Reversible addition-fragmentation chain transfer polymerization of glycidyl methacrylate with 2-cyanoprop-2-yl 1-dithionaphthalate as a chain-transfer agent

A reversible addition-fragmentation chain transfer (RAFT) agent, 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN), was synthesized and applied to the RAFT polymerization of glycidyl methacrylate (GMA). The polymerization was conducted both in bulk and in a solvent with 2,2'-azobisisobutyronitrile (AIBN) as the initiator at various temperatures. The results for both types of polymerizations showed that GMA could be polymerized in a controlled way by RAFT polymerization with CPDN as a RAFT agent; the polymerization rate was first-order with respect to the monomer concentration, and the molecular weight increased linearly with the monomer conversion up to 96.7% at 60 degreesC, up to 98.9% at 80 degreesC in bulk, and up to 64.3% at 60 degreesC in a benzene solution. The polymerization rate of GMA in bulk was obviously faster than that in a benzene solution. The molecular weights obtained from gel permeation chromatography were close to the theoretical values, and the polydispersities of the polymer were relatively low up to high conversions in all cases. It was confirmed by a chain-extension reaction that the AIBN-initiated polymerizations of GAM with CPDN as a RAFT agent were well controlled and were consistent with the RAFT mechanism. The epoxy group remained intact in the polymers after the RAFT polymerization of GMA, as indicated by the H-1 NMR spectrum. (C) 2004 Wiley Periodicals, Inc.