Thermophysical properties of binary mixtures of polyethylene glycol 400 with n-propanol

Densities (rho), viscosities (eta) and refractive indices (n(D)) of the binary system polyethylene glycol 400+n-propanol have been measured at (293.15, 298.15 and 303.15) K and at atmospheric pressure, over the entire composition range. From experimental results, the values of excess properties have been calculated and fitted to the Redlich-Kister equation. Negative deviations are observed for excess molar volumes, deviation in viscosities and excess internal pressures, while positive deviations are observed in the case of refractive indices and excess Gibbs energies of activation of viscous flow at all of the temperatures and in the entire concentration range. Of the studied models, the Jouyban-Acree model is suitable for describing the viscosity of the PEG 400+n-propanol binary system. The refractive index predicted by the Newton-mixing rule shows the best agreement with experimental values. The values of thermodynamic functions of activation viz., Delta G(#), Delta H-# and Delta S-#, are positive for the PEG 400+n-propanol binary system.