Thermodynamic and transport properties of binary mixtures containing 1,2-propanediol with 2-methoxyethanol and 2-ethoxyethanol at different temperatures

Abstract

In the present investigation density, speed of sound, and viscosity have been reported for binary liquid mixtures of 1,2-propanediol (1,2-PD) with 2-methoxyethanol (2-ME) and 2-ethoxyethanol (2-EE) over the entire composition range at T= (298.15–323.15) K. From the experimental data, excess molar volume, ($V_m^E$), excess isentropic compressibility, (${\kappa }_s^E$), excess molar isentropic compressibility, (${\kappa }_{s,m}^E$), excess speed of sound, ($u^E$), excess isobaric thermal expansion,${\alpha }_p^E$, and deviation in viscosity ($\Delta \eta$) of liquid mixtures have been calculated. The excess partial molar volume,${\overline{V}}_{m,1}^E$, ${\overline{V}}_{m,2}^E$ , excess partial molar isentropic compressibility, ${\overline{K}}_{s,m,1}^E$${\overline{K}}_{s,m,2}^E$ over the whole composition range together with partial molar volume,${\overline{V}}_{m,1}^0$, ${\overline{V}}_{m,2}^0$, partial molar isentropic compressibility ${\overline{K}}_{s,m,1}^0$,${\overline{K}}_{s,m,2}^0$, excess partial molar volume,${\overline{V}}_{m,1}^{0E}$, ${\overline{V}}_{m,2}^{0E}$ and excess partial molar isentropic compressibility, ${\overline{K}}_{s,m,1}^{0E}$,${\overline{K}}_{s,m,2}^{0E}$ at infinite dilution have also been calculated. All excess properties have been correlated using the Redlich-Kister smoothing polynomial equation. The $V_m^E$ results are analysed in the light of Prigogine-Flory-Patterson theory. Analysis of each of the three contributions viz. interactional, free volume, and P* to $V_m^E$ has shown that interactional contribution and free volume effect are negative for all the mixtures, and P* contribution is positive for the mixtures of 2-ME. The variations of these parameters with changes in composition and temperature have been discussed in terms of intermolecular interactions prevailing in these mixtures. Further, the viscosities of these binary mixtures were correlated theoretically by using various empirical and semi-empirical models and the results were compared with the experimental findings.