Homo- and copolymerization of styrene and alkylstyrenes with the highly active catalyst system CpTiF3/MAO

Syndiotactic copolymers with p-methylstyrene, p-tert-butylstyrene and a-met hylstyrene were obtained using fluorinated half-sandwich catalyst systems. In the presence of p-alkylstyrenes the activities were high. The incorporat ion fo p-alkylstyrenes is nearly as good as it is for sytrene. Molar masses increase using p-alkylstyrene comonomers. The steric hindrance of the a-me thyl group in a-methylstyrene results in low activities and poor incorporat ion rates. Since the melting points of the copolymers are lower than the me lting point of the sytrene homopolymer the products are easier to process. Crystalline p-tert-butylstyrene-rich copolymers were obtained if appropriat e crystallization procedures were carried out.