PECULIARITIES OF HOMOPOLYMERIZATION AND C OPOLYMERIZATION OF ETHYLENEWITH PROPYLENE USING IMMOBILIZED VANADIUM CATALYSTS

To clarify the nature of activation of ethylene polymerization initiat ed by heterogeneous metallo-complex catalysts, which is observed in th e presence of propylene, the kinetic regularities of copolymerization and consecutive co- and homopolymerization of ethylene and propylene w ith vanadium catalysts supported on aluminum oxide were investigated. The surface of a support was studied by thermodesorption mass spectrom etry, and the conditions for the preparation of immobilized catalytic complexes differing in the character of the interaction of transition metal with the support were found. It was shown that the activation o f ethylene polymerization in the presence of propylene is possible onl y when the catalysts used contain a dispersed phase of the transition- metal compound on the support surface. The effect of activation depend s on the morphology of nascent polymer and the structure of catalyst m atrix and is determined by the ability of the catalyst to undergo frag mentation induced by the forming polymer.