Volumetric properties of aqueous solutions of mono, and diethylethanolamines at temperatures from 5 to 80 °C II

Densities of aqueous solutions of monoethylethanolamine (MEEA) and diethylethanolamine (DEEA) were measured over the whole range of concentrations at temperatures from 5 to 80 °C. Densities of these systems show different behavior at both lower and higher concentration of ethanolamine. This behavior was classified into two zones: at x2=0.12 for (MEEA+water) and at x2=0.04 for (DEEA+water) mixtures. It is found that in the low concentration zone the effect of alkyl groups could be shown as: CH3>C2H5>2(CH3)>2(C2H5) The excess molar volumes and excess molar enthalpies of (alkylethanolamine+water) mixtures show similar dependence on the size of the alkyl group present in the alkyethanolamines. The excess molar volumes have the most negative value for the (ethylethanolamine+water) system, while the excess molar enthalpies of the (MEEA+water) system have the more negative value.