Abstract:Nitrogen-rich heterocycle compounds are new generation primary explosives. They have excellent initiating and firing properties and enviroment friendship. The research key point is to design and synthesize the intermediates or ligands of nitrogen-rich heterocycle, nitrogen-rich heterocycle ligand complex compounds as well as their salt forms. The ligands of the new generation primaries are 5-nitrotetrazole (5-NT), 5-hydrazinotetrazole (5-HT), 1, 5-diaminotetrazole (1, 5-DAT) and triazoles. They all have the similar performances such as aromaticity, high heat of formation and high nitrogen content (61%~85%) which could be designed to high-energy insensitiveness primary explosives as complex cation, complexs anion and salts forms. Tetraammine bis(5-nitrotetrazolato) cobalt(Ⅲ) perchlorate (BNCP) is already used in laser and semi-conductor bridge(SCB) detonators. Homologous compounds of BNCP (5-NT ligand based Ni/Cu/Zn), DAT ligand based Cu/Fe/Co/Ni complex cation and 5-NT ligand based ferrous/Cu/Co/Ni complex anion, hydrazinotetrazole or hydrazinotrizole ligand based Hg/Cu/Co/Ni/Cd and DTA ligand nitrate/perchlorate are widely researched. The typical primary explosives are [Cu^Ⅱ(DAT)₅(NO₃)]NO₃, (NH₄)₂[Fe^Ⅱ(NT)₄(H₂O)₂], (NH₄)₂[Cu^Ⅱ(NT)₄(H₂O)₂].

Abstract:Six optimized stable 3, 6-bis(1H-1, 2, 3, 4-tetrazol-5-yl-amino)-1, 2, 4, 5-tetrazine (BTATz) dimers were found on the potential energy surface and their electronic structures have been obtained by using density functional theory (DFT) at the B3LYP/6-31G^* level. The largest corrected intermolecular interaction energy of the dimer calculated with basis set superposition error correction (BSSE) and zero point energy (ZPE) correction is -68.82 kJ·mol^-1. The natural bond orbital (NBO) analysis was performed to reveal the origin of the interaction. Based on the vibrational analysis, the changes of thermodynamic properties from the monomer to dimer with the temperature ranging from 200.0 K to 800.0 K have been obtained using the statistical thermodynamic method, founding that the strong hydrogen bonds dominantly contribute to the dimers. The dimerization process can occur spontaneously over the temperature from 200 K to 400 K.

Abstract:The thermal behaviors of tetraethylammonium dodecahydrododecaborates(BHN) were investigated by DSC and TG-DTG techniques. The compatibilities of BHN with 2, 4, 6, 8, 10, 12-hexanitro-2, 4, 6, 8, 10, 12-hexanitrohexaazaisowurtzitane(CL-20), 3, 4-dinitrofurzanfuroxan(DNTF), N-guanylurea-dianitramide(FOX-12), cyclotetramethylenetetranitroamine(HMX), glycidyl azide polymer(GAP), cyclotrimethylenetrinitramine(RDX), ammonium perchlorate(AP), lead 3-nitro-1, 2, 4-triazol-5-onate(NTO-Pb), hydroxyl terminated polybutediene(HTPB), di-2-ethylhexyl sebacate(DOS), 2, 4-toluene diisocyanate(TDI), isophorone diisocyanate(IPDI), cupric adipate(AD-Cu), Al powder and Mg powder were examined by DSC method as well as vacuum stability test. The results indicate that there is one main exothermic decomposition stage for BHN sample, the peak temperature is 305.8 ℃. The compatibilities of BHN with CL-20, HMX, GAP, RDX, AP, NTO-Pb, HTPB, DOS, IPDI, AD-Cu, Al powder and Mg powder are fair. These materials mentioned above can be used as components in preparation of propellants and explosives, whereas, the compatibility of TDI with BHN is bad.

Abstract:Nanoparticles of TiAl alloy were prepared by the flow-levitation method and characterized by transmission electron microscopy(TEM), X-ray diffraction(XRD) and energy dispersive spectrometer(EDS). The influence of the temperature of the droplets on the microstructure of nanoparticles was studied. Results show that the spherical nanopartilces of TiAl alloy are mainly composed of Ti₃Al phase, with the average diameter less than 100 nm and the original atom ratio of Ti/Al. The particle size and phase constituent are affected by the temperature of droplet.

Abstract:2-Amino-4-nitroimidazole was synthesized using 4-nitroimidazole as starting materials, followed by nitration, thermal rearrangement and selective reduction. The condensation of 2-amino-4-nitroimidazole with 3-chloro-2, 4, 6-trinitrobenzenamine led to obtain 2-(3-amino-2, 4, 6-trinitro)phenylamino-4-nitroimidazole in 15% yield. Their structures were confirmed by ¹H NMR, MS and IR. Selective reduction and condensation reaction mechanism were discussed. Thermal behaviors of 2-amino-4-nitroimidazole and its derivative were studied by DSC, decomposition temperatures are 236.32 ℃ and 244.86 ℃, respectively.

Abstract:RDX-CMDB propellants containing guanidinium azotetrazolate(GZT) were prepared by standard cast technique. Properties including energy, combustion, thermal security and the thermal behaviors of RDX-CMDB propellants were studied through theoretical calculations and experimentations. Results indicate that the specific impulse(I_sp), explosion heat(Q) and adiabatic combustion temperature of RDX-CMDB propellants decrease with the replacement of RDX by GZT, and gas volume increases. Replacement of RDX with 15% GZT makes the specific impulse, explosion heat and adiabatic combustion temperature decrease 29.2 s, 1248 kJ·kg^-1 and 800 K, respectively, and gas output increase 10.73 mol·kg^-1. GZT makes RDX-CMDB propellants detonate and deflagrate more easily at high temperature above 200 ℃, but has no obvious influence on thermal security of RDX-CMDB propellants below 100 ℃. For RDX-CMDB propellants without the catalysts(lead and copper composite organic salts), GZT could increase the burning rates and decrease the pressure exponents of propellants, 15% replacement of RDX by GZT results in the increase of burning rate by 1 mm·s^-1 under 7 MPa and the decrease of pressure exponent from 0.86 to 0.70 under pressure 7-10 MPa. For RDX-CMDB propellants with the catalyst, GZT decreases the burning rates and increases the pressure exponents of propellants, 15% replacement of RDX by GZT increases the pressure exponent from 0.47 to 0.69 under pressure 7-10 MPa and decrease the burning rate by 3 mm·s^-1. The TG experiments of RDX-CMDB propellants containing GZT indicate that a mass loss process corresponding to decomposition of GZT appears in the TG curve.

Abstract:A new high-nitrogen compound zinc 5, 5′-azotetrazolate(ZnATZ) was synthesized by mixing the solution of Zn²⁺ and sodium 5, 5′-azotetrazolate(NaATZ), which was prepared via alkaline oxidation reaction using 5-aminotetrazole as a staring materials. The optimal conditions obtained by orthogonal experiments were reaction temperature, 65 ℃; concentration of NaATZ, 0.2 mol·L^-1; concentration of Zn²⁺, 0.5 mol·L^-1; NaATZ/zinc salt (mole ratio), 1:1.5. The structure was characterized by IR and elemental analysis and then the molecular formula C₂N₁₀Zn·2H₂O was confirmed. The results of TG and DSC show that, the initial decomposition temperature of ZnATZ is 192 ℃, the peak temperature is 219 ℃ and the thermal stability of ZnATZ is good. The results of sensitivity show that ZnATZ is sensitive to flame and impact, having important characteristics for ignition or percussion composition.

Abstract:To expose the safety of KClO₄-type pyrotechnics composite, seven 50/50/m/n-KClO₄/Al/epoxy resin/graphite mixture systems(m=n=0; m=3, n=0; m=5, n=0; m=5, n=1; m=5, n=2; m=5, n=3; m=5, n=4) known as samples 1^#-7^# in this work were prepared, respectively. The effects of epoxy resin and graphite on the impact sensitivity of KClO₄-type pyrotechnics composite were studied by standard method GJB772A-1997-601.1, TG-DTA and SEM. The results show that the explosion percent of impact sensitivity for samples 1^#-7^# is 0, 60, 76, 40, 12, 2 and 0, respectively. In comparison with sample 1^#, adding epoxy resin in samples 1^# makes the explosion percent of impact sensitivity of samples 2^# and 3^# enhance and with increasing the amount of epoxy resin in samples 3^#, the explosion percent of impact sensitivity increases. In comparison with sample 3^#, the addition of graphite into samples 4^# makes the explosion percent of impact sensitivity of samples 4^#-7^# decreases and with increasing the amount of graphite in samples 3^#, the explosion percent of impact sensitivity decreases in the order 4^#>5^#>6^#>7^#. The reasons of sensitization of epoxy resin and desensitization of graphite to the KClO₄-Al binary system are discussed.

Abstract:The solid-liquid equilibrium data for TNT and RDX in supercritial carbon dioxide (SC-CO₂) were measured at 303.0, 308.0, 323.0 and 338.0 K, and over the pressures range from 10.0 MPa to 50.0 MPa by an ultraviolet-visible (UV-Vis) detector. The effects of pressure, temperature and support effect (SE) between molecules of RDX and TNT on the solubility of TNT/RDX/SC-CO₂ system were analyzed. The results show that the solubility of TNT and RDX in ternary system TNT/RDX/SC-CO₂ is better than that in binary systems TNT/SC-CO₂ and RDX/SC-CO₂. The values of SE of TNT and RDX increase first and decrease then with the pressure increasing. The pressure turning point occured over the pressure range from 25 MPa to 28 MPa for TNT and from 13 MPa to 20 MPa for RDX.

Abstract:To reduce the water content in PGDN(1, 2-propanediol dinitrate)/DBS(dibutyl sebacate) mixed solution, the effect of pressure, spraying times, material temperature and ventilation condition on dewatering effect were investigated using spraying method. The stability test was done. The results show that the water content in mixed solution can be reduced from 0.2428% to 0.0614% under the conditions of 100 g mixed solution, pressure of 0.08 MPa, material temperature of 71 ℃ and ventilation. The mass recovery of mixed solution after spaying is 100%. Abel value of mixed solution after heating for 15 min in water bath at 80 ℃ does not change, indicating that the water content in mixed solution can be reduced greatly according to the optimized parameters and this spraying method does not cause material loss or reduction of the stability of the mixed solution.

Abstract:3, 3-Bis(difluoroaminomethyl)oxetane(BDFAO) is a new energetic compound. BDFAO was synthesized from 3, 3-bis(chloromethyl)oxetane(BCMO) by amination, esterification and fluorination. Total yield is about 43%. Synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, GC (gas chromatograph) and elemental analysis. It was proved to be BDFAO and its purity is above 97%. The thermal properties of synthesized BDFAO were investigated by TG-DTA(thermogravimetry and differential thermalanalysis). Results show it has better thermal stability and its melting point is about 43.5 ℃. The sensitivities of BDFAO were determined by GJB772A-1997. The impact sensitivity H₅₀ is about 28.5 cm(5 kg hammer), the friction sensitivity is 100% (90° angle, 3.92 MPa) and it is insensitive to impact but sensitive to friction.

Abstract:According to the requirement of propellant binder, a series of novel segmented thermoplastic polyether polyurethane elastomers (TPU) based on tetrahydrofuran-ethylene oxide copolyether (PET) as the soft segments and 1, 3-bis(isocyanatomethyl)benzene (XDI) extended with hydroquinone-bis(β-hydroxyethy)ether (HEQQ) as the hard segments were synthesized to study the relationships between morphology and properties. The experimental techniques utilized were dynamic rheological behaviors, FTIR, WAXD, DMA, GPC and the miscibility with nitrate ester. The results show that the storage modulus(G′), loss modulus(G″)and the complex viscosity(η^*) of the blends increase gradually with increasing fraction of hard segment content, and the TPU has a higher molecular weight with polyurethane characterization and typical microphase separation, and exhibits excellent the complex viscosity of TPU with 45% hard segment contents to meet requirements of propellant in terms of lower T_g of soft segments, good miscibility with nitrate ester, while the strain decreases WAXD results indicate that all elastomers are completely amorphous at all levels of hard-segment concentration.

Abstract:In order to improve the accuracy of the test for boron powders combustion heat and determine the main factors affecting the uncertainty of boron powders combustion heat test under the combustion-supporting condition, the direct assessment method was adopted to analyze the uncertainty based on boron powders ignition and combustion characteristics as well as the principle of boron powders combustion heat test under the combustion-supporting condition. The impact degree of various factors on uncertainty of boron powders combustion heat value testing were calculated. Results show that the main factors affecting the uncertainty for boron powders combustion heat test are the temperature rise of the calorimetric system, the calorific value of combustion-supporting agent, and the mass of boron powders involved in the combustion. Reducing the uncertainty of calorific capacity of the calorimetric system, can increase the accuracy of measurement for boron powders combustion heat value. The relative uncertainty of boron powders combustion heat value test using combustion-supporting agent is only 0.95%.

Abstract:The pin shape probe and corresponding experiment method was designed to measure the precision steady detonation velocity. The steady detonation velocities of sheet insensitive high explosive (IHE) based on TATB at the restricted by polymethylmethacrylate, stainless steel and aluminum alloy were measured by needle shape pins, and the uncertainty of measurement velocity was analyzed. The result shows that the uncertainty of detonation velocity in IHE based TATB measurement using this method is not exceed 19 m·s^-1, and the relatively uncertainty is not exceed 0.25%. Results are accordant with the precision detonation physics experiment result of Los Alamos National Laboratory (LANL). It is a high precision detonation velocity measurement method for precision detonation physics.

Abstract:A new process of fabricating micro-pores oblate spherical powder (MOSP) with closed-pore structure was put forward, which is based on the traditional ball propellant process and the way of making the micro-capsule. 7% sodium sulfate solution is used as a dispersion medium for making MOSP instead of water. This method can effectively avoid the hole connection structure between pore walls in MOSP caused by water which is dissolved in nitrocellulose solution. Both changing the dosage of inner water phase and chemical foaming are used to prepare MOSP with closed-pore structure. The results indicate that: MOSP with uniform pore and closed-pore structure can be prepared when the amount of the inner water phase is less than 30 mL; MOSP with uniform pore, closed-pore structure and low bulk density can be prepared when 29% of solvent is evaporated.

Abstract:The thermal decomposition and combustion characteristics of nitramine propellants containing N-guanylurea-dinitramide(FOX-12) were studied by DSC-TG, a closed bomb and an interrupted-burning testing instrument. The results show that NC-NG and FOX-12 in the nitramine propellant begin to decompose simultaneously. Adding FOX-12 makes the pressure exponent of the nitramine propellant reduce to less than 1. With the rising of the FOX-12 content, the decline extent of the pressure exponent in the low pressure of 10-20 MPa is larger than that in high pressure range of 40-420 MPa.

Abstract:In order to further improve the combustion performance of the modified single base gun propellant, the modified single base gun propellants 1^# and 2^# were prepared via the energy-increased and desensitized process to the 5/7 single base gun propellant with web of 0.55 mm. The solvent extraction process was adopted in the energy-increased and desensitized process of preparing the sample 2^#. The surface appearance was investigated by SEM. The bulk densities were determined by a standard container method. The combustion performances under constant volume were analyzed by a closed bomb test. The results show that the structure of propellant 2^# is solidish. The bulk density of propellant 2^# is increased from 0.888 g·cm^-3 to 0.920 g·cm^-3. The initial combustion of propellant 2^# is steady and the grain split point is delayed from 6.0 ms of propellant 1^# to 7.0 ms of propellant 2^#. The combustion end is delayed from 6.0 ms of propellant 1^# to 8.0 ms of propellant 2^#. The combustion progressivity of propellant 2^# is enhanced, revealing that propellant 2^# has an excellent combustion performance.

Abstract:The modified single-based propellant was prepared by the "impregnated-deterred-coated" technology.The combustion and interior ballistic performances of the propellant were investigated by closed-bomb and 857-30 mm gun.The structure of the modified single-based propellant was analyzed.The results show that in comparison with conventional single-based propellant, the muzzle velocity of modified single-based propellant increases by 5% at least at normal, high and low temperatures.The modified single-based propellant has the characteristics of low temperature coefficient when used in the 857-30 mm gun.It is resulted from the formation of the zipper structure with end sealing and the softness of the body surface.

Abstract:Hopkinson pressure bar and X-ray CT tomography scan equipment and devices were used to test and evaluate a bridge-wire detonator′s performance in high acceleration overload environments.According to test results, the failure mode and the weak properties were obtained.A structure reinforced detonator was designed through materials optimization, structural optimization and reinforcement, transition charge solidified.The results show that reinforced detonator can withstand the impact of more than 100000 g and pulse with width of about 100 μs.After the high acceleration impact, the detonator performance and basic structure nearly do not change, revealing that the performance of bridge-wire detonator against high acceleration overload is enhanced.

Abstract:A prediction method of the no-firing current of electric explosive device was studied.The electric-thermal parameters of the electric explosive device such as resistance and heat loss coefficient were measured with the non-destructive transient pulse test system, then the heat loss coefficient was redeemed using the no-firing current measured by the Bruceton method.The no-firing current of the electric explosive device was predicated using the radial basis function(RBF) neural network.The results show that the predicted result is consistent with that measured with the firing validated test system, and the electric explosive device with the larger predicted value owns the larger firing probability.The mean predicted current equals to the firing current measured by the Bruceton method.

Abstract:In order to explore the thermal hazard of fireworks, the adiabatic reaction processes of dry and wet white-light fireworks mainly composed of barium nitrate were studied by an accelerating rate calorimeter(ARC).The curves of change in adiabatic reaction temperature with time and in temperature rise rate with temperature were obtained.The pseudo-inverse matrix method was used to calculate the apparent activation energy and pre-exponential factor for the exothermic reaction of two fireworks and the measured data were modified by thermal inertia factor of ARC.The results show that the initial temperature, final temperature, initial self-heating rate, maximum self-heating rate, maximum self-heating rate temperature and time to maximum rate of the exothermic reaction are 567.75 K, 740.48 K, 0.17 K·min^-1, 61.56 K·min^-1, 707.5 K, 145.93 min for dry fireworks and 363.59 K, 1128.8 K, 0.07 K·min^-1, 0.77 K·min^-1, 799.47 K, and 1480.86 min for wet fireworks, respectively, indicating that wet fireworks are easier to reaction, and the reaction rate of dry fireworks is faster than that of wet fireworks.

Abstract:Ordered nanoporous materials possess unique properties, such as high surface area, uniform and tunable pore size, and abundant morphologies and have attracted a lot of interests since the first discover of microporous molecular sieves and become a special field.This paper provides a comprehensive review of current research activities in ordered nanoporous materials, including silicon, silica, alumina, carbon, polymer and metal organic frameworks(MOFs), for their applications to energetic materials in catalysis, sorption, separation, detection, chemical sensor, nanocomposition, and so on.Finally, the prospects for future investigations are proposed.

Abstract:The origination and features of mechanochemistry and its applications and developments situation in the research field of energetic materials were introduced and discussed.The mechanochemistry of energetic materials can be divided into experimental and theoretical researchs.Current developments, both at home and abroad, in theoretical researches for the mechanochemistry of energetic materials were summarized and reviewed.The investigation results on the triggered mechanism, the relation of structure and property, and theoretical prediction of properties of energetic materials were analyzed.The development prospect of mechanochemistry in energetic materials was prospected with 70 references.

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