Abstract:Three-component Mannich reaction of cyclohexanone, aromatic aldehydes and aromatic amines catalyzed by a basic functionalized ionic liquid，1-butyl-3-methylimidazolium hydroxide (［bmim］OH), was investigated. Under the optimum reaction conditions as n(cyclohexanone)：n(aromatic aldehydes)：n(aromatic amines)：n(［bmim］OH)=1：1：1：0.1, and at room temperature for 10 h with CH₃CH₂OH as a solvent, the yields of β-amino ketones was obtained with 75%-91%. The factors influencing the Mannich reaction were discussed including solvents, the structure of aldehydes and amines. The ionic liquid, which is environment friendly, was recycled at least 5 times without significant loss of activity.

Abstract:The energetic binder poly(2,2-dinitropropyl acrylate) (PDNPA) was synthesized by the free radical polymerization of 2,2-dinitropropyl acrylate in toluene with azobisiosbutyronitrile as initiator,and were characterized by FTIR,¹HNMR,UV and DSC. The effects of initiator concentration and temperature on polymerization were investigated. Results show that the average molecular weight of the polymer decreases and molecular weight distribution (MWD) becomes narrow as increasing initiator concentration. Monomer is with 60% conversion obtained at 80 ℃ within 2 hours. The thermal decomposition temperature of PDNPA is 252.8 ℃.

Abstract:Two novel ferrocene derivatives (oxalylferrocene and oxalyl(ethylferrocene)) were synthesized by using acylchoride as acylating agent, anhydrous aluminum chloride as catalyst and 1,2-dichloroethane as solvent. The structures of the titled compounds were characterized by ¹HNMR, FT-IR, MS and elemental analysis techniques, and the thermal decomposition properties of AP with 5%(weight) titled compounds were investigated by differential thermal analysis (DTA) and thermogravimetry(TG). Results show that the maximum weight loss rate peak temperature of AP is reduced by about 100 ℃ when adding 5%(weight) ferrocene derivatives.

Abstract:To study the method of controlling the combustion stability in bulk-loaded liquid propellant gun, a 2-D model of gas jet expansion process in the stepped-wall chamber was developed. The unsteady process of gas jet interaction with liquid was simulated by the commercial software FLUENT. The influences of chamber configuration, jet pressure and nozzle diameter on jet shape were discussed. The isothermal and isobaric graphs and density isograms of gas jet field were obtained. Results show that when the stepped-wall chamber dimension ratio is 0.8, and jet pressure is more than 30 MPa, or nozzle diameter is more than 2 mm, gas jet expansion process is unsteady. Mixing process between gas and liquid is strong. The calculated expansion displacement of gas jet is in good agreement with the experimental data.

Abstract:Ultrafine 2,2′,4,4′,6,6′-hexanitrostilbene(HNS-F) was prepared with obtained HNS-Ⅱ by recrystallization and vibration cavity comminute, and was characterized. Results show that the particle sizes of HNS-F distribute from 0.1 μm to 20 μm, and its BET specific surface area increases to 9.10 m²·g^-1. The differential scanning calorimetry (DSC) analysis and thermal decomposition kinetics calculation indicate, compared with HNS-Ⅱ, the melting point and enthalpy of decomposition of HNS-F increase, and its temperature of the exothermic peak decreases, and its activation energy decreases to 201.6 kJ·mol^-1. 50% threshold energy for slapper detonator charged with HNS-F decreases to 0.557 J.

Abstract:The submicron HMX/ FPM₂₆₀₂ composite explosive was prepared by solution-aqueous suspension technology with ultrasound and supercritical fluids antisolvent (SAS) coating technology, and were analyzed by component analysis, scanning electron microscope (SEM) and Fourier transformation infrared spectrometer (FT-IR). Its detonation performance was tested as well. Results indicate that the solution-aqueous suspension technology is not suitable for preparation ultra-fine composite explosive, whereas SAS technology has not any pollution.

Abstract:To study the detonations waves propagation characteristics of hexanitrostilbene (HNS), the critical thicknesses of HNS with particle size of 20 μm, 9 μm, 89 nm and densities of 1.0,1.570 g·cm^-3 were measured by wedge shaped charge test. Results indicate that the HNS particle size has obvious influence on detonation wave propagation. With the decreasing particle size of HNS, the critical thickness decreases, and the propagation capability of detonation waves increases. Increase of charge density is advantageous to detonation waves propagation. When the charge density of HNS-Ⅳ(89 nm) is 1.570 g·cm^-3, it′s critical thickness is 0.46 mm.

Abstract:The crystal quality and properties of spherical HMX such as particle size distribution, morphology, particle defects, chemical purity, thermal properties and sensitivities were characterized by laser light scattering, optical microscopic, optical microscopic with matching refractive index, density gradient technique, differential scanning calorimetry (DSC)and sensitivity tests. Results show that the crystal quality of HMX particles is improved after being spherically disposed. Comparing with original HMX particles, spherical HMX particles become more round and more smooth, their internal and surface defects are reduced, the particle diaphaneity is better, the particle density distribution becomes narrow, thermal stability and rheology of explosive based on spherical HMX particles are improved.

Abstract:Tetraacetyldibenzylhexaazaisowutzitane (TADBIW) was the debenzylation compound of hydrogenolysis of hexabenzylhexaazaisowurtzitane (HBIW). Triacetyltribenzylhexaazaisowurtzitane (TATBIW) was the partial debenzylation compound of hydrogenolysis of HBIW. The influence of TATBIW on the hydrogenolysis of TADBIW were studied. Results show that TATBIW is less stable than TADBIW and easily decomposes in formic acid, and its by-products inhibit the hydrogenolysis of TATBIW. The amount of catalyst is increased to 1%, the final product triacetyltriformylhexaazaisowurtzitane (TATFIW) is obtained.

Abstract:On the basic of “time to ignition and degree of super criticality law”, a kind of new calculation method of scale time of adiabatic explosion under the marginally supercritical condition was worked out. Based on that and with application of Lambert W function, the function of ambient temperature and time to ignition of marginally supercritical system, under uniform and distributed temperatures were worked out. The definition and calculation of high temperature ignition reliability of energetic materials were given. Results show that the relationship between supercritical ambient temperature and time to ignition of marginally supercritical exothermic system is a function, which is decided by activation energy, frequency factor, quantity of reaction heat, specific heat, density and other physical and chemical parameters of exothermic system.

Abstract:Numerical simulation of TNT explosion in air was performed by AUTODYN software. Post-detonation burning effect in negative oxygen balance explosive was considered in the numerical calculation model. Calculated results including peak overpressure,specific impulse and positive time were compared with that calculated by similitude equations and experimental data from Baker. Results show that airblast peak overpressure near explosive calculated by Brode equation is much larger than that AUTODTN software and Henrych equation, because the peak pressure of airblast can not be distinguished from that of detonation products.

Abstract:Gap test was used to study the shock sensitivity G₅₀ of composite charge composed of Ф20 mm×20 mm JO-9159 and extrusion-cast explosive (ECX) with thickness of 3, 5, 10, 20 mm. The shock sensitivity of composite charge was simulated by LS-DYNA finite element method and compared with the experimental results. Results show that there is a good agreement between experimental and simulated results. The G₅₀ of composite charge is between that of JO-9159 and ECX, and it descends with first order exponential decay form of G₅₀=12.96+5.13e^-h/6.41 with the thickness of ECX increasing.

Abstract:A method was introduced for predicting impact sensitivity of explosives by the artificial neural networks. Combining with the topological parameters and the quantum-chemical parameters which obtained by analyzing the fully optimized geometries and the vibration analysis of 36 CHON explosive molecules using the density functional theory (DFT) method at the B3LYP/6-31G^* level, seven molecular descriptors close related to H₅₀ were selected, including total electronic energy，lower unoccupied molecular orbital energy，oxygen balance index，number of oxygen atoms， active index, indicator of aromaticity （0 or 1）， indicator of —CH in α （0 or 1）. And the artificial neural network (ANN) with these descriptors as neurons in the input layer was established to predict impact sensitivity of explosives. The predicted data of the ANN were compared with experimental and those of two traditional models established by the oxygen balance index (OB₁₀₀) and the active index (F) respectively. Results show that the root mean squares errors of ANN model is 17.84 cm and that of the two traditional models is 42.71 cm and 36.47 cm respectively.

Abstract:The interface of the multi-medium fluid was caught with Level-Set and the interface was dealt with modified Ghost Fluid Method. The coefficients of JWL about detonations were obtained from isentropic expansion data calculated by Kihara-Hikita-Tanaka (KHT) and were programmed. The energy output of underwater explosion for TNT and PETN was calculated. Results show that energy output calculated by the program is consistent with that calculated by explosion similar rules, and the error is less than 10%.

Abstract:To investigate the feasibility of discriminating explosive type with RGB image of fireball of explosion, the curves of time vs area with intensive light on the images were obtained on the basis of a lot of photographs of explosion of condensed explosive with small dosage (30 g) by the high speed photography, and multi-dimension eigenvector space to describe firelight of explosion of condensed explosives was built by using feature parameters of configurations of curves of area vs time. And finally the linear three-type pattern recognition with optimal eigenvector was made by applying three-type Bayes′s decision rule and generalized fisher criterion. The test data of TNT, RDX, HMX were discriminated. Results show that the inaccuracy is 10.07% of pattern recognition built by the training set, while it is 17.48% of pattern recognition with using Jackknifing method in the total sample sets.

Abstract:The density-functional theory(DFT) method of the Amsterdam density functional (ADF) was used to calculate the geometry and frequency of 4-amino-1,2,4-triazol-5-one (ATO). The calculated results were compared through varying basis sets and relativity effect. The geometry, Mayer bond orders, net charges of atoms, frontier orbital energy and the main atomic orbital percentage were calculated. Results indicate that the basis sets in ADF program have a great influence on the calculation. Results obtained by the basis set of TZP are good conformity with the experimental. The crystal field theory was used to calculate the energy band structure and density of state (DOS) on ATO. The properties of ATO are similar to insulators.

Abstract:In order to study the low-pressure heat treatment on density and inner quality of pressed PBX, pressed PBX specimens were treated in isostatic pressing machine with pressure range of 5-10 MPa for 2-4 hours and repeated for 1-3 times. The properties of pressed PBX before and after treatment were compared. Results show that low-pressure heat treatment releases internal stress, increases relative density of PBX from 96.53%-98.83% to more than 99%, improves inner quality, and restrains growth of pressed PBX charges.

Abstract:The microstructural changes of Φ20 mm×5 mm polymer bonded explosives (PBX) sample based on HMX pressed at 50-250 MPa were investigated by scanning electron microscopy(SEM). The particle size distributions of HMX were measured by laser particle size analyzer. Results show that as the porosity in samples reduces, the crystal twinning and cracking in pressed PBX increases obviously. The mean particle diameters of HMX is 34.37 μm before being pressed, and after being pressed under 50,100,250 MPa, the mean particle diameters of HMX are 31.16 μm , 27.90 μm and 26.37 μm, respectively.

Abstract:Solubility parameters of bonding agent hydroxy terminated polybutadience (HTPB),conventional plasticizers and curing agent in solid propellant were calculated respectively by amorphous cell dynamics(ACD)，Synthia and Blend methods to predict the miscibility of these components. Results show that: Synthia method quantitatively simulates solubility parameters while ACD method qualitatively simulates solubility parameter, and Blend method exhibits the miscibility of components directly and the effects of extrinsic factors such as temperature and mole fraction. Simulation results are agreement with experimental results. The conventional plasticizers usually meets the miscible request of HTPB. The miscibility of isophorone diisocyanate(IPDI) or trimethylaziridinyl phosphine oxide(MAPO) with HTPB is better than that of toluene diisocyanate(TDI) and hexamethylene diisocyanate(HDI). The selection of curing agent emphasizes on curing effect, not miscible request but which may affect curing effect. The miscibility of energetic plasticizer with HTPB is not well.

Abstract:The effect of thermoplastic polyurethane elastomer (TPUE) on mechanical properties of modified double-base propellants was investigated by dynamic mechanical analyzer (DMA) and tensile strength measurement, and its function mechanism was analyzed by scanning electron microscope (SEM). Results show that TPUE remarkably improves mechanical properties of propellants. The elongation of the propellants increases by above 50% at room temperature and high temperature, while at low temperature tensile strength increases by 15% and elongation by 16% because the TPUE enhances the adhesion strength between filler and binder and decreases “de-wetting”. The variation of α-relaxation was explained through “free volume theory” and activation energy of relaxation process as well. It is concluded that the mechanical properties at high temperature are related to the magnitude and the activation energy of α-relaxation on tanδ, while those at low temperature are related to activation energy of the β-relaxation on tanδ or “fragility parameter”.

Abstract:The effect of refined cotton, carbon fiber content and length on the safety of caseless ammunition and self-ignition temperature of simulating bore test was analyzed by testing the ignition point of 5 s delay of the propellants containing carbon fiber or refined cotton,impact sensitivity and temperature of simulating bore test. Results show that the impact sensitivity of the caseless ammunition is depressed when adding carbon fiber with content of 0.5%-1.5% and length of 10 mm, the anti-spontaneous-combustion temperature is hoisted by adding carbon fiber and the anti-spontaneous-combustion time is prolonged at the same temperature.

Abstract:The closed bomb test system was used to investigate the burning rate of B/KNO₃. Results show that the linear burning rate increases as the pellet density decreases, and the product formation rate of B/KNO₃, which affects pressure-time curves, is significantly affected by the pellet size. Additionally, the linear burning rate B/KNO₃ is not consistent with single exponent equation, and can be expressed with step-wise function. Below 7 MPa, the linear burning rate is proportional to pressure. But as pressure higher than 7 MPa and lower than 50 MPa, the linear burning rate does not change with pressure.

Abstract:The combustion of gas-generating compositions (GGC) including composite oxidants (KClO₄/NH₄NO₃) and fuels (methylcellulose, MC; wooden powders, WP) under atmosphere was studied. Results show that for samples of KClO₄/NH₄NO₃-MC with various value of oxygen balance, the combustion rate of samples decreases with the decreasing content of KClO₄ in compositions. Variation of combustion rate of samples KClO₄/NH₄NO₃-WP is more complicated. By analyzing the experimental results, the maximum of combustion rate of samples studied appears at oxygen balance of -15%. This may be concerned with the mass law and the special properties of heterogeneous chemical reactions appeared in condensed phase of burned samples.

Abstract:Based on sensitivity distribution and the definition of margin of firing reliability for initiating explosive devices given in GJB376, the quantitative relationship between producer risk and margin of firing reliability of initiating explosive devices was deduced. According to the relationship and up-and-down method test data, the margin of firing reliability and producer risk of a stab detonator are 1.74 and 0.003% respectively, and the margin of firing reliability and producer risk of an electronic detonator are 1.48 and 0.00096% respectively. Results show that the quantitative relationship between producer risk and margin of firing reliability of initiating explosive devices is accordant with practical products.

Abstract:Through the histogram method and Kolmogorov test, it was obtained that the sensitivity coefficient of variation for D6-2 artillery primer and mechanical explosive devices approximated the normal distribution of (0.34,0.1²),(0.3, 0.1²), respectively． Using the upper limit of coefficient of variation for mechanical explosive devices, the reliability design for initiating explosive device was developed. Results indicate that the coefficient of variation determined is practical for the reliability design.

Abstract:The bilateral reliability model for initiating explosive devices was studied in order to improve the assessment precision. The calculation method was proposed for the lower limit of bilateral reliability based on the classical two-rank approximate limit,and the simulation tests were conducted By Monte Carlo method. Results show that the precision is suitable for the requirements of reliability assessment for initiating devices when the amounts of samples are 20-30. And the feasibility and applicability is validated by tests with stab detonators compared with the other methods.

Abstract:The emissivity of condensed-phase product particles was corrected by using impact factor of particle size. Combined with combustion model of aluminum, the emissivity of condensed-phase product particles and flash radiation model of pyrotechnic deflagration, the formula relationship between Al particles diameter and radiation intensities of pyrotechnic composite was put forward. It is concluded that the higher radiation intensity is, the smaller aluminum size of flash pyrotechnic composite is. Binary mixtures containing KClO₄ and Al with mass ratio of 50：50, and trinary mixtures containing KClO₄, Al and 3% epoxy with mass ratio of 50：50：3 were prepared, and their radiation intensities were determined experimentally. Results show that there is agreement between the theoretical conclusion and experimental results.

Abstract:Combustion characteristic of Zr-O₂ was studied. Emission spectrum of Zr-O₂flashlamp was also tested. Results show that the higher the ignition voltage (22 V) is, the more the oxygen (0.7 MPa) is and the smaller Zr strip (0.3~0.5 mm) is, the higher fire ratio is. The spectrum of Zr-O₂ pyrotechnics is distributed from 500-900 nm, and it has stronger emission strength in near infrared region of 700-900 nm. The spectrum characteristics are almost the same in different ratios of fuel/oxygen.

Abstract:The interaction of ammonium dinitramide (ADN) and mixture of nitroglycerin and nitrocellulose (NC+NG) systems under the higher temperature was investigated by NBK LAWA gasometric measuring system. Results show that compared with the sum of maximum standard volume of evolved gas from systems ADN and (NC+NG), maximum standard volume of evolved gas from the ADN/(NC+NG) mixture (626.8 mL·g^-1) decreases, but the decomposition rate increases evidently, and the activation energy decreases to 82.58 kJ·mol^-1, which shows that there is a strong interaction between ADN and (NC+NG).

Abstract:In order to obtain the standard substance 3-nitro-1,2,4-triazol-5-one (NTO), it is necessary to establish the corresponding chemical certification method in its preparation. Using methanol as solvent and sodium methanol standard solution as titrant, the certification of NTO standard substance was investigated by non-aqueous titration. The results show that the method can exclude disturbance of impurity with better accuracy and precision, and the average purity value of NTO standard substance is 99.88% and the standard deviation is 0.16% after 27 times of repeated determinations.

Abstract:The progress of the aging of double-base propellant, nitrate ester polyether (NEPE) propellant, hydroxy-terminated polybutadiene (HTPB) propellants was reviewed. The aging monitoring methods including spectroscopy method and embedded subminiature sensing devices have been used in recent years abroad. Aging under constant strain or stress, interface dewetting, health monitoring system, aging modeling and simulating are the main trend in the future.

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract: