Amphiphilic block copolymers using miscellaneous omega-functional poly(ethylene oxide)'s as transfer agent

Full Paper: Free radical polymerizations of styrene, ethyl methacrylate, bu tyl acrylate and vinyl acetate were carried out in the presence of unsatura ted peroxyketals, dithiobisthiocarbonates and thiols used as transfer agent s. The latter functions were then introduced at the end of poly(ethylene ox ide) (PEO) chains and the oligomeric transfer agents obtained subsequently served to prepare amphiphilic block polymers by free radical polymerization . The chain transfer coefficient of these transfer agents with respect to g rowing polystyryl radicals were found to decrease with their chain length. PEO transfer agents exhibiting only low molar masses appeared to be of prac tical use.