FT-IR Spectroscopic study of excess thermodynamic properties of liquid mixtures containing N-methylformamide with 2-alkoxyethanols at various temperatures

Abstract

Densities, speeds of sound and viscosities were measured for the binary mixtures N-methylformamide (NMF) with 2-alkoxyethanols (2-methoxyethanol (ME), 2-ethoxyethanol (EE) and 2-butoxyethanol (BE)) at T=(303.15 to 318.15) K. These experimental data have been used to calculate excess volume (VE), excess isentropic compressibility (κsE), deviation in viscosity (∆η) and excess Gibbs free energy of activation of viscous flow (G⁎E). The excess partial molar volumes, V̅m,1E and V̅m,2E and excess partial molar volumes V̅m,1°E, and V̅m,2°E at infinite dilution have also been calculated. The variations of these properties with composition of binary mixtures suggest loss of dipolar association, difference in size and shape of the component molecules, dipole–dipole interaction and hydrogen bonding between unlike molecules. The excess parameters have been fitted to the Redlich–Kister equation and the results were analyzed in terms of acid–base interactions, hydrogen bond, and dipole–dipole interaction between unlike molecules. Further, the FTIR spectra have been recorded at 298.15K and found to be useful for understanding the presence of hydrogen bonding between oxygen atom of carbonyl group of N-methylformamide and hydrogen atom of the –OH group of 2-alkoxyethanols molecules in the present liquid mixtures. A good agreement is obtained between excess quantities and spectroscopic data.