Infinite-dilution activity coefficients of solvents in solvent-polymer systems from inverse gas-liquid chromatography

The infinite-dilution activity coefficients of organic solvents of various polarities in polystyrene and polycarbonate were determined by inverse gas-liquid chromatography. The obtained values were compared with those calculated from energy interaction parameters and the properties of pure: substances with the use of the UNIFAC-FV group-contribution quasi-chemical model and the lattice-fluid equation of state. The predictive capabilities of these approaches are assessed. The values of the thermodynamic Flory-Huggins parameter, which is a criterion of solvent-polymer compatibility, were calculated from the infinite-dilution activity coefficients. Recommendations concerning solvent selection are made.