Abstract:A series of energetic salts （5-11） were synthesized by reacting polyamino-fused heterocyclic 4，7-diaminopyridazino［4，5-c］furoxan （4） with nitrogen-rich energetic acids including NTO or some other high-nitrogen nitroamino derivatives. The structures of 5-11 were characterized by nuclear magnetic resonance （NMR） spectroscopy， elemental analysis and infrared spectroscopy. In addition， the ¹⁵N NMR spectrum of 6 was measured and assignedbased on the quantum calculations. The crystal structure of 9 was also confirmed by single crystal X-ray diffraction. The detonation properties of these compounds （5-11） were calculated by Explo5 （version 6.05.02） software， and the impact and friction sensitivities were also measured. Among them， compound 5 exhibits good detonation performances （D_v： 8816 m·s^-1， P： 32.1 GPa） and low sensitivities（IS： 15 J， FS： 200 N）.

Abstract:Aiming at the problems that the crystallization methods （evaporation， antisolvent and cooling， etc.） of the conventional explosive are difficult to accurately control the uniformity of supersaturation and the low solvent recovery rate， an organic solvent nanofiltration（OSN） membrane crystallization apparatus based on pressure-driven and cross-flow filtration was designed and used to study the membrane crystallization process of 1，3，5，7-tetranitro-1，3，5，7-tetrazacyclooctane（HMX）. The effects of key process parameters （temperature and pressure） on the crystal morphology and particle size were discussed， and the crystal morphology and structure were compared with those of evaporative crystallization. The HMX crystals after recrystallization by both methods were characterized by scanning electron microscopy（SEM），X-ray powder diffractometer（XRD） and thermogravimetric-differential scanning calorimeter（TG-DSC）. The long-term operational stability of the nanofiltration membrane was further investigated， and the solvent recovered by permeation was used to re-crystallize. Results show that by the optimal control of temperature and pressure， the membrane crystallization process can obtain β-phase HMX with narrow particle size distribution （coefficient of variation < 46%）， high crystal density （ρ_avg=1.8997-1.9004 g·cm^-3） and excellent thermal stability. Compared with evaporation crystallization， the supersaturation control in the membrane crystallization process is easier to operate， and the prepared crystal morphology is more uniform. After repeated use， the rejection of HMX molecules in the solvent still remained above 92%， showing a good permeation selectivity stability. The β-phase HMX crystals with an median particle size of 34.92 μm and a coefficient of variation of 37.22% can still be prepared by membrane crystallization using permeation-recovered solvent， indicating that this technology can realize the efficient recovery and reuse of the crystallization solvent.

Abstract:To investigate the effect of mesoporous carbon nanospheres （MCS） on the thermal decomposition properties of cyclotrimethylenetrinitramine（RDX）， MCS was prepared by double template method with the particle size of about 350 nm. RDX crystals were introduced into the pore and surface of MCS by host-guest chemistry technology. The morphology and structure of MCS and MCS/RDX composite were characterized by scanning electron microscopy （SEM） and X-ray powder diffraction （XRD）. The interface interaction between MCS and RDX was studied by Fourier transform infrared spectroscopy （FTIR） and differential scanning calorimetry-thermogravimetry （DSC-TG）. Compared with pure RDX， the decomposition temperature of MCS/RDX composite decreased by 13 ℃ and the heat release increased. The apparent activation energy decreased from 234.87 kJ·mol^-1 to 126.48 kJ·mol^-1. The sensitivity tests were carried out by the drop hammer impact sensitivity instrument and the electrostatic spark device. Compared with the pure RDX， the impact sensitivity and electrostatic spark sensitivity of the obtained MCS/RDX composite are apparently reduced. Therefore， the obtained MCS has good catalytic performance for the thermal decomposition of RDX and can reduce the sensitivity of RDX.

Abstract:Diatomite particles with size distribution of 200-300 μm were used as emulsifying matrix carrier to prepare low detonation velocity emulsified explosive. The microscopic properties of diatomite were characterized. The effects of diatomite mass fraction on the particle size and detonation mechanism of explosive were analyzed. The density， detonation velocity and air explosion shock wave pressure of explosive were measured. The compatibility of diatomite and emulsified matrix was tested. The results show that when the mass fraction of diatomite increases from 15% to 35%， the particle size of explosive is negatively correlated with the content of diatomite， the density of explosive decreases from 0.79 g·cm^-3 to 0.51 g·cm^-3， and the detonation velocity decreases from 2561 m·s^-1 to 1655 m·s^-1. The peak pressure of air explosion shock wave decreases from 0.061 MPa to 0.023 MPa. The addition of diatomite has no effect on the thermal stability of emulsified matrix， and the diatomite and emulsified matrix do not react with each other under room temperature or heating conditions. The detonation velocity and the peak pressure of air explosion shock wave of the explosive stored for 2 days and 120 days drop less than 5%， indicating that diatomite has good compatibility with emulsified matrix.

Abstract:Aluminum based hydrogen storage composite fuel namely Q3 with a content of boron 15% and MgH₂ 15% was prepared by means of chimeric assembly. The powder had a spheroidic morphology. Its theoretical combustion heat was as high as 34.8 MJ·kg^-1. Thermogravimetric Analysis （TGA） was employed to test the oxidation performance of spherical aluminum and Q3. The results indicated that the initial oxidation temperature of Q3 was 430 ℃， which was around 100 ℃ lower than that of spherical aluminum. When the temperature was up to 1000 ℃， the weight of Q3 increased by 60% due to the oxidation， which was higher than that of spherical aluminum （23%）. This result indicated that the aluminum based hydrogen storage composite fuel had a better ignition performance and higher oxidability. The tests of underwater explosion with two RDX based explosive formulas containing 35% metal powder or equivalent Q3 were carried out respectively. The test results showed that for the formula with equivalent Q3， the explosion specific shock wave energy was reduced by 3.0%， the specific bubble energy was increased by 9.5%， and the total explosion energy was increased by 7.6% in contrast to the counterpart formula containing aluminum. The metal hydride and aluminum in aluminum based hydrogen storage composite fuel could effectively improve the energy release efficiency and rate of boron， resulting in increasing the total energy of the explosive in underwater explosion.

Abstract:In order to study the effect of polymers such as polyolefin， polyester， polyurethane and polyether on the mechanical properties of DNAN and its mixed explosives， the physical miscibility of different polymers with DNAN was studied by X-ray testing， in which polymers were microcrystalline wax（WAX）， polyisobutylene（PIB）， polybutylene succinate（PBS）， polyadipic acid hexanediamine（PA） and poly（3，3-di（nitrate ester methyl） oxybutyl）（PBNMO）. The solidification process of the polymer-containing samples was observed by microscopic. The dynamic crystallization characteristics of the samples during solidification were analyzed， and the linear velocity of crystal growth was calculated. Based on the optimized polymer， the influence of polymer content on the mechanical strength of DNAN and its mixed explosives was studied by material testing machine. The mechanical strengthening mechanism of polymer to DNAN and DNAN based explosives was analyzed. The results show that PBS， PA and PBNMO have good mutual solubility with DNAN under the action of hydrogen bonds or π bonds. The addition of fusible polymer makes the solid-liquid interface of DNAN crystals smooth and the solidification linear velocity decreases by more than 54%. Among them， the PBNMO has the most obvious improvement on the crystal morphology and solidification linear velocity of DNAN. PBNMO could significantly improve the mechanical properties of DNAN and its based explosives， and the mechanical strength increases with the increase of polymer content. When the polymer PBNMO content was 2%， the tensile strength and shear strength of DNAN based explosives increase more than 100%. The mechanism study shows that the fusible polymer can improve the mechanical properties of DNAN-based explosives by improving the microstructure of the sample and forming the “reinforced concrete” structure to reduce the internal defects and improve the crack growth resistance.

Abstract:In order to explore the effects of explosive environments on the oxidation and combustion of aluminum nanoparticles （ANP）， the mechanisms of high temperature combustion of ANP in nitroglycerin （NG）， 1，3，5-trinitro-1，3，5-triazine （RDX） and 1，3，5-triamino-2，4，6-trinitrobenzene （TATB） environments under different heating methods were studied by molecular dynamics simulation. The results show that the oxidation capacity of NG， RDX and TATB to ANP reduces in order， and the different explosive environments have different effects on the microscopic mechanism of combustion. As the oxidizability of explosive environment becomes weaker， the degree of ANP crack weakens at rapid heating， and with the oxidation becomes slower， the main coordination number of Al atom in final formed Al cluster decreases from 7 in NG environment to 6 in TATB environment. Besides， the dissociated Al atoms from ANP form some large Al clusters with about 100 atoms in the TATB environment， which also inhibits the oxidation of ANP. There is little difference on the number of Al clusters between different explosive environments at programmed heating. However， the number of Al clusters formed after ANP cracks is less as the oxidizability of the explosive environments decreases at constant heating and adiabatic heating. The number of Al clusters continues to increase in a short time thereafter due to the reason that the small Al clusters are less likely to agglomerate in a weakly oxidizing environment. ANP in NG environment mainly reacts with the oxygen-containing products decomposed from explosives， and the formed Al clusters are oxidized more completely. Nevertheless， ANP could react with N₂， CN and other oxygen-free products in RDX and TATB environments， which leads to the formation of Al clusters containing C， H and N atoms， and thus the oxidation of Al clusters is not complete.

Abstract:To determine the compatibility of 3，4-Dinitrofurazanfuroxan （DNTF） with different polymeric passivators， models of fusion-cast explosives were constructed. These fusion-cast explosives were mixtures of DNTF with polymethyl methacrylate（PMMA）， fluororubber （F₂₆₀₃）， cis-butadiene rubber （BR）， or polyvinylidene fluoride （PVDF）. The molecular dynamics （MD） simulation method was used to study the compatibility between DNTF and the above-mentioned four polymer passivators from the radial distribution function， solubility parameter and Flory-Huggins interaction parameter under the COMPASS force field. The nature of the intermolecular interaction force in the blends was revealed. The compatibility of the four blend systems was further experimentally verified by using the vacuum stability tests （VST）. The results show that the intermolecular radial distribution function values for individual components are lower than that between two different components in the blends. The solubility parameters of these systems are less than 3 J^1/2·cm^-3/2. The interaction parameter values of the systems are less than the critical interaction parameter value. The outgassing volume of these systems are all less than 0.6ml， indicating that DNTF is compatible with PMMA， F₂₆₀₃， BR and PVDF. The numerical simulation results are well consistent with the experimental results.

Abstract:Modular artillery charge system （MACS） is one of the main charge structures for large-caliber howitzers. To accurately study the interior ballistic characteristics of single modular artillery charge system and analyze the variation law of gas flow and pressure wave in the chamber， a combustion experiment platform for MACS was designed to carry out the combustion experiment of single modular artillery charge system. According to the characteristics of modular artillery charge system， the axisymmetric two-dimensional two-phase flow interior ballistic model of modular charge was constructed in different regions. Based on the high-order accurate Monotonic Upstream-centered Scheme for Conservation Laws （MUSCL）， the numerical simulation of the ignition process of single-module charge was carried out. The results show that the calculated results are in good agreement with the experimental results. The calculated maixmum errors of the pressures at different test points are less than 4%， indicating that the mathematical model established and calculation method used can describe the combustion process of single modular artillery charge system well. The results also show that before t=5.0 ms， the combustion of the module cartridge has little effect on the internal flow field of the module. The gas of main propellant can"t diffuse into the charge chamber in time due to the obstruction of the end cover of the cartridge.Only the gas of the ignition tube has a certain effect on the flow field in the chamber. The maximum pressure in the chamber during this period is about 4.3% higher than that before the right end of the fire tube is not broken. After the rupture of the cartridge， there is a pressure difference of 3.05 MPa at the boundary between the cartridge and the chamber， so that the propellant gas and solid particles flow rapidly along the axial direction to the free space of the chamber. A strong reflection of the pressure wave is formed at the bottom of the projectile. After that， the pressure wave oscillates repeatedly and gradually weakens.

Abstract:In order to study the influence of degree of cone angle， cone diameter and thickness of conical liner on shaped charge jet effect and optimize the structure of liner， orthogonal test with three factors and four levels was designed. ABAQUS software was used to simulate the shaped charge jet to penetrate the target， and weighted gray correlation method was used to analyze the orthogonal test results of jet target penetrating. The correlation degree between the angle， diameter and thickness of the cartridge and the effect of jet target penetrating was obtained. The results show that the cone angle has the greatest effect on shaped charge jet， and the cone diameter and thickness have the secondary effect. The parameter combination of liner for the best shaped charge jet target penetrating is： cone angle 61.2°， cone radius 18 mm， thickness 1.05 mm. Using the best combination of parameters， the maximum velocity of the shaped charge jet is 5855 m·s^-1， the depth of the penetrating target is 59.43 mm， and the opening diameter of the penetrating target is 8.24 mm. The research results can provide theoretical guidance for the application of shaped charge jet penetration.

Abstract:This review focused on the four major construction methods of 1，2，3-triazole energetic materials and corresponding research progress since the 1960s， including： Ⅰ） energetic compounds constructed based on 1-amino-1，2，3-triazole； Ⅱ） energetic compounds constructed based on dicyano substituted 1，2，3-triazole； Ⅲ） 1，2，3-triazole based energetic compounds prepared through azide involved cyclization reaction； Ⅳ） fused polycyclic energetic compounds built from 1，2，3-triazole. By analyzing the relationship between the molecular structure and energetic properties of several representative 1，2，3-triazole based energetic compounds， the influence of molecular structures on their energetic performances and stabilities could be profoundly clarified. Meanwhile， the potential application values of the mentioned high-performance 1，2，3-triazole based energetic compounds， such as their application prospects of main explosives， heat-resistant explosives and lead-free primary explosive， were discussed， providing a reference for the design and development of next-generation high energy density materials （HEDMs）.