III International Conference

PP-II-73STUDY OF MULTICENTER NATURE OF SUPPORTED ZIEGLER-NATTA TYPECATALYSTS OVER DATA ON MOLECULAR WEIGHT DISTRIBUTION ANDCOMPOSITION HETEROGENEITY OF POLYOLEFINESMatsko M.A., Echevskaya L.G., Мikеnаs Т.B., Vanina M.P., Zаkhаrоv V.А.Boreskov Institute of Catalysis SB RAS, Novosibirsk, RussiaE-mail: Matsko@catalysis.ruOne of the most important problems in olefin polymerization over highly activesupported Ziegler-Natta (ZN) type catalysts is the regulation of polymer structure andmolecular mass distribution (MMD). It is known that supported ZN catalysts areheterogeneous on the reactivity of active centers (multisite catalysts). However the nature ofthe heterogeneity remains unclear so far.In this work the heterogeneity of active centers of supported titanium magnesium (TMC)and vanadium-magnesium catalysts (VMC) was studying based on the data on thecomposition and distribution of polyolefins fractions. Separation of polyethylene (PE) andethylene-α-olefins copolymers onto narrow fractions (Mw/Mn=1-2) was done with newmodern equipment (TREF prep.mc2). Based on detailed analysis of polymer narrow fractionsby GPC and IR-spectroscopy the quantity and distribution of the different types of activecenters in TMC and VMC were established. The parameters affecting on the distribution ofactive centers in these catalysts have been determined.298