Enhancing control of macromolecular architecture by synergistic combination of atom transfer radical polymerization, nitroxide mediated polymerization, and reversible addition-fragmentation chain transfer polymerization.

摘要

Various synthetic methodologies to prepare well-defined macromolecular architectures by a combination of controlled radical polymerization (CRP) techniques were studied.;Chapter I presents an overview of the three main CRP techniques, namely nitroxide mediated polymerization (NMP), atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAF1) polymerization. Chapter II describes the use of dithioesters as alkyl pseudohalides initiators/chain transfer agents (CTAs) for the concurrent ATRP and RAFT polymerization of methyl methacrylate (MMA) and styrene (St). The extension of this work to ARGET ATRP with alkyl pseudohalides as initiators/CTAs is presented in Chapter III. The advantages offered by this improved polymerization process are detailed, with a special focus on decreasing the amount of soluble copper complexes used. Chapter IV introduces a simple, versatile, and one-step method to prepare various CTAs for RAFT polymerization via atom transfer radical addition-fragmentation (ATRAF) in the presence of alkyl halides, copper catalyst, and bis(thiocarbonyl) disulfides. Chapter V illustrates the use of a dibromotrithiocarbonate (DiBrTTC) inifer to prepare block copolymers by concurrent and/or sequential ATRP and RAFT polymerization. The effect of monomer, catalyst and CTA structure on the polymerization mechanism is detailed. Chapters VI and VII present the synthesis of block copolymers from conjugated and non-conjugated monomers by sequential RAFT polymerization and ATRP with haloxanthate inifers. Chapter VI and VII detail the synthesis of poly(vinyl acetate) and poly(vinylpyrrolidone) block copolymers, respectively. The synthesis of multisegmented degradable polymers by atom transfer radical cross-coupling (ATRC) between dihalogenated polymers obtained by ATRP and dinitroxide compounds is demonstrated in Chapter VIII. Chapter IX illustrates the synthesis of cyclic polymers by intramolecular ATRC of alpha-nitroxy, o-bromo polymers prepared by ATRP with an initiator carrying an alkoxyamine function. Chapter X introduces the synthesis of dynamic covalent gels prepared by radical polymerization of MMA with a trithiocarbonate crosslinker. The swelling properties were studied and showed that the reorganization of the gels, under the appropriate stimulus, yielded an increase of the swelling ratio, due to a decrease of the contractile forces generated by the swelling. The potential application of dynamic covalent crosslinkers to prepare materials that can be reprocessed and/or mended is briefly exemplified. Chapters XI describes the development of liquid and vapour phase inhibition systems for the distillation of acrylic acid.