pVT Data Analysis for the Prediction of Vapor Sorption in Glassy Polymers through the Nonequilibrium PC-SAFT Model

The first implementation is presented for the Restrained Swelling (RS) version of the Nonequilibrium Thermodynamics for Glassy Polymers (NET-GP) approach, which counts on the PC-SAFT EoS to express the equilibrium properties of polymer-solute mixtures. Examples for application of the resulting model (NE-RS) PC-SAFT to the prediction of gas and vapor solubility in conventional glassy polymers are first discussed. Emphasis is put on the role of pVT properties for pure polymer species, as measured at both melt and glass conditions. The first application is then presented for the NE-RS approach to the analysis of gas and vapor solubility data in a polymer with intrinsic microporosity, for which pVT data in the melt phase cannot be measure and reliable values for the volumetric properties at glassy conditions are not available. In the latter analysis, both kinds of pVT properties are eventually retrieved from the best fit of the selected solubility data and the result for the polymer pVT characteristics are finally compared with those recently presented in the literature as obtained after the use of “Dry Glass Reference Perturbation Theory“ (DGRPT), within the same NET-GP approach.