SYNTHESIS AND CHARACTERIZATION OF AMPHIPHILIC DIBLOCK COPOLYMER OF POLYSTYRENE AND POLYVINYL-ALCOHOL USING ETHANOLAMINE-BENZOPHENONE AS PHOTOCHEMICAL BINARY INITIATION SYSTEM

Amphiphilic diblock copolymers of polyvinyl alcohol (PVA) and polystyr ene (PS), which are very difficult to prepare by common polymerization methods, have been obtained by initiation of the polymerization of st yrene and vinyl acetate successively, followed by hydrolysis, using th e ethanolamine-benzophenone (BP) charge-transfer complex (CTC). The ef fects of solvents, concentration of monomer, BP, ethanolamine, and PS prepolymer, with a reactive imino group (PSa), on the photo-induced ch arge-transfer polymerization (CTP) of St and block copolymerization of VAc are discussed. The copolymer of PS-b-PVAc and the hydrolyzed prod uct, PS-b-PVA, were characterized by FTIR, NMR, and GPC in detail. The effect of PS chain length on the crystallization of PVA was described . (C) 1998 John Wiley & Sons, Inc.