Investigation on some thermophysical properties of poly(ethylene glycol) binary mixtures at different temperatures

Densities q and viscosities eta for the binary mixtures of poly(ethylene glycol) + water, + 1,2-ethanediol, + 1,3-propanediol, + 1,4-butanediol over the entire concentration range were determined at temperatures (298.15 to 308.15) K with 5 K interval. The experimental data were used to calculate the excess molar volume V-m(E), coefficient of thermal expansion alpha, excess coefficient of thermal expansion alpha(E), excess Gibbs free energy of activation Delta G*(E), and other activation parameters (i.e., Delta G*; Delta H*; Delta S*). The values of excess properties were fitted to Redlich-Kister polynomial equation to estimate the binary coefficients. The excess refractive index n(E) and electronic polarizability alpha(e) of PEG + water binary mixtures were also determined from the experimental values of refractive indices. The viscosity data were correlated with Grunberg-Nissan and Tamura-Kurata equations. Moreover, the Prigogine-Flory-Patterson theory has been used to correlate the excess molar volumes of the studied mixtures. (C) 2012 Elsevier Ltd. All rights reserved.