Phase behavior of polymer–solvent mixtures

Phase equilibria for mixtures of a polymer and a supercritical solvent are investigated by means of Expanded Gibbs Ensemble simulations. Our results indicate that such systems exhibit both lower and upper critical solution temperature (LCST and UCST) phenomena. Closed-loop miscibility diagrams are observed for systems with no specific preferences for like and unlike components. The results of our simulations for Lennard–Jones polymer–solvent mixtures are in qualitative agreement with experimental data for polymers in supercritical solvents.