Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The density, viscosity, and surface tension of aqueous solution of 1,4-bis-(2-hydroxypropyl)-piperazine (HPP) sulfate, corresponding to a molar ratio of HPP to sulfuric acid of 2:1, were measured at different temperatures, up to 333.15 K. The HPP sulfate mass fraction ranged from (0.062 to 0.372). The density and viscosity experimental data have been correlated with different equations. Results showed that the density, viscosity, and surface tension of the aqueous solution of HPP sulfate decreased as the temperature increases. The density and viscosity increased with mass fraction of HPP sulfate, whereas surface tension decreased linearly with temperatures from (303.15 to 333.15) K. The density and viscosity correlated values are in good agreement with the experimental ones. The surface tension of the aqueous solution of HPP sulfate decreased with HPP sulfate mass fraction quickly in HPP sulfate mass range of (0.062 to 0.248); however, when HPP sulfate mass fraction was from (0.248 to 0.372), the decrease rate obviously reduced, suggesting that molecular association in HPP sulfate solution played an important role on surface tension.