Densities and viscosities of (ethylene glycol - water) and (1,3-propanediol - water) binary mixtures at high temperatures of 373.2 and 473.2 K and high pressures up to 40 MPa

Densities and viscosities of ethylene glycol - water and 1,3-propanediol - water binary mixtures have been measured over the whole composition range at 373.2 K and 473.2 K and at pressures up to 40 MPa. The excess molar volumes combined with partial molar volumes, and viscosity deviations have been calculated from the measurement data. The activation Gibbs free energy of viscous flow has been also evaluated from the density and viscosity data. These results were compared with the previously reported results of the monohydric alcohol - water mixtures with the same carbon numbers to discuss the effect of hydroxyl group and alkyl chain length on these properties in the wide range of temperature and pressure. The physical properties of the alcohol - water mixtures were strongly influenced by the molecular structure of the alcohol molecules under the studied conditions. In particular, the excess molar volumes and viscosity deviations showed very different behaviors for monohydric and dihydric alcohol - water mixtures.