Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

Densities, viscosities and speeds of sound of the binary liquid mixtures of N-methyl-2-pyrrolidone (NMP) with Cyclohexylamine (CHA) , Cyclohexanol (CHOL) and Cyclohexene (CHE) at temperatures of 303.15 - 318.15 K are measured over the entire composition range. From the experimental values excess molar volume , deviation in isentropic compressibility Aks, excess free length , deviation in viscosity Ac are computed. The variation with the temperature and concentration are discussed in terms of molecular interactions. All the excess parameters and deviations are fitted to Redlich - Kister polynomial equation to estimate the binary interaction parameters and mean deviation from the regression lines. The sign and magnitude of the computed parameters are discussed to reveal the nature and type of interactions existing between the component molecules in the binary mixtures. Thermodynamic investigations under the present study reveals the strong inter molecular interactions between the unlike molecules in the binary systems of NMP + CHA, NMP + CHOL whereas in the other binary system NMP +CHE the reverse trend is observed due to dispersion forces. The strength of interaction of CHA, CHOL and CHE with NMP found to follow the order CHA greater than CHOL greater than CHE. FT-IR studies of these mixtures have been estimated and analyzed to study the interactions between unlike molecules. A good agreement is observed between the excess parameters and FT-IR studies.