Thermochimica Acta, Vol.616, 42-48, 2015
Molar heat capacity of aqueous solutions of 1,3-diaminopropane and 1,4-diaminobutane and their piperazine blends
The molar heat capacity, C-p, of aqueous 1,3-diaminopropane (DAP), 1,4-diaminobutane (DAB) and their corresponding blends with piperazine (PZ) were measured at temperatures from 303.2 K to 353.2 K by differential scanning calorimetry. The correlation of C-p of the aqueous binary mixtures with temperature and concentration was successfully described by a Redlich-Kister type equation using excess molar heat capacity data. A modified Sohnel and Novotny equation was used to represent the temperature and concentration dependence of C-p of the ternary mixtures. The average absolute deviations between the experimental and the predicted C-p data were 0.2% and 0.1% for the binary and ternary mixtures, respectively. The results suggest that the experimental data presented in this work were represented well by the proposed correlations. (C) 2015 Elsevier B.V. All rights reserved.