Preparation of a Copolymer of Methyl Methacrylate and 2-(Dimethylamino)ethyl Methacryalte with Pendant 4-Benzyloxy-2,2,6,6-tetramethyl-1-piperidinyloxy and its Initiation of the Graft Polymerization of Styrene by a Controlled Radical Mechanism

摘要

The macroinitiator of a copolymer (PMDBTM) of methyl methacrylate (MMA) and 2-(dimethylamino)ethyl methacrylate (DAMA) with 4-benzyloxy-2,2,6,6- tetramethyl-l-piperidinyloxy (BTEMPO) pendant groups was prepared by the photo- chemical reaction of tertiary amine groups of the copolymer with benzophenone in the presence of BTEMPO. The radical copolymerization of MMA and DAMA was carried out first with azo-bis-isobutyronitrile (AIBN) as an initiator; then, the dimethylamine groups of the copolymer constituted a charge-transfer complex with benzophenone under UV irradiation, and the methylene of ternary amine and diphenyl methanol radicals were produced. The former was capped by BTEMPO, and the nitroxide (BTEMPO)was attached to the polymeric backbone. The amount of pendant BTEMPO on PMDBTMWas measured by lH NMR.PMDBTM initiated the graft polymerization of styrene via a controlled radical mechanism, and the molecular weight of the PMD-g- polystyrene increased with the polymerization time.