Density, Viscosity, and Excess Properties of MDEA + H2O, DMEA + H2O, and DEEA + H2O Mixtures

This study presents measured density and viscosity of N-methyldiethanolamine (MDEA) + H2O, Dimethylethanolamine (DMEA) + H2O, and Diethylethanolamine (DEEA) + H2O mixtures. The density was measured at amine mass fraction w(1) from 0.3 to 1 for the temperature range 293.15-353.15 K. The excess molar volumes V-E were determined from density data. Redlich-Kister type polynomials were proposed to fit V-E and density deviation ln(rho(gamma)) to represent measured densities. The viscosity was measured at amine mass fraction w(1) from 0.3 to 1 for the temperature range 293.15-363.15 K. The viscosity deviation eta(E) and excess free energy of activation for viscous flow Delta G(E)* were determined from measured viscosities and examined for intermolecular interactions among mixture molecules. Correlations were proposed to fit viscosity data with acceptable accuracies. The McAllister's three-body model was adopted to fit kinematic viscosities determined from density and dynamic viscosity data. The results showed the importance of examining intermolecular interactions that are discussed in McAllister's four-body model to improve the accuracies of data fits.