Vapor-liquid equilibria of N,N,N′,N′ tetramethylethylenediamine (TMEDA), tetramethylpropylenediamine (TMPDA) and their aqueous solutions

The vapor pressures of (N,N,N′,N′ tetramethylethylenediamine (TMEDA) + water), (tetramethylpropylenediamine (TMPDA) + water) binary mixtures, and of pure N,N,N′,N′ tetramethylethylenediamine and tetramethylpropylenediamine components were measured by means of a static device at temperatures between 273 and 363 K. The data were correlated with the Antoine equation. From these data excess Gibbs functions (GE) were calculated for several constant temperatures and fitted to a three order Redlich-Kister equation using the Barker's method. The two binary systems show a positive azeotropic behavior. The TMEDA aqueous solution exhibits positive deviations in GE for all investigated temperatures over the whole composition. The (TMPDA + water) system shows the same behavior except for T = 273.15 and 283.15 K where a sinusoidal shape is observed. Additionally, the NRTL and UNIQUAC models have been used for the correlation or prediction of the total pressure.