A STUDY OF THERMODYNAMIC AND INTERACTION PARAMETERS OF OLEIC ACID WITH SOME APROTIC SOLVENTS AT TEMPERATURES OF 303.15, 308.15, AND 313.15 K

Abstract

Density (ρ) and viscosity (η) of binary mixtures of oleic acid with 1,4-dioxane, N,N-dimethylformamide (N,N-DMF) and dimethylsulfoxide (DMSO) were measured over the entire composition range at 303.15, 308.15, and 313.15 K. The excess molar volume (V^E), deviation in viscosity (Δη), and excess free energy of activation of viscous flow (G*^E) were calculated using corresponding experimental data as a function of composition. Interaction parameters d₁₂, H₁₂, T₁₂, and W_vis/RT were determined from experimental data of viscosity using the well-known two-body models of Dolezalek-Schulze, Grunberg-Nissan, Tamura-Kurata, and Katti-Chaudhari respectively. The parameters M₁₂ and M₂₁ were calculated using the three-body McAllister relation, and it was found that correlating ability significantly improves for these nonideal systems as adjustable parameters increase. The excess and deviation functions V^E, Δη, and G*^E were found to have positive values, and these values indicate the presence of dispersion forces as forces of molecular interactions in these binary mixtures. The computed results were fitted to the Redlich-Kister polynomial equation. The main thrust of this study is to correlate the excess properties and interaction parameters with the nature of molecular interactions between the mixing components.

Keywords:

• Aprotic solvents
• Binary mixtures
• Density
• Interaction parameter
• Oleic acid
• Viscosity

Acknowledgment

Thanks are due to UGC (New Delhi) for financial assistance and to Prof. N. V. Sastry for his criticism, help, and suggestions.

Notes

^a Bernardo-Gil et al., 1990.

^b Cedeño et al., 2000.

^c Papanatasiou and Ziogas, 1992.

^d Contreras, 2001.

^e Liu et al., 1999.

^f Bhuiyan and Uddin, 2008.

^g Nikam and Kharat, 2003.

^h Joshi et al., 1990.

ⁱ Baragi et al., 2005.

^j Aralaguppi et al., 1997.

^k Nikam et al., 1996.