Anionically polymerized tough impact polystyrene, useful for preparation of shaped bodies, films, fibers or foams, comprises initiator composition and has low residual monomers and oligomer content and good injection molding properties

摘要

An anionically polymerized tough impact polystyrene of melt/volume flow rate MVR of at least 8-20 cm3/10 minutes (as measured by EN ISO 1133 at 200 degrees C test temperature and 5 kg nominal load) is new. Independent claims are also included for: (1) a process for preparation of the tough impact polystyrene by anionic polymerization of styrene in the presence of a styrene/butadiene block copolymer, using an alkali metal organyl as anionic polymerization initiator, e.g. s-butyl lithium, and an aluminum, magnesium or zinc organyl as retarder, e.g. triisobutylaluminum (TIBA); (2) a shaped body, film, fibers or foam obtained from the tough impact polystyrene.