Fickian diffusion in glassy polymer‐solvent systems

Abstract

Abstract A free‐volume theory is developed for the analysis of Fickian diffusion processes in glassy polymers. Equations are presented for the prediction of mutual diffusion coefficients in concentrated glassy polymer‐penetrant systems. The concentration dependence of the mutual diffusion coefficient is dependent on how much free volume the solvent contributes to the system and on how the addition of solvent affects the densification of the polymer matrix. © 1992 John Wiley & Sons, Inc.