Synthesis, Theoretical Calculation And Application Research On Cocrystal Ammonium Energetic Materials

A seires of new kind perchlorate ammonium cocrystal energetic materials were designed and prepared. The synthesis process, crystal structure, explosive properties and application have been studied. The contents and conclusions are as follows:1. The synthesis process and crystal structure of SY (Triethylenediamine/Ethylenediamine perchlorate salt) and MT (Triethylenediamine/Methylamine perchlorate salt) were studied. The optimal synthesis process for SY is EDA (Ethylenediamine):TEDA (Triethylenediamine):HC104=1:1.9:9.6. Single crystal diffraction analysis indicates that SY belongs to orthorhombic system with cell parameters of a=8.1030(16)A, b=24.725(5)A, c=10.195(2)A. MT was prepared by TEDA (Triethylenediamine): Methylamine:HC104=3.6:1:3.8, which belongs to monoclinic system with cell parameters of a=8.9750(18)A, b=17.836(4)A, c=10.455(2)A. It is easy to form hydrogen bond between perchlorate and amine, and the calculation results indicate there are three different kinds of hydrogen bond in the new cocrystal energetic materials.2. The theoretical calculation of SY and MT was conducted. CASTEP was employed to calculate cell parameters of SY with different computational methods (LDA-CA-PZ, GGA-PBE and GGA-PW91). The results show that band energy of SY can be divided into four parts:0～-10eV,-10eV～-15eV,-15eV～-22.5eV,-25eV～-30eV. It is found that the top of calence bands has large dispersion, wheras the bottom of conduction has nearly small dispersion. The calculation of MT show that band energy of SY can be divided into four parts:5eV～8eV,0eV～-14eV,-17eV～-21eV and-25eV～-27eV.3. High pressure calculation of SY was investigated to find out the relationship between pressure and crystal structure. CASTEP code of Materials Studio was used to calculate SY under high pressure (0-100GPa). The results show that the cell parameters of SY were decreased while pressure increased under0-10GPa. But it is unusual at2GPa where a and c were increased. Electrons from s and p orbits move toward lower energy part. With the increase of pressure, the density of states of SY is broader, the band gap become narrower.4. The structure of SY was characterized and the synthesis processes were optimized. The crystal of SY was got by solvent evaporation method. SY was characterized by FTIR, HNMR spectroscopy, X-ray diffraction (XRD) and single crystal diffraction analysis. The results show that SY is the combination of SE and YE with the ratio of1:1.5. Explosive properties and application of SY were studied. The thermal explosion temperature for5s, impact sensitivity, fraction sensitivity, flame sensitivity and electrostatic spark sensitivity were tested. The results show that SY is a promosing energetic mateiral. The investigations of SY application show that SY can be used as primary and secondary explosive in detonator. Also it can be used in separate initiation system which can be applied in the fuse to enhance its safety because of no use of detonators. The third usage of SY is in the port cover of rocket-ramjet engine, and the performance show that it had prominent advantages.