Ethylene/hexene copolymerization with the heterogeneous catalyst system SiO2/MAO/rac-Me2Si[2-Me-4-Ph-Ind]2ZrCl 2: The filter effect

Abstract

The main focus of this study is the ethylene/hexene copolymerization with the silica supported metallocene SiO2/MAO/rac-Me2Si[2-Me-4-Ph-Ind]2ZrCl 2. Polymerizations were carried out in toluene at a reaction temperature of 40°C-60°C and the cocatalyst used was triisobutylaluminium (TIBA). The kinetics of the copolymerization reactions (reactivity ratios rE/H, monomer consumption during reaction) were investigated and molecular weights M̄w, molecular weight distributions MWD and melting points Tm were determined. A schematic model for the blend formation observed was developed that based on a filtration effect of monomers by the copolymer shell around the catalyst pellet. © Wiley-VCH Verlag GmbH, 1999.