No abstract

The aluminohydride of zirconocene Me3SiCp2ZrH3AlH2 was supported on pre‐treated SiO2, and its catalytic activity for ethylene polymerization and ethylene‐1‐hexene copolymerization was evaluated in order to compare with the corresponding activity of the complex in solution. As expected for systems based on metallocenes, the aluminohydride of zirconocene complex showed higher activity in solution than in suspension, however its thermal and kinetic stability was significantly increased. The effect of the co‐catalyst concentration (MAO) on the activity and the molecular weight of the polymers are also reported in this study, finding that in heterogeneous phase low concentrations of MAO were used to activate the pre‐catalyst. The MW of the polymers and copolymers synthesized with the supported Me3SiCp2ZrH3AlH2/SiO2 could be controlled by adding molecular hydrogen (H2) as chain transfer agent in the polymerization and copolymerization reactions.