Synthesis, characterization and micelle formation of amphiphilic graft copolymers

The macromonomer method is a useful tool for the preparation of various graft copolymers with well-defined structure and composition. Macromonomers were prepared by anionic polymerization of styrene followed by a direct coupling reaction of polystyryllithium with an excess of vinylbenzyl chloride. The control of the terminal functional groups is particularly important to ensure the reactivity of macromonomers in the radical copolymerization; the degree of functionality was determined by both n.m.r. and u.v.-vis. spectroscopy to be from 85-99%. Graft copolymers were synthesized by radical copolymerization of(vinylbenzyl) polystyrene macromonomer with 2-hydroxyethyl methacrylate (HEMA), or with acrylic acid. The organization ability of the copolymers to form micelles was investigated by H-1 n.m.r. spectroscopy, and verified by their ability to stabilize emulsions. These copolymers were found to be effective surfactants for emulsion polymerization of polystyrene latexes. (C) 1997 Elsevier Science Ltd.