Prediction of activity coefficients in polymer and copolymer solutions using simple activity coefficient models

Using an extensive database that covers activity coefficients in systems of polymers and copolymers with nonpolar and polar solvents, we test the pred ictive capabilities of two simple activity coefficient models: the Entropic -FV (free volume) and a recent modification of UNIFAC by Zhong et al. (Flui d Phase Equilib. 1996, 123, 97). The only information required for their ap plication is the structure of the components and in the case of Entropic-FV also their molar volumes. The results, which include solvent and polymer a ctivity coefficient predictions (the latter based on data from molecular si mulation), indicate that both models provide satisfactory predictions-excep t where association is present-considering their simplicity, with the Entro pic-FV one being superior to the modified UNIFAC proposed by Zhong et al. T he latter, however, is a very good alternative when no accurate molar volum es are available.