INVESTIGATION ON THE POLYMER PARTICLE GROWTH IN ETHYLENE POLYMERIZATION WITH PS BEADS SUPPORTED RAC-PH2SI(IND)(2)ZRCL2 CATALYST

The mechanism of polyethylene particle growth was investigated using p oly(styrene-co-divinylbenzene) (PS beads) supported rac-Ph2Si(Ind)(2)Z rCl2 catalyst. From the analysis of the resulting polyethylene particl es by SEM (scanning electron microscopy) and EPMA (electron probe micr oanalysis), it was found that the active species are located on the su rface layer of catalyst particles and that the catalytic species are u niformly distributed throughout the polymer particles, whereas the cor es of PS beads, which lack a potential active species, were not disint egrated during polymerization. These results suggest that the PS beads supported catalyst also follows the fragmentation and replication pro cess as frequently observed with the MgCl2 supported Ziegler-Natta cat alysts. (C) 1998 Elsevier Science Ltd. All rights reserved.