Microwave-Assisted One-Step Synthesis of Poly(2-oxazoline)-Based Block Copolymers Using a Dual Initiator for CROP and RAFT Polymerization

초록

As a facile and rapid one-step synthesis of block copolymers, a range of poly(2-oxazoline) (POx)-based block copolymers were synthesized in a one-step procedure under microwave irradiation in a significantly shortened period of time using 4-cyano-4-(dodecylthiocarbonothioylthio)pentyl-4-methylbenzenesulfonate (CDPS) and 4-cyano-4-(dodecylthiocarbonothioylthio)pentyl-4-nitrobenzenesulfonate (CDPN) as a dual initiator for living cationic ring-opening polymerization (CROP) and reversible addition-fragmentation chain transfer (RAFT) polymerization. 2-Methyl-, 2-ethyl-, and 2-isopropyl-2-oxazoline were polymerized for the POx block via CROP, and methyl acrylate, methyl methacrylate, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, and 4-acryloylmorpholine were polymerized for the other block via RAFT polymerization. The resulting POx-based block copolymers showed narrow molecular weight distributions, indicating that the CROP and RAFT polymerization proceeded independently in a controlled manner. CDPS and CDPN were found to be useful dual initiators for the microwave-assisted one-step synthesis of POx-based block copolymers.