Low ppm Atom Transfer Radical Polymerization in Dispersed Media and Electrochemically Mediated Reversible Addition-Fragmentation Chain-Transfer Polymerization

This thesis summarizes my PhD research study in the mechanistic study of atom transfer radical polymerization (ATRP) in aqueous dispersed media and electrochemically mediated reversible addition-fragmentation chain-transfer (eRAFT) polymerization.The introductory chapter (Chapter I) reviews the history and development of RDRP, focusing on ATRP and RAFT polymerization. Their principle, mechanism, media, kinetics, and resulting polymer materials are presented.Chapters II – VI cover the mechanism study of ATRP in miniemulsion and emulsion under different low ppm ATRP techniques using an ion-pair catalyst. Chapter II presents the activator regenerated by electron transfer (ARGET) ATRP in miniemulsion. The selection of structure and concentration of the surfactant, copper concentration, target degree of polymerization, are discussed. The synthesis of block, star and brush copolymers are conducted. Chapter III discusses the key factor for application of the ion-pair catalyst to an ab initio emulsion. Chapters IV – V explores the application of photomediated ATRP in miniemulsion and ab initio emulsion. The impact of surfactant amount and solids content which influence the optical properties of the miniemulsion are investigated, as well as temporal control, chain extension and gradient copolymer preparation. Chapter VI presents an enzyme-deoxygenation system in miniemulsion and emulsion ATRP, which allows synthesis of hydrophobic polymers without physical displacement methods.Chapters VII – VIII investigate the synthesis of block copolymers and hairy nanoparticles in miniemulsion ATRP. Chapter VII discusses the optimal conditions to chain extend a less active macroinitiator with a more active monomer under low copper concentration. Chapter VIII explores approaches for chain extending a hydrophobic crosslinked nanoparticle with hydrophilic or zwitterionic polymer chains.Chapters IX – XI discuss pathways to employ electrochemistry in the initiation and control over RAFT polymerization. Chapter IX presents initiation of RAFT polymerization by electrochemical reaction of an external diazonium salt initiator. Chapter X combines the benefit of eATRP and RAFT in a synergistic mechanism. The radicals are generated in eATRP, and controlled simultaneously by ATRP and RAFT. In sight of the RAFT chain-transfer agents (CTAs) as alkyl pseudohalides, Chapter XI employs copper catalysts in eATRP to activate the CTAs. The contribution of ATRP and RAFT to the control is discussed.Published works with minor relevance to this thesis are included as appendices