Solvent diffusion in amorphous polymers: Polyvinyl acetate-toluene system

In a previous publication (Tihminlioglu et al., J Polym Sci Part B: Polym P hys 1997, 35, 1279), we presented an extensive analysis of the polyvinyl ac etate-toluene system. The inverse gas chromatography (IGC) technique was us ed to measure phase equilibria and diffusion coefficients above and near th e glass-transition temperature of a polymer. At temperatures above the glas s transition, the capillary column model developed by Pawlisch et al. (Macr omolecules 1987, 20, 1564) was used. For the finite concentration region, t he modified model of Tihminlioglu and Danner (J Chromatogr A 1999, 845, 93) was applied. Data obtained with the IGC method were in agreement with data measured with the gravimetric and piezoelectric sorption techniques. In th is work, we revisit the partition coefficient issue and provide some new da ta at lower temperatures. At temperatures near the glass-transition tempera ture, the modification of the capillary column model proposed by Vrentas et al. (Macromolecules 1993, 26, 6670) was used for the infinite dilution reg ion. The diffusion data correlated well with the Vrentas-Duda free-volume m odel. (C) 2000 John Wiley & Sons, Inc.