Diffusion and swelling of carbon dioxide in amorphous poly(ether ether ketone)s

The interaction of the supercritical carbon dioxide (sc-CO2) with the amorphous poly(ether ether ketone) was systematically investigated by desorpted measurement. The PEEK films were treated with CO2 at different pressure, temperature and soaking time. The gravimetric desorption data were kinetically and thermodynamically evaluated assuming Fickian diffusion. The behavior of desorpted diffusion deviated from Fickian diffusion, when the pressure increased and ranged between 3 and 28 MPa. Swelling and diffusion of CO2 in relation to system temperature and pressure were discussed. Some different extrapolated methods were introduced here to obtain the C0. Comparison to the gas contents in these film samples containing different side group, the effects of side groups on the gas diffusion and solubility were discussed. The data of gas permeability could be cited to validate this result.