Abstract:Nitration of aromatic hydrocarbon and nitrogen heterocyclic by N₂O₅ was summarized. N₂O₅ /nitric acid system is a very powerful nitration reagent and particularly valuable for the nitration of highly deactivated aromatics. N₂O₅ /organic solvent system is a much milder and more selective nitration reagent, which is suitable for the cases that the substrates or products are sensitive to acid or water, and for region-selective O-nitration. Furthermore, the synthesis and pilot-plant-scale process of N₂O₅ were also summarized.

Abstract:To reduce the sensitivity of explosives while maintaining the high energetic characteristics, a kind of new molecule explosive with low sensitivity and high energy is required. In this paper, the insensitive property of explosives containing pyridine rings is combined with the high energy of nitramine explosives, and the concept of new nitramine explosive containing pyridine ring is proposed, into which the nitramine group with N—N bonds is introduced as much as possible. Based on the research of regular relationship between molecular as well as crystal structure and explosive property as well as security performance, the molecular structures of several target compounds and their synthetic method are designed. Then synthetic routes are obtained with different synthetic reactions such as condensation, N-nitration, N-oxidation and C-nitration and so on.

Abstract:2,2-dinitro-1,3-propangdiol was synthesized using nitromethane and 38.5% formalin as raw matieral via two-step reaction, retraction and oxidative nitration, replacing the traditional oxidant of silver nitrate by sodium persulfate and potassium ferricyanide. The overall yield was more than 24.1% and purity was more than 97%. The effects of molar ratio of oxidated system, reaction temperature and reaction time on yields were investigated during oxidative nitration by orthogonal experiment.The optimum reaction conditions are as follows: K₃Fe(CN)₆, 0.1 mol, Na₂S₂O₈, 0.25 mol, reaction temperature, -5～0 ℃, reaction time, 4 hours.

Abstract:Dinitrotoluene(DNT) was prepared by nitrating toluene with nitric acid(97%) to avoid the use of mixed sulfuric acid/ nitric acid which is troublesome and energy-expensing for recycling. After investigating the factors affecting the nitration, the optimized conditions were worked out and might be as follows: molar ratio of nitric acid/ toluene 81, temperature 60 ℃, and time 1 h. The resulting DNT′s yield was 94%, purity was 98.8%, ratio of 2,4-DNT to 2,6-DNT was 4.3.

Abstract:The green synthesis of three 1,3,5-substituted (acetyl, propionyl and butanoyl) hexahydro-s-triazines was performed in various ionic liquids (ILs). The effects of the type and addition of IL, reaction temperature and time were investigated and discussed. The IL′s activity and selectivity depend on their acidity. The ideal ILs are sulfuric acid functional ones which could give a yield of target compounds up to 80% at 1 h reaction time. These kinds of ILs have selectivity of higher than 98%, and could be reused for three times without reducing activity. The characterizations of prepared ILs and triazine derivatives have been done with FTIR, ¹HNMR, MS and elemental analysis.

Abstract:Two kinds of desensitized propellants 1,5-diazido-3-nitrazapentane (DIANP) propellant and high-energy nitramine propellant) were desensitized with polymer deterrent NA in water medium. The migrations of NA deterrent in two kinds of propellants were investigated by accelerated aging tests,closed-bomb tests and interior ballistic tests respectively. The concentration profiles of deterrent NA in two kinds of propellants before and after long-term storage were studied by FTIR microspectroscopy. Results show that there are not significant changes in the explosion heat,p-t curves,interior ballistic and the concentration profiles. The migration ability of NA deterrent is weak in DIANP and nitramine propellants. The propellants desensitized by polyester NA should be stable in the interior ballistic.

Abstract:Ionic liquid-DMSO co-solvent system (20∶80 w/w) for recrystallizing RDX was investigated at 70 ℃. A non-agitated cooling crystallization method was employed for RDX growth and main collection, and rest RDX were collected by added some water or methanol to the filtrates. All the RDX samples were investigated by the DSC thermograph and SEM. The results obtained by the DSC thermograph and SEM show the thermal stability, purity, shape and quality of recrystallized RDX by Ionic liquid -DMSO co-solvent systems are improved while the H₂O-precipitated or the MeOH-precipitated materials are not. The recrystallized RDX in the DMSO-C₆mimBr co-solvent system are better than others.

Abstract:The RDX/RF gel composite energetic particles were prepared by means of emulsion process and sol-gel techniques. The particle size was controlled by the composition of the surfactant system, temperature and time of reaction. The structure of gel particles were characterized by scanning electron microscopy (SEM), BET method, X-ray powder diffraction (XRD),and differential thermal analysis (DTA). Result shows that the particles have a size of 50-200 nm, the explosive is crystallized within the nano-dimensional pores of RF gel matrix. The mean crystal size of RDX in RDX/RF gel composite energetic particles are 30-50 nm. The specific surface area of RDX/RF gel composite energetic particles is 56.3 m²?g^-1 and the temperature of exothermal peak decrease about 33 ℃.

Abstract:ε-CL-20 was recrystallized from single(alcohol, dichloromethane, acetone and ethyl acetate) and mixed (alcohol-acetone, alcohol-ethylacetate,dichloromethane-acetone, dichloromethane-ethyl acetate and acetone-ethyl acetate with different volume ratio) solvents. The resulting crystal forms were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). ε-CL-20 changes its crystal form only when recrystallizing from acetone, ethyl acetate, and alcohol-acetone;while has little change from other solvents, particularly, from the mixed solvents. The types of recrystallized CL-20 are much dependent on the volume ratio of two components of the mixed solvents, and the crystal transition reflects the "solvent effect". The structure of the recrystallized CL-20 from mixed solvents composed of two components is identical with the one obtained from the component with higher dipole moment. This may be relate with solubility of ε-CL-20 in such solvents, while solubility is dependent on the dissolution parameters and the supersaturation degree of the solution.

Abstract:A new green primary explosive copper (Ⅰ) nitrotetrazolate (CuNT) was synthesized from cuprous chloride,sodium 5-nitrotetrazolate,etc. The synthesis process was studied through single factor experiment. The results show that CuNT is of good free-running property,hygroscopicity and thermal stability. The compound is insensitive to impact,flame and static discharge. Also,the minimum quantity experiment shows that the CuNT has a fairly high explosion capacity that only 20 mg could detonate the RDX. In some initiating devices,CuNT may be a substitute for Pb(N₃)₂ and lead styphnate.

Abstract:By adopting coprecipitating method, the green primary explosive ferric styphnate-ferric hypophosphite (FSFH) was synthesized from styphnate-ferric and sodium hypophosphite. The thermal and explosive properties(impact, friction, flame, electrostatic spark sensitivity, the minimum initiating charge) were studied. The results show that FSFH is high friction sensitivity with 50 angle and 100% fire. The FSFH and lead azide are almost equal in impact, flame and electrostatic spark sensitivity. The thermal decomposition peak of FSFH is 205.88 ℃ with initial temperature of 185.36 ℃, which indicates that FSFH is weak primary explosive and can be used as primer charge and stab initiating composition.

Abstract:By using DFT method of quantum chemistry, the tetraamminediazido cobalt(Ⅲ) perchlorate（DACP) molecule structure parameters were calculated. The DACP structural characteristics, spectrum performance and photochemical decomposition mechanism were analyzed. Results show that the nucleophilic center was N,atom in NH₃ and N₃, the electronic center was Cl in ClO₄ and Co atoms. The DACP outside electron was moved from N atom in —N₃ to Cl atom in —ClO₄. The transition energy was divided into many levels. there was sequence absorbing peaks in the range of 340.99-699. 89 nm. The DACP theory IR spectra were calculated at BLYP/DNP level. The results of calculation on IR were essentially consistent with experimental values.

Abstract:A novel explosive driven flyer initiation device with changeable velocity was designed. Flyer initiation tests with different densities PETN were finished and the history of velocity of flyer was observed by VISAR. Parameters of JWL EOS of PETN with different densities were calculated by VLW EOS. Velocities of flyer was simulated by the finite element hydrocode Ansys/Ls-dyna, which were coincided with results of tests. It testified feasibility of numerical method to calculate velocity of flyer. The relationships between flyer velocity and density of PETN were gained,so that the velocity of flyer could be adjusted from 2660 m?s^-1 to 3150 m?s^-1 with corresponding pressure range of 54-86 GPa.

Abstract:The nano-energetic materials Al-MoO₃ was prepared by immersing the powders in a solvent and then mixing the two powders including nano-Al and MoO₃ with an ultrasonic mixer. The performance of nano-energetic materials Al-MoO₃ was analyzed by means of Scanning Electron Microscopy (SEM) and Differential Scanning Calorimetry (DSC). The electrical match and laser match were prepared, and their ignition sensitivities were tested. Results shows that nano-energetic materials Al-MoO₃ react at high temperature (above 520 ℃) and gives out lots of heat. Voltage ignition sensitivity of electrical match and laser ignition sensitivity of laser match, with 50% sensitivity is 22.8 V and 5.1 mJ respectively.

Abstract:The desensitized triple base propellants containing NGu were prepared by polymer deterrent technology with and without saturator, their surface structure were charactericed by electron microscopy and combustion characteristics were investigated by means of the ignition test, closed-bomb tests and interior ballistic tests. Results show that there does not exist the surface structure destroy and the ignition characteristics is good for propellant desensitized with the saturation agent. The ignition time is prolonged. The propellant with the saturation agent has great combustion progressivity and good interior ballistic at the same time.

Abstract:Effects of lead(Ⅱ) 8-hydroxyquinolinate (PbHql₂), copper(Ⅱ) 8-hydroxyquinolinate (CuHql₂), nickel(Ⅱ) 8-hydroxyquinolinate (NiHql₂), aluminium(Ⅲ) 8-hydroxyquinolinate (AlHql₃), lead(Ⅱ) copper(Ⅱ) 8-hydroxyquinolinate (PbCuHql₄), lead(Ⅱ) nickel(Ⅱ) 8-hydroxyquinolinate (PbNiHql₄), copper(Ⅱ) nickel(Ⅱ) 8-hydroxyquinolinate (CuNiHql₄) and their mixtures on the combustion characteristics (at the pressure range of 4.0~10.0 MPa) of NEPE propellants were experimentally studied. Results show that the burning rates increased and the pressure exponents decreased in a certain extent with the addition of 8-hydroxyquinoline metal derivatives. The pressure exponents could be decreased efficiently with the addition of copper(Ⅱ) 8-hydroxyquinoline metal derivatives and the burning rates could be increased obviously with the addition of nickel(Ⅱ) 8-hydroxyquinoline metal derivatives, such as, the pressure exponent at the pressure range of 4.0~7.0 MPa could be decreased to 0.54 by CuHql₂/PbCuHql₄/CB system,the burning rate at the pressure of 4.0 MPa could be increased about 53.4%, and the pressure exponent at the pressure range of 4.0~7.0 MPa be decreased to a satisfied value of 0.58.

Abstract:The surface properties of AP with various particle sizes and nitrocellulose (NC) with various content of nitrogen, and the interface properties between NC and AP were studied by using the dynamic contact angle and interface tension technique. And the effects of the surface and interface properties on mechanical properties of Composite Modified Doublebase Propellant Containing AP and Aluminium were also investigated. It was shown that the surface energy of AP increases with the increase in its particle size, while the surface energy of NC increases with the increasing nitrogen content of NC. At the same time, the particle size of AP plays a key role on the interface energy and adhesion energy between NC and AP, and the interface energy and adhesion energy decrease with decreasing particle size of AP. But the effect of interface energy decreasing on mechanical properties of the propellants is higher than that of adhesion energy, and the higher tensile strength of propellant is obtained when particle size of AP decreases. In addition, as the nitrogen content of NC decrease, the interface energy between NC and AP decrease and corresponding adhesion energy increase. The high tensile strength of corresponding propellant is also obtained herein.

Abstract:The compatibilities of triaminoguanidinium azotetrazolate(TAGZT) with main components of propellants were studied by DSC and VST experiments, respectively. Results show that TAGZT has good or fair compatibility with nitrocellulose(NC), glycidyl azide polymer(GAP), polyethylene(PEG), diethylphthalate(DEP), 2-nitrodianiline(2-NDPA), cyclotetramethylenetetranitroamine(HMX), cyclotrimethylenetrinitramine(RDX) and aluminum power(Al), but bad compatibility with NC+NG, m-dihydroxybenzene(Res) and N-nitrodihydroxyethylaminedinitrate(DINA); TAGZT had no interactions with DEP, GAP, 2-NDPA or Al, moderate interactions with NC, HMX or PEG, and intensive interactions with DINA, Res and RDX.

Abstract:Thermal behavior of poly 5-vinyltetrazole was studied by thermogravimetry-derivative themogravimetry (TG-DTG). The specific heat capacity of poly 5-vinyltetrazole was determined by the micro-thermal method and theoretical calculation. The results show that the thermal decomposition reaction kinetic equation of the second (main) decomposition stage is: dα.-dt=10^21.03.-β 3.-2(1-α)×［-ln(1-α)］^1/3exp(-2.292×10⁵/RT), the critical temperature of thermal explosion is 588.63 K, the adiabatic time-to-explosion of poly 5-vinyltetrazole was calculated to be 251.4 s.

Abstract:The vulnerability response charactcristics of the explosive PMX-1 charge in 12.7 mm bullet impact test, fast cook-off test and slow cook-off test by consult the MIL-STD-2015C “Hazard Assessment Tests for Non-nuclear Munitions”, and the mechanism of response were studied. Results show that the PMX-1 passes the tests and it′s an insensitive explosive.

Abstract:In order to solve the problems such as the explosive charge safety during penetration, an insensitive explosive charge is designed started with choosing explosive size, size distribution and charging processes to endure high overloading. The impact and friction sensitivities were tested. Results show that after size distribution and deterred, the thinner of the HMX, is the lower of sensitivity will be. The density of charge is improved to 1.8 g·cm^-3 by special technique which controlles explosive charge quality. The experiment research on safety of explosive charge was carried out with test projectiles penetrating reinforced concrete. It indicates that test projectiles are in good condition and the charge is unreactive during penetration.

Abstract:Differential Scanning Calorimeter（DSC），Accelerating Rate Calorimeter(ARC) and Reaction Calorimeter (RC) were used to study thermal hazard of dinitrotoluene(DNT) nitration. DSC results show onset temperature T0 of trinitrotoluene(TNT) is 298.38 ℃, which is lower than that of DNT. ARC results demonstrate that TNT starts to decompose at 232 ℃, and T_D24 of TNT decomposition is about 224 ℃. Based on RC test results, there is a large amount of heat release during DNT nitration, and the heat generation at 110 ℃ is 1.4 times heat generation at 90 ℃, in which a large part comes from the exothermal side reaction actually. Therefore, temperature should be controlled strictly to avoid acutely exothermal side reaction and product decomposition.

Abstract:1,3,5triamino2,4,6trinitrobenzene (TATB) is a widely applied high explosive,which usually needs to be recrystallized for different application requirements. TATB recrystallization methods such as cooling recrystallization and antisolvent crystallization were introduced. Dimethyl sulfoxide (DMSO),sulfolane,concentrated H2SO4 and alkali are commonly used as solvents. By varying stirring rate, cooling rate and antisolvents adding rate,TATB with different crystal shape and different particlesize can be obtained. The crystallization in the process of TATB synthesis and the properties of recrystallized TATB were presented. The effect of solvents on recrystallization and prospect of TATB recrystallization research were discussed also.

Abstract:Recent research progress in clean nitration of toluene, including the application of nitrating reagent and catalyst is presented. Their specific features,merits and demerits are outlined, and the perspectives of the catalytic nitration of toluene are prospected. The potential application of dinitrogen pentoixde nitrating reagent and catalysts for catalytic nitration of toluene is put forward. It is a clean nitrated technology in vast prospects of industrial application.

Abstract:Nitroimidazole heterocyclic compound 2, 4-dinitroimidazole (2, 4-DNI) has been synthesized. Its molecular structure was characterized by IR, MS, 1H-NMR, 13CNMR and elemental analysis. The experimental thermal stability, sensitivity and security of 2,4-DNI show that 2,4-DNI is well thermal stable, better than RDX and other nitramine explosives, has low mechanical sensitivity approaching to TATB or TNT and good electrostatic sensitivity. So, it will be one insensitive or low sensitivity high explosive has promising applications in many insensitive ammunitions in future.

Abstract:本文为大摘要

Abstract:Institute of Chemical Materials, CAEP, Mianyang 621900, China

Abstract:Institute of Chemical Materials, CAEP, Mianyang 621900, China

Abstract:Institute of Chemical Materials, CAEP, Mianyang 621900, China

Abstract:Institute of Chemical Materials, CAEP, Mianyang 621900, China