Evaluation of Water Activity in H2O-PEG400-PEG6000 Solutions between 318.15 and 348.15 K

Abstract

The vapor pressure of H2O(1)-polyethylene glycol 400(2)-polyethylene glycol 6000(3) solutions was evaluated experimentally in a temperature range between 318.15 and 348.15 K and in a broad range of concentrations. The dependence of the solvent activity on composition was evaluated and correlated by means of a polynomial expression, in terms of concentrations, volumetric and mass fractions, and temperature, obtaining in all cases standard deviations less than 0.0086 and 0.0106 for a1(φ2,φ3,T) and a1(w2,w3,T), respectively.