Magnesium chloride supported metallocene catalysts in olefin polymerizations

MgCl2 supported systems and homogeneous Cp2ZrCl2 and Et(Flu)2ZrCl2 catalysts were used to investigate their behavior in ethylene and propylene homopolymerization. MgCl2 was activated by vigorous ball milling with ethyl benzoate. Two types of catalysts were prepared: immobilizing the metallocene catalyst directly on the carrier and also immobilizing the metallocene catalyst on the carrier pretreated with methylaluminoxane (MAO). Polymerization was carried out in toluene at 50°C and 60°C. MAO was employed as cocatalyst in all polymerizations. Molecular weight, molecular weight distribution, melting point and crystallinity were determined. It is important to report that the molecular weight distribution of polymers, obtained from MgCl2 supported metallocene catalysts, remained narrow (around 2).