Abstract:In order to establish a safe, effective and green method, the reduced-sensitivity HMX was prepared by recrystallization from ionic liquid-solvent system with solvent-nonsolvent technique, using a series of ionic liquids [mimH]NO₃, [mimBSO₃H]NO₃, [Et₃NH]NO₃ and [Et₃NBSO₃H]NO₃ as crystal assistants, acetone and cyclohexanone as solvent. Results show that the reduced-sensitivity HMX with spherical crystal can be recrystallized at 60 ℃ at the stirring rate of 750 r·min^-1 in the presence of ionic liquid [mimBSO₃H]NO₃ (1.5% weight of HMX) using cyclohexanone as solvent. The obtained HMX is smooth surface and neat edge with thermal decomposition peak temperature of 288 ℃, and impact sensitivity of 4%.

Abstract:Hexanitroazobenzene(HNAB) was prepared via nucleophilic substitution reaction and oxidation reaction using picryl chloride as raw materials. The intermediate and final product were characterized by MS, IR and ¹H NMR. The reaction conditions were optimized. The nucleophilic substitution reaction conditions are determined as: hydrazine sulfate 2.0 g, 2, 4, 6-trinitrochlorobenzene 7.6 g, methyl alcohol 15 mL, triethylamine 6 mL, reaction time 24 h under 45 ℃. The oxidation reaction conditions are determined as: 1, 2-bis(2, 4, 6-trinitrophenyl)hydrazine 2.0 g, iron(Ⅲ) nitrate nonahydrate 7.1 g, cumulative grinding 8 h. The total yield is 68.5%. Thermal behaviors of HNAB were studied by DSC and TG. The thermal decomposition mechanism of HNAB is classified as random nucleation and growth with n=1. The activation energy, pre-exponential factor and mechanism function of the thermal decomposition process of HNAB obtained by the Ozawa′s method are 123.48 kJ·mol^-1, 3.965×10¹¹ s^-1, f(α)=(1-α), respectively.

Abstract:Ionic liquid 1-sulfonicacidpropyl-3-methylimidazole hydrosulfate [MIMPS][HSO₄] was prepared as a catalyst to synthesize 2, 6-diamino-3, 5-dinitropyrazine-1-oxide(LLM-105) from nitration of 2, 6-diacetamido-pyrazine-1-oxide with N₂O₅/solvents. The structures of intermediates and LLM-105 were determined by ¹H NMR, IR and MS. The effects of reaction solvents, amount of [MIMPS][HSO₄], reaction temperature, reaction time and repeated use of [MIMPS][HSO₄] on the yield of LLM-105 were studied. Results show that the optimized reaction conditions are: CH₃NO₂ as solvent; reaction temperature 55 ℃; reaction time 6 h. The yield of LLM-105 is 72.2%.The ionic liquid is suitable for repetition use.

Abstract:Ammonium 2, 4, 5-trinitroimidazole was synthesized by a new method, using 4-nitroimidazole as primary materials, followed by iodinaton, nitralysis and salifying with ammonia in yield of 33.3%. The structure was confirmed by MS and IR. Thermal behavior of ammonium 2, 4, 5-trinitroimidazole was studied by DSC and TG, melting and decomposition temperatures are 254.52 ℃ and 308.31 ℃, and the mass loss due to overall reaction (203.6-399.9 ℃) is 94%. Friction and impact sensitivities are 2% and 18%, respectively, and it was a low sensitivity energetic materials.

Abstract:Two novel 1, 2, 3-triazine compounds-6-nitrobenzene[3, 4-e]-1, 2, 3-triazine-4(1H)-oxime and pyrazole[3, 4-e]-1, 2, 3-triazine-4(1H)-oxime were prepared using 2-cyano-4-nitroaniline and 3-amino-4-cyanopyrazole as starting materials via the reactions of oxime and diazotization. The structures of intermediates and target compounds were characterized by means of IR, ¹H NMR, ¹³C NMR, elemental analysis and MS. The influences of different factors on the yield of oxime were studied. The suitable synthetical condition of 2-amino oxime-4-nitroaniline were confirmed that the material ratio of 2-cyano-4-nitroaniline and hydrochloric hydroxylamine was 1: 1.20, 80 ℃, pH=10, reaction time 2 h and the yield was 95.6%. The suitable synthetical conditions of 3-amino-4-amino oximepyrazole were that the material ratio of 3-amino-4-cyanopyrazole and hydrochloric hydroxylamine was 1: 1.25, 80 ℃, pH=10, reaction time 2 h and the yield was 79.3%. The reaction mechanism was studied, and the reasons why it occured that the different amino in the reactions of diazotization and elimination were analyzed.

Abstract:Multi-channel data acquisition instrument of pressured solidification process was designed. The solidification process, change of temperature field and cooling velocity of RDX/TNT 60/40 and Ba(NO₃)₂/microcrystalline wax 60/40 were studied under adscititious pressure and atmospheric pressure respectively. The freezing point of RDX/TNT 60/40 is 83 ℃ under 0.6 MPa and 77 ℃ under atmospheric pressure. Both temperature of phase transformation and cooling velocity of various monitoring point under 0.6 MPa pressure are higher than that under atmospheric pressure, and the entire solidification process is shortened. For the experiment of Ba(NO₃)₂/microcrystalline wax 60/40, there is no obvious temperature of phase transformation under 0.6 MPa pressure and atmospheric pressure, and the cooling velocity under pressured condition is higher than that under atmospheric pressure. The pouring of RDX/TNT 60/40 show that the shrinkage defects of melt-cast explosive grain can be avoided effectively using pressured cooling technique.

Abstract:The ignition characteristics and the law of hot-spot formation on composite explosive subjected to drop weight impact were investigated by using the coupled thermo-mechanical method, selecting the thermo-elastic-plastic material model from nonlinear dynamics finite element software ANSYS/LS_DYNA, and simulating chemical exothermic reaction of explosive in the heat generation rate and considering the exothermic reaction of composite explosive itself. The finite element model used to simulate impact sensitivities was built by taking comp.B explosives as a caculation example. The results show that the numerical simulation method is feasible to simulate the transient heat release and the fast rise of temperature in composite explosive. The high temperature hot-spot in comp.B explosive is easily formed with the increment of up impact plunger velocity. When the velocity of up impact plunger is 5 m·s^-1, the hot-spot temperature enhances, and at 0.7 ms the hot-spots close to or above the critical temperature are formed, and ignition reaction occurs. The calculated results provide the theoretical foundations to judge the explosive impact ignition.

Abstract:Sensitivities to heat, laser, impact, friction, flame and electrostatic spark for tetraamnine bis(5-nitrotetrazolato) cobalt(Ⅲ) perchlorate (BNCP) and BNCP doped with carbon nanotubes (CNTs) and carbon black(CB) were measured and studied by DSC, laser sensitivity test and standardization methods GJB5891.22, 24, 25, 27-2006. Results show that (1) CNTs and CB make the semiconduction laser initiation threshold value of BNCP decrease; (2) the 50% ignition threshold values of BNCP doped with 5% CNTs and 5% CB are 13.76 mJ and 5.06 mJ, respectively; (3) the peak temperature of main exothermic decomposition reaction at a heating rate of 10 ℃·min^-1 for BNCP, BNCP/CNTs 10-20 nm mixture and BNCP/CB mixture are 289.87 ℃, 277.75 ℃ and 276.67 ℃, respectively; (4) the sensitivity decreases in the order BNCP > BNCP/CNTs > BNCP/CB for impact and flame sensitivity, BNCP/CB > BNCP/CNTs > BNCP for friction sensitivity, and BNCP/CB > BNCP > BNCP/CNTs for electrostatic spark sensitivity.

Abstract:CuO aerogel was prepared by sol-gel method combined with supercritical fluid drying. Polyacrylic acid and 1, 2-propylene oxide were used as dispersant and accelerant of Cu(Ⅱ) ion hydrolysis. Al/CuO nanothermite was prepared under the moderate and non-toxic condition. The characteristics of structure and thermal behavior were investigated by Brunauer Emmett Teller(BET), scanning electron microscopy(SEM), energy dispersive spectrometer(EDS), X-ray diffraction(XRD), differential thermal analysis(DTA)-differential scanning calorimetry(DSC). Results show nano-Al particles and CuO aerogel are composited uniformly. From DSC curve, Al/CuO nanothermite has two exothermic peaks at 598 ℃ and 752 ℃. And the rapid combustion process is accompanied with bright flame.

Abstract:In order to prevent the aggregation and growth of HMX explosive crystal, the influence of different addition of PVP on shapes and growth of HMX crystals was studied by the spray-crystal method and heat dying, using polyvinyl pyrrolidone as reagent of shape control, DMSO as solvent and deionized water as anti-solvent. The characterization and functional group of PVP-HMX particles were researched by the field emission scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). The impact sensitivity of PVP-HMX was tested by standardization method GJB772A-1997. The results show that the crystal size distribution of HMX is the same as before heat drying when PVP addition was 0.4%. The particle size of HMX is nearly spherical, and size distribution is under control of 1-3 μm. HMX has not appeared new functional group peak. In comparison with the raw materials HMX, the characteristic drop height of impact sensitivity H₅₀ of PVP-HMX increases by 248.3%.

Abstract:2-Azido-N, N-dimethylethylamine (DMAZ) is a new low-toxic liquid fuel which can be used to replace propellant of hydrazine and its derivatives. To improve the synthesis efficiency of DMAZ, the reaction kinetics of 2-chloro-N, N-dimethylethylamine hydrochloride with sodium azide in aqueous solution was studied using ultra-violet absorption spectrometry. The results show that the reaction can be considered as a second-order reaction. The reaction rate constants are 1.337×10^-3, 3.403×10^-3, 7.082×10^-3 L·mol^-1·min^-1, respectively, at 337.15, 347.15, 357.15 K. The apparent activation energy (E_a) is 83.5 kJ·mol^-1 and the pre-exponential factor (k₀) is 1.19×10¹⁰ L·mol^-1·min^-1.

Abstract:The effects of ZrO₂ and ZrB₂ on combustion performances of screw extrusion double-based (DB) propellant composed of 57% of NC, 33% of NG, 0.7% of carbon black and copper salt, 2.0% of lead salt and 7.3% of other additives were studied. Their reaction mechanisms were explored by steady combustion photos and the temperature distribution of combustion zone. The results indicate that when lead/copper combustion catalysts are partly replaced respectively by ZrO₂ and ZrB₂, the burning rate of the DB propellant at 7 MPa can increase, and its low pressure combustion plateau moves to above 7 MPa, and is broadened to 13 MPa, and with decreasing the granularity of ZrO₂ and ZrB₂, the burning rate of propellant increases, showing that ZrO₂ and ZrB₂ have better catalytic effects on this propellant.

Abstract:In order to investigate the effect of LiF coating on the thermal oxidation characteristics for amorphous boron powder, the thermal analysis experiment of boron coated with LiF (B^LiF) was conducted by DSC-TG. Propellant samples containing B^LiF were prepared. The heat of detonation and heat of combustion were determined by an oxygen bomb calorimeter. The effects of B^LiF on the energy release features in primary combustion and after-burning processes of the propellant were discussed. The results indicate that in comparison with amorphous boron, B^LiF shows a fast oxidation reaction at 599 ℃, and a 39.9% higher percentage of boron participated in B/O reaction. The propellant containing B^LiF makes primary combustion and after-burning energy release efficiencies (η_c1 and η_c2) increased and combustion efficiencies of B enhanced significantly from 65.48% to 81.57%. This is due to the consumption of B₂O₃ layer on the boron particle surface via endothermic reaction of LiF and B₂O₃ at high temperature and the acceleration of B/O reaction.

Abstract:The effects of the content and particle size of Al powder in formulation on the impact sensitivity, friction sensitivity and electrostatic spark sensitivity of NEPE propellant were studied. Results show that with increasing the contene of Al powder with particle sizes of d₅₀=90 μm and 41 μm, decreasing the content of HMX in formulation and increasing particle sizes of Al powder, the friction sensitivities of NEPE propellant become lower and electrostatic spark sensitivity was enhanced. The Al powder with smaller particle sizes coated by binder makes the electrostatic spark sensitivities of NEPE propellant lower.

Abstract:The binder film of 3, 3-bis(azidomethy)oxetane-r-(glycidyl azide)(BAMO-r-GAP)copolymer/N100/IPDI system was synthesized using BAMO-r-GAP copolymer as pre-polymer, N100 and IPDI as curing agent and BDO as chain extended agent. The Fourier transform infrared(FT-IR)spectrometer, differential scanning calorimetry(DSC) and thermogravimetry-derivative thermogravimetry(TG-DTG) were used to characterize the binder film, and the mechanical properties was also measured. Results show that the tensile strength of the binder film is raised to 0.87 MPa, and the breaking elongation is above 106%. The glass transition temperature (T_g) of the binder film is about -50 ℃ and the thermal decomposition starts at 217.0 ℃, which means the binder film has good thermal stability.

Abstract:The detonation performances of aluminized explosives are the typical non-ideal detonations. Because of the multiphase flowing and reacting at the front of detonation, it was difficult to obtain the detonation parameters by calculation. Assumed that the metal particles have no reaction at the front of detonation, and have the same pressure and velocity with the detonation products, using the continuum model and the general C-J relation, the full equations were obtained. Given the data of experimental detonation velocity, we can obtain the detonation pressure, particles velocity and the released heat at the front of detonation by solving the full equations. The calculations of two explosives with different aluminium content show that with the decrease of detonation velocity, the detonation pressure, mass velocity and explosion heat also deceased. When the explosives with different aluminium contents have the same detonation velocity, the higher the aluminium content, the larger the detonation pressure and the explosion heat. The calculation assumptions and the calculation model also given discussed.

Abstract:To study the effects of ignition process on interior ballistic performance of a small-size solid rocket motor, the model for interior ballistic calculation including ignition process of small-size solid rocket motor and verification plan were set up. The numerical calculations interior ballistic performance with 1.0 g, 0.8 g, 0.6 g and 0.4 g igniter masses were carried out. The tests of 1.0 g and 0.8 g igniter mass were done. The compute result and test data were basically consistent. The results indicated that: the effect of ignition process on interior ballistic about small-size solid rocket motor is obvious for the small combustion chamber volume. The igniting charge density and pressure peak increase, stable operating time of motor decreases as the igniter mass increases. The 1.0 g igniter mass is estimated by empirical formula, 1.0 g igniter mass brings too high pressure to motor, the value of pressure reaches three times the stable pressure. 0.8 g igniter mass meets ignition reliability and general design requirements, and the maximum pressure is 27.08 MPa, and stable work time is 159 ms, and 0.8 g igniter mass is suggested for the small-size solid rocket motor.

Abstract:Using LS-DYNA numerical simulation and orthogonal optimizing design method, dual mode warhead with arc-cone liner was optimized. The effects of dual mode warhead structure parameters (curvature radius, cone angle, thickness of arc-cone liner and the height of the explosive charge) were analyzed, and the arc part-cone part-ratio on the formation of explosively formed penetrator (EFP) and jetting projectile charge (JPC) were discussed. The numerical simulation results show that thickness is the main factor to affect tip velocity while cone angle is to determine length-diameter ratio and velocity gradient; both the performances and formation of EFP and JPC are better in the second optimization when the optimum combination, as curvature radius, cone angle, thickness and the height of the explosive charge is 0.45D_k, 145°, 0.04D_k and 1.0D_k respectively, where D_k is shaped charge diameter, that is the arc takes up smaller part.

Abstract:According to the characteristics of the drill-jamming accidents, a kind of multi-directional linear cumulative cutter in which twelve hollow copper pipes distributed evenly around the cylindrical explosive was designed. The linear cumulative cutter explosion principle and penetration process were studied through the numerical simulation method, which used the lagrange method of the LS-DYNA procedure, then the numerical calculations and experimental results were compared. The numerical simulation results showed that the twelve copper pipes formed twelve jets, slugs and 'tails' which moved after the jets under the pressure of detonation. Then these twelve jets moved along twelve different planes which were formed from the central axis of the copper pipes and explosive respectively(the angle between two neighboring planes was 30°). The velocity of the jet tip and slug were approximately up to 3530 m·s^-1 and 1180 m·s^-1 respectively. The target steel pipe primarily formed swell and fracture under the detonation pressure, then it was cut by twelve jets(the penetration velocity was about 2550 m·s^-1), eventually resulting in the formation of twelve slits. The steel pipe deformation results and the quantity of slits are in consistent with the experimental results, and this technology is applied successfully to the drill-jamming accident of three hundred meters deep drilling. Moreover, it is noted that the charge and cost are reduced respectively by 80% and 50% at least compared with existing normal cutter. In addition, the structure of cumulative cutter is simple and easy to be processed.

Abstract:A type of new perfusion explosive was prepared through the perfusion molding process, in which expired SF-3 double-based propellants were used as ingredients and the charge of propellant particles were filled with energetic fluid. The detonation performance of the perfusion explosive was studied through the witness plate test. Explosion reaction was recorded by high-speed camera. The shock wave overpressure and release energy were measured by the air explosion and underwater blast respectively. The results show that through the perfusion molding process, expired SF-3 double-based propellants can be reused to manufacture industrial explosive with excellant performance. With the sensitizer content increasing, the detonation sensitivity increases, but the detonation velocity, overpressure and the release energy almost keep the same. The density of this perfusion explosive can be 1.52 g·cm^-3, and the detonation velocity is 6600 m·s^-1 when the diameter is 60 mm. TNT equivalence of the explosive is over 1 when the proportion distance range is 1.65~4.5 m·kg^-1/3. The shock wave energy is 1.57 MJ·kg^-1 and total energy is 4.16 MJ·kg^-1, both more than the common industrial explosives, but slightly lower than TNT.

Abstract:The constant volume burner is a kind of test method to measure the burning rate of solid propellant under high pressure. Heat loss of the constant volume burner is one of the most important factors affecting the test accuracy of burning rate. Heat loss rate equation was derived to study the various factors on the rate of heat loss. The assessment method of the uncertainty of heat loss rate has been established, and the uncertainty also has been obtained. According to the study, it was known that the sample propellant burning surface, the gas constant volume specific heat, gas pressure, gas temperature are main factors of the uncertainty of the heat loss rate, and burning surface is the most important factor. The precision of propellant sample size should be increased to reduce the deviation of propellant burning surface of the sample.

Abstract:According to combustion theory and chemical structure of o-chlorobenzylidene malononitrile(CS), the principle for destroying CS by Incineration was analyzed, and the reaction products and equation of the incineration were determined. By incineration experiments, the major influencing factors on the incineration effect, such as single feed-in waste quantity, feed-in time interval, temperatures of the first and second firebox were discussed. Moreover, the optimized parameters for destroying CS by incineration equipment were determined. As a result, CS can be thoroughly destroyed by the special incineration equipment under the optimized parameters that the excess air coefficient is 2.0, the feed-in waste quantity is 400 g each time, the feed-in time interval is 3 min, the temperature of the first firebox is 750 ℃ and the second firebox is 1100 ℃.

Abstract:The use of 2, 4, 6-trinitrotoluene(TNT) as liquid carrier in traditional melt cast explosives limited their application in high performance weapons for the requirement of the insensitive ammunition. Replacement of TNT by low melt point explosive and intermolecular eutectic mixtures was attempted. This review summarized and compared the previous researches of low melt point explosives and ethylenediamine dinitrate/ammonium nitrate(EA), ethylenediamine dinitrate/ammonium nitrate/potassium nitrate(EAK), nitroguanidine/ethylenediamine dinitrate/ammonium nitrate/potassium nitrate(NEAK) and methyl nitroguanidine (MeNQ)-based intermolecular eutectic mixtures, and it reveals that theory investigation of the formulation is the direction for future development.

Abstract:The investigation progress and current developments of polyazides were reviewed. The methods of synthesizing and characterizing polyazides were extensively summarized and compared. The polyazido anions and acid-base complexes formed by reaction of polyazides and Lewis base were briefly introduced. The structural modification and derivation method of polyazides were outlined.

Abstract:Progress of synthesis and performance of several energetic triazolium salts as new TNT replacements is systematically reviewed, 4-amino-1, 2, 4-triazolium perchlorate(4-ATP), 1-methyl-4-amino-1, 2, 4-triazolium perchlorate (MATP) and 1-amino-3-methyl-1, 2, 3-triazolium nitrate(1-AMTN) are the best candidates to replace TNT, and the research field in the future for these energetic triazolium salts have been prospected.

Abstract:The strategies, methods, paths, characters, starting materials and nitrating systems of synthesizing 2, 4, 6-trinitro-2, 4, 6-triazacyclohexanone(Keto-RDX) were summarized, analysized and reviewed with 22 references. Considering that direct method using urotropine and urea as starting materials has the advantages of less steps, lower cost and higher yield and the disadvantages of difficult separation and purification from a mixtures of Keto-RDX and RDX, while the multistep method of synthesizing Keto-RDX via 1, 3, 5-triazine intermediates has the disadvantages of more reaction steps and higher cost and the advantages of easier separation and purification.

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