Polymerization of ethylene by the Zieglar-Natta catalyst systems - TiCl4/Al(C2H5)(3) supported on carbon blacks

The kinetics of ethylene polymerized on the TiCl4/AlEt3/carbon blacks with TiCl4/AlEt3/carbon black catalyst system was investigated, and a model was established. It is shown that the polymerization is determined by the featu res of the polymerization processes on the surface of the fillers, which de pends on the surface adsorption of the AlEt3 and a monomer and the surface reaction rate between them. A comparison of catalysts supported on two kind s of carbon black, acetylene black and the N550, has been made. It is found that the polymerization rates are directly a proper trend to the surface a rea of the two supports. Furthermore, the influence of the Al/Ti ratio, Ti content and the polymerization temperature on polymerization kinetics has b een studied. The relation between the polymerization rate and temperature h as been investigated in detail and described by the Arrenius law. In additi on, it is found that in contrast to the unsupported TiCl4, the interplay be tween the catalyst and the carrier is considerably important in the polymer ization kinetics. (C) 2000 Elsevier Science Ltd. All lights reserved.