Synthesis and properties coming from the copolymerization of propene with alpha-olefins using different metallocene catalysts

Abstract

Copolymerization of propene with two alpha-olefins (1-hexene and 1-octadecene) using iso- and syndioselective metallocene catalysts (EtInd(2)ZrCl(2), Et(2-MeInd)(2)ZrCl2, Me(2)SiInd(2)ZrCl(2), Ph(2)CFluCpZrCl(2) and Me(2)CFluCpZrCl(2)) activated with methylaluminoxane (MAO) is reported. The so-called comonomer effect was seen in the catalytic activity of the Me(2)SiInd(2)ZrCl(2)/MAO system. Incorporation of syndiotactic copolymers was greater than that of isotactic copolymers. The molecular weight of the isotactic copolymers was not affected significantly by the presence of the comonomer, but the molecular weights of the copolymers obtained with the syndioselective catalysts decreased with increasing comonomer concentration in the medium. Tensile properties were studied. Syndiotactic copolymers with incorporation of the order of 6 mol% of 1-octadecene presented elastomeric properties.