Photoinduced atom transfer radical polymerization in a polar solvent to synthesize a water-soluble poly(2-methacryloyloxyethyl phosphorylcholine) and its block-type copolymers

摘要

Photoinduced atom transfer radical polymerization (ATRP) has promising applications because it requires small amounts of transition metal catalysts and low temperatures, and can be extended to numerous monomers. We investigated the photoinduced ATRP of 2-methacryloyloxyethyl phosphorylcholine (MPC) in a polar medium and prepared block-type copolymers with a poly(MPC) segment. Polymerizations in methanol at room temperature were rapid and well-controlled under photo-irradiation, with a linear relationship between monomer conversion and actual exposure time. Extension of polymer chains to prepare ABA triblock-type copolymers composed of poly(MPC) and poly(glycidyl methacrylate (GMA)), which possesses a reactive epoxy group in the side chain, was achieved by one-pot photoinduced ATRP in a shorter time and under milder reaction conditions than those in conventional ATRP. The synthesized poly(MPC) and its ABA triblock-type copolymers had sufficiently narrow molecular weight distributions. These results endorse photoinduced ATRP as an attractive technique to obtain water-soluble polymers with a poly(MPC) segment. (C) 2015 Elsevier Ltd. All rights reserved.