Reversible Addition-Fragmentation Chain Transfer Polymerization Of (Methyl) Methacrylate Initiated By γ-Ray Irradiation

γ-Ray initiated polymerizations possess many merits as compared with traditional radical generating methods. It could be conducted easily at ambient temperature without adding any thermal or photo initiators, which offered a easy method to prepare purer polymers.The polymerizations of methyl methacrylate (MMA) and methyl acrylate (MA) in the presence of trithiocarbonates, dithiocarbamates, and 2-cyanoprop-2-yl dithionaphthalenoate (CPDN) were investigated in this thesis. The results are summarized as the following:(1) Theγ-ray initiated bulk polymerizations of MMA and MA were mediated by dibenzyl trithiocarbonate (DBTTC) and dinaphthalen-1-ylmethyl trithiocarbonate (DNTTC). The results indicated that both the trithiocarbonates were quite inert in the polymerization of MMA. The reason has been concluded as following: when the leaving group of the RAFT agent was phenylethyl or naphthalen-1-ylmethyl group, the poly(methacrylyl) group would fragmentate preferentially during the initial transfer reactions, and the addition-fragmentation transfer equilibrium couldn't be established. With this conclustion, as the monomer changed to a less substituded monomer compared to MMA, such as MA or so, the polymerization should show living characteristics. The polymerization results do show"living"characteristics in the case of MA. The polymers with controlled molecular weights and narrow molecular weight distributions could be synthesized with appropriate irradiation dose rate and irradiation time.(2)γ-Ray initiated RAFT polymerizations of MA were conducted in bulk using five dithiocarbamates as RAFT agents: 2-methyl-benzoimidazole-1-carbodithioic acid benzyl ester, 2-phenyl-benzoimidazole-1-carbodithioic acid benzyl ester, 2-pheny-indole-1-cardithioic acid benzyl ester, 2-(carbazole-9-carbothioylsulfanyl)...