Chain Transfer Agents for RAFT Polymerization: Molecules to Design Functionalized Polymers

Abstract

Reversible addition fragmentation chain transfer (RAFT) agents have been used to prepare macromolecules derived from a wide range of vinyl monomers and is also known to be one of the most effective methods in achieving controlled/living polymerization. The most significant benefit of RAFT polymerization is that it allows the preparation of new polymeric architectures, with low polydispersity and various end-group functionalities. [ 1 ] One key factor in controlling RAFT polymerization is the design of the initial chain transfer agent by the variation of Z and R groups (Scheme 1). To date, cumyl and cyanoisopropyl groups seem to be the most versatile R groups, while the phenyl group is currently one of the best stabilizing groups (Z group) for controlling the polymerization process.121 The R groups based on ester and amide leaving groups have been the focus of recent studies. [ 3 ] Scheme 1.