Investigation of the Phase Behavior of a HNIW center dot TNT Cocrystal System and Construction of Ternary Phase Diagrams

摘要

The influence of temperature and solvent on the phase behavior of a 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane-2,4,6-trinitrotoluene (HNIW center dot TNT) cocrystal system has been investigated. The ternary phase diagrams for HNIW and TNT in acetonitrile and ethyl acetate have been constructed at 25 and 35 degrees C, indicating that the cocrystal dissolves incongruently in acetonitrile and congruently in ethyl acetate. The results show that the solubility ratio of the two cocrystal components does not provide a reliable and accurate way to predict whether the phase behavior of the HNIW center dot TNT cocrystal is congruent or incongruent. The construction of the ternary phase diagram identified the thermodynamic stability regions for the cocrystal. The appearance of the phase diagram depends strongly on the choice of solvent, and the temperature has a weak effect on the phase diagram. By proper selection of the ratios, the HNIW center dot TNT cocrystal has been prepared by an isothermal slurry conversion crystallization method and systematically characterized.