Abstract:Based on the calculated results at DFT-B3LYP/6-31G* or HF/6-31G* level, heats of formation for 49 energetic compounds were calculated using atomization reactions and physical chemistry equation. By comparing the theoretical and experimental results, a good linear correlation between the experimental heats of formation (y) and the ones calculated at B3LYP/6-31G* level (x) is obtained. For the investigated energetic compounds, the linear equation, the correlative coefficient and the standard deviation are y=-75.79 0.98x, 0.990 and 28.21, respectively. Heats of formation obtained by using the linear equation are close to the experimental ones. The results show that by means of atomization reactions and using the results of B3LYP/6-31G* calculation, heats of formation for energetic materials can be obtained. In comparison, the same method based on the results at HF/6-31G* level is not fit for calculating the heats of formation for energetic compounds.

Abstract:An ESZ KTTV instrument of a new, relatively simple construction has been applied to determination of electric spark sensitivity of 29 polynitro arenes, expressed as spark energy, EES, required for 50percent initiation probability. The thermal stability thresholds, Tmax, were calculated from the published Arrhenius parameters of monomolecular thermal decomposition of the studied compounds, predominantly obtained under the conditions of the Russian manometric method. An approximate relationship has been found between the ln EES values and threshold Tmax values. In the sense of this relationship, the compounds studied fall into several subgroups. The reason of the said diversification lies in the decomposition reaction rate at the temperature of onset of their thermal decomposition. It has been found that in each subgroup increasing thermal stability of polynitro arenes is accompanied by increasing electric spark sensitivity of these substances. This fact must be taken into account if we deal with the problem of electric spark energy transfer into the reaction centre of the molecule.

Abstract:The mesoscopic structures of TATB(1,3,5-triamino-2,4,6-trinitrobenzene)-based PBXs(polymer bonded explosive)and their time evolutions were investigated using the dissipative particle dynamics(DPD)method.The results show that most of the polymers are condensed to spheres and only several polymer chains extend into TATB,the polymers form reseau structure in TATB.TATB is fixed in the polymers,but can not be wrapped perfectly by the polymers.At the same time,with the increasing of the temperature and the content of the polychlorotrifluoroethylene(PCTFE)monomers in the polymer,more polymers are dispersed in TATB.When the temperature is up to 400 K,the polymers form the alveolate structure,and wrap TATB perfectly.

Abstract:A mixed ligand complex of manganese(Ⅱ) carbohydrazide azide, Mn(CHZ)₂(N₃)₂ (CHZ=carbohydrazide), was synthesized and characterized by using 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 triclinic, Pī space group, a=8.2217(17), b=8.7427(18), c=9.4532(19), α=86.376(4)°, β=69.104(3)°, γ=74.019(3)°, V=609.8(2)A³, Dc=1.738 g·cm^-3, Z=2, R₁=0.0316, wR₂［I>2σ(I)］=0.0826 and S=1.132. The central Mn(Ⅱ) ion is sixcoordinated with two carbohydrazide molecules and two monodentate azido ligands, and carbohydrazide serves as bidentate ligands through the carbonyl oxygen atom and one of the terminal nitrogen atoms. The thermal decomposition mechanism of the complex was studied by using differential scanning calorimetry (DSC), thermogravimetryderivative thermogravimetry (TGDTG) and FTIR techniques. Results show that the final residue of thermal decomposition at 500 ℃ is MnO.

Abstract:Tetraacetylhexaazaisowurtzitane(TAIW), the precursor to CL20, was condensed with formaldehyde, acetaldehyde or chloroacetaldehyde, and three new isowurtzitane derivatives, 3,5,9,11tetraacetyl14oxo1,3,5,7,9,11hexaazapentaacyclo［5.5.3.0²,⁶.0⁴,¹⁰.0⁸,¹²］pentadecane, 13,15dimethyl3,5,9,11tetraacetyl14oxo1,3,5,7,9,11hexaazapentaacyclo ［5.5.3.0²,⁶.0⁴,¹⁰.0⁸,¹²］ pentadecane and 13,15dichloromethyl3,5,9,11tetraacetyl14oxo1,3,5,7,9,11hexaazapentaacyclo ［5.5.3.0²,⁶.0⁴,¹⁰.0⁸,¹²］ pentadecane, were synthesized and structurally characterized by elemental analysis, IR , 1H NMR, 13C NMR and MS. The results show that characteristics of the proton spectra of this new type caged compound are two signals at δ=6.2 and 5.4 in a 21 ratio. The three new compounds may be used as potential precursors of new energetic materials.

Abstract:2,6Diamino3,5dinitropyridine1oxide (ANPyO) was synthesized using 2,6diaminopyridine as the starting materials in two steps including nitration and Noxidation. The yields of nitration reaction and Noxidation reaction are 90% and 84%, the overall yield of ANPyO is 75%, which indicate that it is a better method than the method RitterLicht reported(45%). The detonation velocity(7000 m·s^-1, 1.50 g·cm^-3), exthermic peak (365 ℃) on the DSC curve, 5 s delay explosion point (>400 ℃), friction sensitivity (>360 N) and impact sensitivity (250 cm) for ANPyO were studied. Results show that ANPyO and 1,3,5triamino2,4,6trinitrobenzene (TATB) are about equal in the detonation and safety property, so ANPyO will be a new promising insensitive explosives in the energetic materials field.

Abstract:A preparation method of 1-amino-1,2,3-triazole was developed.The glyoxal bishydrazone was synthesized from glyoxal and aqueous hydrazine,and then glyoxal bishydrazone was oxidated with activated manganese dioxide to give 1-amino-1,2,3-triazole.The structure of 1-amino-1,2,3-triazole was confirmed by IR,elemental analysis,NMR and MS.Results show that 1-amino-1,2,3-triazole with high purity(96%)can be optimally got by crystallization from acetonitrile.The optimal amount of manganese dioxide is 2.8 N to the amount of glyoxal bishydrazone,and the reaction can be achieved within 2.5 h with the yield of 78.30%.In addition,the reaction mechanisms of decomposition and synthesis of 1-amino-1,2,3-triazole were discussed.

Abstract:The explosive RDX with high yield (129.4%) was prepared by the perfluorooctanesulfonic acid (C₈F₁₇SO₃H,PfOS)catalyzed nitrolysis of hexamethylenetetramine using perfluorodecalin (C₁₀F₁₈, cis and transmixture) as fluorous solvent. The process produced smaller waste acid and nitrate than that in traditional process. Effects of amount of nitric acid, catalyst, and ammonium nitrate, reaction temperature, reaction time,and the ratio of fluorous phase to water phase on nitrolysis were investigated. Results show that the fluorous system containing 10% PfOS and 0.5 equiv. of ammonium nitrate with 10 equiv. of nitric acid can give the RDX with yield of 129.4% (calculated on the basis of one mole of hexamethylenetetramine producing one mole of RDX ) at 20 ℃ after 6 h. The fluorous phase containing catalyst can be easily and efficiently recovered and reused by simple phase separation.

Abstract:The two postprocessing methods distilled under negative pressure and extraction were studied with the rude products of hydroxy terminal polyepoxy chloropropane (CTP),azido polyethers (ATP) and highmolecularweight azido polyethers (HATP) as the postprocessing thing. Results show that it is very difficult to get rid of cyclic crown ether and lowmoleculeweight oligomer by distillation under negative pressure. But extraction can get ideal postprocessing result. Isopropyl alcohol, petroleum ether (60-90 ℃) and the mixed solvent (mixed by isopropyl alcohol and petroleum ether) were chosen as extraction solvents. Extraction results indicate: (1) The extracting power of three extracting agents is in proper order: the mixed solvent＞isopropyl alcohol＞petroleum ether; (2) Isopropyl alcohol extracts lowmoleculeweight polyols preferably,and petroleum ether extracts cyclic crown ether preferably,while the mixed solvent has two extraction results at the same time; (3) For the rude products of CTP,ATP and HATP,the number average molecularweight (Mn) and functionality (f) can be increased after extraction by the mixed solvent. For HATP,Mn can be increased from 2500-3200 to 3000-4000; f can be increased from 1.99-2.00 to 2.46-2.97; the content of lowmoleculeweight oligomer can be decreased from 4.1%-8.2% to 0.3%-2.3%.

Abstract:The recrystallization of 2,6diamino3,5dinitropyrazine1oxide (LLM105) was studied. Results show that mean particle diameter, purity and impact sensitivity of LLM105 may be quite different by different crystallization methods. The products obtained by cooling crystallization and solvent (DMOS)nonsolvent(hot water) crystallization have low impact sensitivity, the value of H50 are 120.0 cm and 108.3 cm. Thermal properties of LLM105 were studied by DSCTG, VST, TG and thermal explosion test. Thermal properties parameters of LLM105 are shown respectively: DSC exothermic onset temperature is 341.2 ℃ (heating rate 10 ℃·min^-1); VST: 0.016 mL·g^-1/120 ℃/48 h; loss of weight: 0.13%/120 ℃/48 h; thermal explosion temperature for 5 s explosion delay is 367.5 ℃. The results of VST show that LLM105 has good compatibility with HMX, AS, F₂₃₁₁, F₂₃₁₄ and estane. Measured detonation velocity of LLM105 (LLM105/F₂₃₁₄=95/5, 1.845 g·cm^-3, 96.4% TMD) is 7991 m·s^-1. The experimental results of pressuredensity curve show that LLM105 has good pressingmolded property.

Abstract:The physical and chemical properties of a new energetic polymer adhesive (ATP28) were analyzed. Adding four plasticizers into ATP28 respectively,the plasticities of the explosive mixtures containing ATP were studied by viscosity tests. Comparing the detonation velocities of the explosive with ATP or HTPB as its adhesives,the effect of the ATP28 on the explosion energy was studied. The experimental results show that the viscosity of the energetic adhesive with DOA is decreased by 97%. Temperature plays an important part in the viscosity system. Detonation velocity of explosive formulation containing ATP28 is 7350 m·s^-1. It is shown that detonation velocity can be improved evidently by adding ATP28.

Abstract:Finite element numerical simulation based on transient thermalstress coupled analyses was conducted to understand the temperature, stress and dimensions for PBX cylinder during temperature rising. Results show that with temperature rising, heat transfers from surface to inner; stress augments rapidly at beginning, even arrives to 2.37 MPa, then reduces with temperature difference decreasing, the size of PBX cylinder is grown and its density is decreased by about 0.008 g·cm^-3. Numerical simulation can preliminary determine the regularity of stress distribution. And heating process has been optimized to try to decrease the rate of temperature rising and ensure at least 1800 s temperatureconstant time.

Abstract:Three kinds of HMX samples with different morphologys and particle sizes were prepared by screening,ball milling or solvent/nonsolvent methods,respectively,and characterized by laser granularity measurement and scanning electron microscope (SEM). The mechanical sensitivity and thermal decomposition of the samples were studied by impact sensitivity test,friction sensitivity test and DSC analysis. Results show that there are no obvious trends of the mechanical sensitivities depending on its d₅₀ for screening samples. However,for ball milling samples,the impact sensitivity reduces,and the friction sensitivity increases as its d₅₀ decreases. For solvent/nonsolvent samples,both the impact sensitivity and friction sensitivity decrease as its d₅₀ decreases. Moreover,the average value of activation energy of thermal decomposition for ball milling samples is 262.184 kJ·mol^-1,which is much higher than that (238.902 kJ·mol^-1 and 242.343 kJ·mol^-1) for the samples prepared by solvent/nonsolvent and screening methods.

Abstract:Machining is considered as one of the most important procedures as for complicated components of polymer bonded explosives(PBX).A definitive modified time hardening theoretical creep model was used to predict clamping deformations of different structural PBX parts under various clamping forces,which affects cutting accuracy directly.Simulation of vacuum absorbed spherical shell shows that displacements of points on profile increase with latitude,and its vector has an included angle to radial.When cam-ring chuck gripping a PBX parts,both the maximum deformation and stress appear in the contact area,and the value of internal is smaller than that of the external to a certain extent.Comparing simulation of vacuum absorbed hollow hemisphere with experimental data gauged by micrometer,the creep model has a better accuracy and reliability in the first twenty minutes,and the simulational results larger than test later with a less than 10% extent error within an hour.

Abstract:Electrostatic accumulation caused from RDX explosive and RDX/Al composite explosive friction was tested with a onemeter long flume. The results show that RDX obtain electrons while sliding on flume, and electrostatic accumulation (which is from -3.0 μC·kg^-1 to -5.0 μC·kg^-1) has a linear relationship with the mass of RDX. The characteristic of static electricity and electrostatic accumulation change after the addition of aluminum powder. The maximum electrostatic accumulation of RDX/Al is 1.19 μC·kg^-1 while that of RDX is -4.89 μC·kg^-1. Electrostatic accumulation changes from 0.35-0.50 μC·kg^-1 to 0.70^-1.20 μC·kg^-1 with the proportion of Al powder increasing from 20% to 30%. The electrostatic accumulation of RDX/Al composite explosive increases from 0.50 μC·kg^-1 to 1.20-1.50 μC·kg^-1 after addition 3%-8% organic solvents, such as petroleum ether and ethyl acetate.

Abstract:The prilled ammonium dinitramide(ADN)was coated by polyurethane binders(PU)for reducing it's hygroscopicity.The surface appearance and hygroscopicity of ADN after coating were analyzed by SEM and weighing method.Results show that a kind of floccule of PU is formed on the surface of ADN,which makes the hygroscopicity of ADN after coating less than that before coating evidently.When coated ADN is exposed in the atmosphere for 30 days with the RH less than 60%,the hygroscopicity of coated ADN is only 0.136% and does not increase with the increasing of exposure time.The thermoanalysis and mechanical sensitivity test show that the PU has little effect on the melting point,decomposition peak and enthalpy of coated ADN,but makes the mechanical sensitivity of ADN increase.Friction and impact sensitivity of ADN before and after coated are 30%,60%,30.5 cm,and 27.8 cm,respectively.

Abstract:Thermal decomposition of RDXCMDB propellants with burning rate catalysts (leadgallate，Cu(Ⅱ)paminobenzoic acid and carbon black) was investigated by using TGDSCFTIRMS simultaneous techniques. On the basis of changes in main gaseous products,the effect of the catalysts with various components on the characteristic values for TGDTG and DSC was discussed. Results show that the burning rate catalysts change the initial thermal decomposition mechanism of RDX. The C—N bond split which is in exothermic process has a predominance over competing branch reaction N—NO₂ bond split which is in endothermic process. The relative quantity of CH₂O (with negative heat of formation ΔH0f) produced from the decomposition of NC/NG component increases. The burning rate catalysts can make decomposition heats of the propellants increase and thus the burning rate rise. The compositions composed of nanosized lead saltcopper saltcarbon black have the best catalytic effect on RDXCMDB, and make the most obvious changes of the characteristic values and make the biggest enhancement of burning rate.

Abstract:Effect of content and granularity of aluminum powder(Al)on the combustion characteristics and energy properties of casted CMDB propellants were studied,and the combustion mechanism was also investigated.Results show that energy of the CMDB propellant increases with the increasing of Al content,and optimal Al content is 8%.The burning rates of the CMDB propellant at lower pressures increase in a great extent when the proportion of common Al and nano Al is 1:1,and the burning rate exponents of the propellant under 7-15 MPa decrease to lower than 0.45.

Abstract:Because of the fuel-rich propellant's high heat value and combustion temperature,the common stainless steel crucible and oxygen bomb's parts are always burned in the combustion heat testing process.In order to realize the proper testing of combustion heat,some fireproof materials' characteristics and their application in the combustion heat testing of fuel-rich propellant were studied.Those fireproof materials include acid washing asbestos,C/C compound materials,Al₂O₃ chinaware and tungsten crucible.The results show that the C/C compound materials have heat reaction while the acid washing asbestos,Al₂O₃ chinaware,and tungsten do not have heat reaction under high temperature and oxygen atmosphere.The application of three kinds of fireproof materials in testing the fuel-rich propellant's combustion heat show:Al₂O₃ chinaware can be used for only one time;spreading the acid washing asbestos in the tungsten crucible can improve the experimental value which is 94% theoretical value.

Abstract:Porous silicon was prepared by electrochemical anodized method,and the porosity and film depth of porous silicon prepared under different anodized conditions as well as the effect of anodized conditions,sodium perchlorate concentration and storage methods on the explosion characteristics were studied. Results show that the porosity of porous silicon increases with the increasing of current density,and is stable when current density is 50 mA·cm^-2. With the increasing of hydrofluoric acid concentration,the porosity of porous silicon decreases; with the increasing of anodizing time,the porosity increases firstly and then decreases; the porosity reaches the maximum when the anodizing time is 30 min. Film depth is thicker when anodizing time is longer,and its growth speed is about 2 μm·min^-1. Porous silicon cracks on surface and contains silicon columns internal which are 40 μm in length and 2-3 μm in width. Porous silicon/NaClO₄ composite can explode when sodium perchlorate concentration is higher than 0.1 g·mL^-1 and the porous silicon is fresh or dipping in the ethanol within 7 days.

Abstract:The collapse and formation process of quasi-spherical explosively formed projectile(EFP)was simulated by nonlinear dynamic software AUTODYN.Effects of structure parameters of liner outer curvature radius(R₂)and liner thickness(h)on the velocity and length/diameter ratio of EFP were studied.Results show that as the increasing of outer curvature radius and liner thickness,velocity and length/diameter ratio of EFP decrease.The relationship between outer curvature radius and liner thickness of the quasi-spherical EFP is obtained.X flash radiographs of EFP with structure parameters h=0.136Dk and R₂=0.76Dk are obtained.The results of numerical simulation are well agreement with X flash radiographs.

Abstract:A new polymer bonded plastic explosive was developed to meet the needs of explosion hardening.The polymer bonded plastic explosive based on RDX was made up of insensitive additives,plastic additives and the additives adjusting detonation velocity.The explosion hardening experiments on Hadfield steel of rail frogs show that the hardness on the surface of rail frogs can reach from HB170-190 to HB260-280 after explosion hardening one time and to HB310-330 after explosion hardening two times.The results show that performance and hardening process of the explosive are stable and reliable.

Abstract:Aluminum powders with contents of 2%-14% were added into the formulation when the temperature of emulsion explosive is about 70 ℃. Electrical measurement was used to get the detonation velocity of emulsion explosive containing aluminum, and the underwater tests were used to obtain the shock wave energy and bubble energy of explosive. At the same time the explosion heat was calculated by GAS triangles. The effects of aluminum powder contents on performance of emulsion explosive were analyzed. The results show that detonation velocity of emulsion explosive containing aluminum decreases with the increasing of aluminum powder contents, but explosion heat, shock wave energy and bubble energy increase with the increasing of aluminum powder contents.

Abstract:In order to find out how the branch structure affected the characteristic of shockwave propagation,LS-DYNA software was used to compute,and simulate certain shockwave propagating through the branch tunnels with different angle,and the overpressure/momentum(ratio)bench mark to measure "plane wave" was proposed.The results show that overpressure(ratio)bench mark is well suited for describing anomaly distribution,and momentum(ratio)bench mark can provide better measure for shockwave damage.Along with increasing of the branch deflexion angle,the primary tunnel momentum increases and the branch tunnel momentum decreases,and plane shockwave recover distance also increase but will not exceed six times equivalent diameter.

Abstract:The wastewater with HMX and RDX was treated by photodegradation process in the presence of cadmium sulfide doped with copper as photocatalyst under UV and Vis irradiations. The influence on the degration of Cu% as dopant in CdS/Cu nanoparticles, pH of solution, dosage of photocatalyst and concentration of explosives were studied. The XRD patterns and UV-Vis spectra were used to characterize the nanoparticle. Results show that the degradation efficiency for HMX and RDX wastewater reaches 85%-88% in the presence of Cd_0.95Cu_0.05S under 180 min UV irradiation. The dosage of 160.0 mg·L^-1 of photocatalyst and the pH of 7 are the optimum. A gradual decrease in degradation at the first two cycles is seen.

Abstract:Octahydro1,3,5,7tetranitro1,3,5,7tetrazocine (HMX) is one of the most important energetic materials used in various propellants and explosives. The βHMX undergoes a phase transition into δHMX before detonation. The study of the β→δ phase transition in the HMX can deepen our understanding of the sensitivity,detonation process and storing safety of HMX. The crystal structure of HMX,kinetics of the β→δ phase transition and the influencing factors of phase transition were reviewed. The crystal quality of HMX and the solid additive effect on the β→δ phase transition were proposed as the future research direction.

Abstract:The development and application of cyclophosphazene compounds in energetic materials were reviewed.The structures,properties,relevant reactions and applications of hexachlorocyclotriphosphazene and octachlorocyclotetraphosphazene and their substitutes were further introduced.Based on cyclotriphosphazene and cyclotetraphosphazene,the experimental and theoretical research progresses in the compounds substituted by azido,amine and nitro groups were summarized,and the application in energetic materials was prospected.

Abstract:Compared with traditional technology,microreactor shows advantages in safety,energy consumption,less pollution,quick response rate,short reaction time and so on.The advantages,structures of microreactor were introduced,and its applications in the strong exothermic reaction process were summarized.

Abstract:The structure of a typical crystal explosive (HMX) was studied with loose normal and recrystallized grains by 225 kV micro-focus X-ray industrial volume CT (μVCT) .The micro-hole ratio was quantitatively analyzed with dimension of 0.2-1 mm. The cubic array of attenuation coefficient restoration of sample was obtained with the voltage of 130 kV and the current of 50 mA and the dimensional resolving power of 7.1 μm.

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