Journal of Chemical and Engineering Data, Vol.66, No.1, 494-503, 2021
Solution Thermodynamics of Caprolactam in Different Monosolvents
In this work, the solubility data of caprolactam (CPL) in 18 solvents were measured from 278.15 to 313.15 K by a static gravimetric method. The results illustrated that with increasing temperature, solubility of CPL increased. The solubility in 2-methoxyethanol is the highest, whereas the lowest for n-Heptane. Additionally, the modified Apelblat equation, the nonrandom two-liquid (NRTL) model, and the lambda h equation were used to fit solubility data of CPL obtained in all of the 18 solvents by experimental methods. It can be seen from the results that all of the four selected models could provide preferable fitting results with average relative deviation lower than 5%. Furthermore, the thermodynamic properties of CPL during the dissolving process were also calculated and analyzed based on the NRTL model and experimental solubility data, including the enthalpy change, the Gibbs energy change, and the entropy change during the dissolution process.