A transition metal mediated chain transfer agent controlled polymerization process is described. The process combines the advantages of atom transfer radical polymerization (ATRP) and reversible addition fragmentation transfer (RAFT) polymerization. Synthesis of chain transfer agents useful in the disclosed processes is also disclosed. Other improvements on ATRP RAFT processes are also described.
Poly(vinylacetate)-b-polystyrene, poly(vinylacetate)-b-poly(methylacrylate) and poly(vinylacetate)-b-poly(methyl methacrylate) block copolymers with low polydispersity (M(w)/M(n) < 1.25) were prepared by successive reversible addition-fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP) employing a bromoxanthate iniferter (initiator-transfer agent-terminator)