AMPHIPHILIC HETEROARM STAR COPOLYMERS OF POLYSTYRENE AND POLY(ETHYLENE OXIDE)

Amphiphilic heteroarm star copolymers bearing polystyrene (PS) and pol y(ethylene oxide) (PEG) branches have been synthesized by sequential a nionic 'living' copolymerization. These samples have been characterize d adequately and shown to exhibit rather well-defined structures. The functionality of the stars is influenced mainly by the molar ratio of divinylbenzene per living ends and the molecular weight of the linear PS tetrahydrofuran, which is not a selective solvent for the different arms. Finally, it has been shown that the PEO arms can be crystallize d, forming well-defined spherulites. This ability is strongly affected by the PEO content and the thermal history of the samples.