MEASUREMENT OF VAPOR SORPTION EQUILIBRIA OF POLYMER-SOLUTIONS AND COMPARATIVE CORRELATION BY G(E)-MODELS AND LATTICE EQUATIONS OF STATE

Solvent sorption equilibrium data of binary solvent-polymer systems we re measured with a vacuum electro-microbalance equilibrium cell. Teste d solvents were benzene, n-pentane, cyclohexane, n-hexane, water and m ethanol. Polymers tested were poly(dimethylsiloxane), poly(iso-butylen e), poly(propylene oxide) and poly(vinyl. alcohol). Data obtained in t he present study, together with existing literature data, were correla ted by two g(E)-models, such as UNIQUAC and the Flory-Huggins model, a nd four equations of state which stem from the lattice fluid theory, s uch as models proposed by Flory, Sanchez and Lacombe, Panayiotou and V era, and the NLF model proposed recently by the present authors. For e ach solvent-polymer system, the provided models give a quantitative co rrelation. The advantages and drawbacks of the g(E)-model and equation of state approaches are also discussed.