Abstract:A method and a calculation formula for calculating the non-isothermal kinetic parameters ［the apparent activation energy(E) and the apparent pre-exponential constant (A)］ of the exothermic crystallization/solidification reaction from peak temperatures of non-isothermal DSC curves under different constant cooling rate conditions were presented. The suitability conditions of calculating the values of E and A by the formula and Kissinger′s equation were compared, considering that Kissinger′s method is not suitable for calculating the values of E and A of exothermal crystallization/solidification reaction. Minus value of E obtained by Kissinger′s method for the titled reaction is unreasonable.

Abstract:The thermal decomposition of RDX-CMDB propellants with burning rate catalysts ［lead-gallate (GDPB), Cu(Ⅱ)-p-aminobenzoic acid (PAC) and carbon black (CB)］ was investigated by pressure differential scanning calorimetry (PDSC). The effect of nano and un-nano catalysts on its thermal decomposition was compared. Results show that the pressure and the burning rate catalysts with different components affect the characteristic values of PDSC and the relative releasing heat of RDX. The characteristic values of PDSC（≤14 MPa）and pressure can be correlated to burning rate using an empiric equation by binary regression. The equation includes parameters that show the contributions of pressure and exothermic rate to burning rate. At high pressures (8-14 MPa), the plateau effect of propellants and the effect of composite catalysts with different components on burning rate can be described by this equation too.

Abstract:The geometries of tetrahydrodicyclopentadienes(THDCPD) and its derivatives were optimized at the B3LYP/6-31G level, vibration frequency analysis was also involved. The heat capacity and enthalpy at different temperatures were obtained by statistic thermodynamics. In order to calculate standard enthalpies of formation for the derivatives of THDCPD, isodesmic reactions were designed. The average molar volume and theoretical density were estimated using the Monte-Carlo method based on 0.001 e·bohr^-3 density space. Furthermore, the detonation velocity and pressure of the derivatives were estimated by the Kamlet-Jacbos equation. Results show that the total energies with the number of nitro groups are linear, and the derivatives of endo-THDCPD is more stable than the exo ones. The possible mechanism may be started by C—NO₂ bond breaking, not the homogeneous cleavage of framework C—C bond. With the temperature increasing, the heat capacity and enthalpy increase,and the increments of heat capacity is degressive,which is conversed to the enthalpy. Also,the detonation velocity and pressure increase evidently with the increasing of the nitro groups′ number.

Abstract:A new compound of mono-ammonium trinitrophloroglucinolate ［NH₄(H₂TNPG),TNPG=Trinitrophloroglucinol］ was synthesized and characterized by elemental analysis and Fourier transform infrared (FT-IR) spectrum. Its crystal structure was determined by single crystal X-ray diffraction analysis. The crystal belongs to monoclinic, C2/c space group, a=9.307(2)Å, b=21.144(6)Å, c=9.797(2)Å, β=99.56(3)°, V=1901.0(8)ų and Z=8. The compound is an ionic compound consisting of a cation NH_{4⁺ and an anion C6H2N3O9^-, and it is the mono-substituted salt of TNPG. Since the existence of complicated hydrogen bond networks and electrostatic attraction between NH4⁺ cation and C6H2N3O9^- anion, the compound possesses better stability and low sensitivity. The thermal analysis of the compound was studied by using differential scanning calorimetry (DSC), and thermogravimetry thermogravimetry-derivative analysis (TG-DTG). Under nitrogen atmosphere with the heating rate of 10 ℃·min^-1, the thermal decomposition of the compound show only one intense exothermic decomposition process at 219.2-234.3 ℃ on the DSC curve, and the decomposition products are nearly all gaseous products. Sensitivity Test revealed that the title compound is very insensitive to external stimuli.}

Abstract:Infrared spectroscopy technique was used to analyse the corrosion products from certain ammunition exploder stored for 10 years, “blast gas” from smoke composition stored for 1 year and chemical structure change of materials in smoke composition simulatedly stored for years. The results show that, the main reason for the ammunition exploder falure is that PVAC is degraded to HAc, and HAc diffuses to exploder inside leading to its corrosion. The main reason for the smoke composition falure is that NaHCO₃ accelerates Rhodamine B Extra decomposition and releases gas. Failure mechanism of certain ammunition and smoke composition and prevention failure measurements were proposed.

Abstract:Pliable composite films were prepared based on phase change materials (PCM) through the following steps. Firstly,octadecane/nature rubber latex with high stability was prepared with composite emulsion technology. Secondly,phase change pliable composite films with complex shape were prepared through dipping process. Finally,major properties of the composite films were measured,including mechanical property,thermal property and sealing property. Results show that the composite PCM film is a favorable energy storing media with latent heat of 237.1 kJ·kg^{-1. It also has excellant mechanical and air-proof properties with elongation factor at divulsion of 1135% and air transmission coefficient of 3.71×10-17 m2·Pa－1·s－1 respectively. Therefore,it can be used for energy storing purpose of geometrically complicated structure.}

Abstract:Nano-RDX/RF composite film was obtained by sol-gel method, which was arranged as sol preparation, sol heating, glass base lifting-pulling, and film drying. The composite film appeared semitransparent and brown to yellow from optical microscopy. Results show that shorter time sol-heating results in thiner film with less surface roughness, less conglutination to base,and easily to disconnect, while longer time sol-heating resluts in thicker film with better conglutination to base and worse roughness. RDX distributes in the film everywhere on the whole but discretely on the scale of 2.4 μm according to EDS results. XRD curve of RDX/RF film shows the superposition of RF non-crystal bread curve and RDX crystals diffraction curve. RDX diffraction peaks are broadened and its crystal size is calculated to be lower to 43 nm. Nano-RDX/RF film prepared by sol-gel method can be controllable, which is better than that by physical vapor deposition method and can be applied in microminiature initiating apparatus.

Abstract:Branched glycidyl azide polymer (B-GAP) was obtained at 100 ℃，using poly epoxy chloropropane,sodium azide,and sodium hydroxide as reactants and glycol as initiator. B-GAP was transformed to branched glycidyl azide polymer nitrate (B-GAPN) with concentrated nitric acid at -20-0 ℃. Reaction parameters were used to controll molecular weight and hydroxy number of B-GAP,and moecular weight of B-GAPN. The preparation product B-GAPN is testified by infrared spectrum analysis which indicates evident decrease of hydroxy group and emergence of nitrate peak.

Abstract:Nitration of toluene was carried out with nitric acid(67%) in the presence of SO₃H-functional ionic liquids［SO₃H(CH₂)₄mim］X (X^-=pTSO-, CF₃COO^-, BF₄^-) to develop a green nitration process. Results show that ［SO₃H(CH₂)₄mim］CF₃COO has the best catalytic activity. The conversion of toluene can be up to 65.1%, the yield of mono-nitrotoluenes can be 40.7% and the ratio of ortho/para can be 1.24, when the mole ratio of toluene to nitric acid is 1：1, the absorption of ionic liquid is five percent of the substrate by molar, the reaction temperature is 80 ℃ and the reaction time is 22 hours.

Abstract:Nano-TiO₂ powder was prepared at different treatment temperatures by sol-gel method. The effects of nano-TiO₂/UV photocatalytic degradation reaction on TNT and HMX were explored at different reaction temperatures and different intensities of light source. The results show that the degraded effects of the nano-TiO₂/UV system are more excellent than that of only UV reaction system, the degraded ratios for TNT and HMX can be up to 93.46% and 94.12% respectively. The catalysis activity of TiO₂ is affected by granularity, and the degraded capability of anatase TiO₂ calcined from 490 ℃ is better than that at other treatment temperatures. It is good to improve the degraded ratios at higher reaction temperatures and stronger intensities of UV light source. The kinetic reaction mechanisms of the photocatalytic degradations conforms to the Langmuir-Hinshelwood Model and the reaction rate for HMX is faster than that for TNT.

Abstract:The dinitrotoluene (DNT) wastewater treatment was investigated in a semi-continuous supercritical water oxidation system with the temperatures from 425 ℃ to 570 ℃ and the resident time from 0 s to 60 s at 24 MPa and 300% excess oxygen. Results show that increasing temperature and resident time can increase the DNT and chemical oxygen demand (COD) removal efficiencies. Treatment for approximately 20 s at a pressure of 24 MPa, temperature of 550 ℃ and oxygen excess of 300%, results in destruction efficiencies of over 98.89% for DNT and 98.99％ for COD. The DNT and COD removal efficiencies are strongly dependent on temperature and resident time during 425-550 ℃ and 0-20 s. Under the treatment condition of 425-550 ℃, 24 MPa and 300% excess oxygen, the reaction order respect to DNT is 3.630, the activation energy is 24.19 kJ·mol^-1, and the Arrhenius pre-exponential factor is 7.109×10⁵ s^-1.

Abstract:The outfield static blast experiment of a new type single-event fuel air explosive (SEFAE) and its test equipment was carried out. The blast/shock wave parameters were measured and the after-burning phenomena were studied. Results show that the biggest blast fireball diameter of the testing bomb with 30 kg SEFAE is 17.4 m, which is 76.65 times of the original diameter of charge. According to the overpressure curves, two positive pressure zones are found. The second positive pressure zone which is aroused by after-burning is in regulation. The second shock wave is formed outside fireball and the pressure flat roof accumulated by compressed waves is inside fireball. The peak value of the second shock wave is no less than 40% of the first one′s and the second impulse is 12.5%-43.7% of overall impulse. Thus the effect of the second shock wave on blast/shock wave power can not be neglected.

Abstract:he ANSYS/LS-DYNA3D finite element analysis software and the Arbitrary Lagrangian-Eulerian (ALE) algorithms were used to simulate the formation processes of shaped charge jet under different ways of initiation,such as one point ignition, the liner top two ring line ignition,axial charge outer wall center one ring line ignition and three ring line ignition. Calculated results show that ways of initiation have great influence on jet performance. Different ways of initiation produce different shapes of detonation wave. The jet tip velocity produced by the ignition ways of the liner top two ring line is increased by 11.6% than that by the one point ignition, the jet tip velocity through the liner the axial charge outer wall ignition is lower than that by any other ways of the top of the liner, and the jet tip velocity produced by the liner the axial charge outer wall three ring line is decreased by 18% than that by the ignition ways of the liner top two ring line. The confirmation experiment was carried out. The simulation results are in accordance with the experimental data.

Abstract:The coaxial measurement system of electrical conductivity for the detonation products was improved. The average electrical conductivities of cast TNT mixed with RDX, Al, KCl were studied, and the curves of maximal average electrical conductivity vs RDX fraction α in cast TNT/RDX compositions were obtained. Results show that the maximal average electrical conductivity decreases with the increasing of RDX fraction α in cast TNT/RDX compositions. The electrical conductivity of aluminized TNT is obviously higher than that of TNT, and the maximal average electrical conductivity of TNT 95/Al 5 (density 1.662 g·cm^-3) is over 4 times of cast TNT (density 1.618 g·cm^-3). Also the electrical conductivity of TNT/RDX increases when KCl is mixed in TNT/RDX compositions.

Abstract:Compressibility of porous materials was considered, shock temperature rise effect on the dynamic strength of front jet was analyzed theoretically. Penetration test results show that the porous copper liner with 11.4% porosity has better penetration ability than the homogeneous one when the standoff distance is between 1.3 and 3 charge diameters (CD), and the maximum penetration of porous jet is 1.12 times than that of copper one. The temperature rise in the porous liner is much higher, which is helpful to decrease jet viscosity and dynamic strength and increase the stretching ability at low standoff distance.

Abstract:The HMX explosive with particle size of 587.3 nm and precision press loading technique were selected, different sizes of channel were desogned with LZ12. The detonation propagation critical characteristic of superfine desensitived HMX in channel was studied. The results show that the critical size of linear charge is 0.4 mm×0.4 mm, the limit size of linear charge is 1.2 mm×1.2 mm, and critical size of convex charge is 0.5 mm×0.5 mm, when the charge density is 1.77 g·cm^-3.

Abstract:Bullet impact tests for four different sizes （Φ100 mm×45 mm（1^#），Φ50 mm×100 mm（2^#），Φ75 mm×150 mm（3^#） and Φ100 mm×200 mm（4^#）） PBX-2 explosives were carried out by improving test method. The time of bullet perforating target and velocity after perforating target were obtained. The reaction overpressure for different size explosives were measured. The reaction properties for different size PBX-2 explosives were analyzed in bullet impact test. Results show that the reaction of PBX-2 explosive is more violent with longer size. The numerical simulation of bullet impact test for 1^#, 2^# and 4^# samples was completed by ANSYS/LS-DYNA, and the calculated results are in accord with test results.

Abstract:Numerical simulation results with AUTODYN software revealed Jing Ping Lu′s parameters of PBXW-115 ignition and growth model underestimate energy release of Al powders combustion. The effects of artificial viscosity coefficient and mesh density on simulation results were discussed. The larger artificial viscosity coefficients and coarser meshes can smear off peak pressure of shock wave severely,but affect impulse little. Based on Bocksterner′s underwater explosion experimental results,parameters of Miller energy release model were solved inversely. Weighted coefficient of impulse was twice as much as that of peak pressure in objective function. New model parameters obtained from underwater explosion test can express the size effect of aluminized explosive and can be applied to numerican simulation of near field and far field, while Lee-Trave model parameters can only be applied to the numerical simulation of near field and small yield underwater explosion.

Abstract:The surface free energy and its dispersive, polar, electron acceptor and electron donor components of RDX were determined by the Washburn equation with thin-layer wicking technique. The diiodomethane and 1-bromonaphthalene, which are neutral probe liquids, were used to determine the dispersive component of RDX. And the ethylene glycol and formamide, which are polar probe liquids, were used to determine the polar components of RDX. The results show that the surface free energy and its dispersive, polar, electron acceptor components increase with the increasing of particle size. And the electron donor component takes the opposite trend. Films of RDX/HTPB/IPDI with 15% mass content of RDX with different particle size were prepared. The effect of particle size and surface free energy of RDX on the mechanical properties of HTPB propellant were studied. The results show that the maximum stress well-regulated varies with the interface adhesion energy between HTPB/IPDI binder system and every RDX particle, which is y=0.5242+0.6973exp(-1.616w⁰_adh). The maximum stress of RDX/HTPB/IPDI system decrease with the increasing of the interface free energy of every RDX particle.

Abstract:To investigate the structure of azidodeoxycellulose(AC) and the miscibility of AC with plasticzers,structure and solubility parameters were simulated by molecular mechanics (MM) method and molecular dynamics (MD) method with COMPASS force filed. Results show that the excellent agreement is obtained between the simulated and experimental data for vibrational frequencies and X-ray diffraction (XRD) spectra; the simulation value of solubility parameter for AC is 20.86 (J·cm^-3)^1/2 at 298 K. The predicted order of miscibility of AC with plasticizers is: triethylence glycol dinitrate(TEGDN)＞diethylence glycol dinitrate(DEGDN) ≈acetone＞nitroglycerin(NG) ＞1,2,4-butanetriol trinitrate(BTTN).

Abstract:Triaminoguanidine is a kind of non-azide nitrogen-rich flammable compound,which has some advantages of high nitrogen,good thermal stability,and high positive formation enthalpy,etc. In order to provide references of developing the triaminoguanidine energetic compounds,the current situation about molecular structure feature,preparation,physicochemical properties,explosion characteristics and application of triaminoguanidine energetic compounds in energetic materials was reviewed with 53 references.

Abstract:In order to confirm the effect of Mg and Al powders on combustion performance and boron oxidation efficiency of boron-based fuel-rich propellant in gas generator, the burning rate of three types of propellants in different batches were studied at various pressures and the contents of boron trioxide (B₂O₃) and total boron (B) in propellant combustion residues were determined by chemical method. The experimental results show that Mg content in propellant affects the combustion performances of propellant obviously. When the content of boron and total contents of Mg and Al in propellant are 30% and 6%, respectively, it was designed that the different ratios of Mg and Al in the propellant were as follows: the content of Mg is 0%, 3%, 6%, whereas, the content of Al corresponds to 6%, 3%, 0%, respectively. Burning rate and pressure exponent of the propellant increase with increasing of Mg powder content. The contents of B₂O₃ in combustion residues are related to Mg content in propellant. When Mg content in propellant increase, the content of B₂O₃ in combustion residues decrease; the efficiency of oxidized boron decrease with increasing of Mg content in the propellant and increasing of the combustion chamber pressure. Mg powder in the propellant can restrain the oxidation reaction of boron in the condensational state of the propellant and can increase the burning rate and pressure exponent for the boron-based fuel-rich propellant.

Abstract:The dynamic mechanical properties of NEPE propellant aged for various times at 75 ℃ were measured by dynamic mechanical analysis(DMA). Results show that in the low temperature region, a single relaxation is observed in tanδ-temperature curves, which is glass transition relaxation. The peak value of tanδ and temperature increase with the increase of aging time and test frequency. The effect of the plasticizer contents on tanδ varies with storage aging condition. In seal condition, the tanδ value decreases with the plasticizer content reduction.

Abstract:The effect of carbon content of poplar charcoal on ignition temperature, moisture absorption, hydrogen content and volatiles content was studied. By using SEM, XPS, FT-IR, GC/MS, the appearance of surface, element contents, functional groups distribution and products of pyrolysis were characterized. Results show that charcoal contains a variety of macromolecular alkanes, functionalized polyunclear aromatic compounds,such as acids, ethers, esters, and phenols. Its stoichiometry is C₁₂H₄O₂ and the lowest ignition temperature is 184-186 ℃.

Abstract:The main development directions of aminimide compounds synthesized by unsymmertrical dimethyl-hydrazine (UDMH) during the past decade were reviewed. The main chemical properties of aminimides, such as pyrolysis, photolysis and polymerization, were analyzed. The mechanism of pyrolysis was compared with that of photolysis. The applications of aminimides in latent curing agents, surfactants, molecular identification and drugs were summarized. Results show that the preparation and applications of aminimides are an effective approach to reclaim scrap UDMH.

Abstract:In many foreign countries, the impulse thruster (mainly combustion-gas jet type) has been widely used in some conventional munitions for trajectory correction including conventional missiles,glide bombs,cannon launched munitions and rockets and the like. In recent years,it has also been a great interest in researching the impulse thruster used for improving the ballistic accuracy of some projectiles in our country. The studies on the structures,performances and applications of some typical impulse thrusters developed by some foreign countries were simply summarized. Besides,the up-to-date progresses in this research field in our country were also introduced. In addition,some opinions on the future impulse thruster were put forward: firstly,to use semiconductor or metal-film bridge as the element for igniting,and compositions mainly used in initiators or pyrotechnics as output charge,or to use conventional propellants as output charge by improving the charging technology,may be one of the trends for future combustion-gas jet type impulse thruster; secondly,carrying out some basic researches on slug-shot type impulse thruster will be an important part in the research field of thruster in domestic and abroad in the near future.

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