| 摘要 |
High molecular weight syndiotactic polystyrene having greater than 96% syndiotacticity can be produced in very high yield (greater than 92%) 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 an 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 toluene or styrene, at carefully controlled temperatures in the range -15 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.
|
