Mechanisms of gas permeation through polymer membranes

The objective of the present study is to investigate the mechanisms by which gases are transported in and through polymer membranes, and the dependence of these mechanisms on pressure and temperature. Recent work has been focused on the permeation of gases through membranes made from glassy polymers, i.e., at temperatures below the glass transition of the polymers (Tg). During the past report period, a new theoretical model of gas solubility in glassy polymers was developed and tested with experimental data from the literature. This model describes satisfactorily the shape of solubility isotherms over wide ranges of pressure and temperatures, and is particularly useful for penetrant gases which ranges of pressure and temperatures, and is particularly useful for penetrant gases which plasticize (swell) glassy polymers. Work also continued on the behavior of light gases in poly (alkyl methacrylates). 18 refs., 6 figs.