Boronic Acid-Terminated Polymers: Synthesis by RAFT and Subsequent Supramolecular and Dynamic Covalent Self-Assembly

Abstract

Well-defined homopolymers and block copolymers with boronic acid-functional end groups were prepared by reversible addition−fragmentation chain transfer (RAFT) polymerization and subsequently investigated for the potential to undergo model supramolecular and dynamic covalent self-assembly in aqueous and organic media. By employing a boronic acid-functionalized RAFT chain transfer agent, end-functional polymers were prepared without recourse to postpolymerization functionalization. The polymerizations of styrene, N,N-dimethylacrylamide, and N-isopropylacrylamide all led to homopolymers of controlled molecular weight that were capable of subsequent chain extension to form well-defined block copolymers. The amphiphilic and stimuli-responsive block copolymers were capable of self-assembly into micellar aggregates. Quantitative retention of the boronic acid chain termini during polymerization was spectroscopically demonstrated, and two types of dynamic covalent transformations involving these moieties were inv...