Simultaneous measurements of the density and viscosity of 1-hexene + 1-decene mixtures at high temperatures and high pressures

Abstract

The density and viscosity of binary 1-hexene+1-decene mixtures have been simultaneously measured over the temperature range from 298 to 470K and at pressures up to 196MPa using hydrostatic weighing and falling-body techniques, respectively. The measurements were made for three concentrations of 0.25, 0.50, and 0.75 mass fraction of 1-decene. The combined expanded uncertainty of the density, pressure, temperature, and viscosity measurements at the 95% confidence level with a coverage factor of k=2 is estimated to be 0.15 to 0.30%, 0.05%, 0.02K, and 1.5 to 2.0%, respectively, depending on temperature and pressure ranges. The measured densities and viscosities were used to calculate excess molar volumes and viscosity differences. It is shown that the values of excess molar volume for 1-hexene+1-decene mixtures are positive, while the viscosity differences are negative at all measured temperatures and pressures over the whole concentration range. The measured densities and viscosities were also used to develop a Tait-type equation of state and viscosity correlation model for liquid 1-hexene+1-decene mixtures. Theoretically based Arrhenius–Andrade type equations with concentration dependent coefficients were used to represent the temperature and concentration dependences of the measured viscosities for liquid 1-hexene+1-decene binary mixtures at atmospheric pressure.