SYNTHESIS, CHARACTERIZATION AND MICELLE FORMATION OF AMPHIPHILIC GRAFT-COPOLYMERS

The macromonomer method is a useful tool for the preparation of variou s graft copolymers with well-defined structure and composition. Macrom onomers were prepared by anionic polymerization of styrene followed by a direct coupling reaction of polystyryllithium with an excess of vin ylbenzyl chloride. The control of the terminal functional groups is pa rticularly important to ensure the reactivity of macromonomers in the radical copolymerization; the degree of functionality was determined b y both n.m.r. and u.v.-vis. spectroscopy to be from 85-99%. Graft copo lymers were synthesized by radical copolymerization of(vinylbenzyl) po lystyrene macromonomer with 2-hydroxyethyl methacrylate (HEMA), or wit h acrylic acid. The organization ability of the copolymers to form mic elles was investigated by H-1 n.m.r. spectroscopy, and verified by the ir ability to stabilize emulsions. These copolymers were found to be e ffective surfactants for emulsion polymerization of polystyrene latexe s. (C) 1997 Elsevier Science Ltd.