Abstract:The critical temperature and pressure of fluororubber-ethyl acetate-CO₂ ternary system are investigated by the static visual method at constant volume. On the basis of the results, NTO based polymer bonded explosive (PBX) is prepared by supercritical fluid anti-solvent method. The feasibility of the technique and the technology is validated by means of the sample component analysis,performance testing, absorbance testing, infrared spectra and SEM etc.

Abstract:Thermal cycling tests of TATB based polymer bonded explosives (PBX) samples are undertaken at the scope from －40～75℃. Their dimensions, mechanical properties and detonation performance are also tested before and after the thermal cycling test. The results show that the dimension of TATB based PBX increases with the increasing of cycle number, but the rate of dimension-growth reduces obviously. Because of the surface de-bonding during the thermal cycling test, its modulus, strength and creep properties decrease a little after thermal cycling test. Owing to the void growth during the thermal cycling test, its shock sensitivity increases, but its detonation velocity keeps no change.

Abstract:A mild, low cost synthetic method of glycidyl nitrate is developed via so called one-pot procedure. Epichlorohydrin added dropwise to the dilute nitric acid (35 wt%) resulted in ring-opening reaction at about 20 ℃. Ring-closing occurred then by the addition of aqueous sodium hydroxide. Glycidyl nitrate was obtained in moderate yield (60%) and its structure was characterized by Fourier transform infrared spectroscopy, hydrogen and carbon nuclear magnetic resonance and elemental analysis.

Abstract:The effect of the explosive charge with variable clearance and the charge filled with oxidant gel solution into its clearance on detonation performacnce is studied by using ionization method. Experimental results show that steady detonation of the explosive charges with axial clearance of 2 mm is not affected evidently，and detonation velocity of the charges reduce after being filled with the gel solution; however, steady detonation is affected greatly by charge segments and radial clearance size, and detonation performance is improved after being filled with the gel solution.

Abstract:Effect of confinements on insensitive high explosive (IHE) is studied by photoelectric test. Results show that adding confinement can not enhance the steady-state detonation velocity of IHE markedly, but makes the confinement be faster than that of inconfinement mainly resulting from the wave impedance of confinement material, and the effect becomes more obvious as the wave impedance of confinement material increase.

Abstract:By using nonlinear finite element analysis software LS-DYND, the process of warhead oblique penetrating the target with various impacting velocity, impacting angle, and material property is calculated and analyzed. It was found that the penetration property of warhead can be improved by increasing the material plastic flow stress and material ductibility and adjusting flight position when warhead penetrates the target. The numerical simulation results show that the deformation of warhead reduces while the front parts of the missile pre-impact the target.

Abstract:Under standard condition (p_e/p_c=７０∶１) ,the energy parameters of the propellant containing 3, 4-dinitrofurazanfuroxan (DNTF) are calculated by CAD system of propellant energy calculation. Results show that the specific impulse of the DNTF monopropellant is 2696.4 N·s·kg^-1 and is similar to that of the CL-20 monopropellant. The theoretical specific impulse and characteristic velocity of propellants including hydroxy-terminated polybutadiene composite propellant, composite modified double base propellant and GAP propellant are increased by DNTF substituting the ingredient RDX or AP. DNTF has no chlorine and its friction sensitivity is much lower than that of RDX, therefore, DNTF introduced into the propellant composition is helpful for the comprehensive performance of the propellant.

Abstract:Ammonium nitrate（AN）, used as oxidizer of low signature and smokeless propellants, is a promising candidate. However there are some problems for AN-based propellant in ignition and combustion. One way to resolve ignition and combustion difficulties for AN-based propellant is to lower AN decomposition temperature, and to accelerate the thermal decomposition of AN. Effect of metal oxide, organic metal salt (OME), energetic binder and hexanitrohexaazaisowurtzitane(HNIW) on the thermal decomposition of AN are studied by DSC and TG-DTG. Results show that catalysts lower the endothermic decomposition temperature of AN to a certain extent and energetic components accelerate the exothermic decomposition process of AN.

Abstract:Initial crystalline and crystalline change under isothermal crystallization and various aging conditions are studied by Differential Scaning Calorimeter (DSC) and Modnlated DSC (MDSC). The initial crystalline is very small from our experiments and crystalline tested by DSC results from thermal relaxation and subcooling crystallization. Isothermal crystallization rate at 80 ℃ is the fastest, which is about the 0.85 T_m(melting temperature); crystalline of F₂₃₁₄ increases while aging at different conditions, longer time and high temperature will result in more crystalline.

Abstract:The gelation of hydrazine nitrate-hydrazine hydrate double components is studied. Sorts of gelling agents and the appropriate addition of gelling agents for the system in which the ratio of hydrazine nitrate and hydrazine hydrate is from 60∶40 to 70∶30 are given: HPAM 0.8%、guar gum 1.2%、CMCNa 1.8%. The ratio of absorbing moisture and TG analysis of gelled samples are tested.

Abstract:The adsorption manners of two fluorine-polymers on TATB crystal surfaces are simulated and the structures are optimized by MD(COMPASS forcefield,NVT) method and smart minimizer method in Discover/Material Studio. Results show that: (1) The order of atomic positions changes of TATB and the spreading size of polymers is: (010)＞(100)＞(001), when there are interactions between them. (2) Two polymers can be attracted by TATB crystal. TATB can also be bonded by F₂₃₁₁ and F₂₃₁₄which has more efficiency than F₂₃₁₁. (3) The abilitiy of TATB crystal surfaces to adsorb polymers decreases as follows: (010)＞(001)＞(100).

Abstract:A new manufacturing technique is proposed for transferring the waste double-base mortar propellant into oblate spherical propellant used in powder loads. The transferring process comprises grinding waste propellant, dispersing in water, swelling of grinded waste propellant powder in solvent, stirring for spheroidization, washing oblate propellant, screening and drying, obtaining the polished surface of the oblate propellant. The suitable process conditions are: ratio of solvent volume to propellant powder quality 1.0~2.0 ml·g^-1, ratio of water volume to propellant powder quality 6.0, consistence of dispersant in water 1.0 wt%~2.0 wt%, stirring speed 500~600 r·min^-1（linear velocity 4.0~5.0 m·s^-1）, swelling temperature and time 65~68 ℃ and 30 min respectively. Thus, the bulk density of the oblate spherical propellant increased from 0.70 g·cm^-3 to 0.95 g·cm^-3 (the crude propellant is), the flowing time of the propellant decreased from 7.5 s to 4.0 s. Experimental results show that the ballistic performance of the propellant meets the requests of American Standard PATMI.

Abstract:For seeking metal powder interference agent with optimal extinction performance in outer space, the relationship model between each components content in metal powder and extinction performance is established on the basis of Drude model. The extinction parameter Q_e/d of brass is calculated by Mie theory. Results show that when the zinc content in brass powder is lower, the extinction performance increases with the increasing of zinc content and the extinction performance is optimal when the zinc content reaches 42%. The experimental results demonstrate the rationality of the conclusion.

Abstract:The whole process of thermal decomposition of (2,2′,4,4′,6,6′)hexanitro-stilbene (HNS ) is investigated by using TG-DTG,TG-MS and in-situ thermolysis rapid scan FTIR coupling techniques.Kinetic parameters of the thermal decomposition of HNS are obtained and a possible decomposition mechanism is suggested. Results show that the thermal decomposition process can be divided into two stages: (1) forming "explosive coke" via the nitro-nitrite isomerization on the C-NO₂ p-substituted to α-CH bond and the decomposition of "five cycled compound" intermediate between α-CH and o-nitrio in the first stage, (2) releasing CO₂ and other gases via "explosive coke" decomposing in the second stage.

Abstract:Octogen HMX is separated from nitrocellulose by acetonitrile dissolved water separated out in composite modified double-base propellant and determined by HPLC on C18 alkyl-bond column (4.6 mm×200 mm, 10 μm) ,using a mixture of acetonitrile and water with the ratio of 46 to 54 by volume as the mobile phase,at a flow-rate of 1.0 mL·min_－1 ,UＶ-detection at 254 nm for the final determination. Tests for relative standard deviation and recovery are made: 0.82% for relative standard deviation′s and 99.62% for recovery are obtained for octogen at the content of 21% by quality in propellant .

Abstract:The correlation of the ageing time of double-base propellant GATo-3 at 75 ℃（t_age） between the times needed for color change of standard methyl violet test （t_cch）and between the time-to-explosion of standard methyl violet tests at 120 ℃（t_exp）for aged and unaged samples is verified by variance analysis. Results show that (1)because statistic F＜F_0.99 for t_cch, the relativity between variables, t_age and t_cch is not obvious and t_cch can not be used as a criterion for evaluating the safety storage life of the propellant, (2)because F＞F_0.99 for t_exp, the relativity between t_age and t_exp is obvious and t_exp can be used as a criterion of evaluating the safety storage life of the propellant.

Abstract:Compound technique of perforating can effectively control the perforating direction and the fracturing expansion. The feasibility of this technique used in rupturing coal seams is analyzed. The experiments of perforating and fracturing are carried out on coal samples and the experimental effects are satisfactory. Compound technique of perforating and fracturing is promising in coal seams.

Abstract:The experimental and theoretical study of polynitrocubanes carried out at home and abroad, such as synthetic routes, structures, physical and chemical properties, and detonation performance are reviewed.

Abstract:A high insensitive explosive compound, 2,4-dinitroimidazole (2,4-DNI) synthesized by nitrating 2-nitroimidazole and thermal rearrangement of 1,4-dinitroimidazole, is reviewed. The properties of 2,4-DNI, such as thermal decomposition, crystallization characteristics, explosion performance, friction sensitivity and impact sensitivity are summarized.

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