ZHU Wei-hua , HUANG Hui , HUANG Heng-jian , XIAO He-ming
2013, 21(5):557-562. DOI: 10.3969/j.issn.1006-9941.2013.05.001
Abstract:Ab initio molecular dynamics in conjunction with multiscale shock technique was used to study the initial decomposition of HMX, TATB, and PETN crystals under shock wave loading. Results indicate that the decompositions of HMX, TATB, and PETN under shock loading are triggered by the N—O bond, N—O bond and C—O bond breaking, respectively. As the simulation continues, the electronic delocalization in their systems increases and the band gap between conduction and valence bands decreases gradually. Then, metallic states in the systems begin to appear and increase. Under shock loading, the decreasing order of the time for the trigger bond cleavage for TATB, HMX and PETN is in agreement with the increasing sequence of their experimental shock sensitivity. This suggests that there is a relationship between structure or initiation decomposition mechanisms and sensitivity to shock wave.
LIU Dong-mei , XIAO Ji-jun , ZHU Wei , XIAO He-ming
2013, 21(5):563-569. DOI: 10.3969/j.issn.1006-9941.2013.05.002
Abstract:To explore theoretically the sensitivity criterion and the mechanical properties of PETN explosive crystal, molecular dynamics (MD) simulation periodic at 195, 245, 295, 345, 395 K for (4×3×4) super cells and its cutting model along (100) crystalline surface was conducted by COMPASS force field in the NPT ensemble. The results show that as the temperature increases, the maximum bond length (Lmax) of their O—NO2 trigger bond increases, the interaction energy (EO-N) between O atom and N atom of the O—NO2 trigger bond decreases and the cohesive energy density (CED) decreases. These results agree with the experimental fact that PETN becomes more sensitive as the temperature increases. The Lmax、EO-N and CED can be used as the theoretical criteria to predict the heat and impact sensitivity under certain conditions. With increasing the temperature, the elastic coefficients and elastic modulus decrease, the stiffness of PETN crystal decreases and the flexibility increases, which agrees with the experimental fact, indicating that the MD simulation of PETN cutting model is able to yield more concrete quantitative results.
YANG Jun-qing , WANG Gui-xiang , GAO Pin , GONG Xue-dong
2013, 21(5):570-577. DOI: 10.3969/j.issn.1006-9941.2013.05.003
Abstract:Five structurally similar —ONO2 and —N3 derivatives of pentaerythritol, including tetraazido pentaerythritol (TAPE), pentaerythritol triazido nitrate (PTAN), pentaerythritol diazido dinitrate (PDADN), pentaerythritol azido trinitrate (PATN), and pentaerythritol tetranitrate (PETN) were studied by the B3LYP/6-31G * method. The molecular geometric configurations were optimized and vibration analyses were performed. Their densities, heats of formation, thermodynamic functions, detonation performances and specific impulses were estimated. The bond dissociation energy (EBD) of the possible trigger bond and the activation energy (Ea) of the hydrogen transfer reaction were computed. The results show that in comparison with PTAN, PDADN, PATN and PETN, TAPE has the maximum heat of formation among five derivatives and specific impulse level approaching that of PETN. The detonation performance and stability of PATN are close to those of PETN, and better than that of other derivatives, including PDADN. The pyrolysis of TAPE with —N3 is initiated from the transfer of H to —N3 which leads to the elimination of N2 and has an Ea of 130.57 kJ·mol-1. The pyrolysis of other derivatives containing —ONO2 is started from the rupture of the O—NO2 bond with an EBD of 130.91~137.45 kJ·mol-1. These energy values satisfy the stability requirements for the energetic compounds.
TONG Wen-chao , WANG Shi-wei , WU Bi-dong , YANG Li , ZHANG Tong-lai
2013, 21(5):578-582. DOI: 10.3969/j.issn.1006-9941.2013.05.004
Abstract:The single crystal of calcium nitriminotetrazolate pentahydrate [Ca(NATZ)(H2O)5], a novel green initiating explosive was prepared by slow evaporation method. Its structure was characterized by a X-ray diffractometer. The crystal is triclinic, space group P1 with crystal parameters of a=0.64803(13)nm, b=0.74328(16) nm, c=1.0348(2) nm, α=74.482(8)°, β=72.487(9)°, γ=74.755(9)°, V=0.44888(16) nm3, Z=4, Dc=2.050 g·cm-3. On the basis of the structure characteristics of Ca(NATZ)(H2O)5, its decomposition mechanism was studied. The full optimized geometry and orbital energy analysis of Ca(NATZ)(H2O)5 were performed with the HF6-311G and B3LYP-6-311G methods using the Gaussian 03 program. Its thermal stability was studied. Rusults show there are two steps in its thermal decomposition which is agreed with expriments.
2013, 21(5):583-588. DOI: 10.3969/j.issn.1006-9941.2013.05.005
Abstract:The crystal morphology of α-RDX was predicted by using Bravais-Friedel-Donnary-Harker(BFDH) and attachment energy (AE) models. Results show that the crystal important growth surfaces are morphologically (111), (020), (002), (200) and (210), in which, (111) is the most important growth surface. The analyses of the crystal growth surface structures of RDX show that (002), (200) and (111) are polar, while (020) is a non-polar surface. (210) has the strongest polarity among five growth surfaces. It can be predicted that in the polar solvent, (210) will be morphologically important growth surface and the importance of (111) is reduced, while (020) is come to be disappeared. The recrystallization experiment in acetone solvent of RDX indicates that (210), (111), (002) and (200) are revealed on the finally RDX crystal morphology, whereas (020) is disappeared.
YU Hai-li , DUAN Xiao-hui , TAN Xue-rong
2013, 21(5):589-593. DOI: 10.3969/j.issn.1006-9941.2013.05.006
Abstract:The effect of temperature on the crystallization of cyclotetramethylene tetranitramine(HMX) in dimethylsulfoxide(DMSO) solvent was investigated by molecular dynamics simulation. The diffusion coefficients of DMSO and HMX and binding energy between HMX and DMSO were calculated in 278-378 K. The process of nucleus formation of HMX was simulated at 298 K. The results show that the interaction force between HMX and DMSO is ascribed to the van der Waals′force and electrostatic force. The HMX molecular nucleation most easily takes place at 358 K.The nucleation makes the diffusion coefficient of HMX decrease.
WANG Xiao , YAO Da-hu , BAI Sen-hu , WANG Cun-dong , HE Yu-xin , ZHANG Yu-qing
2013, 21(5):594-598. DOI: 10.3969/j.issn.1006-9941.2013.05.007
Abstract:The influences of temperature, content of nitroglycerin(NG), structure of diisocyanate on the diffusion behaviors of NG in elastomeric polyurethane were investigated by the molecular dynamics method with COMPASS(Condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies) force field. The mixed models of NG and different elastomeric polyurethane were also constructed and optimized. The mean square displacement of NG in mixtures was obtained by the molecular dynamics simulation of NPT(constant-temperature, constant-pressure ensemble) and NVT(constant-temperature, constant-volume ensemble). The diffusion coefficients were obtained by the Einstein equation. The results show that the order of magnitude of diffusion coefficients of NG in elastomeric polyurethane reaches 10-8 cm2·s-1, which is in agreement with experiment. The diffusion coefficients increase with the increasing of chain flexibility, and increase slowly when the temperature belows 308 K and then increase quickly. At meanwhile, the diffusion coefficients decrease slowly at first, and quickly when the content of NG exceeds 14%.
HE Piao , ZHANG Jian-guo , MAN Tian-tian , WANG Kun , ZHANG Shao-wen
2013, 21(5):599-603. DOI: 10.3969/j.issn.1006-9941.2013.05.008
Abstract:The electronic properties of 1, 5-diamino-tetrazole(DAT) and isomerization reaction kinetics were studied based on density functional theory. The geometry structure, vibration frequencies, natural bonding orbital, and zero point energy (ZPE) of stationary points involved in the reaction was calculated at B3LYP/6-311G level of theory. The intrinsic reaction coordinate theory (IRC) was used to obtain the minimum energy path (MEP). The reaction potential energy curve was obtained by calculating the single point energy with CCSD (T) method. The rate constants are evaluated from 200 to 1000 K using transition state theory (TST), TST/Eckart and Canonical variational transition state theory (CVT). Results show that N(4) and N(9) in DAT molecule participate easily in coordination with metal atoms, forming a series of coordination compounds. The isomerization reaction for DAT displays azide-cyclization mechanism. At gaseous case, the reaction is exothermic and spontaneous, with lower reaction activation energy.
WEI Xian-feng , LONG Xin-ping , HAN Yong
2013, 21(5):604-608. DOI: 10.3969/j.issn.1006-9941.2013.05.009
Abstract:The detonation performance parameters of different types of explosives were predicted with VLWR (Virial-Wu-R) code, and three sets of solid carbon parameters, including graphite parameters, diamond parameters and liquid carbon parameters were used. The component of equilibrium state for detonation products was determined based on the minimum Gibbs free-energy principle. The free-energy calculation of solid carbon in original VLWR program was modified by selecting the solid carbon phase in the calculation process. The Gibbs free-energy of graphite, diamond and liquid carbon were calculated by revised VLWR program. The most likely phase of carbon at C-J point for the detonation products was determined from three kinds of carbon phases, then the detonation parameters of explosive were calculated based on the minimum Gibbs free-energy principle. The detonation parameters of dozen CHNO explosives, including RDX, HMX, PETN etc were calculated with carbon phase selection. Results show that the calculated results were in good agreement with the experimental ones.
WANG Jun , JING Mei , ZHANG Xiao-yu , MA Qing , LI Jin-shan , SHU Yuan-jie
2013, 21(5):609-611. DOI: 10.3969/j.issn.1006-9941.2013.05.010
Abstract:New polynitropyrazole explosive molecules were designed with 3, 4, 5-trinitropyrazole (TNP) as "matrix" structural unit using energetic groups including nitro, nitramino, azo and azoxy, as substitute of the acidic hydrogen atom TNP. And the explosion parameters of designed explosives were calculated by Brinkley-Wilson(B-W) rule for explosion decomposition products, Rothsteine′s method for detonation velocity and Kamlet method for C-J pressure. And the calculated results were compared with those of RDX and HMX. It indicates show that the designed explosives are a new class of high energy density compounds (HEDMC) with high density, detonation velocity and detonation pressure which are close to RDX even HMX. The stability of designed explosive molecules are predicted favorable, due to pyrazole ring with aromaticity in the molecules, with aromaticity.
JI Yue-ping , GAO Fu-lei , HAN Rui , CHEN Bin , WANG Ying-lei , LIU Wei-xiao , LIU Ya-jing , YAO Yi-lun
2013, 21(5):612-615. DOI: 10.3969/j.issn.1006-9941.2013.05.011
Abstract:The solubility parameter of 1, 5-diazido-3-nitrazapentane(DIANP)was estimated by group contribution method and determined by turbidity titration method. The solubility of DIANP in different solvents was studied. Results show that the estimated values are in accordance with the determined ones. The solubility parameter of DIANP is determined as 22.29 (J/mL)1/2.The solubility of DIANP in different solvents follows the ""better miscibility with similar solubility parameter"" principle.
JI Chun-liang , LI Jie , LUO Yun-jun , ZHANG Chao-yang
2013, 21(5):616-623. DOI: 10.3969/j.issn.1006-9941.2013.05.012
Abstract:Effects of seven solvents on the feature bond lengths, nitro group charges, dipole moment, solvation energy and bond dissociation energy of 22 common explosive molecules were investigated by the density functional theory (DFT) and polarization continuum model (PCM). Results show that the solvent molecules can polarize the explosive molecules and change the electronic structure of explosive molecules so as to influence their geometric construction and energy. For the solvents with a dielectric constant between 0-10.36, as the polarity of the solvent increase, the feature bond length and solvation energy of explosive molecules decrease, whereas the negative nitro group charge and the dipole moment increase.
LU Xiang-hui , ZHOU Chun-gui , WANG Zhi-jun , ZHANG Ming , DUAN Jia-qing
2013, 21(5):624-628. DOI: 10.3969/j.issn.1006-9941.2013.05.013
Abstract:To study the dynamic responses of armored vehicle to explosive loading, three-dimensional simulation of an armored vehicle model composed of 4340 steel and rubber was performed by an AUTODYN software. The explosion process of 8701 explosive with different charge mass condition was calculated. The response parameters of three observation points on the side of steel plate such as overpressure, displacement and acceleration were obtained. The regularity of dynamic response for the observation points was analyzed. Results show that the closer from the explosion source location or the greater the loading charge, the earlier the response time of the vehicles, the more intense the node oscillation, the larger the oscillation amplitude and the shorter the duration.
2013, 21(5):629-637. DOI: 10.3969/j.issn.1006-9941.2013.05.014
Abstract:Computer simulation methods such as quantum chemistry calculation, molecular mechanics, molecular dynamics and dissipative particle dynamics were introduced. Its applications on different situations of interactions which exist in explosive dimer, trimer and crystal, between different explosive molecules, explosive molecule and the additives, different additives and on the interface were summarized. Future development of computer simulation for intermolecular interactions in composite explosive was prospected, the improvement of accuracy and speed, the modification and development of molecular forcefield, and the actualization of multi-scale simulation are considered as the hotspots of the research.
ZHAO Dong-mei , ZHANG Guo-fang , BI Fu-qiang , FAN Xue-zhong , ZHAO Feng-qi
2013, 21(5):638-643. DOI: 10.3969/j.issn.1006-9941.2013.05.015
Abstract:In order to improve the stability of unstable compound 1-amino-1-hydrazine-2, 2-dinitroethylene(AHDNE), the inclusion of AHDNE was studied. The presence of inclusion interactions of host compounds p-tertbutyl(p-nitro)calix[n]arenes(n = 4, 6, 8), β-cyclodextrin (β-CD) and β-cyclodextrin nitrate (β-NCD) with AHDNE was demostrated by UV-vis absorption spectra. The stoichiometric ratio and stability constants of the inclusion complexes were determined. The results show that the inclusion ratio is 1:1 and the stability constants of the inclusion compounds derived from the p-nitrocalix[n]arenes and β-NCD are ten times higher than those of their unnitrated precursors. The stability constants of the inclusion complexes coming from both p-nitrocalix[6]arene and β-NCD reach above 2×104. XRD analyses of host -guest compound, inclusion complex and physical mixture confirmed the formation of inclusion complexes. The sensitivities of β-NCD/AHDNE inclusion complex are lower than those of AHDNE and β-NCD.
LIU Jin-jian , LIU Zu-liang , LIN Xiang-yang , CHENG Jian , FANG Dong
2013, 21(5):644-648. DOI: 10.3969/j.issn.1006-9941.2013.05.016
Abstract:Two transition metal (Ni(Ⅱ) and Cu(Ⅱ)) complexes were synthesized using 2, 4, 6-triamino-3, 5-dinitropyridine-1-oxide (TANPyO) as ligand and characterized by FT-IR spectroscopy, elemental analysis, DSC and TG-DTG. Effects of the two complexes on the thermal decomposition of ammonium perchlorate (AP) were studied. The sensitivity properties of TANPyO were tested according to specifications of standardization method GJB772A-1997. Results show that the thermal decomposition processes of two complexes both consist of one violent exothermic peak with metal oxides residues. The two complexes make the higher thermal decomposition temperature of AP decrease by 47.14 ℃ and 98.24 ℃, the decomposition reaction accelerate and the exothermic quantity increase, revealing that the two complexes have good catalytic effect on the thermal decomposition of AP. The drop height of impact sensitivity is 300 cm. The friction sensitivity and electrostatic spark sensitivity are zero, showing that TANPyO is an insensitive energetic compound.
DAI Xiao-gan , Wang Juan , WEN Yu-shi , Huang Yi-min , DAI Ming-hong
2013, 21(5):649-652. DOI: 10.3969/j.issn.1006-9941.2013.05.017
Abstract:In order to study characteristics of deflagration to detonation transition(DDT) of unheated and heated explosives, the DDT test device for heated explosive was designed. And the PBX-2 explosive samples with Φ30 mm×400 mm were made. The processes of temperature changing for device shell and explosive were measured by thermocouples. The transmitting time and distance were analyzed by ionic probe. The characteristic of DDT for unheated and heated explosives were gained. The results show that DDT is more difficult to occur for PBX-2 explosive at 85 ℃ than room temperature.
TU Xiao-zhen , LI Wei , WEI Xing-wen , LU Xiao-jun
2013, 21(5):653-655. DOI: 10.3969/j.issn.1006-9941.2013.05.018
Abstract:To study the detonation performance of TATB based polymer bonded explosive (PBX) at high temperature, the sensitivity to shock wave, detonation velocity, detonation pressure and specific kinetic energy of the TATB based PBX at 25 ℃ and 75 ℃ were tested by standard gap test, electrometric method, standardization method, ZWB253-2008 and cylinder test, respectively. Results show that in comparison with those of 25 ℃, the shock wave sensitivity and specific kinetic energy of PBX at 75 ℃ increases, whereas the detonation velocity decreases slightly and the detonation pressure does not change obviously.
YANG Gui-hong , WANG Guang-jun , GONG Yan-qing , SUN Yong-qiang
2013, 21(5):656-659. DOI: 10.3969/j.issn.1006-9941.2013.05.019
Abstract:In order to measure flying velocities of controlled tungsten alloy fragments under detonation driven, comb targets method was used to study the initial velocities. Schematic of comb targets and typical signal of comb targets were discussed. The experimental results of flying law and long distance flying time of tungsten alloy fragments were validated by laser measurement method and theoretical flying law of fragments. The results show that the comb targets method is feasible.
ZHANG Zhou-mei , WANG Pei-yong , SHEN Yi-lin , ZHANG Ye , WANG Guo-qiang , JIA Yu-xin , XU Shuan-lao , FAN Long-long
2013, 21(5):660-663. DOI: 10.3969/j.issn.1006-9941.2013.05.020
Abstract:The Split Hopkinson Pressure Bar (SHPB) test was use to study the performance of stab delay initiating device affected by overload shock. The structural damage of stab delay initiating device was analyzed by CT. Results show that performance and structural damage of stab initiating device are distinctly different after overload test. When the interface of initiating device charge moves, the delay time becomes short, and the sensitivity of stab delay initiating device decreases after overload, the energy output do not change much.
LI Xue-jun , CONG Xiao-min , DU Zhi-ming , ZHAO Jia-yu
2013, 21(5):664-667. DOI: 10.3969/j.issn.1006-9941.2013.05.021
Abstract:In order to explore the possibility of rare-earth elements usage in luminescent pyrotechnics, magnesium powder as combustion agent and starch as binder, seven kinds of pyrotechnic composites containing Ce, Pr, Sm, Eu, Tb, Dy and Yb as oxidants were designed and prepared. The combustion spectra of each pyrotechnic composite were recorded by a transient spectral radiometer.Their spectral distributions were analyzed. Results show that the higher the negative oxygen balance of pyrotechnic composites, the greater the radiation intensity of characteristic spectum.The characteristic radiation spectra distribution region of pyrotechnic composites containing different rare-earth elements is similar. The spectral radiation of pyrotechnic composites containing Eu distributes in red light region.
ZHANG Guang-quan , LIU Xiao-bo , HUANG Ming
2013, 21(5):668-674. DOI: 10.3969/j.issn.1006-9941.2013.05.022
Abstract:Nitroguanidine(NQ) is an insensitivity explosive with certain reaction activity, which can react with some nucleophiles to give many NQ derivatives, including N-methyl-N′-nitroguanidine (MeNQ), 3-amino-1-nitroguanidine (ANG), hydrazobis(nitroformamidine) (HABNF) 1-(2, 2, 2-trinitroethylamino)-2-nitroguanidine (TNEANG), 3, 5-diamino-1-nitroamidino-1, 2, 4-triazole (DANAT), 2-nitroimino-5-nitrohexahydro-1, 3, 5-triazine (NNHT), 1, 2-dinitroguanidine (DNG). These derivatives belong to energetic materials, part of which has been applied. Synthesis methods of this kind of energetic NQ derivatives were reviewed. The performance characteristics of some compounds in these energetic NQ derivatives were introduced with 50 references
CHEN Yan-kun , LUO Xing-bai , ZHEN Jian-wei , ZHANG Yu-ling
2013, 21(5):675-680. DOI: 10.3969/j.issn.1006-9941.2013.05.023
Abstract:Application status of drop weight impact test, air gun test, split Hopkinson pressure bar test and dynamic extrusion physical simulation test in study of dynamical mechanical properties of propellant were introduced.The progress of dynamical mechanical properties of propellant was reviewed. Considering damage and low temperature brittleness of propellant bullets, the mechanics analysis of propellant impacting projectile body and the numerical simulation models of breaking need further study.
WEI Xing-wen , LI Ming , ZHOU Xiao-yu , HUANG Zhong
2013, 21(5):681-683. DOI: 10.3969/j.issn.1006-9941.2013.05.024
Abstract:A representative volume element (RVE) model was developed to investigate the thermal conductivity of three-phase polymer bonded explosive (PBX), and the fraction and distribution of the fillers and pores were taken into consideration. The influence of porosity on the thermal conduction of PBX was analyzed. Results show that the thermal conduction of PBX decreases exponentially with the increase of porosity.
LI Yi , LI Zhao-qian , HUANG Hong-chi , PEI Chong-hua
2013, 21(5):684-687. DOI: 10.3969/j.issn.1006-9941.2013.05.025
Abstract:A kind of antistatic nitrocellulose (NC) membrane was successfully prepared via the liquid phase mixing complex method using NC as raw materials and selecting carbon series conductive filler to NC. The antistatic performance, mechanical property and microstructure of antistatic NC membrane were characterized by high resistance meter, static sensitivity tester, electronic universal testing machine and field emission scanning electron microscope, respectively. The results show that when 1.0% conductive filler is added, the surface resistivity and volume resistivity of the antistatic NC membrane are 2.2×109 Ω and 7.5×109 Ω·m. respectively. Compared with unmodified NC, the surface resistivity and volume resistivity of the antistatic NC membrane are reduced by 6 orders of magnitude and 3 orders of magnitude, respectively. The electrostatic spark sensitivity of the antistatic NC membrane is 2.31 J. Compared with unmodified NC the electrostatic spark sensitivity of the antistatic NC membrane is increased by 14%, revealing that the antistatic NC membrane has better antistatic performance. The mechanical property parameters of the antistatic NC membrane are improved, showing that the addition of conductive filler does not degrade the mechanical property of NC.The formation of interlaced conductive networks in the products is conduciue to the electrostatic charge dissipate.
ZHANG Min , GE Zhong-xue , BI Fu-qiang , XU Cheng , LIU Qing , LI Tao-qi
2013, 21(5):688-690. DOI: 10.3969/j.issn.1006-9941.2013.05.026
Abstract:Using sodium 5-nitrotetrazolate dihydrate as starting material, 2-dinitromethyl-5-nitrotetrazole (HDNMNT) was synthesized via the reactions of substitution and nitration-hydrolysis with a total yield of 51.89%. The structure of HDNMNT was characterized by means of 1H NMR, 13C NMR, Fourier Transform Infrared Spectroscopy(FTIR) and elemental analysis. In order to study the performance of HDNMNT, the density, enthalpy of formation and detonation parameters were calculated theoretically, the thermal stability was analyzed by the differential scanning calorimetry(DSC) method. Results show that the density of HDNMNT is up to 1.880 g·cm-3, the enthalpy of formation is 273.0 kJ·mol-1, and the detonation velocity and detonation pressure are 8.732 km·s-1 and 35.4 GPa, respectively, which can be camparative with RDX. However, the decomposition temperature of HDNMNT is only 120 ℃, showing a relatively poor thermal stability.
ZHANG Zhi-gang , LU Xian-ming , MO Hong-chang , LI Lei , YAO Yi-lun , LIU Ya-jing
2013, 21(5):691-692. DOI: 10.3969/j.issn.1006-9941.2013.05.027
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ZHOU Xiao-qing , LI Hong-zhen , LIU Jia-hui , ZHANG Qi , XU Rong , YANG Zong-wei , LAN Lin-gang
2013, 21(5):693-695. DOI: 10.3969/j.issn.1006-9941.2013.05.028
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Editorial Board of Chinese Journal of Energetic Materials
Vol. , No.,
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