POLYMERIZATION OF ETHYLENE USING HIGH-ACTIVITY ZIEGLER-TYPE CATALYSTS- ACTIVE-CENTER DETERMINATION

The concentration of active centers of a high-activity magnesium chlor ide-supported Ziegler-Natta catalyst has been determined using three d ifferent methods. The initial active center concentration has been det ermined by quenching the reaction slurry with MeOT. To determine the c oncentration of the propagation species along the course of the polyme rization the radio-tagging agent, (CO)-C-14, and the tagging agent, CS 2, were used. CS2, was also investigated as a tagging agent of the gro wing chains, in a metallocene catalyst system. The results obtained we re compared to obtain some insight about the reliability of each metho d and the kind of information each method can provide. (C) 1998 John W iley & Sons, Inc.