Abstract:The hydroxyl butylenes cellulose,a thermoplastic energetic bonder intermediate, was synthesized by the reaction of butadiene monoxide and a novel cellulose which was treated respectively by high pressure and high temperature steam explosion at 3.0 MPa,4.0MPa,4.8MPa and was characterized by SEM to indicated that the morphological and supermolecular structure of the treated cellulose was destroyed compared with untreated cellulose. The products were characterized and analyzed by FTIR and X-ray diffraction and DSC. The effects of reaction conditions such as temperature,time,concentration and reaction ratio,on the synthesis were investigated,and the synthesis condition was optimized.The test results show that the material proportion,temperature,stirring style and charging sequence are the four main factors that influence the synthesis.

Abstract:The fully optimized geometries of 66 energetic molecules have been calculated by means of four semiempirical MO methods (PM3、AM1、MNDO and MINDO/3). The heats of formation were obtained. The correlation between the calculated heats of formation of each method and experimental ones has been investigated. It is found that there is a good linear correlation between heats of formation calculated by PM3 method and experimental ones. The linear equation for these 35 compounds which have experimental values is ΔH_f,EXP=-4.98+1.03 ΔH_f,cal , the linear correlative coefficient,R, is 0.976, and the root mean square deviation is 37.53. The linear equation can be used to predict the gas-phase heats of formation of energetic compounds. The results calculated by AM1 method is not so good as the ones by PM3 method, while MINDO/3 and MNDO methods are not fit for calculating heats of formation of these compounds. Therefore, PM3 method is the best one for predicting heats of formation for energetic materials among the four semiempirical MO methods.

Abstract:The kinetics of the thermal decomposition reaction of methyl ethyl ketone peroxide (MEKPO) with sulfuric acid of different concentration had been studied by an Accelerating Rate Calorimeter (ARC). The curves of the rate of temperature rise and pressure versus temperature of these reactions were attained. Following thermal decomposition kinetics, the apparent activation energy (E_a) and the preexpontial factor (A) of the decomposition reaction of MEKPO and its mixture with sulfuric acid were obtained by analyzing the ARC data. From the curves of the rate of temperature rise and pressure versus temperature,along with the kinetic parameters,the effects of 1% and 3% sulfuric acid on the decomposition reaction of MEKPO were analyzed.

Abstract:Three types of RDX crystals were prepared. The first one was obtained from the direct production process, and the other two were recrystallized from the first one in acetone and in cyclohexanone respectively. The mechanical performances of these three RDX crystals were tested and analyzed. Among them, the one recrystallized from cyclohexanone possesses the best mechanical performances. The pressed charge column of this kind of RDX crystal did not appear breakage until the pressure was brought to 383 MPa. Besides, the crystal from cyclohexanone exhibits a smoother surface, a better transparency, and a more regular shape in comparison with others. A number of experimental results related to different RDX crystals are presented in this paper, which would be useful for RDX′s molding application.

Abstract:The precipitation polymerization of acrylonitrile in cyclohexane was carried out to encapsulate ammonium nitrate. The hygroscopicity and caking tendency were studied. The effects of the coated ammonium nitrate was observed by SEM and the contact angle of AN was measured by contact angle test apparatus in different test liquid. The reasons why AN hygroscopicity was reduced after being coated were analyzed.

Abstract:The paper presents an experiment on the thermal shock damage of JOB-9003 and its evolution course in water under different temperatures (from 2 ℃ to 24 ℃,26 ℃,28 ℃,30 ℃,32 ℃) by using digital ultrasonic testing system. The intensity of the different damage accumulation degree (damage factor) has been tested. A fitted curve relationship between ultrasonic characteristic parameters (especially ultrasonic gain) and the damage accumulation degree of JOB-9003 explosives was found. It′s measured that the threshold (D_C) of the damage of JOB-9003 explosives is 0.223. The results prove that ultrasonic testing method is reliable to study the thermal shock damage of JOB-9003 and its evolution course,and provide the technique supports on studying dynamic state response of explosive to different load conditions.

Abstract:The unsymmetrical dimethylhydrazine(UDMH) and initial oxidation products were characterized by gas chromatography-mass spectrometry,and the content of main components were identified. The results show that the oxidation sample contains dimethylamine,UDMH,unsymmetrical dimethylhydrazone,formaldehyde dimethylhydrazone,N-nitroso dimethylamine,acetaldehyde dimethylhydrazone,1,1,4,4-tetramethy-1,2-tetrazene and dimethyldizene in initial oxidation stage under oxidation time minor to 100 h in air,and the content of dimethylamine,formaldehyde dimethylhydrazone and N-nitroso dimethylamine increas in this stage,but the content of dimethylamine decreases and that of N-nitroso dimethylamine increases quickly while forming new oxidation substances in the following process. The presentation of fragment ion peak of m/z=42～43 in all the MS spectra of the compounds containing nitrogen proves that the break reaction of N—N bond in molecules of UDMH and organic oxidation products containing nitrogen easily take place under heating.

Abstract:This paper has studied the technological process for preparation of grain potassium picrate (PK), which can meet the requirements of production in batches. In this study, the technological conditions for preparation of grain PK, i.e. the rescrystallization of PK, the reaction of picric acid with potassium hydroxide, the granulation of PK etc. were optimized. A number of properties of grain PK, including thermal stability, sensitivities for heat, impact, flame, friction and electrostatic spark, compatibility, heat of combustion, and detonation volume etc. were measured and evaluated. At present, the preparation has been scaled-up to several hundred grams. The product has already been applied to many ignition devices in the military industry.

Abstract:The principle and method for testing the atomized field of liquid propellants with a pulsed laser holography were introduced. The distribution patterns and sizes of the atomized droplets of a liquid propellant were analyzed based on its spraying experiments. The experiment shows that the sprayed particle diameter is around 10～20 μm under high pressure of the chamber,and diameter distribution can be adjusted effectively by the pressure. It′s proved that the laser holography is useful for the investigation and application of liquid propellant.

Abstract:Based on the fact that explosives are insensitive to microwave radiations under some conditions, microwave desiccation had been applied to all of the coarse-grained TATB, submicron TATB and fine RDX. The experimental results show that it is possible to substitute high temperature drying with microwave desiccation for coarse-grained TATB. In combination of low temperature drying and microwave desiccation, the specifications of the dried coarse-grained TATB could meet the requirements. For both of the submicron TATB and fine RDX, the microwave desiccation possesses advantages of high efficiency and high speed while without remarkable particle agglomeration.

Abstract:Phase diagram of a tertiary mixture composed of two solid components (2,4-DNT and 2,6-DNT) and one liquid component(ethanol or sulphuric acid) was first set up by solubility approach. The solubility of both 2,4-DNT and 2,6-DNT in ethanol or sulphuric acid,and the cocrystallizing point of the tertiary mixture were determined. From the experimental results,it is concluded that in order to precipatate more 2,6-DNT,the crystallization process should be carried out at higher temperature for solvent of ethanol,but at lower temperature for solvent of sulphuric acid.

Abstract:A new compound 3,5-diamino-2,4-dinitrochlrobenzene was synthesized from sym-trichlorobenzene by nitration and amination. Its melting point is 204～206 ℃. Its structure was proved by FT-IR,NMR,MS and element analysis. And its surface shape was characterized by SEM.

Abstract:Phosphomolybdic acid catalyst was prepared. Regioselectivities of nitration of toluene with nitric acid in the presence of phosphomolybdic acid catalyst prepared under different calcination temperatures were investigated. It was found that nitration of toluene without CCl₄ in the presence of a catalyst calcinated at 200 ℃ for 1.5 h gave a yield of 86.5% of mononitrotoluene with high para-selectivity,the ortho-para-isomer ratio being 1.33.

Abstract:Effects of nano-SiO₂ on the dispersibility and infrared interference performance of complex carbon powder smoke composition were studied. The results show that nano-SiO₂ can increase dispersibility of smoke composition,and the dispersibility of smoke composition increases with the increase of nano-SiO₂ which prolongs the infrared screening time of smoke.

Abstract:Using the high-pressure ignition unit,the ignition capability of the TNT and Comp.B to hot-wire was studied in different pre-pressure. The results prove that the environment pressure has some effects on the ignition threshold value of explosive. The ignition threshold values of TNT and Comp.B decrease as the pressure increases.

Abstract:To investigate the detonation character of CHClF₂-air mixed gas,a numerical calculation method based on the theory,which the free energy is considered to be the minimum value at the equilibrium state after the reaction,was used to calculate the reaction parameters of mixed gas. The reaction temperature and pressure of the mixed gas were calculated in the different initial pressure and concentration. The results show that the reaction pressure and temperature increase along with initial pressure. The reaction temperature and pressure of mixed gas including 20 percent CHClF₂ are the maximal.

Abstract:The synthesis of 3-nitro-1,2,4-triazole-5-one and its lead salt have been scaled up to 100 g process. In addition, the technological conditions of NTO′s preparation were optimized,i.e. raising the reaction temperature in two stages and reducing the amount of nitrating agent. The dependence of reaction time and reaction temperature on NTO′s yield were determined. The improvement of preparation technology has led to a high yield(81.8%) and top quality of NTO.

Abstract:The good performances of 1,1-diamino-2, 2-dinitroethylene (FOX) have attracted people′s much attention in the field of energetic materials. This paper reviews the latest development of the research works on FOX-7, and the followings concerned are included. (1) Theoretical studies: The detonation velocity, detonation pressure, thermal stability, a number of thermodynamic properties and molecular structural parameters for FOX-7 have been calculated; (2) Synthetic routes: Several synthesis procedures and their modification for FOX-7 are described. At the present time, the preparation of FOX-7 has been scaled-up to 7kg/batch. (3) Properties: Quite a number of properties of FOX-7 have been measured and studied, and the related data are cited in this paper, including density, reactivity, thermal stability, compatibility, sensitivity, detonation parameters etc. It can be concluded that sensitivity of FOX is lower than that of RDX, but its energy level is close to that of RDX. Moreover, FOX is compatible with usual additives used for energetic materials. It is expected that FOX-7 has a good potential applications in insensitive munitions.

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