MODIFICATION OF ALKYD RESINS AND SEED OIL BASED REACTIVE DILUENTS FOR HIGH PERFORMANCE COATINGS A Dissertation Presented to The Graduate Faculty of The University of Akron In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Brittany A. Pellegrene August, 2019 MODIFICATION OF ALKYD RESINS AND SEED OIL BASED REACTIVE DILUENTS FOR HIGH PERFORMANCE COATINGS Brittany A. Pellegrene Dissertation Approved: Accepted: Advisor Department Chair Dr. Mark Soucek Dr. Sadhan Jana Committee Member Interim Dean of the College Dr. Thein Kyu Dr. Ali Dhinojwala Committee Member Dean of Graduate the School Dr. Younjin Min Dr. Chand Midha Committee Member Date Dr. Tianbo Liu Committee Member Dr. Chelsea Monty-Bromer ii ABSTRACT Alkyds, one of the most commonly used binders for coating systems, are modified polyesters derived from seed oils. They find utility in several coating applications, including architectural, industrial and wood coatings. Formulation involves the use of reactive diluents to decrease the viscosity and trigger the autoxidative curing mechanism of the alkyds to avoid the use of volatile organic compounds (VOCs). This work studies the modification of alkyds and reactive diluents and the differences between the coating performance of these additives. Two differently functionalized alkyds and reactive diluents were synthesized and formulated into high solids alkyds coatings. Alkoxysilane and fluorine functionalities were chosen to improve adhesion, hardness, and chemical and corrosion resistance of the coating system. The resulting coatings were analyzed for performance, tensile properties, corrosion resistance and weatherability. ESEM-EDX was used to observe the distribution of the fluorine and alkoxysilane in the cross-section of the coating. Stratification was observed for the modified reactive diluents at high concentrations, and these coatings showed improved adhesion and corrosion resistance. The modified alkyds performed better in terms of mechanical properties, but stratification was not observed. iii Next, the moisture sensitivity of alkoxysilanes was studied by looking into the effect of various relative humidity conditions on the curing and performance of alkoxysilane-functionalized alkyd coatings. These coatings were evaluated for drying time, adhesion, hardness and mechanical properties. At high humidity, the alkoxysilane- functional reactive diluents dried more quickly and formed harder coatings than the unmodified control. The functionalized alkyds showed enhanced adhesion and tensile strength at high humidity. Thirdly, fluorinated alkyds and reactive diluents were compared to understand the effects of molecular weight and viscosity on the stratification and performance of these coatings. The additives were found to create more hydrophobic and chemically resistant coatings without detrimental effects on other properties. The reactive diluents showed more stratification, with decreased mechanical properties. The fluorinated alkyd system improved corrosion resistance without sacrificing other coating properties. In this case, the added mobility of the reactive diluent did not improve the final properties of the coatings. In the final part of this work, novel soybean oil-based reactive diluents were developed, based on an ene reaction between soybean oil and maleic anhydride, which was characterized using FT-IR, 1H-, 13C- and 2D NMR spectroscopy and MALDI-ToF mass spectrometry. The resulting maleated soybean oil was further modified with various nucleophiles, containing allyl ether or methacrylate functionalities. The efficacy of these reactive diluents in decreasing viscosity was evaluated, as well as the crosslink density, tensile properties and coating performance. These novel reactive diluents efficiently reduced viscosity without a significant decrease in performance of the resulting coatings. iv ACKNOWLEDGMENTS I would like to thank the wonderful people without whom this would not have been possible. Firstly, I would like to acknowledge my advisor, Dr. Mark Soucek, and thank him for his counsel, encouragement and support throughout my time here. I’d also like to thank my committee members, Dr. Thein Kyu, Dr. Tianbo Liu, Dr. Younjin Min and Dr. Chelsea Monty-Bromer for their comments and advice. I would like to especially thank Dr. Monty- Bromer for her help with modeling corrosion data. I would like to extend gratitude to Dr. Kevin Cavicchi for the financial support in these last few semesters and for always offering guidance and ideas. Additionally, to the staff and technicians in the department, your help was always greatly appreciated, especially Dr. Paula Watt, Christopher Paige, and Thomas Quick. I also want to thank Diana Woolf for her willingness to go above and beyond for students, and for her support and encouragement to me throughout this process. I would like to express sincere gratitude to my colleagues in the Department of Polymer Engineering. Thank you to Dr. Ryan Salata for your mentorship and for teaching me the ways of alkyds. To Dr. Nick Teo and Marisa Tukpah, thank you for your friendship and for many lunches and study sessions. To my lab mates in Dr. Soucek’s group, especially Anisa Cobaj, thank you so much for your support, advice and understanding. I v would also like to especially thank Ted Hammer for his experimental support and for always being willing to help. I want to express sincere gratitude to my parents and family for their constant love and encouragement, as well as for instilling in me the work ethic and follow-through necessary to achieve my goals. I definitely could not have made it this far without you. And last, but definitely not least, to my very best friends, Emily Brahler, Audrey Fletcher, Anna Holdren, J.D., and Becky VanVoorhis, thank you for everything, for letting me complain and being there for me throughout these last 15 plus years of friendship. I owe a lot to each one of you. Finally, and above all, I want to express my sincere gratitude and appreciation to Dillon Lloyd for his unwavering support, encouragement and the unending sacrifices he has made throughout this journey and over the last 9 years. Your love, advice and encouragement have been instrumental in helping me reach this achievement. vi TABLE OF CONTENTS Page LIST OF FIGURES ............................................................................................................ X LIST OF TABLES .......................................................................................................... Xvii CHAPTER ........................................................................................................... 1 ............................................................................................................ 4 2.1 Environmentally Friendly Coatings ........................................................ 4 2.2 Seed Oils ................................................................................................. 5 2.3 Linseed oil ............................................................................................... 8 2.4 Autoxidation and driers ........................................................................... 8 2.5 Alkyd Resins ......................................................................................... 11 2.6 High Solids Formulations ..................................................................... 17 2.7 Reactive Diluents .................................................................................. 18 2.8 Ene Reactions ........................................................................................ 20 2.9 Inorganic/Organic Hybrid Coatings ...................................................... 21 2.10 Fluorinated Polymers ............................................................................ 25 2.11 Self-Stratifying Coatings ...................................................................... 26 2.12 Corrosion............................................................................................... 28 2.13 Exterior Durability ................................................................................ 31 vii ........... 36 3.1 Abstract ................................................................................................. 36 3.2 Introduction ........................................................................................... 37 3.3 Experimental ......................................................................................... 39 3.4 Results ................................................................................................... 47 3.5 Discussion ............................................................................................. 72 3.6 Conclusions ........................................................................................... 77 .......................................................................................................... 80 4.1 Abstract ................................................................................................. 80 4.2 Introduction ........................................................................................... 80 4.3 Experimental ......................................................................................... 83 4.4 Results ................................................................................................... 87 4.5 Discussion ............................................................................................. 98 4.6 Conclusions ........................................................................................