Citation
Ferulic acid, homovanillic acid, vanillic acid, and hydroxybenzoic acid

Material Information

Title:
Ferulic acid, homovanillic acid, vanillic acid, and hydroxybenzoic acid biomass derived monomers for commodity plastic mimics
Creator:
Suda, Elizabeth R
Place of Publication:
[Gainesville, Fla.]
Publisher:
University of Florida
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Language:
english
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1 online resource (127 p.)

Thesis/Dissertation Information

Degree:
Master's ( M.S.)
Degree Grantor:
University of Florida
Degree Disciplines:
Chemistry
Committee Chair:
MILLER,STEPHEN ALBERT
Committee Co-Chair:
WAGENER,KENNETH B
Committee Members:
SMITH,BEN W
Graduation Date:
12/13/2013

Subjects

Subjects / Keywords:
Acetates ( jstor )
Copolymers ( jstor )
Hydroxybenzoic acids ( jstor )
Molecular weight ( jstor )
Monomers ( jstor )
Nitrogen ( jstor )
Pets ( jstor )
Polymerization ( jstor )
Polymers ( jstor )
Zinc ( jstor )
Chemistry -- Dissertations, Academic -- UF
biomass -- monomers -- plastics
Genre:
Electronic Thesis or Dissertation
born-digital ( sobekcm )
Chemistry thesis, M.S.

Notes

Abstract:
The central goal of this project is to chemically functionalize and polymerize biorenewable structures into viable and sustainable macromolecular materials. The polymeric materials we seek to synthesize will not only replace existing petroleum based materials, but will do so with improved thermal characteristics as well as prove potentially degradable. Motivation for this outcome stems from steadily increasing petroleum prices, concerns over security of oil supply and trepidations about climate change. Biomass, the only renewable source of fixed carbon, is a primary candidate for such products [1]. Global interest in bio-derived and recyclable materials has increased exponentially due to the possibility for increased profitability and a positive reputation as promoting "green living" for companies. Producing biomass derived products would hopefully result not only in economically competitive products, but would do so while minimizing energy usage, chemical waste, and toxic emissions [2]. The specific focus of this research is synthesizing aromatic/aliphatic based polyester monomers which will be polymerized to produce thermoplastics with thermal properties rivaling that of commercially produced polyethylene terephthalate (PET) and polystyrene (PS). 13 Homovanillic acid (HVA), ferulic acid (FA), vanillic acid (VA) as well as hydroxybenzoic acid (HBA) were the monomers chosen. After functionalization, these biomass derived monomers would be attractive starting materials for both homopolymerizations and copolymerizations for obtaining A-B type copolyesters. Novel aromatic polyester copolymers were synthesized from these monomers with the intent to serve as greener alternatives to both polyethylene terephthalate (PET) and polystyrene (PS). In addition, the effects of the chemical structure on the thermal properties were studied. ( en )
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Thesis:
Thesis (M.S.)--University of Florida, 2013.
Local:
Adviser: MILLER,STEPHEN ALBERT.
Local:
Co-adviser: WAGENER,KENNETH B.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-12-31
Statement of Responsibility:
by Elizabeth R Suda.

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Embargo Date:
12/31/2015
Resource Identifier:
907474139 ( OCLC )
Classification:
LD1780 2013 ( lcc )

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FERULIC ACID, HOMOVANILLIC ACID, VANILLIC ACID, AND HYDROXYBENZOIC ACID: BIOMASS DERIVED MONOMERS FOR COMMODITY PLASTIC MIMICS By ELIZABETH R. SUDA A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA I N PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2013

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2013 Elizabeth Suda

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For my grandparents: Eldred and Dorothy Adams and my parents: Laurie and Elde en Suda

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4 ACKNOWLEDGMENTS First and foremost I thank Dr. Stephen Miller and the other members of my committee; Dr. Ken Wagener, and Dr. Ben Smith for their mentoring a s program at the University of Florida. In addition, I acknowledge the Miller research group and all members of the Butler Polymer Program for their help, encouragement, and friendship during this process. Special thanks go to fellow Miller group member, Emma Bradic, who assisted in several of the monomer syntheses and obtaining molecular weights of some of the polymers. In addition, many thanks to Ion Ghiviriga, Director of NMR Services at the University of Florida, whose expertise proved pivotal in obtaining the molecular weights of our polymers. I would also like to thank my TriGator, Florida Track Club, and Florida Running Club teammates and coaches for their daily inspiration and for cheering me on when I could not see Gainesville for their strength and the love of several pseudo grandparents. Finally, to my family, those with whom I share a genetic code, and to those with whom I share something even deeper, thank you.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ ............... 4 LIST OF TABLES ................................ ................................ ................................ ........................... 7 LIST OF FIGURES ................................ ................................ ................................ ......................... 8 LIST OF ABBREVIATIONS ................................ ................................ ................................ .......... 9 ABSTRACT ................................ ................................ ................................ ................................ ... 11 CHAPTER 1 POLYMERS A GENERAL CONCERN ................................ ................................ ............... 13 Historical perspective ................................ ................................ ................................ ............. 13 Challenges with Production of Specialty Polymers ................................ ................................ 16 Greening of Polymer Chemistry ................................ ................................ ............................. 18 Examples of Commercially Relevant Green Polymers ................................ .......................... 20 Glass Transition Temperature and its Relevance to Polymer Characterization ..................... 22 Determinants of Glass Transition Temperature (Tg) ................................ .............................. 23 Green Chemistry Metrics ................................ ................................ ................................ ........ 26 Improving Green Metrics for Ferulic acid Monomer Synthesis ................................ ............. 28 Con clusions ................................ ................................ ................................ ............................. 29 2 NOVEL GREEN POLYESTERS FROM BIORENEWABLE FEEDSTOCKS AS PET AND PS MIMICS ................................ ................................ ................................ ................... 30 Polyesters: Use and Synthesis Routes ................................ ................................ .................... 30 Poly(ethylene terephthalate) and Polystyrene: Characteristics, Synthesis, and Thermal Properties ................................ ................................ ................................ ............................ 31 Recent Example of Copolyes ters from Biorenewables. ................................ ......................... 34 Ferulic Acid as Biorenewable Starting Material ................................ ................................ .... 35 Antioxidant properties of Ferulic acid. ................................ ................................ ................... 36 Synthesis of Aromatic Polyesters from Ferulic Acid ................................ ............................. 36 Formation of reactive A B monomers: Acetylferulic Acid and Acetyldihydroferulic a cid. ................................ ................................ ................................ ................................ ..... 36 Greening of the monomer synthesis process. ................................ ................................ .. 37 Polymer synthesis. ................................ ................................ ................................ ........... 38 Conclusions ................................ ................................ ................................ ............................. 41 3 COPOLYESTERS OF ACETYLFERULIC ACID AND ACETYLDIHYDROFERULIC ACID ................................ ................................ ................... 42 Copolymers: An Introduction ................................ ................................ ................................ 42

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6 Synthesis of Copolyesters ................................ ................................ ................................ ....... 42 NMR Study and Type of Copolymer Determination ................................ ............................. 43 Determination of Incorporation Ratio. ................................ ................................ ............ 43 Molecular Weight Determination. ................................ ................................ ................... 44 Conclusions ................................ ................................ ................................ ............................. 46 4 COPOLYMERS FROM HOMOVANILLIC ACID AND ACETYLFERULIC ACID ........ 48 Homovanillic Acid: an Amino Acid Derived Metabolite ................................ ....................... 48 Synthesis of Monomers ................................ ................................ ................................ .......... 49 Synthesis of Copolymers ................................ ................................ ................................ ........ 49 Conclusions ................................ ................................ ................................ ............................. 50 5 COPOLYMERS FROM VANILLIC ACID AND HYDROXYBENZOIC ACID WITH FERULIC ACID ................................ ................................ ................................ ..................... 51 6 CONCLUSIONS ................................ ................................ ................................ .................... 54 7 EXPERIMENTAL PROCEDURES ................................ ................................ ....................... 55 Molecular characterizations ................................ ................................ ................................ .... 55 Polymerization procedures ................................ ................................ ................................ ..... 55 Molecular weight determination: Diffusion Coefficient Spectroscopy (DOSY) ................... 56 Synthesis Procedures ................................ ................................ ................................ .............. 57 APPENDIX A: NUCLEAR MAGNETIC RESONANCE SPECTRA ................................ ........ 70 APPENDIX B: POLYMER AND COPOLYMER NMRS ................................ .......................... 75 APPENDIX C: TGA AND DSC DATA OF POLY MERS AND COPOLYMERS .................... 95 LIST OF REFERENCES ................................ ................................ ................................ ............. 125 BIOGRAPHICAL SKETCH ................................ ................................ ................................ ....... 127

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7 LIST OF TABLES Table pa ge 1 1 E factor ranges from various chemical industry sectors. ................................ ................... 28 1 2 Green metrics for synthesis of acetylferulic acid ................................ ............................... 29 2 1 E Factor calculations for acetylferulic acid ................................ ................................ ....... 38 2 2 Copolymerization data employing hot plate and oil bath ................................ .................. 40 2 3 ..................... 40 3 1 Incorporation data of acetylferulic: acetyldihydroferulic aci d copolymerizations ................................ ................................ ................................ ....... 44 3 2 Molecular Weight (Mw) of PET standard samples and their diffusion coefficients (D) ................................ ................................ ................................ ................................ ...... 45 3 3 ................. 45 3 4 ............... 46 3 5 Observed vs. Expected Tg ................................ ................................ ................................ 46 4 1 Thermal properties of HVA: Acetylferulic acid copolymers ................................ ............ 50 4 2 Thermal Properties of HVA: Acetyldihydroferulic acid copolymers ................................ 50 5 1 Acetylvanillic acid and acetylferulic acid copolymer thermal data ................................ ... 52 5 2 Copolymerization data of acetoxybenzoic and acetylferulic acid ................................ ..... 53 7 1 DOSY Results for PET Standards ................................ ................................ ..................... 56 7 2 DOSY Results for Ferulic acid based polymers ................................ ................................ 57

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8 LIST OF FIGURES Figure page 1 1 First generation pet roleum based polymer examples ................................ ......................... 14 1 2 Examples of a polyurethane, polycarbonate, poly acrylonitrile, and polysulphone ........... 15 1 3 Specialty Polymers: Kevlar and Teflon. ................................ ................................ ...... 16 1 4 Examples of Commodity Thermosets. ................................ ................................ ............... 17 1 5 Structure of Polystyrene and Polyethylene terephthalate. ................................ ................. 18 1 6 Polyhydroxyalkanoate (PHA) and Polylactic acid (PLA) ................................ ................. 20 1 7 Polymerization of lactic acid ................................ ................................ ............................. 21 1 8 B ranching on polymer backbone increases Tg ................................ ................................ .. 23 1 9 Polarity effects on Tg. PS (left) Tg 100 C. Poly(4 vinylpyridine) 142C. .................... 24 1 10 Polarity and hydrogen bo nding effects on Tg. ................................ ................................ ... 24 2 1 Esterification reactions ................................ ................................ ................................ ....... 30 2 2 Synthesis of polyesters ................................ ................................ ................................ ....... 31 2 3 Synthesis of PET from terephthalic acid and ethylene glycol ................................ ........... 33 2 4 Catabolic pathways for the degradation of ferulic acid [26]. ................................ ............. 36 2 5 Acetylferulic acid and acetyldihydroferulic acid ................................ ............................... 37 2 6 Synthesis of acetylferulic acid and acetyldihydroferulic acid ................................ ........... 38 2 7 Polymerization of acetyldihydroferulic acid to form PHFA ................................ .............. 38 3 1 Copolymerization of acetylferulic and acetyldihydroferulic acid ................................ ..... 43 4 1 Structures of Tyrosine, Dopamine, and Homovanillic acid. ................................ .............. 48 4 2 Simplified sequence of HVA synthesis ................................ ................................ ............. 48 5 1 Acetylvanillic acid ................................ ................................ ................................ ............. 51 5 2 4 acetoxy benzoic acid ................................ ................................ ................................ ...... 52 7 1 PET calibration curve in HFiP d 2 for M w prediction. ................................ ........................ 56

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9 LIST OF ABBREVIATIONS ABS Acrylonitrile butadiene styrene AE Atom economy A qu Aqueous C at Catalyst CE Carbon efficiency DOSY Diffusion Ordered spectroscopy DP Degree of polymerization DSC Differen tial Scanning calorimetry E factor Environmental factor EPA Environmental Protection Agency EPS Expanded polystyrene foam Equ Equivalent FA Ferulic acid G Grams GPC Gel Permeation Chromotography HBA Hydroxybenzoic acid HDPE High density polyethyle ne HVA Homovanillic acid Hz Hertz IUPAC International Union of Pure and Applied Chemistry L Liter LDPE Low density polyethylene MeOH Methanol mL Milliliter

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10 Mn Number average molecular weight Mw Weight average molecular weight NMR Nuclear magnetic resonance PDI Polydispersity index PE Polyethylene PET Polyethylene terephthalate PHA Polyhydroxyalkanoates PLA Polylactic acid P pm Parts per million PVC Poly(vinyl chloride) PS Polystyrene RME Reaction mass efficiency SAN Styrene acrylonitrile copolymer Tg Glass transition temperature TGA Thermogravimetric anaylsis THF Tetrahydrofuran Tm Melting point T50% Temperature of TGA for 50% weight loss under Nitrogen gas VA Vanillic acid

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11 Abstract of Thesis Presented to the Graduate School o f the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science FERULIC ACID, HOMOVANILLIC ACID, VANILLIC ACID, AND HYDROXYBENZOIC ACID: BIOMASS DERIVED MONOMERS FOR COMMODITY PLASTIC MIMICS By Elizabeth R. Suda December 2013 Chair: Stephen A. Miller Major: Chemistry The central goal of this project is to chemically functionalize and polymerize biorenewable structures into viable and sustainable macromolecular materials. The polymeric materials we seek to synt hesize will not only replace existing petroleum based materials, but will do so with improved thermal characteristics as well as prove potentially degradable. Motivation for this outcome stems from steadily increasing petroleum prices, concerns over secur ity of oil supply and trepidations about climate change. Biomass, the only renewable source of fixed carbon, is a primary candidate for such products [1]. Global interest in bio derived and recyclable materials has increased exponentially due to the poss ibility for increased profitability products would hopefully result not only in economically competitive products, but would do so while minimizing energy usage chemical waste, and toxic emissions [2]. The specific focus of this research is synthesizing aromatic/aliphatic based polyester monomers which will be polymerized to produce thermoplastics with thermal properties rivaling that of commercially produced po lyethylene terephthalate (PET) and polystyrene (PS). Homovanillic acid (HVA), ferulic acid (FA), vanillic acid (VA) as well as hydroxybenzoic acid

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12 (HBA) were the monomers chosen. After functionalization, these biomass derived monomers would be attractive starting materials for both homopolymerizations and copolymerizations for obtaining A B type copolyesters. Novel aromatic polyester copolymers were synthesized from these monomers with the intent to serve as greener alternatives to both polyethylene terep hthalate (PET) and polystyrene (PS). In addition, the effects of the chemical structure on the thermal properties were studied.

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13 CHAPTER 1 POLYMERS A GENERAL CONCERN Historical perspective While recent interest in mass producing biorenewable thermoplasti cs drives innovative research and development in polymer science, the exploitation of renewable resources parallels the elaboration and sophistication of human civilization [3]. The need for shelter, clothing, tools, weapons, utensils, and all types of co atings have called upon them since the inception of human activities, first with a minimum amount of modification and then, progressively, through increasingly elaborate processes aimed at optimizing their specific performance and durability. Natural pro ducts such as rubber from the Hevea trees were being used by Native Americans since the days of Columbus, and modifications to the other natural polymers such as cellulose, starch, and collagen dominated the polymer landscape until the first wholly synthet ic polymer was made at the beginning of the 20th century, a thermosetting phenol formaldehyde resin called Bakelite [3]. A rapid surge of coal based chemistry and later, with the petrochemical revolution of the 20th century, caused the realm of polymers p repared from fossil resources to explode. This resulted in not only huge quantities of plastics, elastomers, fibers, adhesives, paints, and packaging materials, but also presented an astonishing variety of sophisticated macromolecular structures, severing functional roles in all aspects of the emerging technologies proved indispensable [4]. A first generation of these petroleum based polymeric materials could be categorized as occurring during the first 50 years of the 20th century. Throughout this time p eriod came the introduction of polystyrene (PS), polyvinyl chloride (PVC), low density polyethylene (LDPE), polyacrylates, polymethacrylates, glass fiber reinforced polyesters, aliphatic polyamides, styrene butadiene rubber, and the first synthetic paints [5].

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14 Figure 1 1. First generation petroleum based polymer examples. Top Row L R: Polystyrene (PS), Polyvinyl chloride (PVC), Polyethylene (PE), Bottom Row L R: Poly(methyl methacrylate), Polyethylene terephthalate A second generation of polymers occurred from approximately the years between 1950 and 1965 with the dominance of engineering plastics such as high density polyethylene (HDPE), polycarbonates, polyurethanes, epoxy resins, polysulphones, and aromatic polyest ers, in addition to new rubber materials, acrylic fibers from polyacrylonitrile and latex paint [5].

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15 Figure 1 2. Examples of a polyurethane, polycarbonate, polyacrylonitrile, and polysulphone. Following these advances, a third generation of specialty polymers describes the current scene of polymer design with materials with high thermal and chemical stability and high strength and stiffness such as Kevlar and Teflon as well as the improvement upon existing polymers: cr osslinked polyethylene and new fracture tough thermoplastic polyethylenes as well as the economically and scientifically exciting focus on more environmentally compatible or to contribute with our own original biomass derived polymers.

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16 Figure 1 3 Specialty Polymers: Kevlar and Teflon. Challenges with Production of Specialty Polymers While these commodity polymers such as polystyrene (PS) and polyethylene terephthalate (PET) serve crucial functions to society, their production creates significant drawbacks in resource management as well as issues in disposal practices once the product has fulfilled its purp ose. In general, two types of these specialty plastics exist: thermosets and thermoplastics, each of which presents unique recycling problems. By the International Union of Pure and Applied Chemistry (IUPAC) definition, a thermosetting polymer is derive d from a prepolymer in a soft solid or viscous state that changes irreversibly into an infusible, insoluble polymer network by curing. Curing can be induced by the action of heat or suitable radiation, or both [6]. Examples of thermosets include material s such as polyurethanes, urea formaldehyde, melamine formaldehyde, and phenol formaldehyde, which could be used for various applications such as

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17 synthetic fibers (e.g. Spandex) and high resilience foam seating, and high pressure laminates and laminate floo ring [7]. Figure 1 4 Examples of Commodity Thermosets. L R. Phenol formaldehyde, Urea formaldehyde, Melamine formaldehyde. Thermoplastics, such as PET and PS however, are polymers that become pliable or moldable above a specific temperature, and return to a solid state upon cooling. This property allows thermoplastics to be remolded because these intermolecular interactions spontaneously reform upon cooling. In terms of recycling, thermoplastics are able to melt and t herefore possible to reshape and recycle several times, but eventually the quality is too poor for continued one which requires a less thermally robust chemical makeup. Conversely, while it is possible to shred thermosets into chips to be used as filling material or reinforcement material in new products, they will keep their mechanical integrity even after application of intense stress.

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18 Figure 1 5 Structure of Polystyrene and Polyethylene terephthalate. In 2011, the Environmental Protection Agency (EPA) reported that 32 mi llion tons of plastic waste was generated in the US, representing 12.7 percent of total municipal solid waste (MSW). Additionally, only 8 percent of the total plastic waste generated in the US in 2011 was recovered for recycling [8]. The very qualities of durability, resilience, and high impact strength which consumers prize in their plastic products, also make the appropriate disposal of such materials extremely challenging. When placed in direct sunlight, most thermoplastics will eventually deteriorate over time. However, the time scale for such decomposition often proves to outlast the very consumers wh o utilize the products. In addition, these materials will almost never decompose completely when buried in landfills. Only when placed in specially designed food waste commercial composting facilities do these polymers decompose. Furthermore, the polyme rs we seek to replace, that is, polystyrene and polyethylene terephthalate specifically, do not biodegrade for hundreds of years and are resistant to photolysis. Greening of Polymer Chemistry In order to combat these serious challenges, a branch of chemist ry known as green chemistry, has been developed into an internationally accepted design strategy. By definition, eliminate the use and generation of hazardous sub achieve sustainability, researchers applying this cohesive system of principles possess the

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19 exciting ability to harness chemical innovation to meet both environmental and economic goals simultaneously. Speci fically, polymer chemists have embraced the following eight themes as design criteria in order to continue synthesizing useful products while also reducing adverse consequences for future generations: 1. Greener catalysts (e.g., biocatalysts such as enzyme s and whole cells) 2. Diverse feedstock base (especially agricultural products and biobased building blocks) 3. Degradable polymers and waste minimization 4. Recycling of polymer products and catalysts (e.g., biological recycling) 5. Energy generation or m inimization of use 6. Optimal molecular design and activity 7. Benign solvents (e.g., water, ionic liquids, or reactions without solvents) 8. Improved syntheses and processes (e.g., atom economy, reaction efficiency, toxicity reduction) This project seek s to follow this model for sustainability by using starting materials based on biomass, improving upon standard monomer synthesis chemical procedures, as well as reducing amounts or eliminating solvents. Renewable biomass exists naturally on the scale of a bout 180 billion metric tons/year, of which less than 5% is harnessed for use. Of the biomass that is utilized by humans, the majority is in the form of carbohydrates (~75%), which are used in the production of ethanol, furural, d sorbitol sweetener, surf actants, pharmaceuticals, and lactic acid [9]. Another component of biomass, lignin (20%), which is generated by plants via photosynthesis using CO2 from the atmosphere followed by aromatization and polymerization, becomes useful in the form of additives dyestuffs for dispersants, and binders or surfactants for animal feed. A byproduct of

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20 the paper and pulp industry, lignin is proving to be a valuable commodity; over 50 million tons/year of this material being generated in the US. Finally, the remainde r of the useable biomass generated comes from various fa ts, proteins, and terpenes [9] Examples of Commercially Relevant Green Polymers Currently, two such examples of commercially successful biomass derived green polymers are polyhydroxylalkanoates (PHAs) and polylactic acid (PLA). PHAs have been commercialized by Metabolix and Archer Daniel Midlands Company, through a process which relies on genetically engineered microbes, thus achieving the polymer synthesis through fermentation of the renewable raw ma terials [9]. Commercial production of PLA largely rests in the hands of the Cargill owned company NatureWorks [10]. Similar to most thermoplastics, this material possesses the ability to be processed into fibers and films, packaging materials, as well as for various biomedical applications such as sutures, stents, dental implants, vascular grafts, bone screw and pins [11]. Likewise, PLA has also been investigated as a vector for drug delivery, for therapies such as antimicrobial drugs, contraceptives and prostate cancer treatments. In addition, PLA has also been widely used in the field of tissue engineering as a scaffold material to support cell and tissue growth [11]. Figure 1 6 Polyhydroxyalkanoate (PHA) and Polyla ctic acid (PLA) PLA, an aliphatic polyester is derived from corn starch or sugar cane via a ring opening polymerization of lactide. This process has been noted for following the principles of green chemistry in its avoidance of organic solvents, high yiel ds achieved by efficient catalysis, and

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21 waste reduction through recycle streams [9]. In addition, this PLA synthesis process is estimated to use 20 50% less petroleum resources compared to conventional polymers [9]. Alternatively, direct condensation of l actic acid monomers also results in PLA. This less desirable route, however, generates one equivalent of water for every esterification, resulting in lower molecular weight materials due to chain transfer termination by the water molecules, due to its ste p growth mechanism. In addition to being derived from biomass, PLA can also be recycled into monomer by thermal depolymerization or hydrolysis. Finally, when purified, the monomer can also be subsequently reused for the manufacture of virgin PLA. Figure 1 7 Polymerization of lactic acid Despite being labeled as sustainable, PLA has several functional drawbacks due to its high crystallinity, brittleness, lack of total absorption and thermal instability [11]. The backbo ne of PLA is relatively flexible, resulting in Tgs ranging from 30 to 60C, depending on the degree of crystallinity and molecular weight of polymer. This relatively low glass transition renders it unsuitable for applications like hot beverage containers. Additionally, decomposition of this polymer requires a controlled composting environment whereby the material requires high temperature for extended time as well as specialized microbes. Our research specifically aims to synthesize another similarly bio mass derived polymer or copolymer, yet one which demonstrates excellent tunable thermal properties thus creating a potential rival for PET, PS or other petroleum based thermoplastics.

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22 Glass Transition Temperature and its Relevance to Polymer Characterizati on Our main goal in synthesizing biorenewable polymers and copolymers is to produce materials with thermal properties meeting and exceeding those of PET and PS in order to be used in hot food packaging. To understand the influence of thermal properties on polymer characterization, some background on the chemical structure and design and subsequent glass transition temperature of polymers becomes beneficial. Several categories describe the molecular packing or ordering of the polymeric chains: fully amo rphous, semicrystalline, and liquid crystalline. A fully amorphous polymer shows no sharp crystalline Bragg reflections in x ray diffractograms at any temperature, thus appearing as clear materials. These polymers are also unable to crystallize due to their irregular chain structure. Semicrystalline polymers show crystalline Bragg reflections superimposed on an amorphous background. These materials consist of two components differing in degree of order: a crystalline component composed of thin lamell a shaped crystals and an amorphous component. Finally, liquid crystalline polymers (LCPs) are intermediates between the amorphous and crystalline polymers. LCPs are composed of ordered regions in the liquid phase that are incorporated into the main chain of a polymer backbone. LCPs display characteristics of high strength and modulus, favorable dimensional stability, as well as low linear thermal expansion coefficients [12]. The glass transition temperature (Tg) describes the second order transition tempe rature in which the amorphous phase of a polymer evolves from its glasslike solid, brittle state to a rubber like state. Kinetically, as the polymer is heated, the energy of the molecules increases and the once short range vibrations and rotations of the molecule in the glassy state change to more long range molecular motions with greater rotational freedom and segmental motion of the chains. Macroscopically, the enthalpy of the system changes along with a decrease in the

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23 modulus or stiffness of the polym er [5]. If enough heat is added, the polymer will lose its elastomeric properties completely and liquefy. During this transition, conformational changes are confined to small groups of atoms while larger deformations occur due to the stretching of sec ond ary bonds and bond angles. Determinants of Glass Transition Temperature (Tg) Chemical structure is arguably one of the most important factors in determining the Tg of a polymer. That is, molecules with structures that restrict rotation, act to increase t he glass transition, as Tg, is a function of rotational freedom. Any compound having carbon carbon single bonds is capable of existing in an infinite number of conformations unless freedom of rotation is impaired. In the case of polymers, therefore, it f ollows that the bulkier the substituents on the polymer backbone, the less will be the rotational freedom and the higher the Tg. An increase in branching along the polymer chain also increases Tg significantly. Tg 59C Tg 25C Figure 1 8 Branching o n polymer backbone increases Tg In addition to size, polarity also influences Tg. The increased dipole dipole interactions resulting from polar groups along a polymer backbone effect higher Tgs. Furthermore, decrea sed rotational freedom arising from intramolecular hydrogen bonding may also increase the glass transition temperature. Conversely, the Tg of a polymer may decrease over time due to

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24 oxidation or UV light exposure. Finally, the molecular weight of the poly mer also plays a role in its Tg: the higher the molecular weight, the fewer the chain ends, which leads to a lower free volume, better chain packing, and thus higher observed molecular weight [5]. For example, the Tg of PS increases from about 40C at an Mn of 3 ,000 to about 100C at 300,000. Figure 1 9 Polarity effects on Tg. PS (left) Tg 100 C. Poly(4 vinylpyridine) 142C. Figure 1 10 Polarity and hydrogen bonding effects on Tg. PVC (left) Tg 81C. Polyvinyl alcohol (right) Tg 85C. Flory Fox and Fox Equations and Tg of Polymers and Copolymers The relationship between the molecular weight of a polymer system and its glass transition temperature may be quantitatively expre ssed in the Flory Fox equation: K/Mn Where infinite molecular weight

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25 K = an empirical parameter that is related to the free volum e present in the polymer sample Fro m this expression, it becomes clear that the Tg represents the temperature at which the free volume for the segmental motion of the polymer chains achieves a minimum value. This polymeric quality is not only temperature dependent, as its value also relies on the number of polymer chain ends present in the system. Thus, low molecular weight values result in lower Tg values, while increasing values of molecular weight results in an asymptotic approach o f the Tg volume than the units within the chain. Thus, intermolecular polymer covalent bonds are shorter and stronger than the intramolecular bonds that conne ct the polymer chains to one another [17]. The glass transition temperature can also be modified by adding small amounts of low molecular weight diluents, (i.e. plasticizers) to the polymer. The presence of these low molecular weight additives acts to inc rease the free volume of the system and subsequently lowers the Tg, thus allowing for rubbery properties at lower temperatures. This trend is represented in the Fox equation: 1/ Tg = w1/ Tg,1 + w2/Tg,2 where w1 and w2 are weight fractions of component s 1 and 2. Consequently, the Fox equation can also be applied to determine the Tg of the polymer blends, and more importantly for this project, f or statistical copolymers [13].

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26 Green Chemistry Metrics In order to measure the efficiency in a green chemica l process, several parameters have been established in order to quantify the change in chemical procedure, solvent choice, and yield. These metrics will aid in communication of scientific results and potentially facilitate the transfer to industry the adv ances made in the lab. In general, all good metrics must be clearly defined, simple, measurable, objective, and must ultimately drive desired behavior [14]. Examples of om economy, carbon efficiency, reaction mass efficiency, and environmental (E) factor. While these measurements help researchers quantify improvements in green chemistry practices and interface between science and industry, several inherent limitations mu st also be considered when employing such metrics and caution when reporting such values, as outlined below. Atom economy. Atom economy (AE) represents the calculation of how much of reactants remain in the final product. Ideally, a chemical reaction is not only selective but is also an efficient addition (either inter or intramolecular) in which any other reactant is required only in catalytic amounts, with no resulting unnecessary side products. Overall, the goal of all green chemistry reactions woul d be to follow an environmentally benign design, thus maximizing the number of atoms of all raw materials that end up in the product [15]. For instance, in a general reaction: A + B CC + D EE + F G Atom economy = m.w ) This parameter is the ratio of the molecular weight of the target molecule to the sum total of the molecular weights of all the substances produced in the stoichiometric equation for the reaction involved. It takes into account the amount of the reagents incorporated into the end

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27 product. Cycloadditions are examples of transformations with 100% atom economy. For other reactions (e.g. substitution reaction), a 100 % economy can never be reached due to the intrinsic nature of the reaction. The main use of t his parameter is to adapt reaction sequences in a way that transformations with low atom economy are limited to a minimum [16]. Unfortunately, several assumptions need to be made when calculating the atom economy, such as any inorganic reagents are ignored as they are not incorporated into the final product, and solvents and stoichiometry of reagents are also ignored [14]. Carbon efficiency Carbon efficiency (CE), in contrast, does take into account stoichiometry of reactants and products. By definition, this measurement describes the percentage of carbon in the reactants that remain in the final product. The equation for calculating this parameter is as follows: CE = amount of C in product x 100 /total carbon present in reactants This measurement has pr oven quite relevant in the pharmaceutical industry, where carbon skeleton development is paramount. Reaction mass efficiency Reaction mass efficiency (RME) or Effective Mass Yield % also takes into account atom economy, chemical yield, as well as stoich iometry. For a general equation: A + B C RME = molecular weight of product C x yield m.w. A + (mw B x molar ratio B/A) Or more simply, RME = mass of product C x 100/ mass of A + B This metric defines yield in terms of that proportion of the final mass, i.e. the mass of the product, which is made from non products, reagents or solvents that have no known environmental risk associated with them, for

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28 example, water, low concentration saline, dilute ethan Identifying such materials proves challenging in practice, as polymerization reactions involve complex reagents and reactants that have limited environmental or occupational toxicity information. This tool measures th process. There is no account for waste produced, and does not address solvent usage, workup or energy issues. Environmental (E) factor E factor describes the ratio of the mas s of waste per unit of product. Where: E factor = total waste (kg)/ product (kg) The E factor seeks to expose the relative wastefulness of different parts of the chemical processing industries and may be applicable to various sectors ranging from petrochemicals to pharmaceuti cals. Obtaining a relatively high E factor hopefully would inspire innovation that results in reduction of waste. This measurement highlights waste produced in the entire process as opposed to the reaction, thus fulfilling one of the principles of green c hemistry, which is to avoid waste production. The E ultimately defined and accounted for, and where the boundaries of the process are drawn [1 7]. Table 1 1. E factor ranges from c hemical industry sectors. Industry Annual Production (t) E factor Oil Refining 106 108 0 .1 Bulk Chemicals 104 106 <1 5 Fine Chemicals 102 104 5 50 Pharmaceuticals 10 103 25 100 Improving Green Metrics for Ferulic acid Monomer Synthesis Applying these metrics to our own process of creating green polymers offers an interesting picture of the environmental impact of our chemistry. The atom economy of our

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29 acetylation is 100%, as the small molecule acetic acid may be captured and recycled back to its anhydride form. In addition, we were able to improve the carbon efficiency, reaction mass efficiency, as well as E factor of our acetylferulic acid monomer simply by using fewer equivalents of base in our acetylation procedure. Calcu lations of E factors are shown in Chapt er 2. Table 1 2. Various Green metrics for synthesis of acetylferulic acid Mialon et al.[18] Suda et al. Atom Economy (%) 100 100 Carbon Efficiency (%) 54 81 Reaction Mass Efficiency (%) 46 7 7 Environm ental Factor 31 8.5 Conclusions Polymers pervade nearly every facet of modern living and we have come to rely on these materials to provide everything from food containers to protective sports equipment. The production and disposal of such a mas sive entity requires inventive planning and action in order to design a sustainable process. Specifically, synthesis of biorenewable polymers and copolymers with tunable glass transition temperatures rivaling those of PET and PS will be sought. In additi on, limiting the hazardous waste produced as a result of such polymerizations as well as maximizing the atom economy of the reaction will also be primary concerns.

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30 CHAPTER 2 NOVEL GREEN POLYESTERS FROM BIORENEWABLE FEEDSTOCKS AS PET AND PS MIMICS Polyeste rs: Use and Synthesis Routes Polyesters are extremely versatile synthetic polymers, seen in everyday products ranging from fibers, plastics, and coatings. Simple esters are synthesized through either direct esterification, transesterification, or the reac tion of alcohols with acyl chlorides or anhydrides. Mechanistically, this occurs through nucleophilic addition to the carbonyl group. This addition is facilitated by the polar nature of the carbon oxygen double bond, the ability of the carbonyl oxygen at om to assume a formal negative charge, and the planar configuration of the trigonal carbon that minimizes steric interference [9]. Figure 2 1 Esterification reactions Polyester materials, in turn, are synthesized eith er through various step condensation reactions between diacids and dialcohols or through ring opening polymerization of functionalized lactones. In addition, polyesters are usually derived from petroleum. The step polymerization method enables facile in troduction of a large number of substituents per repeat unit. The major drawback of step polymerizations is the inherent requirement for both a very

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31 high purity of monomer, as well as high conversions to produce polymers, thus placing stringent requiremen ts on the position of the esterification equilibrium, the absence of cyclization reactions, as well as precise reagent stoichiometry. Therefore, condensation polymerizations are often carried out in a drive system, accomplished by the use of vacuum, temp erature or gas to remove the water produced. Another disadvantage of step polymerization is the broad molecular weight. Aliphatic polyester synthesis presen ts further problems as the monomers are often thermally unstable and side reactions such as dehydration of decarboxylation readily occur. Therefore, traditional methods to drive the polymerization equilibrium are frequently not suitable for aliphatic poly ester synthesis. Figure 2 2. Synthesis of polyesters Poly(ethylene terephthalate) and Polystyrene: Characteristics, Synthesis, and Thermal Properties Poly(ethylene terethpthalate) (PET), a clear, tough resin of the aromat ic polyester family used for food packing, as a synthetic fiber, as well as thermoforming applications, remains the third most produced polymer in the world after polyethylene and polypropylene. The majority of

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32 the world's PET production is for synthetic fibers (in excess of 60%), with bottle production accounting for around 30% of global demand. In the context of textile applications, PET is referred to by its common name, "polyester," whereas the acronym "PET" is generally used in relation to packaging [19]. PET is widely used due to its excellent mechanical properties: high tensile and impact strength, chemical resistance, clarity when amorphous, as well as its cheap cost of production. PET is clear and possesses an optically smooth surface for orient ed films and bottles as well as excellent barriers to oxygen, water, and carbon dioxide [20]. The production of this polymer, however, renders it environmentally toxic as it is made from terephthalic acid and ethylene glycol, which in turn are derived fr om petroleum and natural gas. Commercially, terephthalic acid is synthesized from p xylene, an aromatic hydrocarbon based on benzene, which subsequently is produced by the catalytic reforming of petroleum naphtha, using acetic acid as the reaction medium. In this process, the reaction occurs at a temperature of about 200 C and pressures between 15 and 30 atm. The most common catalyst is a combination of manganese acetate, cobalt acetate, and hydrobromic acid [21]. In addition, ethylene glycol (EG) is pr oduced from ethylene via hydrocarbons obtained from cracking petroleum. Currently, the global production and consumption of ethylene glycol are about 20 million metric tons in 2010 with an estimated increase of 5 10% per year. EG supports almost every aspe ct of modern everyday life, particularly associated with energy, chemicals, automotives, textiles, transportation, and manufacturing technologies [21].

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33 Figure 2 3 Synthesis of PET from terephthalic acid and ethylene g lycol In addition to its birth from fossil fuels, another limitation of PET is the fact its glass transition temperature is 67 degrees Celsius. This temperature prevents usage of this material for the packaging of any hot food items. Increasing the Tg of polyesters and poly(ethylene terephthalate) in particular, is currently an open frontier in the injection molding applications of these materials. PET with higher Tg will display greater dimensional stability in thermal processing and better barrier prope rties in packaging. This will contribute to expanding the use of PET in highly stringent applications required for special beverage containers and packaging. Streamline hot filling bottle processes requiring materials with a Tg well above the filling tempe rature are good examples of new applications intended today for new PET derivatives. Polystyrene is a synthetic aromatic polymer made from the radical initiated polymerization of styrene, a liquid petrochemical. Of all the styrene used commercially, ~50 % is used to make polystyrene, 20% for elastomers, 15% for acrylonitrile butadiene styrene (ABS) and styrene acrylonitrile copolymers (SAN), 10% in expanded polystyrene foam (EPS), and the remainder is used in a variety of copolymers and specialty material s. The resulting polymer is clear, hard, and brittle, and is a poor barrier to oxygen and water vapor. This ubiquitous material is seen mostly in protective packaging; containers, lids, bottles, trays, tumbles, and disposable cutlery [22].

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34 The first insta nce of this material used was in 1839 when German scientist Eduard Simon coined the word Styrol for a colorless liquid he had obtained by distilling liquid storax, a medicinal balsam found in certain tree species. Simon observed the styrene converting its elf relatively quickly into a resinous solid, which he wrongly hypothesized to be oxidizing. It was not until nearly a century later that Herman Staudinger was able to explain the polymerization mechanism at work: the styrene monomers reacting to form ch ain like molecules that polystyrene [22]. Currently, Dow Chemical produces polystyrene on the industrial scale by employing the dehydrogenation of ethyl benzene. Prepara tion of ethyl benzene, in turn could be arrived at (1) via catalytic alkylation of benzene with ethylene, or (2) from benzene, a natural constituent o f crude oil, and ethanol [23]. Recent Example of Copolyesters from Biorenewables In 2010, Mialon and co workers published the first example of synthesizing poly(hydroferulic) acid from a vanillin, a monomer derived from lignin. Following functionalization of the vanillin into acetylferulic acid using acetic anhydride and base via a Perkin reaction, and redu ction, a bulk polymerization was undertaken to afford poly(hydroferulic) acid. While the first step employs acetic anhydride and sodium acetate other bases could be used. While most acetic acid derives from natural gas via carbonylation of methanol, th e necessary C1 feedstocks for this process can also be synthesized either from wood through anaerobic distillation, after first yielding methanol, or from sustainable fermentation processes. The produced acetylferulic acid was conjugated and yellow due to impurities, yet became colorless following hydrogenation and purification, prior to polymerization to afford the

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35 first reported example of poly(dihydroferulic acid), PHFA. The glass transition temperature of this polymer was found to be 73C, thus excee din g the 67C mark of PET [18]. Ferulic Acid as Biorenewable Starting Material In addition to vanillin, ferulic acid (4 hydroxy 3 methoxy cinnamic acid) is another potential sustainable phenolic monomer derived from lignin. This hydroxycinnamic acid is found covalently linked to polysaccharides by ester bonds and to the various crosslinked components in lignin [4]. Furthermore, ferulic acid (FA) is also seen in the cell walls of plants enhancing the rigidity and strength of the plant. In cereal grains, FA i s essentially found in the bran, the hard outer layer of grain of foods like corn and rice. In addition, ferulic acid is also found esterified to the glucuronoarabinoxylans in pineapple cell walls. In dicots, ferulic acid is present in high amounts in su gar beet pulp, and in the cell walls of spinach, Chinese water chestnut, pine hypocotyles, and carrot. In terms of dry weight, ferulic acid constitutes about 0.14% in barley grains, 0.66% in wheat bran, 0.8% in sugar beet pulp, 0.9% in rice endosperm cel l wall, and 3.1% in maize bran [24]. In addition, up to 2.58% of sugar cane bagasse may be harvested as crude ferulic acid [25]. Remarkably, these sources of ferulic acid are largely discarded by products of crop harvesting, and thus, have the added benef it of being non food competitive. In terms of degradation potential, ferulic acid may be broken down in bacteria by two catabolic pathways which reduce the acid to vanillin as well as 4 ethyl phenol.

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36 Figure 2 4 Catabol ic pathways for the degradation of ferulic acid [26 ]. Antioxidant properties of Ferulic acid Like many other polyphenolic compounds, ferulic acid possesses exciting antioxidant properties. It is known to act as a free radical scavenger by H atom transfe r from the phenolic OH group. As an antioxidant, ferulic acid has the ability to reduce oxidative stress, prevent DNA disease and reduces cholesterol and triglyceride levels thus preventing cardiovascular disease, and retard advancing aging [27]. These p olyphenols are known to act as free radical scavengers according to one o f the following two mechanisms: (1) (2) Electron transfer (ET): ArOH + R Synthesis of Aromatic Polyesters from Ferulic Acid Formation of reactive A B monomers: Acetylferulic Acid and Acetyldihydroferulic acid. A cetylferulic acid was obtained through the use of acetic anhydride and base, after then being poured over ice/water slurry. Facile hydrogenation of the alkene bond occurred by reaction of H2 over palladium on 10% charcoal. Subsequent recrystallization wit h 5:1 ethyl acetate: water produced a white

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37 powder in 78% yield. In addition, we discovered that arriving at acetyldihydroferulic acid could be accomplished either by acetylation as the primary step and reduction as the secondary step, or vice versa. How ever, if reduction of ferulic acid was carried out first, the necessary reaction time increased from 5 hrs to 12 hrs. Figure 2 5 Acetylferulic acid and acetyldi hydroferulic acid Greening of the monomer synthesis proc ess. The acetylation of ferulic acid was accomplished by altering previously reported lignin derived vanillin, through a Perkin reaction by employing 2.8 molar equi valents of acetic anhydride and 3.6 equivalents of pyridine, to successfully create a carbon carbon double bond as well as an acetylation at the hydroxyl functionality of the aromatic ring [28]. We were able to successfully produce acetylferulic acid, in 98% yield, by only using a 1:1:1 ratio of ferulic acid: acetic anhydride: pyridine, thus reducing the original ratio of 2.8: 3.6 equivalents of these respective reactants. We arrived at the product in quantitative yield after a shorter reaction time as we ll: <10 minutes of stirring time compared to 3 hours. We also discovered the sodium acetate as well as sodium hydroxide favorably produces acetylferulic acid, as well. Calculations of the E factor for the monomer synthesis process reveal that previous wo rk yielded a ratio of total waste to product was in excess of 30. Our process with less acetic anhydride and pyridine and no need for workup with water yielded a n E factor of approximately 8.5

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38 Figure 2 6 Synthesis of acetylferulic acid and acetyldihydroferulic acid Figure 2 7 Polymerization of acetyldihydroferulic acid to form PHFA Table 2 1 E Factor calc ulations for acetylferulic aci d Waste componentent s, and Yield Researchers Waste components (g) Product yield (g) E factor Mailon, Pemba, Miller. 350g DI water, Ac2O, Pyridine 11.43 30.62 Suda, Bradic, Miller 500g DI water, Ac2O, pyridine 58.72 8.51 Polymer synthesis. For all polymerizatio ns, the catalyst used was zinc acetate, a common catalyst for producing polyesters, and the reaction was run under nitrogen for 2 hours and vacuum was subsequently applied for 6 hours, with the liberation of acetic acid. These polymerizations were

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39 run at temperatures ranging from 220 degrees to 280 degrees Celsius. Initially, we employed an oil bath for the heating source. This procedure was altered due to the fact high temperatures could not be successfully and safely maintained with the oil bath, which had a flash point nearly coinciding with the reaction temperature. We also noticed that the glass transition temperatures of these copolymers appeared to lack a noticeable trend, thus leading us to hypothesize inadequate melting and stirring prevented ch ain ends from successfully reacting. Following these unsuccessful attempts at polymerization via oil bath heating, we tried a heating mantle allowed temperatur es ranging from 260 to 280 to be obtained as well as created the opportunity for adequate mixing to occur, as well as resulted in an increased glass transition temperature trend as the feed of acetylferulic acid monomer increased. Unfortunately, despite th e upward trend of Tg values versus increased addition of acetylferulic acid using the heating mantle, our molecular weight data suggested that the materials synthesized were oligomers with molecular weight in the 2 5K g/mol range. To address this issue o well as used a larger stir bar and stronger magnetic stir plate. The closed heating mantle proved to be a more facile way of controlling the heat of the system, while the large r stir bar and the stronger magnetic stir plate afforded more uniform stirring during the polymerization process. Our efforts proved fruitful in obtaining a 50:50 copolymer with a molecular weight (Mw, according to DOSY method) of 13,500 using this closed heating system (see Chapter 3).

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40 Table 2 2. Copolymerization thermal data em ploying hot plate and oil bath a Entry (Hot Pl ate) Lab Notebook Reference b %A %B Tg/C 1.1 ES 1 45 0 100 73 1.2 ES 1 57 10 90 50 1.3 ES 1 58 20 80 67 1.4 ES 1 66 30 70 67 1.5 ES 1 68 40 60 106 1.6 ES 1 70 60 40 56 1.7 ES 1 71 100 0 50 Table 2 3. Copolym erization thermal data with a 1 En try Lab Notebook Reference b %A %B Tg/C T50%/C 1.1 ES 1 45 0 100 7 3 422 2.3 ES 1 122 10 90 73 422 2.3 ES 1 163 20 80 70 419 2.4 ES 1 177 30 70 86 422 2.5 ES 1 167 40 60 87 404 2.6 ES 1 116 50 50 95 417 2.7 ES 1 119 60 40 115 440 2.8 ES 1 183 70 30 123 435 2.9 ES 1 179 80 20 125 433 2.10 ES 1 184 90 10 140 435 2.11 ES 1 137 100 0 155 467 a Polymerization conditions: Tp/C = 220, Catalyst (1 mol%) = Zn(OAc)2, a1 Tp/C = 220 (entry 1), Tp/C = 260 280, Nitrogen melt time = 2 hours, Vacuum time = 6 hours, Time of stirring = 30 min, b Notebook abbreviations: Initials lab notebook number page number A= acetylferulic acid, B= acetyldihydroferulic acid

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41 Conclusions Several examples of biorenewable polymers have recently been established in other research groups. None of these polymers p ossess thermal properties mimicking PET and are derived from a non food sustainable source. We synthesized PHFA from ferulic acid, a monomer derived from rice bran, corn stover, or sugar cane, which also has antioxidant potential; it was shown to exhibit a glass transition temperature exceeding that of PET. In addition, we altered the monomer synthesis to increase the sustainability of our process and decreased the E factor of the initial step from ~30 to 8.5.

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42 CHAPTER 3 COPOLYESTERS OF ACETYLFERULIC ACI D AND ACETYLDIHYDROFERULIC ACID Copolymers: An Introduction Two or more monomers covalently bonded to create a high molecular weight species describes a copolymer, as opposed to a homopolymer where only one monomer is used. Copolymers may be classified a s either: alternating copolymers (monomers appear in an alternating fashion), statistical copolymers, block copolymers, or graft copolymers. Statistical copolymers consist of monomeric units randomly distributed along the polymer backbone. Based on the Fo x equation, by combining the two repeat units into one structure, the Tg of the resulting copolymer will fall between the two extremes of the homopolymers. Specifically, by adding varying amounts of a second monomer to our polymer will modify the glass t ra nsition temperature. Synthesis of Copolyesters Technically, some polyester monomers such as ethylene terephthalate themselves may be considered copolymers, since the two monomers, diacid and glycol become incorporated into the synthesis. In this project, we sought to copolymerize acetylferulic acid and acetyldihydroferulic acid in various feed ratios. As the amount of acetylferulic acid increased, so do the glass transition temperatures. This increase may be explained by the fact the amount of sp2 hybri dized carbons increased with the introduction of greater amounts of acetylferulic acid. These sp2 hydridized carbons create less segmental motion along the carbon backbone. Concurrent with this rigidity increase, the temperature at which the material be comes rubber like also increases.

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43 Figure 3 1. Copolymerization of acetylferuli c and acetyldihydroferulic acid NMR Study and Type of Copolymer Determination Proton NMR spectra were obtained for the copolymers with 1,1,2,2 t etrachloroethane as the solvent. Characteristic methoxy, aromatic, and sp2 and sp3 peaks provide crucial information about the structure of the polymers. Determination of Incorporation Ratio Looking at the characteristic sp3 region, we can see an integr ation of 4 protons for the homopolymer of PHFA. Likewise, the homopolymer of acetylferulic acid shows no peak in this same area, as the carbon spacers along the polymer backbone are now entirely sp2 hybridized. Measuring the relative intensities of the p eaks corresponding to the copolymers with the various feed ratios provides a good approximation of the incor poration ratio of each monomer.

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44 Table 3 1. Incorporation of acetylferulic: acetyldihyd roferulic acid Entry Feed Rati o of A Feed Ratio of B % Incorp of B Tg (C) 1 0 100 100 73 2 10 90 87 73 3 20 80 75 70 4 30 70 81 86 5 40 60 67 87 6 50 50 56 95 7 60 40 47 115 8 70 30 18 123 9 80 20 19 125 10 90 10 9 140 11 100 0 0 155 Polymerization conditions: Tp/C = 220 (entry 1), Tp/C = 260 280, Catalyst (1 mol%) = Zn(OAc) 2 Nitrogen melt time = 2 hours, Vacuum time = 6 hours, Time of stirring = 90 120 min A= acetylferulic acid, B= acetyl dihy droferulic acid Molecular Weight Determination Normally, our polymers would be subjected to gas permeation chromatography (GPC) in order to obtain molecular weight data. However, our polymers were insoluble in tetrahydrofuran (THF), the necessary GP C solvent. To meet this solubility challenge, we utilized deuterated hexafluoroisopropanol and employed the NMR technique of Diffusion Ordered Spectroscopy (DOSY) to determine the molecular weight of our polymers. The basic premise of DOSY is that the mo lecular weight of a polymer is directly related to its diffusion coefficient. The coefficients in turn, are determined by using a polymer standard of known molecular weight. For our copolyesters we used PET as our standard. The results of our initial tes ting of our polymers proved rather disappointing as our Mw molecular weights fell in the 2,000 5,000 g/mol. These values suggest that something was

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45 preventing our polymerization from going to completion and instead of high molecular weight material, say s omething in excess of 10k, we essentially made oligomers. While this data reflects the inherent difficulties in carrying out stepwise condensation reactions, whereby nearly 100% conversion is necessary to create high weight materials, we also hypothesize d that we could perhaps increase these numbers by looking into our heating ell as a larger stir bar, allowed for more uniform heating of the system as well as longer stir time. The increased time in the melt allows for more chain ends to react and thus increase the degree of polymerization. To compare our experimental glass tran sition results to those values expected based on the Fox equation, we performed a statistical chi squared test (Excel). Based on a p value of greater than or equal to 0.05, we conclude that 6 out of the 11 samples showed no significant difference in the e xperimental Tg values compared to those calculated values. Table 3 2. Molecular Weight (Mw) of PET Mw (g/mol) D x 1012 (m2/s) 3400 0.70 9870 0.40 3 7000 0.27 51400 0.15 Table 3 3. Molecular Weights of Copolymer apparatus a Entry Reference b Feed ratio of A Feed ratio of B % Incorp B Mw 2 .4 ES 1 177 30 70 81 5400 2.5 ES 1 167 40 60 67 2800 2.7 ES 1 119 60 40 47 3200 2.8 ES 1 183 70 30 18 3400

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46 Table 3 4. Molecular Weights of Copolymers u apparatus a 1 Entry Reference b Feed ratio of A Feed ratio of B Mw 3.1 ES 3 33 0 100 6,100 3.2 ES 3 35 10 90 7,100 3.3 ES 3 5 50 50 13,000 3.4 ES 3 31 100 0 3,300 Table 3 5 Observed vs. Expected Glass Transition Temperatures and Chi Squared Values Entry Feed ra tioA:B Tg Experimental Tg Calculated* 2 p value 1 0:100 155 155 1.00 2 10:90 140 141 0.32 3 20:80 125 117 0.01 4 30:70 123 129 0 .005 5 40:60 115 101 < 0.001 6 50:50 95 95 1.00 7 60:40 87 88 0.32 8 70:30 86 81 0.03 9 80:20 70 84 0.002 10 90:10 73 77 0.05 11 100:0 73 73 1.00 *Calculated values based on Fox equation and incorporation values. a Polymerization conditions: Tp/C = 260 280, a1 Tp/C = 220, Catalyst (1 mol%) = Zn(OAc ) 2 Nitrogen melt time = 2 hours, Vacuum time = 6 hours, Time of stirring = 90 120 min.b Notebook abbreviations: Initials lab notebook number page number,A= acetylferulic acid, B= acetyldihydroferulic acid Conclusions A series of copolymers was created by varying the feed ratios of each monomer: acetyldihydroferulic acid and acetylferulic acid. Proton NMR Analysis of the polymers display that the incorporation ratios parallel the feed ratios of the polymers. DOSY NMR analysis provides evidence that th

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47 uniform heating of the polymerization and creates more opportunity for the chain ends to successfully react and produce relatively high molecular weight material. Following the trend of dec reasing the segmental motion of the polymer backbone leads to increase in glass transition temperature, an increase in the Tg of the copolymers is displayed as the percentage of acetylferulic acid monomer increases.

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48 CHAPTER 4 COPOLYMERS F ROM HOMOVANILLIC ACID AND ACETYLFERULIC ACID Homovanillic Acid: an Amino Acid Derived Metabolite Homovanillic acid (HVA) is a major catecholamine metabolite which in humans, can be measured in the CSF, blood, and urine. Biological synthesis of HVA comme nces with the amino acid tyrosine, which is converted to dihydroxyphenylalanine (DOPA) by tyrosine hydroxylase. DOPA is then converted into dopamine (DA) by DOPA decarboxylase; after several steps this dopam ine gets converted to HVA [28]. Figure 4 1 Structures of Tyrosine, Dopamine, and Homovanillic acid. Figure 4 2 Simpl ified sequence of HVA synthesis

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49 Synthesis of Monomers Homovanillic acid was obtained from Matrix Scientific and us ed as received. The acetylation of the HVA was performed in the same manner as for acetylferulic acid: via acetic anhydride and pyridine. Synthesis of Copolymers We were interested in investigating the effect of incorporating the HVA monomer into our seri es of copolyesters. The HVA monomer has one less methylene spacer unit along the carbon backbone, and we hypothesized, would thus provide a more rigid environment and a subsequent higher Tg value. As demonstrated from the first five copolymerizations in Table 4.1, the glass transition temperature actually decreases as the fraction of homovanillic acid increases. This suggests that the reduction of methylene spacer units in the monomer backbone has a smaller effect on the rigidness of the polymer structur e as compared to the occurrence of sp2 hybridized carbons. The homopolymer of HVA yields a glass transition temperature of 77 C While this temperature falls well below the 155C mark we achieved with the acetylferulic acid homopolymer, it still exceeds the glass transition temperature of PET, and thus, fulfills one of our initial goals of creating a mimic to this material with superior thermal transitions. To further investigate the thermal properties of copolymers containing homovanillic acid, we conduc ted a smaller substudy of acetylated homovanillic acid and acetyldihydroferulic acid. These two monomers, with three sp3 carbons between them in their aliphatic regions, displayed no clear trend in glass transition temperature values. In addition, the 20 :80 feed ratio of acetylated HVA: acetyldihydroferulic acid yielded a copolymer with a Tg of 59 C which unfortunately fell below the baseline value of 73 C needed to surpass PET and since the homopolymer of HVA only saw an increase in glass transition by 4C we chose not to pursue this synthetic route as the high price of homovanillic acid was a limiting factor. Interestingly,

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50 however, the homovanillic acid homopolymer showed a 50% decomposition temperature in excess of 600C which stands as a rarity amon g biobased polymers. Table 4 1 Thermal properties of HVA: Acetylferulic acid copolymers a Entry Reference b Feed % A Feed % B T g (C) T 50% (C) 2.11 ES 1 137 0 100 155 467 4.2 ES 2 37 10 90 120 468 4.3 ES 2 35 20 80 120 479 4.4 ES 2 39 30 70 136 432 4.5 ES 2 41 40 60 123 435 4.6 ES 2 49 50 50 102 401 4.7 ES 2 31 60 40 81 438 4.8 ES 2 35 100 0 77 >600 Table 4 2. Thermal Properties of HVA: Acetyldihydroferulic acid copolymers a Entry Reference b Feed % of A Feed % of B T g (C) T 50% (C) 1.1 ES 1 45 0 100 73 422 5.2 ES 2 55 10 90 67 410 5.3 ES 2 57 20 80 59 334 5.4 ES 2 25 100 0 77 >600 a Polymerization conditions: Tp/C = 220 (entry 1), Tp/C = 2 60 280, Catalyst (1 mol%) = Zn( Ac) 2 Nitrogen melt time = 2 ho urs, Vacuum time = 6 hours, Time of stirring = 90 120 min b Notebook abbreviations: Initials lab notebook number page number A= acetyldihydroferulic a cid, B= acetylhomovanillic acid Conclusions Copolymers consisting of acetylated homovanillic acid and e ither acetylferulic or acetyldihydroferulic acid were synthesized and their thermal properties studied. Homovanillic acid was chosen as a potential monomer because it contains one methylene spacer unit whereas acetyldihydroferulic acid contains two such s pacers. While the Tg of these copolymers with one less methylene unit did not exceed the Tgs of the copolymers consisting mostly of acetylferulic acid, the values were high enough to rival PET. Further work needs to be done in order to synthesize this na tural metabolite from non petroleum sources and at a competitive price point.

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51 C HAPTER 5 COPOLYMERS FROM VANILLIC ACID AND HYDROXYBENZOIC ACID WITH FERULIC ACID Vanillic acid (4 hydroxy 3 methoxybenzoic acid) is an oxidized form of vanillin and is mainly employed as a flavoring agent. Derived from plant sources such as Angelic sinensis (female ginseng), a plant used in traditional Chinese medicine and lignin vanil lic acid offers a possible biomass based monomer with which to copolymerize with our acetylf erulic acid. The lack of methylene spacer units along the polymer back bone suggests that a high glass transition temperature could be obtained. Figure 5 1. Acetylvanillic acid In addition to the attractive notion of its green birth, vanillic acid has also demonstrated effectiveness in the management of immune or inflammatory responses. Likewise, VA also displays a hepatoprotective effect; that is, it suppresses the action on immune mediated liver inflammation. Recently VA has also shown to reduce the severity of symptoms caused b y ulcerative colitis [29] We investigated the ther mal properties of copolymers from vanillic acid and ferulic acid. Interestingly, all samples showed a n initial transition in the range of 31 to 46C. We suspect that this transition correlates with the presence of oligomeric materials in the sample. Once a 50:50 ratio is obtained, however, glass transition temperatures of 140C and above are seen. These high values are most likely attributed to the removal of the sp 3 methylene spacer which was employed in the HVA copolymer series, followed by the replacement with an sp 2 carbonyl carbon in the vanillic acid component. Obtaining higher molecular weights as well as reducing the oligomer content in these samples would most likely show a favorable glass transition trend.

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52 Table 5 1. Acetylvanillic acid and acetylferulic acid copolymer ization thermal data a Entry Lab Notebook Feed Ratio of A Feed Ratio of B T g /C T50%/C Reference b ( acetylvanillic acid) (acetylferulic acid) 6.1 ES 2 111 90 10 32 408 6.2 ES 2 159 70 30 40 430 6.3 ES 2 145 50 50 46,140 438 6.4 ES 2 117 30 70 46,148 416 6.5 ES 2 109 10 90 45,157 431 2.11 ES 1 137 0 100 155 467 aPolymerization conditions: T p /C = 260 280, Catalyst (1 mol%) = Zn(OAc) 2 Nitrogen melt time = 2 hours, Vacuum time = 6 hours, Time of stirring = 90 120 min b Notebook abbreviations: Initials la b notebook number page number Hydroxybenz oic acid (HA) is naturally occurring in the Cocos nucifera (coconut) plant, as well as in acai oil, which in turn, is obtained f rom the fruit of the acai palm [30] Copolymers of acetylbenzoic acid and acetylferulic acid also display the dual glass transit ions in their respective thermograms similar to the vanillic acid copolymers. As expected, the second glass transition temperatures are lower than those seen with the vanillic acid. This is due to the fact the acetoxybenzoic acid copolymers lack the metho xy group on the aromatic unit, and thus allow for more conformational degrees of freedom. The secondary T g s of both the benzoic acid copolymers as well as the vanillic acid copolymers exceed their ferulic acid analogues, further supporting the idea that t he chemical structure of the aliphatic portion largely governs the ability to create a macromolecule with high thermal properties. Figure 5 2 4 acetoxy benzoic acid

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53 Table 5 2 : Copolymerization data of acetoxybenzoic (A) a nd acetylferulic acid (B) a Entr y Lab Notebook Feed Ratio of A Feed Ratio of B Tg (C) T 50% (C) 7.1 ES 2 125 60 40 112 425 7.2 ES 2 127 40 60 133 447 7.3 ES 2 139 10 90 155 442 2 .11 ES 1 137 0 100 155 467 a Polymerization conditions: T p /C = 260 280, Catalyst (1 mol%) = Zn(OAc) 2 Nitrogen melt time = 2 hours, Vacuum time = 6 hours, Time of stirring = 90 120 min b Notebook abbreviations: Initials lab notebook n umber page number

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54 CHAPTER 6 CONCLUSIONS Synthesizing copolymers based on ferulic acid and its derivatives proves an exciting avenue for biomass derived products. Naturally abundant and non food competitive, ferulic acid h olds the potential for being developed into an economically competitive basis for commodity plastic mimics such as PET and PS. In addition, ferulic acid displays extremely attractive qualities as a free radical scavenger and degradation by enzymatic actio n. Using ferulic acid as a starting point and branching out our investigation to include vanillic acid, homovanillic acid, as well as hydroxybenzoic acid, we created a library of homopolymers and copolymers and characterized their thermal properties. Obse rving the glass transition temperature trends of these copolymers, we demonstrated the tunable ability of these products. Namely, these copolymers produced desired T g values as a result of our manipulation of the methylene spacer unit numbers or the relat ive amount of sp 2 versus sp 3 carbons in the backbone, as well as including a methoxy substituent on the aromatic component. While creating biomass derived materials with desirable thermal properties was our original goal for this project, our journey is no t complete. Increasing the molecular weights of the polymers, studying their mechanical properties, as well as conducting a thorough investigation of their degradation pathways remain as crucial areas which still require exploration and analysis. Obtaini ng glass transition temperatures that meet and exceed those of commodity plastics stands as a crucial goal if, as a society, we are to reduce our dependence of foreign oil as well as diminish our carbon footprint for future generations.

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55 CHAP TER 7 EXPERIMENTAL PROCEDURES Molecular characterization s Proton nuclear magnetic resonance (1H NMR) spectra were recorded using an Inova 500 MHz spectrometer. Chemical shift is reported in parts per million (ppm) downfield relative to tetramethylsilane (TMS, 0.0 ppm) or specified solvent. Solvents used were either dimethylsulfoxide (DMSO) or 1,1,2,2, tetrachloroethane. Coupling constants (J) are reported in Hertz (Hz). Multiplicities are reported using the following abbreviations: s, singlet; d, double t; t, triplet; m, multiplet; br, broad. Thermogravimetric analyses were obtained with a TGA Q5000 from TA instruments. Approximately 2 4 mg of sample was massed on a titanium pan and subsequently heated at a rate of 10 degrees Celsius per minute from room temperature to 650 degrees Celsius. Differential scanning calorimetry was obtained with a DSC Q1000 from TA instruments. Approximately 2 5 mg of sample was massed in a sealed pan and cycled through heating and cooling and heating once again at a temperat ure increase rate of 10 degrees Celsius per min. Temperatures for the DSC experiments ranged from approximately 220 degrees Celsius to just under 300 degrees Celsius. Polymerization procedures Initial polymerizations were carried out in a round closed 100 mL bottom flask connected to a Schlenk line with a bump trap. Secondary trials of polymerizations were done in a 250 mL round bottom flask. The flask was loaded with both the monomer(s) and catalyst and was purged with nitrogen and melted while stirring using a heating mantle. The temperature ranged from 220 to 290 degrees Celsius and was regulated with a variac transformer. The melt was kept under nitrogen to allow the formation of oligomers and to limit sublimation. Dynamic vacuum was then applied for at least 6 hours on the molten polymer, driving off acetic acid. Following this application of vacuum, the solid product was cooled, and then dissolved in a 1:1 mixture of trifluoroacetic acid and dichloromethane and then crashed in cold methanol. The polymer was finally obtained and dried on the Schlenk line for several hours.

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56 Molecular weight determination : Diffusion Coefficient Spectroscopy (DOSY) All polymer samples were dissolved in deuterated hexafluoroisopropanol. Diffusion coefficients were me asured by bipolar pulse pair stimulated echo with convection compensation by 2D DOSY NMR technique, in proton spectra. Polyethylene terephthalate (PET) standards were measured first to determine the constants for the DOSY equation. Calculating diffusion c oefficients was determined by applying the following equation: D = kM v Where D is the self diffusion coefficient, M = weight average molecular weight of the polymer ( M w ), and k and v are diffusion constants. Taking the logarithm of the above equation af fords: log(D) = ( v)log(M) + log(k) which provides a linear relationship and allows for the plotting of data to obtain values for constants v and k. Table 7 1. DOSY Results for PET Mw (g/mol) D a x 10 12 (m 2 /s ) 3470 0.70 9870 0.40 37700 0.27 51400 0.15 a H DOSY measurements were performed at 25C in 1,1,1,3,3,3 hexafluoro 2 propanol d 2 (HFiP d 2 ) Figure 7 1 PET calibration curve in HFiP d 2 for M w prediction.

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57 Equation: y = 0.5003x + 1.6176 R = 0.924 From this linear plot, the consta nts v and k were determined to be 0.5003 and k=1.6176, respectively. Table 7 2. DOSY Calculated re sults for c opolymers of f erulic acid based monomers Entry Acetylferulic acid Acetyldihydroferulic acid D x 10 12 m 2 /s M w (g/mol) 1 0 100 0.61 47 50 2 30 70 0.57 5400 3 40 60 0.80 2800 4 60 40 0.75 3200 5 70 30 0.7 2 3400 6 0 100 0.54 6100 7 50 50 0.36 13500 8 100 0 0.73 3300 a Entries 1 b Entr ies 6 Synthesis Procedures Acetylferulic acid (4 o acetylferulic acid). Ten (10) grams of ferulic acid ((E) 3 (4 hydroxy 3 methoxy phenyl)prop 2 enoic acid) was dissolved in 14.7 mL of acetic anhydrid e and 15 mL of pyridine at room temperature and stirred for three hours. The resulting clear liquid was poured over 300 mL of an ice/deionized water slurry. After one hour, the ice/water mixture was filtered by gravity filtration and washed with deionize d water and dried by rotovap. The resulting white powder (4 o acetylferulic acid) was obtained in 94% yield. 1 H NMR ( 500 MHz, DMSO d 6 ): = 12.35 (br. s, 1H), 7.56 (d, 1H), 7.46 (d, 1H), 7.24 (d, 1H), 7.09 (d, 1H), 6.56 (d, 1H), 3.8 (s, 3H), 2.24 (s, 3H) 13 C NMR (500 MHz, DMSO d 6 ): = 168.4, 167.6, 151.1, 143.4, 140.8, 138.3, 123.2, 121.3, 119.5, 111.8, 56.0, 20.4. Acetyldihydroferulic acid (4 o acetyldihydroferulic acid) Fifteen grams of acetyldihydroferulic acid was dissolved in 150 mL of tetrahydrofur an and 80 mL of methanol in a Parr pressure reactor with 1.5 grams of 10% palladium over charcoal. The reaction was stirred

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58 at 30 degrees Celsius under 60 psi of hydrogen for five hours. To remove the palladium, the resulting black solution was vacuum fi ltered through celite, dried over magnesium sulfate and condensed in vacuo The solid was then dissolved in a minimum amount of warm THF and crashed with ice cold hexanes. The resulting yield was 62%. 1 H NMR (500MHz, DMSO d 6 ): = 12.15 (br. s, 1H), 6.98 (s, 1H), 6.93 (d, 1H), 6.76 (d, 1H), 3.72 (s, 3H), 2.79 (t, 2H), 2.53 (t, 2H), 2.20 (s, 3H). 13 C NMR (DMSO, 500 MHz): = 174.1, 168.9, 150.8, 140.1, 137.8, 122.7, 120.3, 113.1, 55.9, 35.5, 30.5, 20.7. Acetylhomovanillic acid (4 o acetylhomovanillic acid) Five grams of homovanillic acid (3 methoxy 4 hydroxyphenyl acetic acid) was stirred with 7.85g acetic anhydride and 8.01 mL of pyridine at room temperature for 3 hours. The resulting mixture was then poured over an ice/water slurry. A yellowing/orange gel resulted which then crashed out to a white precipitate after being placed in the freezer for 3 days. Additional cold methanol was added dropwise to the white ppt and the resulting product was then vacuum dried over night wi th a 64% yield. 1 H NMR (500MHz, DMSO d 6 ) = 12.41 12.29 (m, 1 H), 7.03 (br. s., 2 H), 6.85 6.80 (m, 1 H), 3.75 (br. s., 3 H), 3.57 (br. s., 2 H), 2.28 2.19 (m, 3 H) 13 C NMR (500 MHz DMSO d 6 ) = 173.0, 169.0, 150.8 138.4, 138.2, 134.3, 122.9, 121.9 114.5, 56.2, 20.9 Acetylvanillic acid (4 o acetylvanillic acid). Ten grams of vanillic acid (4 hydroxy 3 methoxy benzoic acid) was stirred with 6.07 g of acetic anhydride with 5.3g of pyridine at room temperature for 3 hours. The resulting mixture was then poured over an ice/water slurry which was subsequently gravity filtered and dried to obtain a light brown/tan colored product in 54% yield.

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59 1 H NMR (500MHz, DMSO d 6 ) = 13.21 (br. s., 1 H), 8.19 (d, 2 H), 7.46 (d, 2 H), 7.21 (s, 1H) 3.86 (s, 3H) 2.27 (s, 3 H) 13 C NMR (500MHz DMSO d 6 ) = 168.6, 167.0, 151.2, 143.3, 129.9, 123.4, 122.5, 113.5, 56.3, 20.8 Acetoxy benzoic acid (4 o acetoxy benzoic acid) Ten grams of 4 hydroxybenzoic acid was stirred with 7.395g of acetic anyhydride with 5.7g of pyridine at room temperature for 3 hours. The resulting mixture was then poured over an ice/water slurry which was subsequently gravity filtered and dried to obtain an off white colored product in 58% yield. 1 H NMR (500MHz, DMSO d 6 ) = 12.96 (br. s., 1 H), 8.08 (d, 2 H), 7.96 (d, 2H), 7.21, (s, 1H) 2.27 (s, 3 H) 13 C NMR (500MHz DMSO d 6 ) = 168.6, 167.0, 151.2 129.9, 123.4, 122.5, 113.5, 56.3, 20.8 Polymer 1.1. PHFA (ES 1 45) Poly(3 (4 hydroxy 3 methoxyphenyl)propanoic acid (pol y(dihydroferulic acid), PHFA 1.63 g (6.8 mmol) of acetyldihydroferulic acid and 0.018 g (0.082 mmol) of zinc acetate dehydrate catalyst (1 mol %) were melted under nitrogen for 2h at 220C while stirring. Vacuum was then applied for 6h, leaving a brown so lid. This solid was dissolved in a 1:1 mixture of trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and resulted in a 1.02 grams of PHFA, corresponding to an 87% Yield. 1 H NMR (500MHz ,1,1,2,2 tetrachloroethane) = 6.98 6.74 (m, 3 H), 3.76 (br. s., 3 H), 3.11 2.85 (m, 4 H) 13 C NMR (126MHz ,tetrachloroethane) = 170.7, 148.8, 137.9, 122.8, 120.3, 115.8, 110.6, 53 6, 35.6, 33.0

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60 Copolymer 2.2 (ES 1 123) (10:90 acetylferulic: acetyldihydroferulic acid). 0.162 g of acetylferulic acid and 1.446 g of acetyldihydroferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were melted under nitrogen for 2h at 2 20C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of trifluoroacetic acid/dichloromethane. After dissolving the solid completely, ice cold methanol was added and a product precipitated out. This product was isolated by filtration and resulted in 0.462 grams corresponding to a 47% yield. Copolymer 2.3 (ES 1 163) (20:80 acetylferulic: acetyldihydroferulic acid). 0.33 g of acetylferulic acid and 1. 291 g of acetyldihydroferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 26 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of trifluoroacetic acid/dichloromethane. After dissolving the solid completely, ice cold methanol was added and a product precipitated out. This product was isolated by filtration and resulted in 0.38 grams, corresponding to a 46 % yield. Copolymer 2.4 (ES 1 177) (30:70 acetylferulic: acetyldihydroferulic acid). 0.489 g of acetylferulic acid and 1. 1465 g of acetyldihydroferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 26 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was di ssolved in a 1:1 mixture of trifluoroacetic acid/dichloromethane. After dissolving the solid completely, ice cold methanol was added and a product precipitated out. This product was isolated by filtration Copolymer 2.5 (ES 1 167) (40:60 acetylferulic: acetyldihydroferulic acid). 0. 655 g of acetylferulic acid and 0.971 g of acet yldihydroferulic acid and 0.024 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 26 0C while stirring. Vacuum was then

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61 applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of trifluoroacetic acid/dichloromethane. After dissolving the solid completely, ice cold methanol was added and a product precipitated out. This product was isolated by filtration and resulted in 0.495 g rams, corresponding to a 78 % yield. Copolymer 2.6 (ES 1 116) (50:50 acetylferulic: acetyldihydroferulic acid). 0.812 g of acetylferulic acid and 0.818 g of acetyldihydroferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were melted under nitrogen for 2h at 260C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of trifluoroacetic acid/dichloromethane. After dissolving the solid completely, ice cold methanol was added and a produc t precipitated out. This product was isolated by filtration. Copolymer 2.7 (ES 1 119) (60:40 acetylferulic: acetyldihydroferulic acid). 0.964 g of acetylferulic acid and 0.648 g of acetyldihydroferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were melted under nitrogen for 2h at 260C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of trifluoroacetic acid/dichloromethane. After dissolving the solid completely, ice cold meth anol was added and a product precipitated out. This produ ct was isolated by filtration. Copolymer 2.8 (ES 1 183) (70:30 acetylferulic: acetyldihydroferulic acid). 1.122 g of acetylferulic acid and 0.486 g of acetyldihydroferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were melted under nitrogen for 2h at 260C while stirring. Vacuum was then applied for 7.5 h, leaving a solid. This solid was dissolved in a 1:1 mixture of trifluoroacetic acid/dichloromethane. After dissolving the s olid completely, ice cold methanol was added and a product precipitated out. This prod uct was isolated by filtration.

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62 Copolymer 2.9 (ES 1 179) (80:20 acetylferulic: acetyldihydroferulic acid). 1.3 g of acetylferulic acid and 0.34 g of acetyldihydroferulic acid and 0.0 213 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 26 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of trifluoroacetic acid/dichloromethane. After dissolving the solid completely, ice cold methanol was added and a product precipitated out. This product was isolated by filtration Copolymer 2.10 (ES 1 184) (90:10 acetylferulic: acetyldihydroferulic acid). 1.45 g of acetylferulic acid and 0.162 g of acetyldihydroferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were melted under nitrogen for 2h at 260C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of trifluoroace tic acid/dichloromethane. After dissolving the solid completely, ice cold methanol was added and a product precipitated out. This prod uct was isolated by filtration. Polymer 2.11. Polyacetylferulic acid (ES 1 137). 1.606g (6.8 mmol) of acetylferulic acid and 0.0182 g (0.082 mmol) of zinc acetate dehydrate catalyst (1 mol%) were melted under nitrogen for 2h at 220C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid / dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and resulted in a 0.67 grams of product, corresponding to an 56% Yield. Polymer 3.1. Po lyhydroferulic acid (PHFA) (ES 3 33). 5.126g of acetylferulic acid and 0.0 62 g of zinc acetate dehydrate catalyst (1 mol%) were melted under nitrogen for 3 h at 220C while stirring o a heating mantle. Vacuum was then applied for 11 h, leaving a solid. This solid was dissolved in a 1:1

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63 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product prec ipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 3.2 (ES 3 35) (10:90) (acetylferulic: acetyldihydroferulic acid). 4.655g of acetylferulic acid and 0.552 g of acetyldihydroferulic acid and 0. 058 g of zinc acetate dehy drate catalyst (1 mol%) were mel ted under nitrogen for 3 h at 220C while stirring. Vacuum was then applied for 8 h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid co mpletely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 3.3 (ES 3 5) (50:50) (acetylferulic: acetyldihydroferulic acid). 2.507 g of acetylferulic acid and 2.603 g of acetyldihydroferulic acid and 0. 059 g of zinc acetate dehydrate catalyst (1 mol%) were mel ted under nitrogen for 3 h at 220C while stirring. Vacuum was then applied for 11 h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluo r o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 3.4 (ES 3 31) (100:0) (acetylferulic: acetyld ihydroferulic acid) ~4.5 of acetylferulic acid and 0. 058 g of zinc acetate dehydrate catalyst (1 mol%) were mel ted under nitrogen for 3 h at 220C while stirring using a magnetic stirrer Vacuum was then applied for 6 h, leaving a solid. This solid was di ssolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried

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64 Copolymer 4. 2 (ES 2 37) (10:90) (acetylhomovanillic: acetylferulic acid). 0.152 g of acetylhomovanillic acid and 1.46 g of acetylferulic acid and 0. 028 g of zinc acetate dehydrate catalyst (1 mol%) were mel ted under nitrogen for 2 h at 220C while stirring. Vacuum wa s then applied for 6 h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 4.3 (ES 2 35) (20:80) (acetylhomovanillic: acetylferulic acid). 0.304 g of acetylhomovanillic acid and 1.280 g of acetylferulic acid and 0.019 g of zinc acetate dehydrate catalyst (1 mol%) were melte d under nitrogen for 2h at 220C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was ad ded and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 4.4 (ES 2 39) (30:70) (acetylhomovanillic: acetylferulic acid). 0. 515 g of acetylhomovanillic acid and 1. 130 g of acetylferulic acid and 0.0 22 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 20 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. Afte r dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 4.5 (ES 2 41) (40:60) (acetylhomovanillic: acetylferulic acid). 0.614 g of acetyl homovanillic acid and 0.966 g of acetylferulic acid and 0.022 4 g of zinc acetate dehydrate

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65 catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mix ture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 4.6 (ES 2 49) (50:50) (acetylhomovanillic: acetylferulic acid). 0. 7843 g of acetylhomovanillic acid and 0.934 g of acetylferulic acid and 0.021 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by f iltration and vacuum dried. Cop o lymer 4.7 (ES 2 31) (60:40) (acetylhomovanillic: acetylferulic acid). 0.922 g of acetylhomovanillic acid and 0.642 g of acetylferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 20 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white p roduct precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 4.8 (ES 2 25) (100:0) (acetylhomovanillic: acetylferulic acid). 1.526 g of acetylhomovanillic acid and 0.022 g of zinc acetate dehydrate catalyst (1 mol%) wer e me lted under nitrogen for 2h at 20 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After

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66 dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 5.2 (ES 2 55) (10:90) (acetylhomovanillic: acetyl dihydro ferulic acid). 0. 152 g of acetylhomovanillic acid and 1.46 g of acetyldihydro ferulic acid and 0.022 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluoracetic acid /dic hloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 5.3 (ES 2 57) (20:80) (acetylhomovanillic: acetyl dihydro ferulic acid). 0. 305 g of acetylhomovanillic acid and 1.295 g of acetyldihydroferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluoracetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 6.1 (ES 2 111) (90:10) (acetylvanillic: acetylferulic acid). 1.276 g of acetylhomovanillic acid and 0.16 g of acetylferulic acid and 0.0182 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluoracetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This wa s product was isolated by filtration and vacuum dried.

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67 Copolymer 6.2 (ES 2 159) (70:30) (acetylvanillic: acetylferulic acid). 1.002 g of acetyl vanillic acid and 0.492 g of acetyldihydroferulic acid and 0.024 g of zinc acetate dehydrate catalyst (1 mol%) w ere me lted under nitrogen for 2h at 22 0C while stirring Vacuum was then applied for 7 h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methan ol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 6.3 (ES 2 145) (50:50) (acetylvanillic: acetylferulic acid). 0. 724 g of acetyl vanillic acid and 0.844 g of acetylferulic acid and 0 .024 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. Af ter dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 6.4 (ES 2 117) (30:70) (acetylvanillic: acetylferulic acid). 0. 4284 g of acety l vanillic acid and 1.204 g of acetylferulic acid and 0.028 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 6.5 (ES 2 109) (40:60) (ac etylvanillic: acetylferulic acid). 0. 146 g of acetyl vanillic acid and 0.1453 g of acetylferulic acid and 0.023 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leavin g a solid. This solid was dissolved in a 1:1 mixture of boiling

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68 trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration a nd vacuum dried. Copolymer 7.1 (ES 2 125) (60:40) (acetylbenzoic: acetylferulic acid). 0.738 g of acetylbenzoic acid and 0.653 g of acetylferulic acid and 0.027 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. After dissolving the solid completely, ice cold methanol was added and a white product precipitated o ut. This was product was isolated by filtration and vacuum dried. Copolymer 7.2 (ES 2 127) (40:60) (acetylbenzoic: acetylferulic acid). 0.484 g of acetylbenzoic acid and 0.962 g of acetylferulic acid and 0.024 g of zinc acetate dehydrate catalyst (1 mol% ) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluoracetic acid /dichloromethane. After dissolving the solid completely, ice cold meth anol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried. Copolymer 7.3 (ES 2 139) (10:90) (acetylbenzoic: acetylferulic acid). 0. 128 g of acetylbenzoic acid and 1.45 g of acetylferulic acid and 0. 020 g of zinc acetate dehydrate catalyst (1 mol%) were me lted under nitrogen for 2h at 22 0C while stirring. Vacuum was then applied for 6h, leaving a solid. This solid was dissolved in a 1:1 mixture of boiling trifluor o acetic acid /dichloromethane. Aft er dissolving the solid completely, ice cold methanol was added and a white product precipitated out. This was product was isolated by filtration and vacuum dried.

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69

PAGE 70

70 APPENDIX A NUCLEAR MAGNETIC RESONANCE SPECTRA Monomer NMRs Figure A 1. 1H NMR spectra of compound 1.0 (acetylferulic acid) Figure A 2. 13C NMR spectra of compound 1.0 (acetylferulic acid)

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71 Figure A 3. 1H NMR spectra of compound 2.0 (acetyldihydroferulic acid) Figure A 4. 13C NMR spectra of compound 2. 0 (acetyldihydroferulic acid)

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72 Figure A 5. 1H NMR spectra of compound 3.0 (acetylhomovanillic acid) Figure A 6. 13C NMR spectra of compound 3.0 (acetylhomovanillic acid)

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73 Figure A 7. 1H NMR spectra of compound 4.0 (acetylvanillic acid) Figure A 8. 13C NMR spectra of compound 4.0 (acetylvanillic acid) Figure A 9. 1H NMR spectra of compound 5.0 (acetylbenzoic acid)

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74 Figure A 10. 13C NMR spectra of compound 5.0 (acetylbenzoic acid)

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75 APPENDIX B PO LYMER AND COPOLYMER NMRS Figure B 1. 1H NMR spectra of polymer 1.1 (polyhydroferulic acid) Figure B 2. 13C NMR spectra of polymer 1.1 (polyhydroferulic acid)

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76 Figure B 3. 1H NMR of compound 2.2 (10:90 acetylferulic:acetyldihydroferulic aci d) Figure B 4. 13C NMR of compound 2.2 (Not available. Polymer sample crashed out of solution.) Figure B 5. 1H NMR of compound 2.3 (20:80 acetylferulic:acetyldihydroferulic acid)

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77 Figure B 6. 13C NMR of compound 2.3 Figure B 7. 1H NMR of compound 2.4 (30:70 acetylferulic: acetyldihydroferulic acid) Figure B 8. 13C NMR of compound 2.4 (Not available. Polymer sample crashed out of solution.)

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78 Figure B 9. 1H NMR of compound 2.5 (40:60 acetylferulic: acetyldihydroferulic acid) Figure B 10. 13C NMR of compound 2.5 (40:60 acetylferulic: acetyldihydroferulic acid)

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79 Figure B 11. 1H NMR of compound 2.6 (50:50 acetylferulic: acetyldihydroferulic acid) Figure B 12. 13C NMR of compound 2.6 (50:50 acetylferulic: acetyldihydroferulic a cid) Figure B 13. 1H NMR of compound 2.7 (60:40 acetylferulic: acetyldihydroferulic acid)

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80 Figure B 14. 13C NMR of compound 2.7 (Not available. Polymer sample crashed out of solution.) Figure B 15. 1H NMR of compound 2.8 (70:30 acetylferulic: ac etyldihydroferulic acid) Figure B 16. 13C NMR of compound 2.8 (Not available. Polymer sample crashed out of solution.) Figure B 17. 1H NMR of compound 2.9 (80:20 acetylferulic: acetyldihydroferulic acid)

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81 Figure B 18. 13C NMR of compound 2.9 (80 :20 acetylferulic: acetyldihydroferulic acid) Figure B 19. 1H NMR of compound 2.10 (90:10 acetylferulic: acetyldihydroferulic acid) Figure B 20. 13C NMR of compound 2.10 (Not available. Polymer sample crashed out of solution.)

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82 Figure B 21. 1H N MR of compound 2.11 (100:0 acetylferulic:acetyldihydroferulic acid) Figure B 22. 13C NMR of compound 2.11 (Not available. Polymer sample crashed out of solution). Figure B 23. 1H NMR of compound 3.1 (ES 3 33) (PHFA) Figure B 24. 13C NMR of compound 3. 1 (ES 3 33) (PHFA) (Not available. Polymer sample crashed out of solution).

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83 Figure B 25. 1H NMR of compound 3.2 (ES 3 35) (10:90 acetylferulic: acetyldihydroferulic acid) Figure B 26. 13C NMR of compound 3.2 (ES 3 35) (10:90 acetylferulic: acetyldihy droferulic acid) (Not available. Polymer sample crashed out of solution). Figure B 27. 1H NMR of compound 3.3 (ES 3 5) (50:50 acetylferulic: acetyldihydroferulic acid) Figure B 28. 13C NMR of compound 3.3 (ES 3 5) (50:50 acetylferulic: acetyldihydrof erulic acid) (Not available. Polymer sample crashed out of solution).

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84 Figure B 29. 1H NMR of compound 3.4 (ES 3 31) (100:0 acetylferulic: acetyldihydroferulic acid) Figure B 30. 13C NMR of compound 3.4 (ES 3 31) (100:0 acetylferulic: acetyldihydroferu lic acid). (Not available. Polymer sample crashed out of solution). Figure B 31. 1H NMR of compound 4.2 (ES 2 37) (10:90 acetylhomovanillic: acetylferulic acid) Figure B 32. 13C NMR of compound 4.2 (ES 2 37) Not available. Polymer crashed out of solu tion.

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85 Figure B 33. 1H NMR of compound 4.3 (ES 2 35) (20:80 acetylhomovanillic: acetylferulic acid) Figure B 34. 13C NMR of compound 4.3 (ES 2 35) Not available. Polymer crashed out of solution. Figure B 35. 1H NMR of compound 4.4 (ES 2 39) (30:70 acetylhomovanillic: acetylferulic acid) Figure B 36. 13C NMR of compound 4.4 (ES 2 39) Not available. Polymer crashed out of solution.

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86 Figure B 37. 1H NMR of compound 4.5 (ES 2 41) (40:60 acetylhomovanillic: acetylferulic acid) Figure B 38. 13C NMR of compound 4.5 (ES 2 41) Not available. Polymer sample crashed out of solution. Figure B 39. 1H NMR of compound 4.6 (ES 2 49) (50:50 acetylhomovanillic acid: acetylferulic acid) Figure B 40. 13C NMR of compound 4.6 (ES 2 49) Not available. Polymer sample crashed out of solution.

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87 Figure B 41. 1H NMR of compound 4.7 (ES 2 31) (60:40 acetylhomovanillic acid: acetylferulic acid) Figure B 42. 13C NMR of compound 4.7 (ES 2 31) Not available. Polymer sample crashed out of solution. Figure B 43. 1H NMR of compound 4.8 (ES 2 25) (100:0 acetylhomovanillic: acetylferulic acid) Figure B 44. 13C NMR of compound 4.8 (ES 2 25) Not available. Polymer sample crashed out of solution.

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88 Figure B 45. 1H NMR of compound 5.2 (ES 2 55) (10:90 acetylhomovanill ic: acetyldihydroferulic acid) Figure B 46. 13C NMR of compound 5.2 (ES 2 55) (10:90 acetylhomovanillic: acetyldihydroferulic acid).

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89 Figure B 47. 1H NMR of compound 5.3 (ES 2 57) (20:80 acetylhomovanillic: acetyldihydroferulic acid) Figure B 4 8. 13C NMR of compound 5.3 (ES 2 57)

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90 Figure B 49. 1H NMR of compound 5.4 (ES 2 25) (100:0 acetylhomovanillic: acetylferulic acid) Figure B 50. 13C NMR of compound 5.4 (ES 2 25) Not available. Polymer sample crashed out of solution. Figure B 51. 1H NMR of compound 6.1 (ES 2 111) (90:10 acetylvanillic: acetylferulic acid) Figure B 52. 13C NMR of compound 6.1 (ES 2 111) Not available. Polymer sample crashed out of solution.

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91 Figure B 53. 1H NMR of compound 6.2 (ES 2 159, ES 2 119) (70:30 acetyl vanillic: acetylferulic acid) Figure B 54. 13C NMR of compound 6.2 (ES 2 159, ES 2 119) Not available. Polymer sample crashed out of solution. Figure B 55. 1H NMR of compound 6.3 (ES 2 145) (50:50 acetylvanillic: acetylferulic acid) Figure B 56. 13C NMR of compound 6.3 (ES 2 145) Not available. Polymer sample crashed out of solution

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92 Figure B 57. 1H NMR of compound 6.4 (ES 2 117) (30:70 acetylvanillic: acetylferulic acid) Figure B 58. 13C NMR of compound 6.4 (ES 2 117) Not available. Polymer s ample crashed out of solution. Figure B 59. 1H NMR of compound 6.5 (ES 2 109) (10:90) (acetylvanillic: acetylferulic acid) Figure B 60. 13C NMR of compound 6.5 (ES 2 109) (10:90) Not available. Polymer sample crashed out of solution.

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93 Figure B 61 1H NMR of compound 7.1 (ES 2 125) (60:40 acetylbenzoic: acetylferulic acid) Figure B 62. 13C NMR of compound 7.1 (ES 2 125) Not available. Polymer sample crashed out of solution. Figure B 63. 1H NMR of compound 7.2 (ES 2 127) (40:60 acetylbenzoic: a cetylferulic acid) Figure B 64. 13C NMR of compound 7.2 (ES 2 127) Not available. Polymer sample crashed out of solution.

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94 Figure B 65. 1H NMR of compound 7.3 (ES 2 139) (10:90 acetylbenzoic: acetylferulic acid) Figure B 66. 13C NMR of compound 7.3 (ES 2 139) Not available. Polymer sample crashed out of solution.

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95 APPENDIX C TGA AND DSC DATA OF POLYMERS AND COPOLYMERS Figure C 1. TGA of polymer 2.1 (PHFA)

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96 Figure C 2. DSC of polymer 2.1 (PHFA)

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97 Figure C 3. TGA of polymer 2.2 (10:90 acetylferulic: acetyldihydroferulic acid)

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98 Figure C 4. DSC of polymer 2.2 (10:90 acetylferulic: acetyldihydroferulic acid)

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99 Figure C 5. TGA of polymer 2.3 (20:80 acetylferulic: acetyldihydroferulic acid)

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100 Figure C 6. DSC of pol ymer 2.3 (20:80 acetylferulic: acetyldihydroferulic acid)

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101 Figure C 7. TGA of polymer 2.4 (30:70 acetylferulic: acetyldihydroferulic acid)

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102 Figure C 8. DSC of polymer 2.4 (30:70 acetylferulic: acetyldihydroferulic acid)

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103 Figure C 9. TGA of polymer 2.5 (40:60 acetylferulic: acetyldihydroferulic acid)

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104 Figure C 10. DSC of polymer 2.5 (40:60 acetylferulic acid: acetyldihydroferulic acid)

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105 Figure C 11. TGA of polymer 2.6 (50:50 acetylferulic: acetyldihydroferulic acid)

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106 Figure C 12. DSC of polym er 2.6 (50:50 acetylferulic: acetyldihydroferulic acid)

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107 Figure C 13. TGA of polymer 2.7 (60:40 acetylferulic: acetyldihydroferulic acid)

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108 Figure C 14. DSC of polymer 2.7 (60:40 acetylferulic: acetydihydroferulic acid)

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109 Figure C 15. TGA of polymer 2.8 (70:30 acetylferulic: acetyldihydroferulic acid)

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110 Figure C 16. DSC of polymer 2.8 (70:30 acetylferulic: acetyldihydroferulic acid)

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111 Figure C 17. TGA of polymer 2.9 (80:20 acetylferulic: acetyldihydroferulic acid)

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112 Figure C 18. DSC of polymer 2.9 (80:20 acetylferulic: acetyldihydroferulic acid)

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113 Figure C 19. TGA of polymer 2.10 (90:10 acetylferulic: acetyldihydroferulic acid)

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114 Figure C 20. DSC of polymer 2.10 (90:10 acetylferulic: acetyldihydroferulic acid)

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115 Figure C 21. TGA of polyme r 2.11 (100:0 acetylferulic: acetyldihydroferulic acid)

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116 Figure C 22. DSC of polymer 2.11 (100:0 acetylferulic: acetyldihydroferulic acid)

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117 Figure C 23. TGA of polymer 3.1 (ES 3 33) (0:100 acetylferulic: acetyldihydroferulic acid)

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118 Figure C 24. DSC o f polymer 3.1 (ES 3 33) (0:100 acetylferulic: acetyldihydroferulic acid)

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119 Figure C 25. TGA of polymer 3.2 (ES 3 35) (10:90 acetylferulic: acetyldihydroferulic acid)

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120 Figure C 26. DSC of polymer 3.2 (ES 3 35) ( 10:90 acetylferulic: acetyldihydroferulic a cid)

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121 Figure C 27. TGA of polymer 3.3 (ES 3 5) (50:50 acetylferulic: acetyldihydroferulic acid)

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122 Figure C 28. DSC of polymer 3.3 (ES 3 5) (50:50 acetylferulic: acetyldihydroferulic acid)

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123 Figure C 29. TGA of polymer 3.4 (ES 3 31) (100:0 acetylferulic : acetyldihydroferulic acid)

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1 24 Figure C 30. DSC of polymer 3.4 (ES 3 31) (100:0 acetylferulic: acetyldihydroferulic acid)

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125 LIST OF REFERENCES [1] Effendi A; Gerhauser, H.; Bridgwater, A.V. Renewable and Sustainable Energy Rev. 2008, 12, 209 2 2116. [2] Chen, G Q.; Patel, M.K. Chem Rev. 2011, 112, 2082 2099. [3] Gandini, A.; Macromolecules 2008 41 24, 9491 9504. [4] Mathew, S.; Abraham, T.E.; Crit. Rev. Biotechnol 2004 24 59 83. [5] Polymer Chemistry: An Introduction; 3rd ed.; Stevens M., Oxford University Press, 1999. [6] IUPAC website: http://www.iupac.org/ [7] Finnveden, G.; Hauschild, M.Z., Ekvall, T.; Guinee, J.; Heijungs, R., Hellweg, S.; Koehler, A., Pennington, D.; Suh, S. J Environ Manage 2009, 91, 1 21. [8] Environment al Protection Agency http://www.epa.gov/osw/conserve/materials/plastics.htm [9] Anastas, P.T.; Beach, E.S. Green Chem. Lett. Rev 2007 1 9 24. [10] Kobayashi, H.; Fukuoka, A. Green Chem 2013 15 1740 1763. [11] Williams, C.K. Chem. Soc. Rev. 2007 36 1573 1580. [12] Chen, B K, Tsay, S Y, Chen, J Y. Polymer 2005 46, 8624 8633. [13] Fox, T.G.; Flory, P.J. J. Applied Phys 1950 21 581 591. reen Chemistry Metrics: Measuring and Monitoring [15] Trost, B.M.; Angew. Chem. Int. Ed. Engl 1995 3 259 281. [16] Van Aken, K.; Strekowski; L.; Patiny, L, Beilstein Journal of Organic Chemistry, 2006 2 3 10. [17] Cun ningham, M.F.; Chatterton, M.; Puskas, J.E.; J of Poly Sci, Pol Chem 2005 43, 22, 5545 5553. [18] Mailon, L.; Pemba, A.G.; Miller, S.A.; Green Chem ., 2010 12 1704 1706. [19] Ulrich, K Thiele (2007). Polyester Bottle Resins, Production, Processing, Properties and Recycling. Hiedlburg, Germany. PET planet. [20] http://plastics.americanchemistry .com/Plastic Resin Codes PDF

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126 [21] Wang, Q.J.; Gao, X.; Gong, H.; Lin, X.R.; Saint Leger, D.; Senee, J.; J. Cosmet Sci 2011 62, 483 503. [22] Wunsch, J.R.; Polystyrene: Synthesis, Production, and Applications Rapra Review Reports, 10 4, 2000 [23] www.building.dow.com/about/invention.htm [24] Mathew, S.; Abraham, T.E. Crit Rev Biotechnol. 2004 24 59 83. [25] Ou., S.; Luo, Y.; Xue, F.; Huang, C.; Zhang, N.; Liu, Z. J Food Eng 200 7 78 4, 1298 1304. [26] Bugg, T.D.H.; Ahmad, M.; Hardiman, E.M.; Rahmanpour, R. Nat. Prod. Rep ., 2011 28 1883 1896. [27] Anouar, E.; Kosinova, P.; Kozlowski, D.; Mokrini, R.; Duroux, J.L., Trouillas, P.; Phys. Chem. Chem. Phys ., 2009 11 7659 766 8. [28] Amin, F.; Davidson, M.; Davis, K.L.; Schizophrenia Bulletin 1992 18 123 147. [29] Kim, S.J.; Kim, M C, Um, J Y, Hong, S H. Molecules 2010 15 7208 7217. [30] Juteau, P.; Cote, V.; Duckett, M.F.; Beaudet, R.; Lepine, F.; Villemur, R.; Bisai llon, J.G. Int. J. Syst. Evol. Microbiol. 2005 55 245 250.

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127 BIOGRAPHICAL SKETCH Elizabeth Ruth Suda, originally from Newburyport, Massachusetts a ttended and graduated Magna cum Laude with a Bachelor of Science in b iology from Emmanuel College in 2003. She continued her undergraduate education through 2004 in order to complete the requirements for a double major in chemistry and completed internships with Harvard Medical School and Beth Israel Deaconess Medical Center. Following graduation from Emmanuel she continued with her work at Harvard Medical School and Harvard Pilgrim Health Care in the Unit of Ambulatory Care and Prevention as a research assistant. Following this newly developed interest in epidemiology, she attended Tufts University Medical Sc hool of Public Health and obtained her Master of Public Health degree concentrating in epidemiology and biostatistics, writing her capstone paper on a cost analysis of Herpes zoster and Post herpetic neuralgia. From summer 2008 to s pring 2010, she return ed to her alma mater, Emmanuel College, as a Special Instructor of Chemistry and Physics, teaching laboratory and lectured in introductory chemistry courses. This experience of imparting her love of learning and chemistry led her to return to graduate sch ool and thus, came to the University of Florida in the fall of 2010 to continue her studies, and joined the Miller Research group in January, 2011. An avid competitive runner, she continues to train and race with both the Florida Track Club and the univ ersity affiliated Florida Running Club. Recently, she earned a national title in cross country (6K) at the National Interscholastic Running Club Association (NIRCA) Championships. She also enjoys needlepoint, red wine and sampling the entire menu at Ga