Prediction of Solubilities and Partition Coefficients in Polymers Using COSMO-RS

Recent
results concerning the prediction of thermodynamic properties
of solutes in polymers are presented. In particular, the computation
of vapor–liquid and gas–liquid equilibria (i.e., liquid
and gas solubilities) in different polymers and partition coefficients
between the polymer and a solvent phase are addressed. Calculations
have been carried out using COSMO-RS theory which combines quantum-chemical
calculations with efficient statistical thermodynamics for intermolecular
interactions. Predictions for vapor–liquid equilibria and for
partition coefficients have been improved by incorporation of polymer-specific
entropic contributions due to free volume effects. It is demonstrated
that a high predictive accuracy is obtained if the polymer is sufficiently
characterized by its composition, density, and crystallinity. The
approach is currently limited to gaseous and liquid solutes and to
linear, i.e. non-cross-linked polymers without any significant swelling.