Permeability of gas mixtures in glassy polymers with and without plasticization

Abstract

In this research, the solubility, permeability and diffusivity of gas mixtures through glassy polymers were comprehensively studied. The diffusivity of the components in the mixture was assumed to be a function of the concentration of all components in the mixture. Then, the permeability of pure species was expanded to the gas mixtures and to check the validity, the model was fitted to the experimental data for permeation of CO2/CH4 through different glassy membranes and the parameters of the model were calculated. Afterwards, the obtained parameters were used for predicting the permeability of CO2 and CH4 in the mixture. The results showed that the solubility, diffusivity, and the permeability of CO2 in the glassy polymers are suppressed in the presence of CH4 as well as plasticization. Moreover, the diffusivity (D) for pure CO2 is significantly pressure dependent in the presence of plasticization whereas with the increase in the CH4 fraction, this dependency decreases due to the reduction in the plasticization.