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End Functionalization of Polyisobutylenes and Their END FUNCTIONALIZATION OF POLYISOBUTYLENES AND THEIR APPLICATIONS IN DYEING POLYOLEFINS AND IN HOMOGENEOUS CATALYSIS A Dissertation by NILUSHA PRIYADARSHANI BORALUGODAGE Submitted to the Office of Graduate Studies of Texas A&M University in Partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Chair of Committee, David E. Bergbreiter Committee Members, Daniel Singleton Karen L. Wooley Jodie L. Lutkenhaus Head of Department, David H. Russell August 2013 Major Subject: Chemistry Copyright 2013 Nilusha Priyadarshani Boralugodage ABSTRACT Non-polar phase selectively soluble polyisobutylene (PIB) is a useful polymer as a polymer support for homogeneous catalysts. Substitution of PIB onto other useful ligands alters the solubility properties of original ligands. However, such chemical modification of PIB polymers is challenging due to its limited synthetic availability. This dissertation describes the end functionalization of this terminal alkene functionalized PIB into variety of other functional groups via variety of chemistries such as electrophilic aromatic substitutions, nucleophilic aromatic substitution reactions and alkylation reactions. PIB-anilines and PIB-phenols can be prepared via electrophilic aromatic substitution reactions of anilines and phenols by PIB-alkene. Excellent oxidative and chemical resistance and nonpolar phase selective solubility of these modified PIB polymers allow these materials to be useful as soluble polymer supports for ligands and transition metal catalysts. This dissertation details immobilization of palladium and ruthenium catalysts on to these modified PIB ligands and their catalytic properties and catalyst recyclability. PIB-bound palladium catalyst was used as a recyclable homogeneous catalyst for cross coupling reactions in a thermomorphic liquid/liquid separation system- biphasic at a lower temperature and monophasic at a higher temperature. Application of a ‘solid solvent’-(Polywax) in place of a organic solvent is also described and improved metal sequestration of this liquid/solid catalyst/product separation compared to the thermomorphic liquid/liquid separation strategy is also ii investigated. A PIB-bound ruthenium visible light photo-redox catalyst was prepared and its catalytic activity and recyclability in free radical polymerization reactions of acrylates is also reported. At the end this dissertation details the extension of PIB’s utility as a nonpolar phase anchor to functionalize polyolefins with dyes. This is illustrated by preparing PIB- bound metallophthalocyanine dyes in a series of reactions starting with 4-nitro phthalonitrile. The non-polar solvent solubility of these dyes allowed their use in dyeing commercial polyethylene and polypropylene. iii DEDICATION This dissertation is dedicated to my family and my husband, Erosh. A special thank to my parents Peter and Mallika Cancius whose hard work in their lives pushed me for this accomplishment today. My sister Geethani and Brother Nilushan have never left my side are very special. Thank you so much Erosh. I could not have done this without your support. I dedicate this work to my American host family John and Joyce Schrader for their love and care throughout my academic career. I made it through these seven years with your encouragement. I would not have writing this today without your love and support. iv ACKNOWLEDGEMENTS I first and foremost thank Dr. Bergbreiter for providing a lab that I could call home and grow up as a strong scientist. His support, guidance, and standards have made this whole experience worthwhile. I also thank Jill for being the friendly face between us and Dr. Bergbreiter. I would also like to thank Prof. Daniel A. Singleton, Prof. Karen L. Wooley and Prof. Jodie Lutkenhaus for serving in my thesis committee and giving me suggestions for my literature seminar, preliminary exam and writing dissertation. I also would like to express my gratitude to my masters adviser Dr. Cristina De Mao, who kept the faith in me and encouraged me for pursuing further into the field. I also would like to thank all the teachers who taught me chemistry during my Bachelor’s degree in the University of Peradeniya, Sri Lanka. A special thank goes to all the mentors and teachers from my primary school (Wilpotha Anura College, Chilaw, Sri Lanka) to the high school (Holy Family Girls College, Wennapuwa, Sri Lanka) who taught me to dream about today. I also thank Drs. Yanfei Yang “Felix”, Yun-Chin Yang “Jeff”, Kristine Tan, Dongmei Zhang for their help in solving my research problems. I also thank our basket ball team future Drs. Jakkrit Suriboot, Yannan Liang, Ilse Nava and Ashley Billings for being so fun loving and spending time outside chemistry lab. I also thank all Bergbreiter group members for all their help and support throughout these five years. v Finally I would like to thank my family for their love and support on my studies towards the Ph.D. degree. I also want to thank the most wonderful my American host family John and Joyce Schrader for their continuous love and care not only in good times especially in those difficult years in my academic and personal life. Especially I want to thank my husband Erosh Boralugodage for his love and support in these years. Without his planning and help, I would not have had such a smooth finish in my Ph.D. career. vi TABLE OF CONTENTS Page ABSTRACT ..................................................................................................................... ii DEDICATION ................................................................................................................. iv ACKNOWLEDGEMENTS .............................................................................................. v TABLE OF CONTENTS .............................................................................................. vii LIST OF FIGURES .......................................................................................................... ix LIST OF TABLES ......................................................................................................... xii CHAPTER I INTRODUCTION ....................................................................................... 1 Functionalization using functional initiators ............................................................... 4 Functionalization using functional terminators ......................................................... 12 Post polymerization modifications of PIB ................................................................ 18 CHAPTER II SYNTHESIS OF TERMINALLY FUNCTIONALIZED POLYISOBUTYLENE DERIVATIVES ...................................................................... 26 Introduction ............................................................................................................... 26 Results and discussion ............................................................................................... 33 Conclusions ............................................................................................................... 50 CHAPTER III RECYCLING AZOBENZENE PALLADACYCLE PRE-CATALYST USING POLYMERIC PHOSPHINE LIGANDS AND POLYETHYLENE AS A CO-SOLVENT ................................................................................................................ 51 Introduction ............................................................................................................... 51 Results and discussion ............................................................................................... 59 Conclusions ............................................................................................................... 74 vii CHAPTER IV GREENER RECOVERABLE AND REUSABLE POLYISOBUTYLENE-BOUND VISIBLE LIGHT PHOTO-REDOX CATALYST IN FREE RADICAL POLYMERIZATION ................................................................... 76 Introduction ............................................................................................................... 76 Results and discussion ............................................................................................... 87 Conclusions ............................................................................................................... 97 CHAPTER V POLYISOBUTYLENE-BOUND ORGANO-SOLUBLE METALLOPHTHALOCYANINES ............................................................................... 98 Introduction ............................................................................................................... 98 Results and discussion ............................................................................................. 110 Conclusions ............................................................................................................. 120 CHAPTER VI EXPERIMENTAL SECTION .............................................................. 122 General methods ...................................................................................................... 122 CHAPTER VII CONCLUSIONS ................................................................................. 149 REFERENCES .............................................................................................................. 153 viii LIST OF FIGURES Page FIGURE 1. Possible olefinic end groups result in a ‘conventional’ cationic polymerization.............................................................................. 4 FIGURE 2. Tri and tetrafunctional initiated multitelechelic three and four arm PIB star structures
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