Determination and correlation of solubility and solution thermodynamics of -HMX in binary solvent mixtures

Experimental solubility data of /3-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (/3-HMX) in three binary solvent mixtures of water + (acetic acid, acetone or DMSO) over the temperature ranges of (283.15-368.15 K) were measured with a gravimetric method under atmospheric pressure. The results all showed that the solubility of /3-HMX monotonously decreases with the increase of water mole fraction except for that in mixture of water + acetic acid through all given temperatures investigated, which exhibited the trends reach maximum then descending according to the increase of water mole fraction. In the temperature ranges examined, it was found that the solubility of /3-HMX in all the tested solvents increased with the rising of temperature. Furthermore, the experimental solubility data in binary solvents was correlated with the modified Apelblat equation, the CNIBS/RK model and the Jouyban-Acree model, which all gave satisfactory results. Additionally, the mixing Gibbs free energy, enthalpy and entropy of /3-HMX in those binary solvent systems were predicted with the correlation of experimental data on basis of the multicomponent NRTL model.