Reversible addition-fragmentation chain-transfer (RAFT) copolymerization of vinylidene chloride and methyl acrylate

The reversible addition-fragmentation chain-transfer (RAFT) copolymerization of vinylidene chloride and methyl acrylate was investigated at 70degreesC in benzene. Three dithioesters were synthesized in high yield by a simple and straightforward transesterification method. These dithioesters were successfully used as reversible chain-transfer agents, as demonstrated by the increase of molecular weight with conversion, a relatively low polydispersity index (I-p =1.5) in comparison with a blank experiment (I-p=1.9), first-order polymerization kinetics and efficient chain extension. Nevertheless, a transfer reaction to vinylidene chloride monomer was considered to address the limitations of the RAFT process for this system. Moreover, a retardation effect was noticeable on the kinetics, depending on the structure and concentration of the transfer agent, leading to lower rate of polymerization for lower targeted molecular weights. (C) 2002 Society of Chemical Industry.