A facile synthesis of pH stimuli biocompatible block copolymer poly(methacrylic acid)-: Block -poly(N -vinylpyrrolidone) utilizing switchable RAFT agents

This paper presents a facile synthesis of poly(methacrylic acid)-block-poly(N-vinylpyrrolidone) (PMAA-b-PNVP) block copolymer utilizing a stimuli responsive RAFT agent that can be switched to offer good control over the polymerisation of MAMs and LAMs. Commercially available acid/base switchable RAFT agents, e.g., 2-cyanopropan-2-yl N-methyl-N-(pyridine-4-yl)carbanodithioate, were used and the block copolymer PMAA-b-PNVP was obtained after the hydrolysis of the corresponding well-defined, low dispersity poly(t-butyl methacrylate)-block-poly(N-vinylpyrrolidone) (P(t-BMA)-b-PNVP). This block copolymer has an advantage over its random copolymer counterpart as it can self-assemble to form micelles under acidic conditions.