METAL-COMPLEX BICENTER CATALYSTS FOR OLEFIN AND DIENE POLYMERIZATION

New bicenter metal-complex catalysts supported on dehydrated microsphe ric silica gel have been synthesized and tested in the polymerization of ethene and butadiene. The catalysts contain two components: a titan ium-magnesium- or chromium-containing compound and an oligodienyl meta l-aluminium complexes with a bridge structure (metal - Zr or Ni). A po ssibility of preparation of linear medium-density polyethylene by poly merization of ethene in gas-phase process without using co; monomers w as established. These catalysts also display high efficiency in the po lymerization of butadiene, the products obtained being the mixtures of cis-and trans-polymers. It was found that titanium-magnesium catalyst s modified by zirconium-organoaluminum compounds are most active in bo th ethene and butadiene polymerization processes. (C) 1998 Elsevier Sc ience B.V.