Acoustic and volumetric study of binary mixtures containing Ethyl propionate with amides at various temperatures

The development of biofuels to replace fossil fuels has recently increased at an exponential rate. Many chemical molecules with a wide range of functional groups make up biofuels. There is a strong correlation between the interactions between these molecules and the performance of biofuels. In this paper, the authors presented the new findings related to interactions existing in ethyl propionate and Formamide(F), N-Methylformamide (NMF), and N, N-Dimethylformamide (DMF) in a pure state as well as in their mixtures. Densities and speeds of sound at various temperatures (298.15–323.15 K) and at ambient pressure 0.1 MPa have been measured for these mixtures. From experimental data, the excess properties such as excess molar volume, $V_m^E$, excess isentropic compressibility, ${\kappa }_s^E$, excess molar isentropic compressibility, $K_{s,m}^E$, excess speed of sound, $u^E$, and excess isobaric thermal expansivity, ${\alpha }_p^E$, of the investigated mixtures were calculated. All the excess parameter values were fitted using the Redlich-Kister polynomial smoothing equation. The results were analysed in terms of molecular interactions. 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 from the experimental density measurements and analytically obtained using Redlich-Kister polynomials. The variations of these parameters with changes in composition and temperature have been discussed in terms of intermolecular interactions prevailing in these mixtures.