Authors: Joshua I.J. Chou, Meng-Hui Li
Heat capacities of ternary systems containing tertiary amine 1-dimethylamino-2-propanol (1DMAP) and polyamine diethylenetriamine (DETA) were measured at 30 wt% total amine concentration and temperature range of 303.15 to 353.15 K. Molar heat capacities of ternary systems were measured by using a differential scanning calorimeter (DSC). In this study, the heat capacities of binary aqueous 1DMAP solutions over the entire range of compositions were also determined. The obtained heat capacity data were correlated as a function of temperature and amine concentration using a modified Söhnel and Novotný equation and a Redlich-Kister expansion for the aqueous 1DMAP/DETA and aqueous 1DMAP solutions, respectively. The calculated molar heat capacities show a good agreement with the experimental data at average absolute deviations of 0.05%, 0.57% and 0.2% for the pure, binary, and ternary systems, respectively. The heat capacities of aqueous mixtures of 1DMAP with DETA presented in this study are, in general, of sufficient accuracy for most engineering-design calculations.
Keywords: molar heat capacity, 1-dimethylamino-2-propanol, diethylenetriamine, Redlich-Kister expansion, Söhnel and Novotný equation