Prediction of infinite dilution solvent activity coefficients in polymer solutions: comparison of prediction models

The modified group-contribution lattice-fluid equation of state (GCLF-EOS), which is capable of predicting accurately vapor-liquid equilibria in polymer-solvent solutions, was developed by calculating group contributions for the adjustable parameters from the equilibrium properties of low molecular weight compounds only. The modified GCLF-EOS has been used to predict the solvent activity coefficients at infinite dilution of solvents, and its prediction results have been compared with those of the original GCLF-EOS, the UNIFAC-free volume (FV), the entropic-FV, and the revised GC-Flory EOS. Extensive statistical analyses were performed using all the currently available experimental data. The modified GCLF-EOS provided the best performance in the prediction of infinite dilution activity coefficients. The modified GCLF-EOS requires only the structures of the solvent and polymer in terms of their functional groups as input information.