Comparison of the polymerization of propene by homogeneous and heterogeneous metallocene/MAO-catalysts under different polymerization conditions

Propene was polymerized using rac-dimethylsilylbis(2-methyl-4-(1-naphtyl)in denyl)zirconium dichloride (rac-[Me2Si(2-Me-4-(1-Naphtyl)Ind)(2)]ZrCl2) und er six sets of conditions: in toluene solution, bulk toluene slurry, bulk w ith the supported metallocene, a stirred bed with polyethene and a stirred bed with NaCl. The first two procedures were carried out with methylalumino xane (MAO) as cocatalyst, the latter four were performed with methylalumino xane supported on silicagel (MAO/SiO2) as activator. The differences betwee n the procedures employed were examined by comparison of the polymer proper ties of the resulting products and activities at different temperatures. Th e polymerization procedure has a significant influence on the products. The polypropenes obtained with the homogeneous catalyst systems have generally high melting points, and molar masses and exhibit very high activities. Th e heterogeneous analogues, on the other hand, gain enhanced stability by su pporting, even at higher temperatures.