ISOSPECIFIC POLYMERIZATION OF ALPHA-OLEFINS IN THE PRESENCE OF METALLOCOMPLEX CATALYSTS FIXED ON GRAPHITE

Studies of activity and stereospecificity in polymerizations of propyl ene and butene-l with several metal-complex catalysts fixed on a graph ite surface are reported. High catalytic activity was observed at a st rictly determined Ti:graphite ratio. Maximum stereospecificity is obse rved at the maximum of catalytic activity. Characterization of the cat alyst obtained from the interaction of TiCl4-(C2H5)(2)AlCl with graphi te by chromatographic, polarographic, X-ray and ESR techMques was dire cted to the origin of the modifying effect of graphite. These results indicated the formation of stable metal complexes containing Ti compou nds with Ti-C2H5 moieties in the sites of crystal-lattice defects. Som e electrophysical and mechanical properties of polypropylene-graphite sample are also presented. Copyright (C) 1996 Elsevier Science Ltd