An improved prediction result of Entropic-FV model for vapor-liquid equilibria of solvent-polymer systems

In this work, entropic expressions of UNIFAC-FV and Entropic-FV models were evaluated by using an extensive database of infinite dilution vapor-liquid equilibrium (VLE) data of athermal systems containing polypropylene, polyethylene, and polyisobutylene. For the infinite dilution athermal systems, performance of the Entropic-FV model was better than that of the UNIFAC-FV model. Then, finite concentration VLE data of non-athermal systems that consisted of 16 polymers and 36 solvents containing a large variety of solvent-polymer systems ranging from nonpolar to polar substances were considered to optimized 46 pairs of group interaction parameters of the Entropic-FV model. For systems containing polar solvents of three types of solvents studied, revised group interaction parameters gave significant improvements from 17.9 to 13.0% average absolute deviation (AAD) of solvent activities. For overall results, improvements were achieved from 15.1 to 12.4% AAD.