Polymerization with zeolite catalysts: II. Vinyl ethers over H-mordenite and H-Y

Abstract

Ethylvinyl, n-butylvinyl and isobutylvinyl ethers all react readily over H-mordenite and H-faujasite (H-Y) near room temperature to produce low molecular weight polymers. Over H-mordenite all follow the kinetic relation, Q t = k(t) 1 2 + γ , where Q t is the mass uptake at constant pressure p and time t. k and γ are coefficients. Over H-Y the kinetics followed the Elovich equation Q t = k ln t + γ. Over both catalysts the rate coefficients were linear functions of pressure, i.e., k = ( ap + b) where a and b are coefficients. As shown previously for n-butylvinyl ether over H-mordenite [Barrer, R. M., and Oei, A. T. T., J. Catal. 30, 460 (1973)], water in small amounts was also a co-catalyst for polymerization of the same vinyl ether over H-Y. The kinetics have been interpreted as indicating that little polymer forms within the channels of mordenite but that within those of faujasite considerable polymer forms and progressively blocks intracrystalline sites. Supporting evidence of this has been obtained by water Sorption in and thermogravimetric analyses of zeolite + polymer composites.