Vapor pressures and thermophysical properties of selected ethanolamines

A thermodynamic study of three ethanolamines, 2-(diethylamino)ethanol, 2-(ethylamino)ethanol and 2-(isopropylamino)ethanol, reporting the measurements of vapor pressure, liquid phase heat capacities, and phase behavior is presented in this work. The vapor pressures were measured using a static method in the temperature interval 238-343 K. After a critical assessment of literature data, selected experimental data were correlated using the Cox equation. The liquid phase heat capacities were measured in the temperature range 265-355 K using Tian-Calvet calorimetry and the phase behavior was investigated using differential scanning calorimetry (DSC) starting from 183 K. For 2-(ethylamino)ethanol and 2-(isopropylamino)ethanol, two monotropically related crystalline forms were identified. To our knowledge, vapor pressure and heat capacity for 2-(isopropylamino)ethanol and phase behavior data for 2-(ethylamino)ethanol and 2-(isopropylamino)ethanol are reported for the first time in this work.