Influence of the catalyst matrix structure of the supported Ziegler-Natta catalysts on the homo- and copolymerization of olefins

The vanadium catalytic complexes immobilized on the same support (aluminium hydroxide, AH) and distinguished by structure and composition have been compared for ethylene and propylene homo- and copolymerization to find relationship between the polymerization activity, copolymerization relative reactivity of comonomers and the supported catalyst structure. The catalytic complexes of vanadium with supported aluminoxanes (II) and catalysts with dispersed solid phase of vanadium compounds on the support surface (III) are more active than catalyst (I) in which vanadium has the covalent bond with surface of support. The relative reactivity of comonomers in copolymerization also depends on type of supported catalyst. The catalysts III unlike I and II can produce the ethylene and propylene copolymers with high content of propylene. The promoting effect of propylene on ethylene polymerization rate takes place only in the presence of catalysts III.