INFLUENCE OF THE CATALYST MATRIX STRUCTURE OF THE SUPPORTED ZIEGLER-NATTA CATALYSTS ON THE HOMOPOLYMERIZATION AND COPOLYMERIZATION OF OLEFINS

The vanadium catalytic complexes immobilized on the same support (alum inium hydroxide, AH) and distinguished by structure and composition ha ve been compared for ethylene and propylene homo- and copolymerization to find relationship between the polymerization activity, copolymeriz ation relative reactivity of comonomers and the supported catalyst str ucture. The catalytic complexes of vanadium with supported aluminoxane s (II) and catalysts with dispersed solid phase of vanadium compounds on the support surface (III) are more active than catalyst (I) in whic h 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 pl ace only in the presence of catalysts III.