Investigation On The Crystallization Thermodynamics And Phase Diagrams Of CL-20/MTNP Energetic Cocrystal

The researches on the 2,4,6,8,10,12-hexanitro-hexaaza-isowurtzitane?HNIW,namely CL-20?based energetic cocrystals have been constantly reported in recent years.However,most of the studies were focused on the simulation and formation mechanism of energetic cocrystals,the design and preparations of cocrystal molecules,and relative characterizations of detonation properties,which were insufficient to the guidance or providing approaches for energetic cocrystal technology in scaling-up preparations and improving the purity.Thus,we utilized the recently reported energetic cocrystal CL-20/MTNP to investigate the solubilities and the complexation effects in organic solvents and relative thermodynamics about crystallization.On the base of previous thermodynamics contents,the phase solubility diagrams and ternary phase diagrams were constructed to design and improve the crystallization operations and provided systematic scientific methods for crystallization thermodynamics.The main contents are below:?1?Using the cooling crystallization methods to prepare the CL-20/MTNP energetic cocrystal.Powder X-ray diffraction and Differential Scanning Calorimetry were used to conduct the characterizations and thermal properties.The solubilities and cocrystal and its two components in five organic solvents were determined by High Performance Liquid Chromatography?HPLC?methods.The classic mathematic models were used to fit the solubility curves of cocrystal and components.The entropy and enthalpy of dissolution for CL-20/MTNP cocrystal and two components in five organic solvents were calculated on the foundation of previous results.?2?Invested the complexation effect of CL-20/MTNP energetic cocrystal in ethanol,ethyl acetate and acetonitrile at 308.15 K and determined the solubility product constants K_sp and the complexation constants K11.The complexation models were fitted by liner equations.?3?Studyed the theoretical and experimental values of eutectic point constants Keu for CL-20/MTNP cocrystal.HPLC methods were used to measure the experimental Keu constants to make comparisons with theoretical Keu values.The phase solubility diagrams of CL-20/MTNP at 308.15 K in ethanol,ethyl acetate and acetonitrile were constructed.?4?The ternary phase diagrams of CL-20/MTNP cocrystal in ethanol,ethyl acetate and acetonitrile at 308.1K were built on the base of the solubilities for cocrystal and components.The single phases ang cocrystal phase were separated and defined by ternary phase diagrams,which provide valuable guidance for preparation methods and theoretical basis.