 400C. While these changes
can be attributed to formation of a PCS-type backbone from PMS during pyrolysis, it is
unclear why the absorption intensities due to the symmetric ps (CH3) vibration of Si-CH3
at 770 cm'1, asymmetric pas (CH3) vibration of Si-CH3 at 830 cm'1 and symmetric stretch
of C-H of Si-CH3 at 2894 cm'1 first increase (from below 300C to at least 350C) and
then decrease at higher temperatures.
CH3CjH3CjH3 CH3 CH2 CH3 CH3
Si-Si-Si-Si - Si -Si- + H-Si-Si
III II II
H H H H H H H
A
H
Si Si ~ CHp
I I
H H
CHo CHo
I I
-Si -Si
I I
H H
(4.6)
The intensities of most of the original absorption bands from PMS-C have
decreased by 600C. By 750C, the well-defined peaks originally associated with the
organosilicon polymer have mostly disappeared, leaving broad peaks associated with C-
H stretching (-2800 cm'1), Si-H stretching (-2140 cm'1), and (3-SiC (-1000 cm'1) (see
Figure 4.80). After heat treatment at 1050C, the only remaining peaks are those
associated with p-SiC. These peaks are at 1000 cm'1 (v SiC) and 1528 cm'1 (unidentified
vibration mode) [Gre72; Fen94; Han97; Zha94B],
Figure 4.81 shows FTIR spectra of polymer PMS-F collected during heat
treatment from 40-600C in nitrogen atmosphere at 1C/min. The changes in intensities
of various absorption bands as a function of temperature are shown in Figure 4.82.


Table M-1. (Contd.)
Batch
Designation
Solvent(s)
Polymer
Yield (%)
GPC MW distribution
Mn Mw PDI
Ceramic Yield (%)
by pyrolysis by TGA b
XRD Results
(1350C/Ar)
PMS-237
Toluene, THF
(95:5)
20.7
945
1157
1.22
PMS-238
Toluene, THF
(95:5)
22.3
888
1277
1.44
45.0
PMS-239
Toluene, THF
(95:5)
11.7
857
1162
1.35
44.0
PMS-240
Toluene, 1,4
Dioxane
(60:40)
38.2
960
2395
2.49
PMS-241
Toluene, 1,4
Dioxane
(40:60)
51.4
899
1865
2.07
PMS-242
Toluene, 1,4
Dioxane
(50:50)
46.9
1653
3631
2.20
PMS-243
Toluene, 1,4
Dioxane
(50:50)
54.7
1004
2438
2.43
PMS-244
Toluene, 1,4
Dioxane
(50:50)
48.1
1055
2028
1.92
PMS-245
Toluene, 1,4
Dioxane
(50:50)
50.4
1126
2419
2.15


141
Table 4.5. FTIR peak assignments for polydimethylsilane(PDMS) polymer.
Peak (cm'1)
Assignment
References
2950
vas (C-H)
1,2
2894
vs (C-H)
1,2
1407
Sas (CH3) from Si-CH3
2,3
1253
8S (CH3) from Si-CH3
2,3
1110
Sas (Si-O-Si or Si-O-C)
1,3
1064
5S (Si-O-Si or Si-O-C)
1,3
830
Pas (CH3) from Si CH3
1,2,3
745
ps (CH3) from Si CH3
1,2,3
689
vas (Si-C)
1,2,3
626
Vs (Si-C)
1,2,3
v = stretching ; 8 = bending ; co = bending ; p = rocking
(1) W. Kriner, J. Org. Chem., 29, 1601 (1964)
(2) A.L. Smith, J. Chem. Phys., 21, 1997 (1953)
(3) A.L. Smith, Spectrochimica Acta, 16, 87 (1960)
(4) A.L. Smith, Spectrochimica Acta, 15, 412 (1959)


73
Figure 3.2. Schematic of reaction assembly for PSZ synthesis


289
heat-treated polymers have bimodal molecular weight distributions. This is undesirable
for two reasons: First, the low-molecular-weight portions of the polymers would
presumably be liquids (if they were isolated from the high-molecular-weight portions). As
noted earlier, solid polymers are needed for fiber formation. Second, the higher
molecular weight portions tend to make filtration of the polymer solutions difficult and
tend to make the polymer solutions unstable toward gelation. Hence, these polymers
are not particularly suitable for fiber formation.
4.3.1.2 Fractional precipitation
Fractional precipitation was carried out on polymer batches that were
synthesized by reacting a mixture of MDCS and MTCS (in 70:30 wt% proportion) with
sodium in a mixture of toluene and 1,4-dioxane at the reflux temperature of the solvent
mixture. The toluene: 1,4 dioxane volume ratios used were 60:40 for PMS-240, 40:60
for PMS-241, and 50:50 for PMS-242-F through PMS-255-F. (Toluene/dioxane was
used for the synthesis because the polymer yields were much higher compared to
polymers synthesized using toluene alone or a toluene/THF mixture, as reported in
section 4.2.2.)
Qiu and Du [Qiu89] have reported that addition of a polar solvent such as
tetrahydrofuran (THF) to a PMS polymer solution prepared with a less polar solvent
(e.g., toluene) aids in the fractional precipitation of the polymer. They fractionally-
precipitated the PMS polymer by adding a 50:50 (by volume) mixture of methanol and 2-
propanol to the polymer dissolved in THF. Following this approach, the as-prepared
polymer solutions in this study were first subjected to rotary evaporation under vacuum
in order to remove the toluene and 1,4-dioxane solvents. After rotary evaporation, the
flask containing the polymer was vented to N2 to minimize contamination from air. Then,
THF was added to the polymer in the proportions listed in Table 4.25.


325
this batch. As discussed earlier, this bonding is attributed to melting of low molecular
weight portions of the PMS polymer used in the spin batch.
A fiber batch prepared with 60% PMS (UF-39s) also had low strength. SEM
observations were not carried out, but it is possible that bonding between pyrolyzed
fibers was also a problem in this batch. In addition, the pyrolyzed fiber diameters were
very large (average of -28 pm). (It has been observed that fiber strengths usually
decrease with increasing diameter [Tor92B].)
Tensile strengths of ~2.2 GPa and ~1.2 GPa were measured for two pyrolyzed
fiber batches (UF-35s and UF-36s, respectively) prepared with 40% PMS. The spin
dopes used in these batches both showed good spinning behavior and the as-spun and
pyrolyzed fibers appeared separable for both batches. The reason for the lower strength
for UF-36s is not known.
The UF-35s fibers were heat-treated in argon at 10C/min to 1500C and 1700C
(1 h hold). The fiber tensile strengths after heat treatment were -2.1 GPa and -1.3 GPa,
respectively. SEM observations were carried out on the 1700C-heat-treated UF-35s
fibers. Figure 4.115 indicates that fiber surfaces are relatively smooth and no obvious
fiber degradation occurred as a result of the heat treatment. The fiber cross-section
(Figure 4.115C) also showed no large defects. More detailed SEM observations were
made on the fracture surfaces of fiber fragments collected during tensile testing. Many
of the fracture surfaces showed the presence of submicrometer pores (Figures 4.116 A-
F). These pores may be the reason for the low tensile strengths for these fibers. These
pores may have developed as a result of the processing conditions used in preparation
of the spin batch. As indicated in Table 4.29, a 1.0 pm filter was the smallest size used
in the filtration operation. (In contrast, the smallest filter used in most batches was 0.45
pm and, in some cases, the smallest filter was 0.1 pm.) Hence, it would be expected


Viscosity (Pa s) shear Stress
312
(A)
140
130 -
120 -
110 -
100 -
90 -
80
O Increasing Shear Rate
Decreasing Shear Rate
O
-
O
-a
-o
i-
10
Shear Rate (s'1)
(B)
15
Figure 4.107. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for UF-35s spin dope.


dwt/d(logM) dwt/d(logM)
280
Figure 4.93. GPC molecular weight distributions for: (A)PMS-219-A and
(B) PMS-219-A-H.


66
have room temperature mechanical properties similar to that of Nicalon fibers, with
average tensile strengths ~3 GPa. In addition, UF fibers showed significantly improved
thermomechanical stability compared to Nicalon, as indicated by lower weight losses,
lower specific surface areas, and improved strength retention after heat treatment to
1700C. Near-stoichiometric UF fibers (UF-HM Fibers) have high tensile strengths
(2.1-3.4 GPa), fine grain sizes (mostly -0.1-0.2 pm), high bulk densities (-3.1-3.2 g/cm3)
and small residual pore sizes (mostly 0.1 pm). These fibers retained -93% of their
initial strength after heat treatment in argon at 1800C.
It is also possible to convert polysilane polymers to silicon carbide fibers directly
without resorting to the preparation of intermediate polycarbosilane polymers. As
discussed in section 2.1.6, West et al. [Wes81; Wes86A] have prepared
phenylmethylsilane-dimethylsilane copolymers, (Polysilastyrene (PSS)), which afford
improved processability over PDMS. However, the fibers prepared from these polymers
require a cross-linking (curing) step to make them infusible in order to survive pyrolysis.
Since the polymers lack Si-H groups (eliminating the possibility of air-curing), the only
operative cross-linking mechanism is by UV irradiation. Thermomechanical data on the
fibers prepared by this method have not been reported.
Lipowitz et al. [Lip89] have prepared SiC fibers from methylpolysilane (MPS)
polymers, synthesized based on Baney et al.s redistribution/substitution reactions of
methylchlorodisilanes (as discussed in section 2.2.6). Fibers were melt spun, cross-
linked (cured) and converted to SiC by pyrolysis. By varying the ratio of alkyl to phenyl
Grignard reagents (used to react the intermediate methylchloropolysilane polymer),
fibers with composition ranging from silicon-rich through stoichiometric to carbon-rich
were produced. The method of cross-linking was not specified but the relatively low


432
[S¡m84], G. Simon and A.R. Bunsell, Mechanical and Structural Characterization of
the Nicalon Silicon Carbide Fiber, J. Mater. Sci., 19 [11] 3649-3657 (1984).
[Tak91], M. Takeda, Y. Imai, H. Ichikawa, and T. Ishikawa, Properties of the Low
Oxygen Content SiC Fiber on High Temperature Heat-Treatment," Ceram.
Eng. Sci. Proc., 12 [7-8] 1007-1018 (1991).
[Tak92], M. Takeda, Y. Imai, H. Ichikawa, T. Ishikawa, N. Kasai, T. Suguchi, and K.
Okamura, Thermal Stability of the Low Oxygen Content Silicon Carbide
Fibers Derived from Polycarbosilane," Ceram. Eng. Sci. Proc., 13 [7-8] 209-
217 (1992).
[Tak94], M. Takeda, J. Sakamoto, Y. Imai, H. Ichikawa, and T. Ishikawa, Properties
of Stoichiometric Silicon Carbide Fiber Derived from Polycarbosilane,
Ceram. Eng. Sci. Proc., 15 133-141 (1994).
[Tak95], M. Takeda, J. Sakamoto, A. Sacki, Y. Imai, and H. Ichikawa, High
Performance Silicon Carbide Fiber Hi-Nicalon for Ceramic Matrix
Composites, Ceram. Eng. Sci. Proc., 16 37-42 (1995).
[TM91 ]. T.D. Tilley and H-G. Woo, Catalytic Dehydrogenative Polymerization of
Silanes to Polysilanes by Zirconocene and Hafnocene Catalysts A New
Polymerization Mechanism, in Inorganic and Organometallic Oligomers and
Polymers, pp 3-12, Eds., J.F. Harrod and R.M. Laine, Kluwer Academic
Publishers, Dordrecht, The Netherlands (1991).
[Ti!93], T.D. Tilley, High-Molecular Weight, Silicon-Containing Polymers and
Methods for the Preparation and Use thereof, U.S. Pat. No. 5 229 481
(1993).
[Tor90], W. Toreki, N.A. Creed, and C.D. Batich, Silicon-Containing Vinyl Polymers
as Precursors to Ceramic Materials, Polymer Preprints, 31 [2] 611-612
(1990).
[Tor92A], W. Toreki, G.J. Choi, C.D. Batich, M.D. Sacks, and M. Saleem, Polymer-
Derived Silicon Carbide Fibers with Low Oxygen Content, Ceram. Eng. Sci.
Proc., 13 [7-8] 198-208 (1992).
[Tor92B], W. Toreki, C.D. Batich, M.D. Sacks, M. Saleem, and G.J. Choi, Polymer-
Derived Silicon Carbide Fibers with Improved Thermomechanical Stability,
Mat. Res. Soc. Symp., 271 761-769 (1992).
[Tor94], W. Toreki, C.D. Batich, M.D. Sacks, M. Saleem, G.J. Choi, and A.A.
Morrone, Polymer-Derived Silicon Carbide Fibers with Low Oxygen Content
and Improved Thermomechanical Stability, Composites Sc. Technol., 51
145-159 (1994).


WEIGHT CHANGE (%)
112
Figure 4.6. (A) Percent change in weight of PCS and PCS+PSZ spin dope as a
function of time due to evaporation of toluene, and (B) absolute weight
change as a function for PCS and PCS+PSZ solutions.


108
Table 4.2. Average fiber extension distances for PCS and PCS+PSZ spin dopes at the
same viscosities used in the fiber spinning experiments.
Polymer batch
# of fibers drawn
Averaqe fiber extension, cm3
PCS
50
11.0815.3
PCS+PSZ
49
14.07 7.4
3 Fiber extension distance was determined by dipping a glass rod in the bulk polymer solution and
drawing fibers until they became separated from the bulk solution.


47
Wood [Woo84] studied the pyrolysis behavior of three different polymethylsilanes
(designated as PMS-I, PMS-II and PMS-III) prepared by Wurtz-coupling reactions of
dichlorosilane with sodium in the presence of hexane, hexane/THF (7:1 volume)
mixture and THF, respectively. Table 2.7 gives a summary of the synthesis conditions
and characteristics for the three polymers. PMS-I showed very low ceramic yield (-25%)
upon pyrolysis to 1000C. The low ceramic yield was attributed to the loss of Si by
volatilization of low molecular weight components (which was confirmed by mass
spectral analysis of the pyrolysis species). X-ray Diffraction (XRD) analysis of the
ceramic residue obtained from pyrolysis of PMS-I showed peaks due to excess Si as
well as SiC peaks. The pyrolyzed ceramic had an overall composition of 67% SiC and
33 wt% Si (calculated based on the Si/C ratio determined by elemental analysis).
Polymer PMS-II showed a ceramic yield of -27% The XRD analysis of the pyrolyzed
ceramic residue showed no Si peaks (for unknown reasons) although elemental
analysis revealed silicon-rich composition (77 wt% SiC and 23 wt% Si). PMS-III showed
a much higher ceramic yield of 60% compared to the other two PMS polymers and had
an elemental composition of 75 wt% SiC and 25 wt% Si. (XRD analysis showed both Si
and SiC peaks.) The differences in the pyrolysis yields were attributed to differences in
cross-linking in the three polymers. Based on NMR data, both PMS-I and PMS-II
contained higher number of Si-H functionalities (which are potential cross-linking sites)
compared to PMS-III. (This suggested that cross-linking was more extensive in PMS-III
due to consumption of Si-H moieties by condensation reactions. Recall that a polar
solvent such as THF aids in the anionic polymerization of methylchlorosilanes with
sodium and leads to formation of polymers which are rich in Si-H groups; these Si-H
groups undergo condensation causing extensive cross-linking in the polymer).


Intensity (Kubelka-Munk Units)
Wavenumber (cm'1)
Figure 4.51. Comparison of spectra of air-heat treated PCS+PSZ fibers (batch 70s) (177C) before and after heat treatment at
600C in nitrogen.


Figure 4.111. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for UF-56s spin dope.


ABSORBANCE (Kubelka-Munk Units)
253
4000 3500 3000 2500 2000 1500 1000 500
WAVENUMBER (cm1)
Figure 4.83. FTIR spectra of PMS polymer F (MDCS, MTCS (70:30 wt%)), toluene-
dioxane (50:50 vol%), 750C to 1150C at 5C/min in nitrogen.


ABSORBANCE
4000 3600 3200 2800 2400 2000 1600 1200 800 400
WAVENUMBER (cm'1)
Figure 4.25. Room temperature FTIR spectra (transmission mode) of Polydimethylsilane (PDMS)
(Nisso Corporation, Japan).
140


4.22. Nomenclature of PMS polymers used in the heat treatment experiments ... 271
4.23. Conditions and results of heat treatment for PMS/PCS polymer blends 282
4.24. Molecular weight distributions for PCS polymers used in the heat treatment
of PMS/PCS blends 283
4.25. Conditions for fractional precipitation of PMS polymers 290
4.26. Results of EMA analysis on fractionally precipitated 1150C-pyrolyzed
(nitrogen) polymers 295
4.27. Conditions for fiber spinning experiments from as-prepared PMS/PCS
polymer blends (non-heat treated) 300
4.28. Tensile strengths of SiC fibers spun from as-prepared PMS:PCS polymer
blends 305
4.29. Conditions and qualitative results for fiber spinning experiments from
heat-treated PMS and PMS/PCS polymer blends 307
4.30. Tensile strengths of SiC fibers spun from heat-treated PMS polymers and
PMS/PCS polymer blends 323
4.31. Elemental analysis by EMA for SiC fibers prepared from heat-treated PMS/
PCS polymer blends 332
4.32. Conditions and qualitative results of fiber spinning experiments for
fractionally-precipitated PMS polymers 333
4.33. Tensile strengths of SiC fibers spun from fractionally-precipitated PMS
poiymers 336
4.34. Elemental analysis by electron microprobe for SiC fibers prepared from
fractionally-precipitated PMS polymers 336
4.35. Results of fiber extension experiments for PMS polymers containing PSZ 341
D-1. Intrinsic viscosity calculations for PCS and PCS+PSZ solutions in toluene 365
D-2. Intrinsic viscosity calculations for PMS polymer in toluene 368
D-3. Intrinsic viscosity calculations for PMS polymer in toluene-1,4 dioxane
mixture (50:50 by volume) 369
E-1. Results of surface tension measurements 371
F-1. Air-heat treatment temperatures and weight gains for PCS and PCS+PSZ
fibers 376
IX


Table 3.1. Properties of reagents in synthesis of polymethylsilane polymers [Dea88],
Chemicals
MW
State (25C)
Density(g/cc)
Boiling Point,C
Methyldichlorosilane
115.00
liquid
1.100
41.0
Methyltrichlorosilane
149.50
liquid
1.275
66.0
Sodium
22.99a
solid
0.968
97.8b
Toluene
92.14
liquid
0.866
110.6
Tetrahydrofuran (THF)
72.11
liquid
0.889
66.0
1,4-Dioxane
88.10
liquid
1.033
101.2
atomic weight; b melting point


38
(Me3CI3Si2), were obtained as fractions from an industrial process for manufacture of
methylchlorosilanes. The catalyst used for the redistribution/substitution reactions of
methylchlorodisilane mixtures was tetrabutylphosphonium chloride. The proposed
reaction scheme for these reactions is shown in Figure 2.9.
The rearrangement of disilanes into a monomer/polymer mixture occurred when
the disilane mixture was heated to 250C. Additional monomeric methylchlorosilanes
formed even after the starting disilanes reacted completely. This occurred by the
reaction of any Si-CI bond with a terminal Si-Si bond in the polysilane backbone. The
amount of monomers formed and the extent of polymerization were controlled by
manipulating the heating schedule and final reaction temperature. The resulting yellow-
colored methylchloropolysilane polymers (MCPS) were soluble in toluene and had
polycyclic structures with seven rings per molecule ((Me2Si)3(MeSi)17CI5)) as determined
by gas chromatography (see Figure 2.10). The Si-CI bonds in the
methylchloropolysilane polymers were highly reactive and permitted easy chemical
modification (such as reaction with Grignard reagents (alkyl-magnesium halide or
phenyl-magnesium halide) to form methylpolysilane polymer (MPS). According to
Baney et al., MCPS polymer reacts readily with Grignard reagents to replace the
reactive Si-CI groups with more stable Si-R groups. The modified polymers can be melt
spun to form fibers which can be subsequently pyrolyzed to SiC as discussed in section
2.4.
The chemical modification of methylchloropolysilanes (MCPS) can also be
accomplished by reducing MCPS over a slurry of lithium aluminum hydride under an
inert blanket in a refluxing solvent such as toluene [Ban83], The excess reducing agent
is neutralized by adding water and aqueous NaOH and the solution is subsequently
filtered to give a yellow-colored polymer of composition ((CH3)2Si)06(CH3Si)04)n).


91
solutions were transferred to glass vials and filtered through 1.0 pm, 0.45 pm, and 0.1
pm filters5 (where applicable) and stored in a refrigerator for use in fiber spinning
experiments.
Some variations in the solution preparation/heat treatment procedures are noted
as follows: (1) The original stock solutions PMS-220-A and PMS-221-A were divided into
two parts. Type B PCS was added to one part (PMS-220-AP and PMS-221-AP) and
type C PCS was added to the other part (PMS-220-AP2 and PMS-221-AP2). The heat
treatment was then carried out separately for these polymer solutions, (2) In the case of
PMS-216-A, PMS-217-AP, and PMS-218-AP, the original stock solutions were divided
into two parts each, and heat treatments were carried out separately, (3) PMS-218-AP
stock solution was divided into two portions (PMS-218-AP and PMS-218-AP2). After the
first heat treatment (PMS-218-AP-H), the total amount of PSZ in the polymer solution
was raised to 14.5 wt% in the second portion and heat treatment was carried out
separately (PMS-218-AP2-H).
3.2.5 Procedure for fractional precipitation of PMS polymers
The as-synthesized PMS polymers (stored in toluene) were subjected to rotary
evaporation under vacuum in order to remove the toluene and 1,4-dioxane solvents
After rotary evaporation, the flask containing the polymer was vented to N2 to minimize
contamination from air. Then, THF was added to the polymer in suitable proportions.
THF, being a polar solvent, promotes fractional precipitation. Typically, 25 ml of TFIF
was added for 8 g of polymer. The polymer solution was then transferred to a conical
flask containing a magnetic stirrer. Polymers PMS-240 through PMS-243 were
fractionally precipitated by adding a mixture of 150 ml of 2-propanol and 150 ml of
5 Puradisk 25TF, Whatman International Ltd., Maidstone, England.


24
Table 2.2. Effect of temperature on polymerization of methylphenyldichlorosilane [Mil93],
( PhMeSiCI2 + Na (PhMeSi)n)
Solvent
Temperature,C
Additive
Yield, %
Mw x 10'3
Mn x 10'3
Toluene
Reflux

25
383, 16 a
267, 8.1
a
Toluene
65

10
1073 b
377 b
Toluene/15%
Heptane
Reflux

9
1390,10.5
a
375, 6 a
Toluene/15%
Heptane
65

9
1367 b
580 b
Toluene/15%
Heptane
Reflux
Diglyme
(15%)
25
23.8 b
9.7 b
Toluene/15%
Heptane
65
Diglyme
(15%)
28
14.2 b
6.7 b
birnodal;b monomodal


13
Time, min
Figure 2.3. Effect of sodium surface area on the rate of consumption of
hexylmethyldichlorosilane [Wor88]; A: 0.20 m2, : 0.67 m2, o: 4.64 m2
per mole of dichlorosilane


Viscosity (Pa s) shear Stress
318
(A)
Figure 4.110. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for UF-42s spin dope.


56
Table 2.9. Peak assignments for IR absorption spectra of vinylic polysilanes [Qiu89B;
Col64]
Peak (cm'1)
Assiqnment
3048 (m)
v (CH=CH2) of Si-CH=CH2
2952 (s)
vas (C-H) of CH3
2894 (s)
vs (C-H) of CH3
2078 (s)
v (Si-H)
1732 (w)
v (C=0)
1582 (w)
v (C=C) of Si-CH=CH2
1397 (s)
8 (Si-CH=CH2)
1246 (vs)
8S (CH3) from Si-CH3
1000-1100 (s) co (CH2) from Si CH2- Si,v (Si-O-Si)
937 (m)
8 (Si-H)
750-850
Vas (Si-C)
v = stretching ; 5 = bending ; co = bending ; p = rocking; vs = very strong; s = strong;
m =medium; w = weak


APPENDIX A
RHEOLOGICAL CHARACTERIZATION OF PCS AND PCS+PSZ SPIN DOPES


CHAPTER 3
EXPERIMENTAL PROCEDURES
3.1 Role of Polyvinylsilazane as a Spinning Aid for Polvcarbosilane
3.1.1 Polymer synthesis
PSZ was synthesized according to the procedures developed by Toreki et al.
[Tor90], This involved polymerization of a cyclic vinylsilazane (1,3,5-trimethyl-1,3,5-
trivinylcyclotrisilazane*) (see Figure 3.1) in the presence of a radical initiator, dicumyl
peroxide (DCP). The reaction assembly used for PSZ synthesis is shown in Figure 3.2.
In a typical PSZ synthesis, 20 g of cyclic vinylsilazane monomer was mixed with 0.090 g
of DCP and 7.5 g of toluene in a 50 ml double-necked flask. Polymerization was typically
carried out under nitrogen at a temperature of 125C for 18 h.
H
N
ch2=ch Si s¡ ch=ch2
HN NH
Figure 3.1. Structure of 1,3,5-trimethyl-1,3,5-trivinylcyclotrisilazane
f Petrarch Systems, Bristol, PA.
72


Table L-1. Results of characterization of PMS polymers synthesized from methyldichlorosilane monomer
Batch
Designation
Solvent(s)
Polymer
Yield (%)
GPC MW distribution
Mn Mw PDI
Ceramic Yield (%)
by pyrolysis by TGAb
XRD Results
(1350C/Ar)
PMS-206 3
Toluene, THF
(95:5)
42.3
55
No Si peaks
PMS-260
Toluene, THF
(95:5)
40.8
PMS-262
Toluene, THF
(95:5)
48.2
760
1156
1.52
45.0
PMS-261
Toluene
(100%)
42.4
642
816
1.27
40.1
PMS-257
Toluene, 1,4-
Dioxane
(50:50)
39.4
1437
2878
2.00
51.5
46.7
Strong Si peaks
PMS-258
Toluene, 1,4-
Dioxane
(50:50)
39.6
1428
3054
2.14
41.6
55.0
Strong Si peaks
PMS-263
Toluene, 1,4-
Dioxane
(50:50)
43.8
1325
2594
1.96
47.5
a Smaller batch size, prepared in 250 ml three-necked flask.
b TGA analysis carried out at 1200C /Ar/10C per min/0 h hold.


366
Table D-1. (Contd.)
PCS + PSZ solution:
Set #1:
Concentration (g/dl)
Efflux times (s)
Ave. efflux time (s)
4.9257
276.47
276.37
276.78
276.80
276.61 0.22
3.5447
261.96
262.49
262.50
262.41
262.34 0.26
2.9864
257.08
257.19
257.13
257.03
257.11 0.07
2.5801
253.54
253.27
253.22
253.22
253.31 0.15
Set #2:-
Concentration (g/dl)
Efflux times (s)
Ave. efflux time (s)
4.6146
273.21
273.35
273.24
273.40
273.30 0.09
3.6917
263.85
263.92
263.71
263.99
263.87 0.12
3.0764
258.11
258.01
257.95
257.97
258.01 0.07
Toluene:
Concentration (g/dl)
Efflux times (s) (to)
Ave. efflux time (s)
231.13
231.25
231.16
231.25
231.20 0.06
Calculations:
Tlrel^^o i Hsp Href 1
c (g/dl)
t(ave)
Tlrel
nsp
Hsp/c (dl/g)
4.9257
276.61
1.1964
0.1964
0.03987
4.6146
273.30
1.1821
0.1821
0.03946
3.6917
263.87
1.1431
0.1413
0.03828
3.5447
262.34
1.1347
0.1347
0.03799
3.0764
258.01
1.1160
0.1160
0.03769
2.9864
257.11
1.1121
0.1121
0.03752
2.5801
253.31
1.0956
0.0956
0.03706
From a plot of n5p/c vs c, [n] = 0.03394dl/g 1.73 x 10"


ABSORBANCE (Kubelka-Munk Units)
Wavenumber (cm'1)
Figure 4.30. Room temperature FTIR spectra for PCS fibers (batch 65s) heat-treated in air at 187C.
152


268
The PMS polymers prepared in this study have low molecular weight in the as-
prepared state (Mn -800-1,000, and Mw -1,100-2,500) and are viscous liquids at room
temperature. The molecular weight needs to be increased in order for the polymers to
be useful for fiber processing. Two approaches were utilized to raise the molecular
weight of the polymer: (i) further polymerization and cross-linking by heat treatment with
and without additives and (ii) fractional precipitation of higher molecular weight fractions.
The results from these approaches are described in section 4.3.1. Section 4.3.2
describes the results of fiber spinning experiments from these polymers.
4.3.1. Methods to increase molecular weight of PMS polymers
4.3.1.1 Heat treatment of PMS polymers
Heat treatment of PMS polymers resulted in increased molecular weight and
cross-linking of the polymers. This is presumed to occur by dehydrogenation reactions
involving Si-H groups. Si-H groups are believed to have the lowest bond energy in the
PMS polymers ([Sch91 ]; [Has83A]). Hasegawa et al. [Has83A] have studied heat
treatment of PCS polymers by IR spectroscopy and proposed that dehydrogenation
reactions involving Si-H occurred at temperatures ~400C. Schmidt et al. [Sch91] have
also suggested from IR results that dehydrogenation reactions involving Si-H groups
take place during low temperature heat treatment of vinylic polysilane polymers. FTIR
spectra showed a decrease in the absorption peak due to the Si-H vibration for
polymers heated at < 200C.
All polymers used for heat treatment in this study were synthesized from a
mixture of methyldichlorosilane (MDCS) and methyltrichlorosilane (MTCS) monomers (in
70:30 wt% proportion). The solvent used in the synthesis was a mixture of toluene and
tetrahydrofuran (95:5 vol%). Polyvinylsilazane (PSZ) (0.5-14.5 wt%), dicumyl peroxide,
DCP, (0.05-1 wt%), and decaborane (B,0H14) were investigated as potential cross-linking


339
23.7 g. Thus, the expected weight loss is -23.7 %. (The observed weight loss was -25
% after 1480C/1 h.)
4.3.3. Fiber extension experiments on PMS polymer spin dopes containing PSZ
The lengths to which fibers can be slowly hand-drawn before they break were
measured on spin dopes prepared using PMS, PSZ, and PMS/PSZ mixtures. (The
technique for hand-drawing fibers is described in section 3.1.3.) These fiber extension
measurements were considered an indication of the spinnability of the batch, i.e., the
ability to spin fibers by extruding (under pressure) a spin dope through a spinneret
having fine-diameter holes.
Fiber extension measurements were carried out on two PSZ polymers, i.e., PSZ
0908A with relatively high molecular weight (Mn8,400, 748,000) and PSZ 0831A
with relatively low molecular weight (Mn2,700, M^l 3,600). Both PSZs are liquids at
room temperature, so the initial experiments were carried out with no solvent additions.
Table 4.35 shows that the fiber extension was almost three times greater for the high-
molecular weight PSZ (i.e., extensions were 17.0 cm and 5.7 cm for the 0908A and
0831A polymers, respectively). It should be noted that PSZ 0908A had much higher
viscosity than PSZ 0831A (see Table 4.35). Therefore, it was not clear from the initial
experiments if the greater fiber extension was due to the higher molecular weight or the
higher viscosity. Consequently, a solution was prepared in which the PSZ 0908A was
diluted with toluene (i.e., 95 wt% PSZ 0908A/5 wt% toluene) in order to obtain
approximately the same viscosity as 100% PSZ 0831A (i.e., -20 Pa s). Table 4.35
shows that the fiber extension of the 95 wt% PSZ0908A solution was still much greater
than the PSZ 0831A polymer. Plence, the higher molecular weight was the primary
factor responsible for greater fiber extension.


Viscosity (Pa s) Shear Stress (Pa)
130
2.0
1.5
O Increasing Shear Rate
Decreasing Shear Rate
PCS (50 wt%)
1.0 -
(B)
0.5 -
0.0
De
li
-0
50
i 1 r-
100 150
200
250
300
Shear Rate (s'1)
Figure 4.17. Plots of: (A) shear stress vs. shear rate and (B) viscosity vs. shear rate
for a 50 wt% PCS solution used in surface tension measurement.


INTENSITY (arbitrary units)
Figure 4.28. Subtraction spectra for PCS fibers (batch 69s) heat treated in N2; 600-40C.
149


239
Table 4.16. FTIR peak assignments for polymethylsilane (PMS) polymer PMS-C (batch
PMS-263).
Peak (cm'1)
Assiqnment
References
2950
vas (C-H) from Si-CH3
1,2
2894
vs (C-H) from Si-CH3
1,2
2800
vs (CH2) from Si-CH3
1,2,5
2133
vas (Si-H)
1,4
2053
vs (Si-H)
1,4
1407
5as (CH3) from Si-CH3
2,3
1253
5S (CH3) from Si-CH3
2,3
1056
v (Si-O-Si) + v (Si-O-C)
1,3,5
838
Pas (CH3) from Si CH3
1,2,3
770
Ps (CH3) from Si CH3
6
v = stretching ;
5 = bending ; p = rocking
(1) W. Kriner, J. Org. Chem., 29, 1601 (1964)
(2) A.L. Smith, J. Chem. Phys., 21, 1997 (1953)
(3) A.L. Smith, Spectrochimica Acta, 16, 87 (1960)
(4) A.L. Smith, Spectrochimica Acta, 15, 412 (1959)
(5) R.M. Silverstein, G.C. Bassler, and T.C. Morrill, Spectroscopic Identification of Organic
Compounds, John Wiley, New York (1981)
(6) J.R. Dung, and C.W. Hawley, J. Chem. Phys., 59(1),1(1973)


dwt/d(logM) dwt/d(logM)
286
Figure 4.97. GPC molecular weight distribution for PMS-217-AP2-H.
Figure 4.98. GPC molecular weight distribution for PMS-218-AP-H.


216
4.2 Synthesis and Characterization of Polvmethvlsilane (PMS) Polymers
The requirements for preparing SiC fibers from PMS polymers are described in
detail in section 4.3. At this point, it is simply noted that it would be desirable to have
PMS polymers which are solid at room temperature, soluble in appropriate solvents for
dry spinning, and infusible upon heat treatment to pyrolyze the polymer to SiC. Wurtz-
coupling polymerization usually leads to low molecular weight polymers which are liquids
[Sey92; Qiu89A], Therefore, it is desirable to increase the molecular weight and/or
degree of cross-linking of the polymers by modifying the synthesis conditions. The
degree of cross-linking is enhanced by using a mixture of monomers of different
functionalities [Qiu89A, BI83], For example, when a trifunctional monomer is added to a
difunctional monomer in Wurtz-coupling polymerization, the resulting polymer becomes
cross-linked due to the introduction of additional branching sites. This is illustrated
schematically for Wurtz polymerization of methyldichlorosilane (MDCS, functionality=2)
and methyltrichlorosilane (MTCS, functionality =3) with sodium in Figure 4.65. In the
present study, PMS synthesis was carried out by using Wurtz polymerization in sodium
using MDCS and MTCS in 70:30 wt% proportion. (The selection of this ratio was based
on observations that mixtures prepared with higher MTCS contents show lower reaction
rates and/or lower reaction yields [Qiu89A; Sal93].) Polymers were also synthesized
using MDCS monomer alone for comparison.
The polymer yields in the Wurtz-coupling polymerization of MDCS and
MDCS:MTCS (e g., 70:30 wt%) with Na are typically low. There may be several reasons
for the observed low yields: (1) There may be insoluble polymer product formed during
polymerization. Wood [Woo84] has reported the formation of up to 15% of insoluble
polymer product in the polymerization of MDCS with Na in hexane:THF (7:1 by volume).
(2) Some soluble polymer could be trapped in the precipitating Na/NaCI colloids during


LIST OF FIGURES
Figure Page
2.1. Schematic showing mechanism of Wurtz coupling polymerization 8
2.2. Effect of reactant addition rate on molecular weight distribution of phenyl
methylsilane 11
2.3. Effect of sodium surface area on the rate of consumption of hexylmethyl-
dichlorosilane 13
2.4. UV-Vis Diffuse reflectance spectrum of purple solid isolated during Wurtz
polymerization 15
2.5. Chemical formulas of polar solvents used in Wurtz polymerization 16
2.6. Schematic illustration of the influence of solvent on the polymer/sodium
particle interaction during Wurtz polymerization 20
2.7. Rate of disappearance of monomer n-hexylmethyldichlorosilane as a
function of time and weight percent of 15-Crown-5 ether 22
2.8. GPC of polymethylsilanes synthesized by Mu and Harrod 32
2.9. Scheme for redistribution/substitution reactions of chlorodisilanes 39
2.10. Structure of methylchloropolysilane polymer 40
2.11. IR spectral changes during pyrolysis of a polysilane polymer 45
2.12. Changes in intensities of pendant groups based on IR spectra for polysilane
polymer 46
2.13. TGA plots for polymethylsilane polymers, prepared by Zhang et al 51
2.14. FTIR spectra of PMS polymer, prepared by Zhang et al 53
2.15. TGA and DTA plots for a VPS polymer heated in nitrogen at 20C/min to
1200C 55
2.16. IR spectra of VPS polymer:(a) 25C (b) 250C (c) 400C (d) 650C
(e) 1000C 57
XI


EXTENSION (cm) EXTENSION (cm)
362
10 15
TRIAL NUMBER
10 15
TRIAL NUMBER
Figure C-1. Fiber extension distances for PCS spin dopes.


183
The influence of PSZ on cross-linking of PCS can be ascertained by comparing
the FTIR spectra (Figures 4.27 and 4.43) and the subtraction spectra for PCS and
PCS+PSZ during the heat treatment from 40C to 600C in nitrogen (Figures 4.28 and
4.45). In the case of PCS, the absorption intensity for Si-H groups increased significantly
until 520C (presumably due to methylene insertion reactions) and then started to
decrease (see Figure 4.27). The subtraction spectra for PCS fibers before and after heat
treatment in nitrogen (Figure 4.28) also show the presence of a strong Si-H absorption
band after 600C. This was not the case for PCS+PSZ. The absorption intensity of Si-H
groups increased only marginally up to ~275C, remained constant till 440C and then
started to decrease (Figure 4.43). The absorption intensity at 1358 cm'1 (5 (CH2) from
Si-CH2-Si) decreased very slightly beyond 275C for PCS+PSZ while it remained
essentially constant up to 600C for PCS. The intensity of absorption peak at 1407 cm'1
(due to 8as (CH3) of Si-CH3 ) decreased much more rapidly starting at 300C for
PCS+PSZ compared to PCS. All of these observations suggest that methylene insertion
reactions are inhibited in the case of PCS+PSZ, most likely due to the interaction of PSZ
with PCS.
Recall that the FTIR spectra for PSZ alone (Figure 4.40) showed a rapid
increase in the intensities of all the absorption peaks during heat treatment from 40 to
120C. This was attributed to continued polymerization/cross-linking of the PSZ during
the initial heat treatment. With further heat treatment above 120C, rapid decreases in
peak intensities were observed for all the absorption peaks (Figure 4.40). Significantly
different behavior was observed for the absorption peak intensities associated with the
PSZ during heat treatment of the PCS+PSZ fibers. First, there were no increases in the
absorption intensities between 40 and 120C (Figure 4.43). Second, the peak intensities


I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and
quality, as a dissertation for the degree of Doctor of Philosophy.
Michael D. Sacks, Chair
Professor of Materials Science and
Engineering
I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and
quality, as a dissertation for the degree of Doctor of Philosophy.
Professor of Materials Science and
Engineering
I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and
quality, as a dissertation for the degree of Doctor of Philosophy.
E. Dow Whitney
Professor of Materials Science and
Engineering
I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and
quality, as a dissertation for the degree of Doctor of Philosophy.
Christopher D. Batich
Professor of Materials Science and
Engineering


385
Table H-3. (Cont'cM
Batch 3:
di(pm)
ditm)
d(avg.)
11.00
13.50
12.25
12.00
14.50
13.25
9.00
13.00
11.00
13.00
13.50
13.25
9.50
11.50
10.50
11.00
14.00
12.50
11.50
14.50
13.00
11.50
13.50
12.50
11.50
12.00
11.75
14.00
14.50
14.25
14.00
14.50
14.25
12.50
15.00
13.75
12.00
13.50
12.75
9.00
10.50
9.75
12.00
14.50
13.25
12.50
14.50
13.50
10.50
15.00
12.75
13.00
15.50
14.25
Average
11.64
13.75
12.69
Std. Dev
1.48
1.31
1.27
Batch 4:
di(nm)
d.2(pm)
d(avg.)
11.00
11.00
11.00
11.50
11.50
11.50
11.50
11.50
11.50
11.00
11.00
11.00
11.50
12.00
11.75
13.00
13.00
13.00
11.00
12.00
11.50
13.00
13.50
13.25
12.50
12.50
12.50
11.50
11.50
11.50
11.50
12.00
11.75
11.50
12.00
11.75
12.50
12.50
12.50
12.50
13.00
12.75
11.00
11.50
11.25
11.50
11.50
11.50
11.50
11.50
11.50
12.50
15.00
13.75
Average
11.78
12.14
11.96
Std. Dev
0.69
1.00
0.80
Load(q)
Strain
TSfGPal
EMfGPal
13.15
0.0075
1.11
147.37
21.82
0.0098
1.56
159.86
6.07
0.0048
0.65
136.38
8.53
0.0045
0.61
135.37
14.50
0.0085
1.66
195.38
22.44
0.0113
1.82
160.82
13.05
0.0054
0.98
180.90
14.40
0.0099
1.16
116.80
26.10
0.0124
2.36
189.74
36.50
0.0210
2.24
144.95
14.02
0.0066
0.86
129.88
16.38
0.0079
1.09
137.29
15.17
0.0073
1.17
160.70
18.93
0.0142
2.50
184.96
20.28
0.0094
1.45
154.27
8.67
0.0040
0.60
150.54
24.99
0.0126
1.98
156.67
37.03
0.0178
2.29
128.85
18.45
0.01
1.45
153.93
8.66
0.00
0.63
22.33
Loadial
Strain
TSfGPal
EMfGPai
9.03
0.0047
0.93
198.68
20.68
0.0097
1.95
201.74
22.08
0.0102
2.08
203.61
26.57
0.0124
2.74
220.75
22.71
0.0102
2.05
201.56
17.44
0.0062
1.29
206.82
29.42
0.0118
2.78
236.10
12.37
0.0055
0.88
160.24
19.47
0.0073
1.56
212.83
17.25
0.0077
1.63
210.86
26.81
0.0109
2.42
221.75
25.12
0.0104
2.27
217.84
22.03
0.0080
1.76
220.76
28.02
0.0102
2.15
211.37
28.70
0.0121
2.83
233.22
7.63
0.0038
0.72
191.77
17.34
0.0076
1.64
214.30
22.17
0.0072
1.48
204.57
20.82
0.0087
1.84
209.38
6.45
0.0026
0.64
16.86


G-1. Weight loss data for PCS, PCS+PSZ fibers (air-heat treated and non-air
heat treated) after pyrolysis at 1150C in nitrogen 378
H-1. Tensile strength data for pyrolyzed PCS fibers (batch 63s) 380
H-2. Tensile strength data for pyrolyzed PCS fibers (batch 64s) 381
H-3. Tensile strength data for pyrolyzed PCS fibers (batch 65s) 384
H-4. Tensile strength data for pyrolyzed PCS fibers (batch 69s) 387
H-5. Tensile strength data for pyrolyzed PCS+PSZ fibers (batch 67s) 390
H-6. Tensile strength data for pyrolyzed PCS+PSZ fibers (batch 68s) 394
H-7. Tensile strength data for pyrolyzed PCS+PSZ fibers (batch 70s) 397
L-1. Results of characterization of PMS polymers synthesized from MDCS 415
M-1. Results of characterization of PMS polymers synthesized from MDCS and
MTCS (70:30 wt%) 417
x


116
literature [Wu82], (Wu obtained an advancing contact angle of 108 and receding
contact angle of 105. No information was available on drop sizes or how the
measurements were carried out). For water on stainless steel, the advancing contact
angle varied from 82 to 85 when the drop size was increased from 0.006 ml to 0.042
ml. The receding contact angles decreased from 85 to 45 for the same range of drop
sizes.
Contact angles of toluene were measured on teflon and stainless steel
substrates. For toluene on teflon, the advancing contact angles ranged from 22 to 33
for drop sizes of 0.20 to 0.50 ml (see Figure 4.8). (0.5 ml was the largest drop size
possible for this particular measurement because of the small substrate size.) Toluene
was considerably more wetting on stainless steel, with advancing contact angles in the
range of only 4.7 to 5 for a drop sizes of 0.006 to 0.042 ml (see Figure 4.9). For toluene
on stainless steel, the maximum drop size possible was <0.05 ml, due to its rapid
spreading on stainless steel.
Contact angles for PCS and PCS+PSZ solutions (polymer concentrations of 33
wt% in toluene) were measured on stainless steel and teflon substrates. The largest
possible drop sizes were used in the measurement to minimize the effects of solvent
evaporation from the droplets of polymer solutions. Figures 4.10, 4.11, 4.12, and 4.13
show the variations in contact angles as a function of drop sizes for PCS on stainless
steel, PCS+PSZ on stainless steel, PCS on teflon and PCS+PSZ on teflon, respectively.
It can be seen that contact angles for PCS+PSZ solution are lower than those for PCS
solution, on both stainless steel and teflon substrates. In addition, contact angles for
PCS and PCS+PSZ solutions are lower on stainless steel substrates than on teflon
substrates.


4.62. Distribution of tensile strengths for fibers after pyrolysis at 1150C in
nitrogen (A) PCS (B) PCS+PSZ 212
4.63. Distribution of diameters for fibers after pyrolysis at 1150C in nitrogen
(A) PCS (B) PCS+PSZ 213
4.64. Average tensile strength vs. temperature for fibers heat-treated in air:
(A) PCS (batch 65s/ 187C air heat treatment), and (B) PCS+PSZ (batch
70s/ 177C air heat treatment) 214
4.65. Schematic for Wurtz polymerization of (a) MDCS (b) MDCS and MTCS
(70:30 wt%) 217
4.66. (a) Gel permeation chromatograms for polymers prepared from MDCS
(A) toluene (B) Toluene:THF (95:5 vol%) (C) Toluene, dioxane (50:50 vol%)
(b) Gel permeation chromatograms for polymers prepared from
MDCS:MTCS(70:30 wt%) (A) toluene (B) Toluene:THF (95:5 vol%)
(C) Toluene, dioxane (50:50 vol%) 221
4.67. Effect of cosolvents on molecular weight of PMS polymers A,B, and C
(prepared using 100% MDCS) 223
4.68. Effect of cosolvents on molecular weight of PMS polymers D,E, and F
(prepared using MDCS/MTCS (70/30 wt%)) 224
4.69. Plot of x]sp/c vs. C for polymer F (batch PMS-256) (MDCS/MTCS (70/30
wt%), toluene/1,4-dioxane (50/50)) in toluene 226
4.70. Plot of r|sp/c vs. C for polymer F (batch PMS-256) (MDCS/MTCS (70/30
wt%); toluene/1,4-dioxane (50/50)) in a mixture of toluene and 1,4-dioxane
(50:50 vol%) 227
4.71. Schematic illustration for solvent effects in polymerization of MDCS (a) in
toluene (b) in a 50:50 mixture of toluene: 1,4-dioxane 228
4.72. Effect of cosolvents on yield for PMS polymers D,E, and F (prepared
from MDCS/MTCS (70/30 wt%)) 230
4.73. Effect of cosolvents on yield for PMS polymers A,B, and C (prepared
from 100% MDCS) 232
4.74. TGA plots (% weight vs. temperature) for polymers prepared with 100%
MDCS 234
4.75. TGA plots (% weight vs. temperature) for polymers prepared with 70:30
wt% MDCS:MTCS 235
4.76. Room temperature FTIR spectra of PMS polymer C (batch PMS-263)
(prepared from 100% MDCS in toluene/dioxane solvent) 237
XVI


Absorbance
61
Figure 2.17. FTIR spectrum of polymethylsilane polymer prepared by Abu-Eid et al.
[Abu92]


287
PMS-220-AP2 sample has a slightly higher initial viscosity compared to the PMS-220-
AP sample. This may reflect the longer aging time for the PMS-220-A solution before
the addition of the PCS.) After heat treatment, the sample prepared with higher-
molecular-weight PCS (i.e., PMS-220-AP-H) gelled, even though the heat treatment
time at the maximum temperature (70C) was only 1 h. In contrast, the sample prepared
with lower-molecular-weight PCS (i.e., PMS-220-AP2-H) had a molecular weight of only
-13,000, despite a heat treatment time of 5 h at 70C. The molecular weight distribution
for this sample is shown in Figure 4.99. The same effect was observed upon heat
treatment of the PMS-221-AP and PMS-221-AP2 samples, i.e., the samples prepared
with higher-molecular-weight PCS gelled despite a shorter heat treatment time at the
maximum temperature. The molecular weight distribution for the heat-treated sample
which was prepared with lower molecular weight PCS (i.e., sample PMS-221-AP2-H) is
shown in Figure 4.100. (It is also noted that the bimodality in the distribution is more
pronounced for PMS-221-AP2-H compared to PMS-220-AP2-H, which again is
consistent with the higher overall average molecular weight for the former sample.)
It is noted that most of the samples in Table 4.23 that contained 14.5 wt% PSZ
either gelled or showed significant increases in molecular weight, even at heat treatment
temperatures as low as 70C. Nevertheless, it is not possible to draw a definitive
conclusion that high PSZ concentrations promote increases in molecular weight upon
heat treatment because too many other variables were changed simultaneously in these
experiments. For example, the DCP concentrations were also higher in these solutions.
Furthermore, it is likely that there were significant variations in the characteristics of the
starting PMS polymers.
In summary, heat treatment is effective in increasing the polymer molecular
weight, but it was not possible to achieve these increases reproducibly. Furthermore,


349
showed oxygen contents up to 30 wt%.) This oxygen incorporation is primarily attributed
to reaction of the polymer with alcohols (i.e., hydrolysis). This was not a problem in the
case of polymers precipitated with acetone as nonsolvent.
It was possible to prepare high strength pyrolyzed SiC-based fibers from
fractionally-precipitated polymers. Some changes in processing conditions were
necessary in order to avoid sticking of as-spun fibers. First, a spinneret with smaller
diameter holes (40 pm diameter, 3-holes) was needed to spin fibers. (This was done so
that a greater portion of the solvent would be evaporated by the time the fibers reached
the winding drum.) Second, some of the fiber batches were prepared with higher
viscosity. (This was done so that less liquid removal would be needed before the fibers
would 'solidify.) The fibers had high tensile strength (~2.4-2.7 GPa) and a near-
stoichiometric composition (66.5 wt% Si, 32.0 wt% C, and 1.5 wt% O) after pyrolysis at
1150C. The fibers, however, showed poor thermal stability upon further heat treatment.
It was observed that PMS polymers were extremely sensitive towards
air/moisture. This is due to the presence of a large number of Si-H groups in the
Therefore, for many practical applications involving PMS polymers (except, for example,
in applications involving use as photoresists in microlithography where sensitivity of
PMS polymers towards oxygen is exploited), it would be necessary to take extensive
precautions during handling to exclude oxygen and water vapor.


276
observations that not all of the molecules which form during the initial polymerization
reaction participate in the polymerization/cross-linking reactions that lead to the
increased average molecular weight after heat treatment.
Figures 4.91a, 4.91b, and 4.92 show GPC molecular weight distributions for
PMS-216-A, PMS-216-A-H, and PMS-216-A2-H, respectively. (PMS-216-A2 was
prepared at the same time as PMS-216-A, and had a composition identical to that of
PMS-216-A. These polymers contained 5 wt% PSZ and 0.5 wt% DCP as additives.)
PMS-216-A2-H showed a larger increase in molecular weight than PMS-216-A-H. This
is presumably due to higher heat treatment temperature (105C vs. 85C). As noted
earlier, however, it was observed that PMS polymers can undergo aging during storage
(e.g., molecular weight increases were observed upon room temperature storage.)
Although the PMS-216-A and PMS-216-A2 listed in Table 4.21 are different portions of
the same solution, heat treatment to produce PMS-216-A2-H was carried out 28 days
after the heat treatment was carried out to produce PMS-216-A-H. (Thus, PMS-216-A2
solution was aged for 28 days longer than PMS-216-A prior to heat treatment.) Hence, it
is possible that the initial molecular weight for PMS-216-A2 may have been higher than
that of PMS-216-A. (In fact, this is suggested from the higher initial viscosity (1.90
mPa*s vs. 1.84 mPa*s), although the difference may be within the experimental error of
the measurement.) Therefore, the higher final viscosity and molecular weight for the
PMS-216-A2-H may reflect not only the higher heat treatment temperature, but also a
higher initial molecular weight due to the longer aging time prior to heat treatment.
The molecular weight distributions remained essentially monomodal for the heat-
treated PMS-216-A-H and PMS-216-A2-H polymers. This may be due to the fact that
overall increases in molecular weight for these samples were much smaller than the
PMS-214-A-H sample. The changes in molecular weight upon heat treatment (100C, 1


CONTACT ANGLE (Degrees) CONTACT ANGLE (Degrees)
118
10
8 -
6 -
4 -
2 -
O Advancing Contact Angle
Receding Contact Angle
O O



n 1 1 r
0.00 0.01 0.02

Trial #1
O O O O O
. 1 1 r
0.03 0.04 0.05
DROP VOLUME (ml)
10
8
6
4
2
0
0.00 0.01 0.02 0.03 0.04 0.05
DROP VOLUME (ml)
Figure 4.9. Advancing and receding contact angles for toluene on stainless
steel substrate as a function of cumulative drop volume.
O Advancing Contact Angle
Trial #2
Receding Contact Angle
O O O O O
O








Table 2.4. Summary of methylsilane polymerization by catalytic dehydrogenation reactions [Mu91 A],
Run
#
Solvent
Catalyst
MeSiH3
(psi x Lb)
O
o
I-'
Time,
days
Amount of
PMS, g
Yield, %
Mwc
Mnc
Mw/Mn
%
Cyclicsc
1
cyclohexene
+toluenea
DMT
(50 mg)
120x0.12
20
6
1.52
90
1590
790
2.01
0.4
2
cyclohexene
+toluenea
DMT
(50 mg)
130x0.12
20
9
1.82
-100
6350
1200
5.30
1.6
3
cyclohexene
+toluenea
DMT
(50 mg)
140x0.12
20
12
1.96
-100
10100
1250
8.10
3.4
4
cyclohexene
+toluenea
DMT
(50 mg)
120 xO.12
45
4
1.68
-100
7890
1240
6.36
0.5
5
cyclohexene
+toluenea
DMT
(50 mg)
110x0.12
65
1
1.53
-100
12990
1260
10.30
0.5
6
Toluene
DMT
(50 mg)
100 xO.12
20
9
0.37
26
830
560
1.48
4.6
7
cyclohexene
+toluenea
DMZ
(60 mg)
110x0.12
20
5
1.43
-92
1730
800
2.16
8
cyclohexene
+toluenea
DMZ
(60 mg)
130 xO.12
20
7
1.81
-100
6010
1080
5.56
0.8
9
cyclohexene
+toluenea
DMZ
(60 mg)
125 xO.12
20
9
1.75
-100
9990
1350
7.40
2.5
10
cyclohexene
+toluenea
DMZ
(60 mg)
100 xO.12
65
1
1.40
-100
Insoluble
11
Toluene
DMZ
(60 mg)
110x0.12
20
7
0.99
64
1020
620
1.65
3.8
a Cyclohexene:toIuene proportion 70:30 (Vol %);b Volume of silane gas used
c Based on the assumption that the low molecular weight species in the gel permeation chromatograms are cyclic oligomers.


45
Figure 2.11. IR spectral changes during pyrolysis of a polysilane polymer (Vllb in Table
2.6) [Car90]; A: initial film; B: 360C (1.5 h hold); C: 454C (1.5 h); D:
650C (1.5 h); E:1200C (1.5 h); F: dispersion of single crystal SiC
whiskers in KBr for comparison.


340
Table 4.35 shows fiber extension results for solutions prepared with fractionated
PMS polymers PMS-240-F and PMS-242-F. The PMS-242-F solutions were prepared at
a viscosity similar to the 100% PSZ 0831A polymer and the 95 wt% PSZ 0908A/5 wt%
toluene solution. The PMS-240-F solutions were prepared with similar flow test times as
the PMS-242-F solutions. (Unfortunately, viscosity measurements could not be made
with PMS-240-F solutions due to the limited amount of material available.)
The fiber extension for PMS-240-F-0 solution was slightly greater than for the
PMS-242-F-0 solution (13.5 cm vs. 12.5 cm). One possible reason for this observation is
the higher molecular weight for the former polymer. (The average molecular weights
were Mw a 8,400 and Mw 5,000 for the PMS-240-F and PMS-242-F polymers,
respectively*. The GPC molecular weight distributions for the as-prepared PMS-240 and
fractionated PMS-240-F polymers and the as-prepared PMS-242 and fractionated PMS-
242-F polymers are shown in Figures 4.101a and 4.101b, and Figure 4.117a and
4.117b, respectively.) It should be noted, however, that the small difference in the fiber
extension distances may also be due to a difference in viscosity. The PMS-240-F-0
solution had a slightly higher flow time, so the viscosity may have been higher also.
Table 4.35 also shows fiber extension measurements for solutions prepared with
PMS/PSZ mixtures. The addition of 14.5 wt% PSZ 0831A to PMS-242-F clearly resulted
in a decrease in fiber extension (9.8 cm for the mixed solution, PMS-242-F-1, vs. 12.5
cm for the PMS-242-F-0 solution with no PSZ). The mixed solution had essentially
identical solution viscosity, flow test time, and solids loading to the solution with no PSZ.
* It is interesting to note that solids loading for the PMS-242-F-0 solution was significantly lower compared
to the PMS-240-F-0 solution (i.e., 78.2 wt% vs. 85.5 wt%). This was somewhat surprising since the
former polymer has a lower molecular weight (Mw a 5,000 vs. Mw 8,400 for PMS-240-F). There are at
least two possible reasons for this observation. First, the PMS-240-F-0 solution may actually have a
higher viscosity. (As shown in Table 4.31, the flow time is slightly higher.) In that case, the higher solids
loading would be less surprising. Second, there may be differences in the polymer architecture.


4.45. Subtraction spectra for PCS+PSZ fibers (70s), 600-40C 180
4.46. Subtraction spectra for PCS+PSZ and PCS fibers at 40C 181
4.47. Subtraction spectra for PCS+PSZ and PCS fibers at 600C 182
4.48. Room temperature FTIR spectra of PCS+PSZ fibers heat-treated in air at
177C 185
4.49. FTIR spectra of air-heat treated PCS+PSZ fibers during heat treatment
to 600C in nitrogen 188
4.50. Intensity vs. temperature from FTIR spectra of air-heat treated PCS+PSZ
fibers 189
4.51. Comparison of spectra for air-heat treated PCS+PSZ fibers before and
after heat treatment at 600C in nitrogen 191
4.52. Subtraction spectra for air-heat treated PCS+PSZ fibers, 600-40C 192
4.53. Comparison of spectra for air-heat treated PCS fibers (batch 65s)
and PCS+PSZ fibers (batch 70s) at 40C 193
4.54. Comparison of spectra for air-heat treated PCS fibers (batch 65s)
and PCS+PSZ fibers (batch 70s) after heat treatment in nitrogen 194
4.55. Average tensile strength for PCS, PCS+PSZ fibers, as-spun and after
heat treatment in (i) nitrogen at 400C (ii) air at 180 10C (iii) air at
180 10C, followed by nitrogen at 400C 197
4.56. Average rupture strain for PCS, PCS+PSZ fibers, as-spun and after
heat treatment in (i) nitrogen at 400C (ii) air at 180 10C (iii) air at
180 10C, followed by nitrogen at 400C 198
4.57. Plots of (a) tensile strength vs. heat treatment temperature (b) %
elongation vs. temperature for polyacrylonitrile (PAN) fibers 200
4.58. Schematic of structural changes taking place in PCS during heat
treatment in air at 180 10C 202
4.59. Average rupture strain vs. temperature for: (A) PCS (batch 69s) and
(B) PCS+PSZ fibers (batch 70s) 206
4.60. Average rupture strain vs. temperature for fibers heat-treated in air:
(A) PCS (batch 65s/ 187C air heat treatment), and (B) PCS+PSZ (batch
70s/ 177C air heat treatment) 207
4.61. Average tensile strength vs. temperature for (A) PCS (batch 69s), and
(B) PCS+PSZ fibers (batch 70s) 208
xv


84
3.2 Synthesis and Characterization of Polvmethylsilane (PMS) Polymers
3.2.1 Starting materials
Polymethylsilane polymer was prepared by Wurtz-coupling reactions of
methyldichlorosilane (MDCS) and methyltrichlorosilane (MTCS) (usually 70:30 wt%
proportion5) with sodium in the presence of toluene, toluene: THF (95:5 % by volume),
or toluene: 1,4-dioxane (50:50 % by volume). The properties of various reagents used
are listed in Table 3.1.
Reactant Charges (Typical):
Methyldichlorosilane (MDCS) (70 wt%) ... 36.85 g (33.5 ml)
Methyltrichlorosilane (MTCS) (30 wt%) .... 15.94 g (12.5 ml)
Sodium (15 wt% excess of equivalent chlorine in monomers) .... 25.4 g
Toluene .... 380 ml
THF .... 20 ml
When 1,4-Dioxane is used:
Toluene .... 200 ml
1,4-Dioxane .... 200 ml
(The toluene: 1,4-dioxane ratios were 60:40, and 40:60 (by volume) for polymers PMS-
240 and PMS-241).
3.2.2 Procedure for polymerization
All polymerization reactions were carried out in a blanket of nitrogen. The
monomer handling operations were carried out in a glove bag under argon. All
glasswares were oven dried at 75C for 12 h after initial cleaning and the reaction
5 One experiment was also carried out with 30:70 MDCS:MTCS ratio.


WAVENUMBER (cm'1)
ABSORBANCE (Kubelka-Munk Units)
243


43
Table 2.6. Ceramic yields and chemical compositions of polysilane homopolymers,
copolymers and terpolymers [Car90],
Batch
Polymer3
Yield (wt%)
Theor.6 Observed0
Inoraanic Residue Analysis (wt%)
Cd Sid Calculated SiC Yield
SiC Yield' (%Theor)'
Homopolymers
I
(CH3-Si-CH3)n
69
1.0
42
58
0.8
1.2
II
(C6H5-Si-CH3)n
33
24.6
55
39
13.7
41.5
III
(C6H13-Si-CH3)n
31
5.8
32
67
5.6
17.5
Copolymers
IV
(C6H5-Si-CH3),0
(CH3-Si-CH3), o
51
13
62
51
7.1
15.4
V
(C6H5-Si-CH3), o
(C6Hi3-Si-CH3)i o
32
8
49
49
5.9
17.9
VI
(CH2=CH-Si-CH3)1 o
(C6H5-Si-CH3)90
36
39.1
65
38
19.5
54.5
Terpolymers (5:5:1)
Vila
(C6H5-Si-CH3)
(C6H13-Si-CH3)
(CH2=CH-Si-CH3)9
36
7
47
54
5.3
15.6
Vllb
(C6H5-Si-CH3)
(C6H13-Si-CH3)
(CH2=CH-Si-CH3)h
36
22
53
42
14.8
41.2
VIII
(C6H5-Si-CH3)
(CH3-Si-CH3)
(CH2=CH-Si-CH3)
52
27
61
45
15.1
29.1
IX
(C6H5-Si-CH3)
(C6H13-Si-CH3)
(CH2=CH-CH2-Si-CH3)
51
21
61
47
11.6
22.8
a The functional groups shown are attached to Si as side groups.
b Theoretical conversion to SiC (for e g., (CH3-Si-CH3)n SiC is 69% conversion).
c Observed ceramic yield.
d C+Si total in some cases exceed 100%. The totals appeared as such in the paper and presumably reflect
experimental error in the measuring technique.
8 The ceramic residue consists of SiC and C. The percentage of SiC is calculated by multiplying the
experimentally observed yield by the factor (100-C)/70 wt% where C is the carbon content of the residue.
(Note that the theoretical composition of SiC is 70 wt% Si/ 30 wt% C.)
' [Calculated SiC yieldd/theoretical SiC yieldb]x100.
9 low MW viscous oil.
h high MW fraction.


INTENSITY (arbitrary units)
WAVENUMBER (cm1)
Figure 4.52. Subtraction spectra for air-heat treated (177C) PCS+PSZ fibers (batch 70s), 600-40C.
192


CONTACT ANGLE (Degrees) CONTACT ANGLE (Degrees)
121
60
50
40
30
20
10
0
0.00 0.05 0.10 0.15 0.20 0.25 0.30
DROP VOLUME (ml)
O Advancing Contact Angle
Trial #1
Receding Contact Angle
O O
O
0
O

60
50
40
30
20
10
0
0.00 0.05 0.10 0.15 0.20 0.25 0.30
DROP VOLUME (ml)
Figure 4.12. Advancing and receding contact angles for PCS (33 wt%)/toluene
solution on teflon substrate as a function of cumulative drop volume.
O Advancing Contact Angle Trial #2
Receding Contact Angle
O Q
O O
o





APPENDIX E
RESULTS OF SURFACE TENSION MEASUREMENTS


201
cross-linking reactions, for the PCS fibers used in this study.* (Thus, only relatively small
increases in tensile strength and rupture strain were observed.) In contrast, heat
treatment in air results in the formation of a significant amount of Si-O-Si, Si-O-C, and
Si-C-O bonds (e.g., see the schematic illustration in Figure 4.58) which allows for much
more extensive increases in molecular weight through chain extension, as well as much
more extensive cross-linking. Hence, larger increases in tensile strength and rupture
strain were observed. (The extension of the chains may occur as a result of oxygen
incorporation in the Si-C backbone. In regard to cross-linking, the results of this study
and prior studies [Has83, Ich90] suggest that Si-H groups are oxidized to form Si-OH
which subsequently condense to form the Si-O-Si linkages illustrated in Figure 4.58.)
The significant increase in both tensile strength and rupture strain for the
PCS+PSZ fibers heat treated in nitrogen only (to 400C) indicates that PSZ is also
effective in increasing the polymer molecular weight and the extent of cross-linking. The
PSZ contains many unsaturated carbon-carbon double bonds* which can presumably
react with PCS to form additional Si-C groups in the polymer backbone. (Recall that the
FTIR spectra (Figure 4.43 in section 4.1.3.1.5) for PCS+PSZ fibers showed a slight
increase in the intensity of the absorption peaks associated with to (Si-CH2-Si) upon heat
treatment in nitrogen.) In addition, it is presumed that the vinyl groups in the PSZ also
promote cross-linking by reaction with the PCS side groups.
Tables 4.11 and 4.12 show tensile properties of PCS and PCS+PSZ fibers (both
as-spun and air-heat treated at 180 10C) heat-treated to various temperatures in the
* Hasegawa et al. [Has83] used gel permeation chromatography to confirm that the molecular weight of
PCS does increase upon heat treatment in nitrogen to 400C. (The PCS used by Hasegawa et al. had
lower molecular weight than the PCS used in the present study.)
* PSZ contains a number of unreacted vinyl (CH=CH2) groups. This is evidenced by the presence of vinyl
absorptions at 3040 cm'1, 1592 cm'1, and 1000 cm'1 in the FTIR spectra of the polymer (see section
4.1.3.2.4).


107
experiments, viz., -35-40 Pa s) and drawing fibers until they became separated from the
bulk solution. Average fiber extensions are shown in Table 4.2, while the results for
individual fibers are shown in Appendix C. Table 4.2 shows that the average fiber
extension for the PCS+PSZ solution was 27% greater than the average extension for
the PCS solution. The differences in fiber extension may be related to a difference in
drying behavior of the polymer solutions (see section 4.1.2.2). (The rate of
evaporation of solvent (toluene) is greater for PCS solutions than for PCS+PSZ
solutions.)
4.1.2 Polymer solution characteristics
To understand the differences in spinning characteristics of PCS and PCS+PSZ
spin dopes, the polymer solutions were characterized by measuring molecular weight
and intrinsic viscosity, wettability on different substrates, surface tension, and rate of
evaporation of solvent from spin dopes.
4.1.2.1 Molecular weight and intrinsic viscosity measurements
Figure 4.4 shows GPC molecular weight distributions for the PCS1 and PSZ*
polymers. It can be seen that molecular weights (Mn and Mw) and polydispersity indices
(PDIs) for the two polymers are similar. However, PSZ has a bimodal molecular weight
distribution. Figure 4.5 shows plots of r¡sp/c vs. c (where r)sp is the specific viscosity and c
is concentration in g/dl) for PCS, PSZ, and PCS+PSZ solutions. Also shown are the
intrinsic viscosity [r|] values which are the y-axis intercepts obtained by extrapolation (to
c=0) of the least- squares fit of the data. Details of calculations of intrinsic viscosities for
these solutions are shown in Appendix D. The intrinsic viscosities of PCS, PSZ, and
* PCS used in this study was-prepared by G. Staab at University of Florida.
* PSZ used in this study was-prepared by G. Schieffele at University of Florida.


330
Figure 4.116. (Contd.)


dwt/d(logM)
278
Figure 4.92. GPC molecular weight distribution for PMS-216-A2-H.


% WEIGHT
235
Figure 4.75. TGA plots (% weight vs. temperature) for polymers prepared with
70:30 wt% MDCS:MTCS. The solvents used in polymerization were
toluene (polymer D, batch PMS-259), toluene/THF (95/5 vol. ratio)
(polymer E, batch PMS-222), and toluene/1,4-dioxane (50/50 vol.
ratio) (polymer F, batch PMS-256).


dwt/d(logM) dwt/d(logM)
411
Figure J-9. GPC distributions for PMS-254 polymer before:(A) and
(B) after fractional precipitation with acetone.


Ic (dl/g)
226
c (g/dl)
Figure 4.69. Plot of r\sJc vs. c for polymer F (batch PMS-256) (MDCS/MTCS
(70/30 wt%); toluene/1,4-dioxane (50/50)) in toluene.


147
8(CH2) of Si-CH2-S¡. This is also consistent with the methylene insertion reactions that
occur in the PDMS to PCS conversion. (In the latter case, the intensity of the absorption
band co(CH2) of Si-CH2-Si formed during the PDMS to PCS conversion is significantly
greater than the intensity of the absorption band 8(CH2) of Si-CH2-Si, as indicated in
Figure 4.24.) However, Figure 4.27 shows that the pas(CH3) of Si-CH3 absorption band
(at 830 cm'1) increased significantly and the 8S(CH3) of Si-CH3 absorption band (at 1253
cm'1) increased slightly in this temperature range. This observation seems to be
inconsistent with the occurrence of methylene insertion reactions. However, the relative
intensity ratios for pas(CH3) with respect to vas(CH) and 8as(CH3) with respect to vas(CH3)
increase only slightly during heat treatment. This is consistent with what is observed in
the methylene insertion reactions, where these ratios are expected to increase slightly
during heat treatment.
Hasegawa et ai. [Has83] suggested that the main reason for the increase in
intensity of Si-H absorption band during heat treatment between 200C and 500C was
the existence of a polysilane skeleton in PCS. The residual polysilane skeleton gets
converted to polycarbosilane skeleton in this temperature regime. (Such a conversion
mechanism corresponds to an increase in Si-H and Si-CH2-Si bonds with an increase in
heat treatment temperature.) Hasegawas FTIR spectra showed a decrease in intensity
of Si-H absorption band beyond 500C. This is possibly due to cross-linking by
dehydrogenation reactions of Si-H bonds. Mocaer et al. [Moc93] have also reported
similar decreases in intensity of Si-H absorption band in the pyrolysis of
polycarbosilazane polymer. The evidence for dehydrogenation was obtained by gas
chromatography which showed the evolution of H2. In this temperature range, the Si-H


220
mixture (70:30 % by weight), toluene (batch D) (5) MDCS:MTCS mixture (70:30 % by
weight), toluene-THF (95:5 % by volume) (batch E) (6) MDCS:MTCS mixture (70:30 %
by weight), toluene-1,4-Dioxane (50:50 % by volume) (batch F). Batches A,B,D, and E
required 40 h for completion of reaction whereas batches C and F required 14 h for
completion. (Reactions were considered essentially complete when the solutions were
no longer acidic, i.e., according to the method described in section 3.2.2.) It has been
reported that [Zei86; Wes86] that prolonged refluxing of the reaction mixture beyond
completion of reaction leads to degradation of polymer molecular weight. Hence,
batches C and F were not refluxed for 40 h for direct comparison with batches A,B,D,
and E.
4.2.1 Effect of synthesis conditions on molecular weight
Figures 4.66a and 4.66b show representative GPC molecular weight
distributions of the six classes of polymers prepared. It can be seen that all the
molecular weight distributions are skewed towards low molecular weight end, indicating
the presence of a significant amount of low molecular weight fractions. Figures 4.67 and
4.68 show bar plots of number-average and weight-average molecular weights for the
same polymers. These figures show that the polymer molecular weights increased when
THF and dioxane were used as cosolvents
This observation can be explained by mechanisms based on the poor solvent
vs. good solvent" concept in Zeiglers model [Zei86], Prior to a discussion of these
mechanisms, it will be helpful to illustrate that a toluene-1,4-dioxane mixture is a poorer
solvent for PMS polymers compared to toluene alone. This was accomplished by
intrinsic viscosity measurements. In a poor solvent, the polymer chains are tightly coiled.
This results in polymer chains with smaller radii and, hence, the polymer solution has
lower intrinsic viscosity. In a good solvent, polymer chains assume an expanded


335
PSZ react with each other, and at sufficiently high concentration, spinning solutions with
these additives either undergo gelation or some precipitates form from the solutions.
Hence, it is not too surprising that the UF-76s batch underwent gelation during spin
dope preparation.
Fiber batches UF-77s and UF-78s were prepared from PMS-252-F (1^^4500),
PMS-253-F (Mw5=7800), PMS-254-F (1^5300), and PMS-255-F (M*5900) in
proportions of 30:15:22:33 by wt%. The spin batch additives were PSZ (0.5 wt%), DB (2
wt%), and polysiloxane, PSO, (6 wt%). (PSO has been reported to be an excellent
spinning aid in the spinning of fibers from PCS polymers [Sac95].) UF-77s fibers were
slightly stuck together in green state, while the UF-78s fibers were highly separable both
after spinning and pyrolysis. The improved separability of the UF-78s fibers was
probably due to the higher spin batch viscosity (48-41 Pa s compared to 37-31 Pa s for
UF-77s).
The UF-75s fibers had high tensile strength (2.72 GPa) after pyrolysis at 1150C
in nitrogen (Table 4.33). The 1150C-pyrolyzed fibers had a near-stoichiometric
composition of 66.5 wt% Si, 32.0 wt% C, and 1.5 wt% O, as determined by electron
microprobe analysis (EMA) (Table 4.34). These fibers showed unexpectedly poor
thermal stability upon further heat treatment. The fibers had total weight losses of 8%,
12 wt%, and 22 wt% after heat treatments of 1480C for 1 h (in argon), 1480C for 10 h
(in argon), and 1845C for 1 h (in argon), respectively. The composition of fibers after
1480C/1 h was determined to be somewhat more carbon-rich (Si:64.5 wt%, C:35.5
wt%, O: 0 wt%) compared to the 1150C-pyrolyzed fibers.
The pyrolyzed 1150C UF-78s fibers had reasonably good tensile strength
(~2.35 GPa, Table 4.33) but showed poor thermal stability at higher temperature. The
weight loss for these fibers was ~25% after heat-treatment at 1480C for 1 h in argon.


(A)
Figure 4.109. Plots of (A) shear stress vs. shear rate (B) viscosity vs.
shear rate for UF-45s spin dope.


APPENDIX M
CHARACTERISTICS OF PMS POLYMERS SYNTHESIZED FROM
MDCS AND MTCS MONOMER MIXTURE


Table 4.21. Conditions for heat treatment of PMS polymers11 containing PSZ, DCP, and DB.
Initial polymer
batch
Additives (wt%)
PSZ DCP DB
Heat treatment
conditions
time(h)(tempC)
Initial
viscosity
mPas
Final
viscosity
mPa-s
%
viscosity
change
Initial
Mnt
Initial
Initial
PDI
Final
Mn
Final
Mw
Final
PDI
PMS-214-A
5
0.5
0
1 (100, 115, 125,
130, 145)
*
*
*
1493
6449
4.32
2614
27039
10.34
PMS-216-A
5
0.5
0
1 (55, 70, 85)
1.84
2.59
41
1263
3760
2.97
1461
7580
5.18
PMS-216-A2
5
0.5
0
1 (105)
1.90
3.43
80
*
*
*
2076
11213
5.40
PMS-217-A
5
0.5
0
1 (100)
1.90
2.84
49
1156
3351
2.89
1768
8213
4.64
PMS-218-A
10
1
0
1 (85, 95, 105,
115, 130)
1.52
4.27
181
*
*
*
*
*
*
PMS-219-A
14.5
1.5
0
1 (140); 94(150)
1.50
12.0
700
1293
4552
3.51
2496
24044
9.63
PMS-223-AD
0.25
0
6
1 (100, 120, 130,
140, 150)
1.90
27.5-12.5
800
*
*
*
*
*
*
PMS-223-AD2
0.25
0
6
1 (120,130);
2(140)
1.80
4.2
130
1629
2626
1.61
1671
3087
1.84
PMS-224-AD
0.25
0
6
2 (130)
1.80
solution gelled
*
*
*
*
*
*
PMS-225-AD
0.25
0
6
1 (100,120,130);
2.75(140)
1.80
7.5
320
*
*
*
1037
1846
1.78
PMS-225-AD2