Scandium Half-Metallocene-Catalyzed Syndiospecific Styrene Polymerization and Styrene-Ethylene Copolymerization: Unprecedented Incorporation of Syndiotactic Styrene-Styrene Sequences in Styrene-Ethylene Copolymers

摘要

We have demonstrated that the combination of a mono(cyclopentadienyl) rare earth metal bis(alkyl) complex such as(C_5Me_4SiMe_3)Sc(CH_2SiMe_3)_2(THF) with [Ph_3C][B(C_6F_5)_4] acts as an excellent catalyst system for syndiospecific styrene polymerization and styrene-ethylene copolyrnerization. By use of this catalyst system, styrene-ethylene copolymers containing syndio-tactic styrene-styrene sequences have been successfully synthesized for the first time. Further evaluation of the properties of these new polymers and application of the present and related catalyst systems to polymerization/copolymerization of other monomers are in progress.