The N-methylpyrrolidone–(C1–C10) alkan-1-ols solvent systems

Abstract

Densities, viscosities and refractive indices of the N-methylpyrrolidone + alkan-1-ols (C₁–C₁₀) binary systems at 298.15 K and atmospheric pressure have been measured over the whole composition range; from these measurements the values for excess molar volumes, mixing viscosities, internal pressures, and excess Gibbs energies of activation for viscous flow were calculated. The molecular interactions in these mixtures can be interpreted on the basis of the variation of the excess and mixing functions with the mixture composition. The cubic equations of state proposed by Soave and Peng–Robinson were used to process the data on excess molar volumes and partial molar volumes using two different mixing rules. Several semiempirical methods for predicting viscosities of liquid mixtures were applied with good results; the ability of the models proposed by Cao (GC-UNIMOD) and Wu to predict viscosity data was also tested.