PROCESS FOR PRODUCING SYNDIOTACTIC POLYSTYRENE

摘要

High molecular weight syndiotactic polystyrene having greater than 96 % syndiotacticity can be produced in high yield (greater than 53 % and as high as 81 %) by polymerizing styrene monomer, under rigorously anhydrous conditions, with a catalyst comprising Cp*M(CH3)3, where Cp* is a single eta <5>-cyclopentadienyl or eta <5>-cyclopentadienyl group optionally covalently bonded to M through a substituent, and M is selected from Ti, Zr, Hf and a co-catalyst comprising B(C6F5)3 dissolved in an aromatic solvent such as tolurene or styrene, at carefully controlled temperatures in the range -30 DEG C to +50 DEG C. The rapid rate of polymerization and high yield make the production of hard, rigid products by reaction injection moulding possible. Low temperature polymerization of poly( alpha -methylstyrene) with very high molecular weight is also contemplated.