Estimation of diffusion coefficients for multiple penetrant/polyolefin systems based on sorption data

Abstract

The binary and ternary diffusion coefficients for gas/polymer systems can be estimated from solubility data and an equation of state to the free volume of penetrant/polymer systems. The system free volume can be calculated by the Sanchez Lacombe equation-of-state (SL-EoS), eliminating the need for viscoelastic data in determination of free volume parameters. Furthermore, this approach accounts for polymer swelling. The model gives reliable predictions for both binary and ternary systems of alkanes and alkenes in polyolefins.