“Living”/controlled polymerization of methyl acrylate mediated by dithiocarbamates under γ‐ray irradiation

γ‐Ray initiated reversible addition–fragmentation chain transfer (RAFT) polymerizations of methyl acrylate (MA) were investigated in bulk using five different dithiocarbamate structures, 2‐phenyl‐benzoimidazole‐1‐carbodithioic acid benzyl ester ( 1b ), 2‐methyl‐benzoimidazole‐1‐carbodithioic acid benzyl ester ( 1c ), 2‐pheny‐indole‐1‐cardithioic acid benzyl ester ( 1d ), 2‐(carbazole‐9‐carbothioylsulfanyl)‐2‐methyl‐propionic acid ester ( 1e ), and carbazole‐9‐carbodithioic acid naphthalene‐1‐ylmethyl ester ( 1f ), as RAFT agents. The experiment results showed that MA polymerized in a controlled way under a low irradiation dose rate, i.e., first‐order kinetic plots, the experimental molecular weights increased linearly with monomer conversions. The polydispersity indices of polymers generally remained at a relatively low value (lower than 1.4). The effect of irradiation dose on the polymerization results was investigated. The obtained polymers were characterized with 1 H NMR and GPC. Chain‐extension reaction was also successfully carried out using the obtained polymer as the macro‐RAFT agent and styrene as the second monomer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1769–1775, 2007