Synthesis of a TiCl_4 Ziegler-Natta Catalyst Supported on Spherical MgCl_2 ? nEtOH for the Polymerization of Ethylene and Propylene

摘要

Experiments designed to prepare Ziegler-Natta catalysts with controlled particle morphology are reported. Different dealcoholation processes are used on the adduct MgCl_2 · nEtOH to prepare the catalysts: either thermal treatment or chemical dealcoholation employing different substances such as titanium tetrachloride, triethylaluminium, dichlor-odimethylsilane, and chlorotrimethylsilane. In addition, dichlorodimethylsilane dealcoholation is also performed after thermal treatment. SEM analysis of adducts, supports, and catalysts is carried out. The obtained catalysts are characterized through impregnated titanium content evaluation. The polyethylenes and poly(propylene)s obtained employing the so prepared catalysts show spherical morphology when examined by optical microscopy.