The University of Southern Mississippi The Aquila Digital Community Dissertations Spring 2020 Huisgen 1,3-Dipolar Azide-Alkyne Cycloaddition “Click” Reaction in Polymer Synthesis and Curing Jie Wu Follow this and additional works at: https://aquila.usm.edu/dissertations Part of the Polymer Chemistry Commons Recommended Citation Wu, Jie, "Huisgen 1,3-Dipolar Azide-Alkyne Cycloaddition “Click” Reaction in Polymer Synthesis and Curing" (2020). Dissertations. 1767. https://aquila.usm.edu/dissertations/1767 This Dissertation is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Dissertations by an authorized administrator of The Aquila Digital Community. For more information, please contact [email protected]. HUISGEN 1,3-DIPOLAR AZIDE-ALKYNE CYCLOADDITION “CLICK” REACTION IN POLYMER SYNTHESIS AND CURING by Jie Wu A Dissertation Submitted to the Graduate School, the College of Arts and Sciences and the School of Polymer Science and Engineering at The University of Southern Mississippi in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Approved by: Dr. Robson F. Storey, Committee Chair Dr. Jason D. Azoulay Dr. Sarah E. Morgan Dr. Sergei Nazarenko Dr. Yoan Simon ____________________ ____________________ ____________________ Dr. Robson F. Storey Dr. Derek L. Patton Dr. Karen S. Coats Committee Chair Director of School Dean of the Graduate School May 2020 COPYRIGHT BY Jie Wu 2020 Published by the Graduate School ABSTRACT This dissertation’s key focus is on utilizing Huisgen 1,3-dipolar azide-alkyne cycloaddition (AAC) reaction in copolymer synthesis and modification, including thermoplastic block copolymer and commercially available two-component polyurethane system. It can be divided into two major projects, introduced as follows. The first project involves the development of a modular synthetic approach toward polyisobutylene (PIB)-based triphasic pentablock thermoplastic elastomer with enhanced moisture permeability. This terpolymer consists of a poly(styrene-b-isobutylene-b- styrene) (SIBS) core and appended hydrophilic polymer blocks (HBs). The SIBS core was synthesized via living cationic polymerization (LCP) of isobutylene followed by sequential addition of styrene. AAC was utilized to chemically attach polyethylene oxide (PEO)- based HBs to the ends of the SIBS core. Structure-morphology-property relationships of those triphasic block terpolymers were investigated. This project is described in detail as Chapter II of this dissertation. The second project focused on developing a series of non-isocyanate polyurethanes (NIPUs) that cure via AAC. In general, an alkyne-functional prepolymer was produced by reaction of propargyl alcohol with a commercially available allophanate-modified polyisocyanate based on hexamethylene diisocyanate; while an azide-functional prepolymer was produced by azidation of a commercially available acrylic polyol. The two prepolymers were then cured via AAC. Chapter III explores the effects of non- stoichiometric ratios of the two NIPU prepolymer components on the final coating properties. After conducting the coating composition-performance ladder study for this ii system, it was concluded that formulating with 35 - 50 mol% excess polyazide component produces coatings with optimized performance and higher crosslink density. Chapter IV introduces the design and study of a new type of low viscosity poly(alkynyl carbamate) prepolymer. A plasticizer specially designed to prevent sacrificing alkyne functionalities was incorporated into the poly(alkynyl carbamate) prepolymer. This approach was highly effective in reducing the prepolymer viscosity and maintaining good final coating performance. Finally, Chapter V reports the development and study of waterborne versions of those NIPUs. To achieve this, the poly(alkynyl carbamate) prepolymer was chemically modified with hydrophilic groups. Stable water dispersion of the system was formulated with the help of small amount of external surfactant and organic coalescent. The final coating performance properties were comparable to their solvent-borne counterparts. iii ACKNOWLEDGMENTS First and foremost, I would like to thank my advisor, Dr. Robson F. Storey, who has been an excellent mentor throughout the years in grad school. You have provided me with utmost support and trust ever since the very beginning when I joined your research group. You have inspired and taught me so much, not to mention knowledge of polymers, research, skills of speaking, writing, and presenting in a professional way, but also the traits and attitudes being a scholar and scientist. Thank you for all the research conference opportunities that you provided me to learn and grow. Thank you for believing in me even at my most difficult times during research. Thank you for supporting and encouraging me even when I made stupid mistakes. It has been the greatest honor and pleasure to have you as my advisor. Thank you! Next, I would like to thank my graduate research committee members, Dr. Azoulay, Dr. Morgan, Dr. Nazarenko, and Dr. Simon, for your advices, support, and guidance for my graduate research and development in the past five years. I would like to thank Dr. William L. Jarrett for your assistance and guidance with NMR. Thank Jessica Douglas for your help with TEM. Thank Ethem Kaya for your guidance on emulsion polymerization. Thank Christopher Scanlon for your help with SEM and being one of the best friends in my grad school years. Thank Wiggins Research Group, Morgan Research Group, Azoulay Research Group, Rawlins Research Group, and Gu Research Group for your assistance with all your instruments. Especially present and past members of Azoulay Research Group, you have provided me with greatest help and advices regarding synthetic organic chemistry. Thank all of the present and past students and friends in PSRC who have given iv me support, advices and inspirations on my research. All of the people and groups above, without you, my research would not be complete. Thank you! Thirdly, I would also like to thank the present and past members of Storey Research Group, especially Dr. Bin Yang, Logan Dugas, Dr. Hunter Cooke, Dr. Corey Parada, Dr. Travis Holbrook, Melanie Bryan, Bayley Peoples, Harrison Livingston, Grace Parker, Dr. Garrett Campbell, and Morgan Heskett. I always say: “It’s the people who you see every day that are the most important.” You and Dr. Storey are the reason why I joined this group. Working with you has filled the hard lives in grad school with joy and laughter. Special thanks to Dr. Bin Yang who has been a great mentor and friend during my earlier years in the lab. To Logan Dugas who has been my best friend in the group since you joined us. To the Covestro team members, Dr. Hunter Cooke, Bayley Peoples, Harrison Livingston, and Grace Parker, thank you for all the support and collaboration on our research project. All of you above, wish you guys the brightest future and happiest lives ever after. Thank you! Lastly, thank my research funding sources, Army Research Project and Covestro LLC. Special thanks to Dr. Alan Ekin and Mr. Alan Bushmire who have been great partners in the Covestro project, and I looking forward to any possible future collaborations with you. v DEDICATION I would like to dedicate this dissertation to my dearest families: my parents, Qing Wu and Aijun Zhang; my lovely wife, Kara Cromer; my aunt and uncle, Jing Wu and Baozhong Shi; my brother and sister in law, George Zhang and Sunnie Lin; and my cousin, Alexander Shi. Your love and support are the reason kept me striving and moving forward during these years of grad school. Specially to mom and dad, thank you so much for loving me and supporting me even across the Pacific Ocean. Thank you for your past visits that warmed my heart the deepest. I wish I have made you proud. I love you. Lastly, to my beloved Kara. You are the best thing that ever happened to me in my life. I feel so lucky to have found you. Thank you for the hot dinners when I work late. Thank you for taking care of everything when I’m busy. Thank you for all of your loving support as the best wife ever. I will love you always and forever. vi TABLE OF CONTENTS ABSTRACT ........................................................................................................................ ii ACKNOWLEDGMENTS ................................................................................................. iv DEDICATION ................................................................................................................... vi LIST OF TABLES ........................................................................................................... xiii LIST OF ILLUSTRATIONS ............................................................................................ xv LIST OF SCHEMES........................................................................................................ xxi CHAPTER I - INTRODUCTION ...................................................................................... 1 1.1 Introduction of Research ........................................................................................... 1 1.2 Thermoplastic Elastomers and Morphology of Block Copolymers ......................... 2 1.3 Polyisobutylene, SIBS, and Previous Related Work ................................................ 4 1.4 Huisgen 1,3-Dipolar Azide-Alkyne Cycloaddition “Click” Reaction ...................... 9 1.5 Polyurethane and Non-Isocyanate