Synthesis of precursors of poly(acryl amides) by copper mediated living radical polymerization in DMSO

The paper describes the optimization of copper(l) mediated living radical polymerization of N-hydroxysuccinimide methacrylate to achieve AB block copoly(acryl amides) offering a route to polymers with potential biomedical applications. Polymerization of N-hydroxysuccinimide methacrylate was carried out using copper(I) bromide/N-(n-propyl)2-pyridylmethanimine catalyst with ethyl-2-bromoisobutyrate as the initiator at three different temperatures (70, 50 and 30 degreesC). Polymerizations at both 70 and 50 degreesC gave relatively high conversion, 72% and 62% respectively after 4 h. Polymerization at 30 degreesC the best linear first-order kinetic plot. The polydispersity remained narrow (1.15) and there was a good agreement between experimental, determined by H-1 NMR, and theoretical M-n. Polymerization of N-hydroxysuccinimide methacrylate was investigated in more detail by following reactions in situ by H-1 NMR. The experimental values of M-n (NMR) were quite close to the theoretical values and the polydispersities were relatively narrow (1.10-1.19). Isolated poly(N-hydroxysuceinimide methacrylate) was used as a macroinitiator for the polymerization of MMA catalyzed by Cu(I)Br in conjunction with N-(n-propyl)-2-pyridylmethanamine ligand leading to block copolymers. A poly(methyl acryl amide) is synthesized indirectly from the reaction of benzyl amine with poly(N-hydroxysuccinimide methacrylate) for 5 h with in DMSO at 50 degreesC under nitrogen. (C) 2003 Elsevier Ltd. All rights reserved.