Correlations among Composition, Temperature, and Density, Viscosity, or Derived Thermodynamic Properties of Binary Mixtures of Tri-n-butyl Phosphate withn-Hexane orn-Dodecane

Abstract

Correlations proposed in this work predict density and viscosity with better accuracy in comparison with existing correlations. Dimensionless specific volume and logarithmic viscosity of binary mixtures are nth order (1 ≤ n ≤ 4) polynomials of the mole fraction of one of the components at the system temperature, and parametric coefficients of such polynomials are mth order (1 ≤ m ≤ 4) polynomials of system temperatures. Parametric coefficients of fitted fourth order Redlich–Kister type equations (RK-eq) are linear functions of temperature. Excess properties and derived thermodynamic properties of both mixtures have been discussed in terms of intramolecular and intermolecular interactions of molecules. Like virial equations of state (EOS), dimensionless RK-eq quantifies to calculate virial coefficients and hence to compute interactions among component 1–1, component 1–2, and component 2–2. Parametric coefficients of the Vogel–Fulcher–Tammann equation of viscosity are polynomials of mole fractions of one of the components.