BLOCK COPOLYMERS INTERPOLYMERIZED WITH IN SITU POLYSTYRENE AND PROCESS FOR PREPARATION THEREOF

摘要

A process for interpolymerizing a vinyl aromatic hydrocarbon polymer and a b lock polymer is disclosed. The process includes the following steps: a) forming a block polymer precursor of at least one polymeric block contain ing conjugated diene monomer contributed units in the presence of an anionic ini tiator and in an inert diluent, the block polymer precursor having living ends; (b) thereafter adding to the block polymer precursor a charge of a vinyl aro matic hydrocarbon monomer and an additional charge of an anionic initiator to simu ltaneously form (1) a block polymer having a terminal block formed from the charge of v inyl aromatic hydrocarbon monomer attached to the block polymer precursor and (2) a poly(v inyl aromatic hydrocarbon) polymer interpolymerized with the block polymer. The practice of this process produces a vinyl aromatic hydrocarbon block ter minated block polymer, such as SBS, interpolymerized with a polymer formed from viny l aromatic hydrocarbon monomer, such as polystyrene. The resultant interpolymer has a h igh Gardner Impact strength and good processibility.