Abstract:The influence of particle size of RDX powder on its microbehaviours of fast reaction is studied by means of shock tube technique and spectrography developed in our laboratory. The results show that the fast reaction of RDX powder with different particle size is first caused by the break of nitrogennitrogen bonds,then CH₂O radical is formed. Break of nitrogennitrogen bonds of coarse RDX powder is easier than that of fine ones. The fast reaction of fine RDX powder is strong. The influence of RDX particle size on the formation of molecule fragments CN,OH,NH is not obvious,while the finer RDX particle size is,the more C₂ ,the less CH are formed.

Abstract:Based on the variation principle derived by reference[4], a new method for computing the critical parameters of thermal explosion is presented. The numerical results obtained from this method show a high computational precision and time saving.

Abstract:Thermal decomposition and combustion characteristics of nitroguanidine(NQ) are analysed.The NQ decomposition hypothesis about the primary stage of combustion is proposed,and the burning rate formula and pressure index formula of NQ propellant are derived.The NQ propellant burning characteristics from 0 MPa to 400 MPa are numerically modeled and calculated, result are in good agreement with the experimental data. The accurate calculated results show that the pressure index decreases at the middle and high pressure region with the addition of NQ to the double base propellant.The reason of low pressure in- dex and the possibility of NQ as a buming rate modifier in nitramine (RDX and HMX) pmpeUant are discussed.

Abstract:The dispersion of ultrafine pulverized RDX (UFRDX) particles in water was studied by measuring the turbidity of the suspension colloids which had been precipitated for a certain time. The surface of some UFRDX particles was modified by adding several surfactants including ionic,nonionic,zwitterionic and composite surfactants. It is found from the results that nonionic surfactant OP and composite surfactants show a good modification effect,especially OP sodium dodecyl benzene sulfonate can OP-sodium dodecyl benzcne sulfonate can ~TeatlY improve the dispersion of UFRDX pmticles in water. The adsorption mechanism ofsurfactants on the particles and the stabilization mechanism of the poticles in water were also studied by measuring the potential of UFRDX particles.

Abstract:Pb(NTO) ₂H ₂O was prepared by mixing the aqueous solution of sodium 3 nitro 1,2,4 triazol 5 onate and lead nitrate.The single crystal structure of Pb(NTO) ₂H ₂O has been determined by single crystal diffraction analysis. The crystal is monoclinic space group P2₁/n with crystal parameters of a =7.262(1)Å, b =12.129(2)Å, c =12.268(3)Å , β =90.38(2)°, V =1080.6(2)Å3^,，Z=4, D_c=2.97g/cm³, μ =157.83cm^-1 , F (000)=888.The final deviation factor R is 0.027.

Abstract:Molecular geometries,electronic structures,heats of formation of the reactants, products and activated complexes for a whole N-H Mannich reaction involving benzoxazolon as pseudo acid component were calculated by semiempirical AM1 quantum mechanical method. According to the calculated activation energies,the mechanism of reaction in acidic media is suggested that formaldehyde reacts with benzoxazolon firstly，then the intermediate reacts with dimethylamine to form Mannich base, and the reason is discussed herein.

Abstract:The application research of silane coupling agents is reviewed,including their use as bonding agents in solid propellant,as additives or surface modifiers in inhibiting or insulating materials and as intermediate layers between the insulating layer and propellant charge. The general action mechanism of silane coupling agents, the bonding mechanism of silane coupling agents with DB propellant,and the prevention role of forming an intermediate layer from NG migration are discussed as well.

Abstract:The development history and present status of nitroxyethylnitramines (NENAs) are reviewed.The main properties of propellants and explosives containing NENAs as plasticizers and their possible application are described with 17 NENArelated references cited.

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