The reduced Redlich-Kister equations for correlating volumetric and viscometric properties of N,N-dimethylacetamide + dimethylformamide binary mixtures at temperatures from 298.15 to 318.15 K

Abstract

Excess molar volumes and viscosity deviations in N,N-dimethylacetamide + dimethylformamide binary mixtures at 298.15, 308.15 and 318.15 K were calculated from experimental density and viscosity data presented in the previous work. Here these experimental values were used to test the applicability of the correlative reduced Redlich-Kister equation and the recently proposed Herráez equation. Their correlation ability at different temperatures, and the use of different number of parameters, is discussed for the case of limited experimental data. These relative functions are important to reduce the effect of temperature and, consequently, to reveal the effects of different types of interactions. Limiting excess partial molar volumes at infinite dilution were deduced from different methods, parameters of molar Gibbs energy of activation of viscous flow against compositions were investigated. The results of these observations have been interpreted in terms of structural effects of the solvents. 1H-NMR studies of these mixtures are also reported. © 2012 Copyright Taylor and Francis Group, LLC.