Synthesis of polymer supported borate cocatalysts and their application to metallocene polymerizations

Polymer supported borate complexes were synthesized using poly(styrene-co-4-bromostyrene) and polystyrene-beads as carriers. These complexes were reacted with rac-Et[Ind](2)ZrCl2 (Ind = indenyl) or Ph2C[(Cp)Flu]ZrCl2 (Cp = cyclopentadienyl, Flu = Fluorenyl) in toluene, at a molar ratio of [Zr]/[B] = 1, to obtain polymer supported catalysts. Polymerizations of ethylene and propylene were conducted over them in the presence of Al(i-C4H9)(3) as an activator. When poly(styrene-co-4-bromostyrene) was used as the carrier, the resulting soluble catalyst showed high activity comparable to those of the corresponding homogeneous catalysts for ethylene polymerization. For propylene polymerization, however, those catalysts showed low-activity. Even though the insoluble catalysts prepared with polystyrene-beads as carrier displayed far less activities for both ethylene and propylene polymerizations, it was found that the shape of polyethylene obtained at 40 degrees C is a replica of the carrier particle. (C) 2000 Elsevier Science Ltd. All rights reserved.