PERMEATION OF CARBON-DIOXIDE IN GLASSY POLY(ETHER IMIDE) AND POLY(ETHER ETHER KETONE) MEMBRANES

Sorption equilibria and permeation rates for CO2, O2 and N2 in poly(et her imide) (PEI) membrane which has a glass-transition temperature of 216-degrees-C and in poly(ether ether ketone) (PEEK) (a typical crysta lline polymer, crystallinity=0.4) membrane, whose glass-transition tem perature is 143-degrees-C, were measured at 25, 30 and 40-degrees-C an d at pressures up to 3 MPa. The pressure dependence of the mean permea bility coefficients of PEEK membrane to 02 and CO2 obeyed the conventi onal dual-mode mobility model, whereas that of PEI membrane to CO2 did not follow the conventional dual-mode mobility model. A modified dual -mode mobility model which takes into account four kinds of diffusive movements was satisfactorily used to simulate the pressure dependence.