Ethylene polymerization using (n-BuCp)₂ZrCl₂ catalyst activated with a cross-linked MAO-supported cocatalyst

A new type of cross-linked methylaluminoxane (MAO)-supported cocatalyst has been prepared by the reaction of a soluble MAO and a cross-liking agent such as an aromatic diamine compound. The cross-linked MAO-supported cocatalyst was used for the polymerization of ethylene in the presence of bis(n- butylcyclopentadienyl) zirconium dichloride, (n-BuCp)₂ZrCl ₂. The catalyst activity of (n-BuCp)₂ZrCl₂ cocatalyzed with the new supported cocatalyst was higher than that of the commercial silica-supported MAO (SMAO) cocatalyst. The molecular weight and the bulk density of the polyethylene produced by using the new supported cocatalyst were slightly higher than those of polyethylene synthesized using commercial SMAO. The resulting polyethylene particles possess spherical morphologies with very few fine particles.