Co- and terpolymerization of ethylene, propylene and higher alfa-olefins with high propylene contents using metallocene catalysts

M.A. VILLAR; M.L. FERREIRA

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY

John Wiley & Sons, Inc.

Año: 2001 vol. 39 p. 1136 - 1148

0887-624X

The copolymerization of propylene/ethylene and terpolymerization of propylene/ethylene/α-olefins using long-chain α-olefins such as 1-octene and 1-decene have been carried out using EtInd2ZrCl2//methylaluminoxane. High concentrations of propylene and low concentrations of α-olefins (near 2 mol % of the total olefin concentration in the liquid phase) were used. The effect of the ethylene concentration in copolymerizations of propylene/α-olefins was studied at medium ethylene contents (12 and 40 mol % in the gas phase). The polymers were molecularly characterized by gel permeation chromatography-multiangle laser light scattering, wide-angle X-ray scattering, Fourier transform infrared spectroscopy, and DSC analyses. The shorter α-olefin studied (1-octene) produced the highest improvement of activity in terpolymerization at 12 mol % ethylene in the gas phase. About 2 mol % of 1-octene in the liquid phase increases the activity and decreases the molecular weight of terpolymers with respect to corresponding copolymers, whereas the mp is increased by almost 30 °C. The ?termonomer effect? is less evident when higher amounts of ethylene are used.