Co- and terpolymerization of ethylene, propylene, and higher alpha-olefinswith high propylene contents using metallocene catalysts

The copolymerization of propylene/ethylene and terpolymerization of propyle ne/ethylene/alpha -olefins using long-chain alpha -olefins such as 1-octene and 1-decene have been carried out using EtInd(2)ZrCl(2)//methylaluminoxan e. High concentrations of propylene and low concentrations of alpha -olefin s (near 2 mol % of the total olefin concentration in the liquid phase) were used. The effect of the ethylene concentration in copolymerizations of pro pylene/alpha -olefins was studied at medium ethylene contents (12 and 40 mo l % in the gas phase). The polymers were molecularly characterized by gel p ermeation chromatography-multiangle laser light scattering, wide-angle X-ra y scattering, Fourier transform infrared spectroscopy, and DSC analyses. Th e shorter alpha -olefin studied (1-octene) produced the highest improvement of activity in terpolymerization at 12 mol % ethylene in the gas phase. Ab out 2 mol % of 1-octene in the liquid phase increases the activity and decr eases the molecular weight of terpolymers with respect to corresponding cop olymers, whereas the mp is increased by almost 30 degreesC. The "termonomer effect" is less evident when higher amounts of ethylene are used. (C) 2001 John Wiley & Sons, Inc.