Vapour-liquid equilibria, enthalpy of vaporisation, and excess Gibbs energies of binary mixtures of {3,3-diamino-N-methyldipropylamine (DNM) (or N,N,N′,N′′,N′′-pentamethyldiethylenetriamine (PMDETA)) + water}

The vapour pressures of the pure components 3,3-diamino-N-methyldipropylamine (DNM) and N,N,N′,N′′,N′′-pentamethyldiethylenetriamine (PMDETA) along with the binary mixtures (DNM + water) and (PMDETA + water) were measured by means of a static apparatus at temperatures between (283 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 four order Redlich-Kister equation using the Barker method. The binary system (DNM + water) exhibits negative deviations in GE values calculated from the vapour pressure data for all investigated temperatures and over the whole composition range. The (PMDETA + water) binary mixture shows a sinusoidal shape for GE at 283.15 K < T < 303.15 K, and a positive deviation in GE for [313.15 - 363.15] K temperature range. Additionally, the NRTL, UNIQUAC models have been used for the correlation of prediction of the total pressure.