Reversible Addition-Fragmentation Chain Transfer (RAFT) Living Polymerization Of Water-soluble Monomer And Application In Miniemulsion System

The research interest of this thesis is concentrated on the two parts: (1) synthesis and characterization of methacrylic acid and maleic acid homopolymers via aqueous RAFT polymerization and their application in miniemulsion polymerization with methyl methacrylate (MMA) or styrene (St); (2) miniemulsion Copolymerization of Methyl Methacrylate andγ-(Methacryloxy)propyltrimethoxy Silane. (1) Synthesis of methacrylic acid and maleic acid Homopolymers via aqueous RAFT Polymerization For RAFT polymerization system, the effects of variations on the rate of polymerization, first-order kinetics, molecular weight and molecular weight distribution have been investigated. These variations included the concentrations of CTAs, concentrations of initiators, kinds of initiator. The results of aqueous GPC analysis have confirmed that the molecular weights of the polymers produced were increased linearly with the conversions of the monomer. And the molecular weight distributions were in the range of 1.02 to 1.3, which was smaller than the theoretical limit of 1.5 for classical free-radical polymerization. On the base of upwards studies, poly(MAA) as macro-RAFT agent, the block copolymerizations of MAA and MMA (or St ) were investigated in miniemulsion polymerization, considering the ratio of monomers. Their structures were conformed by ~1H NMR. Their latices shape were testing by Hitachi H-600 transmission electron microscope , obvious core-shell were observed. And the latices diameter and distributions were determined by High Performance Particle Size HPPS hpp5001 dynamic laser scatter instrument. (2) Miniemulsion Copolymerization of Methyl Methacrylate and γ-(Methacryloxy)propyltrimethoxy Silane Effects of variation on the rate of copolymerization were investigated, including reactive temperatures, the amount of co-stabilizer, the amount of reactive monomer A-174, and concentration of pH adjusting agent. Gas chromatography was used to determine the trace amount of methanol in latex systems, the result indicated that hydrolysis of A-174 distinctly reduced and ensured stability of the unit of A-174 by using the miniemulsion approach.