Densities, Excess Molar Volumes, Viscosity, and Refractive Indices of Binary and Ternary Liquid Mixtures of Methanol (1) + Ethanol (2) + 1,2-Propanediol (3) at P = 81.5 kPa

Abstract

Excess molar volume, VmE, and excess partial molar volume, ViE, of the ternary mixtures of methanol (1) + ethanol (2) + 1,2-propanediol (3) and of two binaries of methanol (1) + 1,2-propanediol (3) and ethanol (2) + 1,2-propanediol (3) have been investigated from the density, ρ, measurements over the entire range of compositions at temperatures (298.15, 303.15, and 308.15) K and at P = 81.5 kPa. The limiting values of the excess partial molar volumes at infinite dilution, ViE,∞, and thermal expansion coefficients, α, of the pure components are also evaluated. The dynamic viscosity, η, of the ternary and the relevant binary mixtures and the refractive indices, nD, of the binary mixtures at temperature 303.15 K were measured. The measured systems exhibited negative values of VmE and become more negative with increasing temperatures. The excess molar volumes, dynamic viscosity, and refractive index deviations were correlated with the Redlich−Kister and the Cibulka equations for the binary and ternary system, respectively. The excess molar volumes, VmE, of the binary mixtures were compared with values from the literature in the region of overlap.