Abstract:The absorption spectra of some primary explosives and explosives were measured,and their laser sensitivities were compared with the different wavelengths laser testes. The results show that there are continuous absorbing peak for DACP in ultraviolet-visible wave,and the laser sensitivity is remarkably increased with 635 nm laser. In 532-1060 nm,there is no relation between BNCP sensitivity and wave. Many new complex compounds have quite high laser sensitivity to 915 nm. According to testing phenomena and results,it is considered that the different laser wavelength shall lead to the different exploding mechanism of compound. If the laser is in ultravioletvisible wave,photons activate choicely electron energy level or destroy weak bond of compound molecule,and result in chemistry reaction,which is photo leading decomposition mechanism. If the laser is in infrared wave,the chemistry reaction mainly is heat decomposition mechanism.

Abstract:The relationship between charge density and loading pressure,and between laser ignition delay time and charge density of Zr/KClO₄ were studied by fiber inserted laser igniter. The density ranges of 0.94-1.39 g·cm^-3 corresponding to the loading pressure ranges of 5-130 MPa and the delay time ranges of 2.83-0.54 ms corresponding to the density ranges of 1.0-1.38 g·cm^-3 were obtained. With the density below 1.25 g·cm^-3,the ignition delay time changes faster with density,and tends to be stable when the density overpasses 1.30 g·cm^-3,with the shortest delay time in 0.54 ms. When the density is lower,such as below 1.07 g·cm^-3 and the corresponding loading pressure is less than 30 MPa,scattering of experimental data is bigger.

Abstract:With the help of the onset temperature (T_e) and maximum peak temperature (T_p) from the non-isothermal DSC curves of tri-base gun propellants M32 and SD at different heating rates (β),the thermal decomposition activation energy (E_K and E_O) and pre-exponential constant (A_K) obtained by Kissinger′s method and Ozawa′s method,the values of specific heat capacity (C_p),density (ρ) and thermal conductivity (λ) obtained by the specifications of standardization method GJB 772A-97-406.1, 401.2 and 409.1, the decomposition heat (Q_d,taking half-explosion heat),Zhang-Hu-Xie-Li′s formula, Smith′s equation andWang-Du′s formulas,the values(T_e0 and T_p0) of T_e and T_p corresponding to β→0,thermal ignition temperature (T_TIT),adiabatic time-to-explosion (t_TIad),thermal sensitivity probability density function ［S(T)］ versus temperature (T) relation curves for infinite cylindrical and spheroidic tri-base gun propellants M32 and SD with radius of 0.05m surrounded with surrounding of 373 K,peak temperature corresponding to the maximum value of S(T) versus T relation curve (T_S(T)max),safety degree (S_d) and critical thermal explosion ambient temperature (T_acr) of tri-base gun propellants M32 and SD are obtained. The results show that the thermal safety of tri-base gun propellant SD is greater than that of tri-base gun propellant M32,and the accelerating tendency from adiabatic decomposition to explosion of the latter is poorer than that of the former.

Abstract:The accelerated aging tests of high energy nitramine propellants,trietheleneglycol dinitrate (TEGN) propellants and nitroguanidine propellants at various temperatures (95,85,75 and 65 ℃) were carried out. The contents of the effective stabilizer in propellants for various accelerated aging times were measured. The kinetic parameters E_a and lnA of effective stabilizer consumption reaction and the probable mechanism functions g(α) were obtained. Results show that the stabilizer consumption reaction in high energy gun propellants can be described preferably by g(α)=-ln(1-α). The regressive correlation coefficients are more than 0.98. The confidence limits are more than 95%. The apparent activation energies of the effective stabilizer consumption reaction are between 110 kJ·mol^-1 and 160 kJ·mol^-1. Activation energies of high energy nitramine propellants are more than that of TEGN propellants. Activation energies of nitroguanidine propellants are between the other two propellants.

Abstract:Applying polymer theory, exploring study on theoretical estimatecalculating tensile intensity of dissolutionaddingplasticity propellant is put up from the side of chemical bond and intermolecular force. Selecting singlebase(SB),doublebase(DB) and TEGDN propellant,theoritalcalculation method of tensile intensity of dissolutionaddingplasticity propellant was studied deeply. Tensile intensities of propellant were tested in the meantime,and compared with theoretical estimatecalculation. It shows that theorital tensile intensity of SB,DB and TEGDN were calculated to be 3.8×10⁷ N·m^-2,11.2×10⁶ N·m^-2 and 10.1×10⁶ N·m^-2,respectively. Their testing values were 3.1×10⁷ N·m^-2,10.6×10⁶ N·m^-2 and 8.9×10⁶ N·m^-2,respectively. It can be concluded that tensile intensity of propellant is mainly provided by intermolecular Van der Waals force. Tensile intensity of dissolutionaddingplasticity propellant can be calculated theoretically by polymer theory.

Abstract:Combustion characteristics of B/BaCrO₄ delay composition were obtained by the technique of high speed camera. Results show that there exist the pulsed combustions and gas flow in the combustion process of B/BaCrO₄ delay composites. The condensed phases of products depend on the content of B,in which the phase is melted drops at lower content of B,but layered substances at higher content of B. When the different pressure of the composition surface is stronger than the stress strength of the solid products,the solid products will be pulled from the composite surface and flow with the gas. The thickness of layered substance of 14% B was 1.2 mm,and the blowed periods of layered substance of 14% B was 17.8 ms. The burning rate of B/BaCrO₄ delay composites increase with the content of B in the range of 8%-16%.

Abstract:Three series of tungsten type delay compositions numbered 0^# (adding no Fe₂O₃),1^# (adding 2% normal Fe₂O₃) and 2^# (adding 2% nanoFe₂O₃) were prepared to investigate the effects of nanoFe₂O₃ on the burning characteristics of tungsten type delay composition. The experimental results show that the changes of burning rate of 1_# and 2_#,compared with 0_#,are not distinct,however,the standard deviation of burning rate of 1_# and 2_# is decreased by 29% and 47%,and the relative error of 1_# and 2_# is decreased by 35% and 51%. Furthermore,the three compositions were tested by using TGDTA method,and the results show that the effects of normal Fe₂O₃ and nanoFe₂O₃ on the thermal characteristics of tungsten type delay composition are similar,and the processes of reaction are changed,moreover the ignition temperature is decreased by about 10 ℃,and the gas productions are reduced.

Abstract:The effect of preparation temperature and polymer additive on superfine HNS particles was studied to investigate its microstructure. The results show that superfine HNS particles disperse well drying 48 h at 22-25 ℃,and aggregates drying 2 h at 100 ℃. The pore volume and specific surface area of HNS-Ⅳ adsorbed 8 h in vacuum at 25 ℃ are larger than that of HNS-Ⅳ adsorbed 2 h in vacuum at 65 ℃. The surface area is not totally depended on mean particle size but linearly changes with pore volume to some extent. The mean particle size of pure HNS-Ⅳ is 0.789 μm,the pore volume and surface area are 0.032 cm³?g^-1 and 15.13 m²?g^-1 respectively. The mean particle size,pore volume and surface area of particles containing 3% polymer are 0.594 μm,0.026 cm³?g^-1 and 11.41 m²?g^-1 respectively. The mean particle size,pore volume and surface area of particles containing 4% polymer respectively are 0.594 μm,0.026 cm³?g^-1 and 11.41 m²?g^-1 respectively.

Abstract:In order to overcome the defects of conventional A5 booster,such as low energy density,high sensitivity and difficulty in meeting the safety of weapons and ammunitions requiring high energy density and low sensitivity in modern war,ultrafine A₅ booster was developed by coating ultrafine RDX with stearic acid. The mould powder of ultrafine A₅ booster was acquired by aqueous suspension technology. The FT-IR spectra and stereo scan photograph of ultrafine A₅ booster show: stearic acid is covered on the surface of ultrafine RDX. The experiment of impact sensitivity indicates: its critical height (H₅₀) is 3.97 cm,which is higher than that of conventional A₅ using 2.5 kg drop hammer; while the experiment of shock wave sensitivity also shows: its critical gap thickness (X_R) is 3.43 mm,thinner than that of conventional A₅,the experiment of energy output shows: its steel engraving is 0.241 mm deeper than that of conventional A₅.

Abstract:Tetraammine-cis-bis (5-nitro-2H-tetrazolato-N²) cobalt (Ⅲ) perchlorate (BNCP) superfine particles were obtained by fluid milling and cryogenic drying methods with absolute ethanol as non-solvent. Their particle sizes were mostly under 2 microns and their surface area were from 3.88 m²?g^-1 to 13.9 m²?g^-1. The results show that their impact sensitivity and friction sensitivity decrease with increase of surface area. Electrostatic sensitivity of superfine particles is higher than that of origin particles while they change indistinctively with increase of surface area. DSC exothermic onset temperature and exothermic peak temperature become lower with the increase of surface area.

Abstract:The diffusion of deterrent in manufacturing process determines the interior ballistic performance of newly manufactured extruded impregnated propellants. The diffusion of polymeric deterrent was investigated by FTIR microspectroscopy. The results show that the concentration profile of deterrent of newly manufactured propellant is in accord with the Second Fickian diffusion model. The diffusion coefficient of deterrent in manufacturing process can be calculated by the concentration profile equation,which is 1.639×10^-13 m²·s^-1. A comparative experiment was carried out between internal standard method and external standard method. The results show that in the internal standard method the mathematical treatment of uniform distribution of NG in deterred layer has no effect on the order of magnitude of the diffusion coefficient,so the systematical deviations of the reconcentration profile obtained from the imperfection of calibration model can be neglected.

Abstract:To explore the effect of environmental humidity on thermal decomposition kinetics of one newtype propellant,six kinds of saturation salting liquid such as CaCl₂·6H₂O,NaHS_O4,NaNO₂,NH₄Cl,KBr, and NaBrO₃ in the experiment were used, and conditions of different environmental humidities were achieved. From the different heating rate experiment (5,4,3,2 ℃/h) on this propellant by using microcalorimeter,some thermal data were obtained under the different relative humidity. According to the Ozawa and Kissinger method of calculating kinetics parameters,the apparent activation energy and frequency constant were obtained,and the results show that the reaction rate constant becomes bigger along with the increment of relative humidity.

Abstract:Combining closed bomb with the selfdesigned device for collecting and measuring gasfired，the main components of gasfired (oxygen,carbon monoxide and nitric oxide) were tested quantitatively. The sensor was calibrated by standard gasmixture device and firstorder standard gas,and RSD≤2.5%. The satisfactory results are obtained from applying the method to the certain propellant formulation (shuangfang3,ETPE,and ZXR etc.).

Abstract:In order to overcome the defects in chemical analysis on determining the content of polyer bonded explosive(PBX),such as low testing rate,inefficiency,highcost and so on,the composition contents of PBX booster explosive were analyzed by UV/Visible spectrophotometric method. The condition of color reaction of HMX was studied and selected in visible spectrum. The measuring wavelength (λ=550 nm) was also determined,and the absorbance of HMX solution with concentration of 0.0018 mg·mL^-1 was given at this wavelength,and the recovery was determined to be 98.9%-101.0%. The HMX content in PBX booster was calculated based on this method,and the analysis result (95.47%) was slightly higher than that of chemical analysis (94.99%).

Abstract:To assess the reliability of initiating devices accurately with small samples,the influence of up-down test on the scale parameter was studied. The experiment scheme was designed with coefficient of variation. Based on the up-down test data,the revised method of the scale parameter was given. The results of simulation calculation show that the revised parameter has better statistical characteristics and related to the test itself little. The reliability assessment method for initiating devices with small samples based on the bootstrap was proposed,and the estimation of the scale parameter was revised,with that the accuracy of assessment was proved by simulation calculation and test. The method was used to assess the reliability of one initiating device,with γ=0.90 and R≥0.999,the result is that the lower limit reliability is 0.99997,similar to 0.99998 got by the run-down method.

Abstract:The properties of a detonator were studied by accelerated life test at the conditions of temperature 60 ℃ and 71 ℃,relative humidity 95%. Results show that the changes ocurr on the single function time,mass and the impact sensitivity of inner charge of the detonator，while the resistances have no significant change. The single function time was unqualified when the samples were aged at the condition of temperature 71 ℃,relative humidity 95% for 14 days. The tested sample′s mass was lost more and more and the impact sensitivity of inner charge became more sensitive when the aging time continued.

Abstract:In order to improve the fire safety and reliability of an explosive device,a butterfly metal film bridge was prepared by adopting a magnetron sputtering technology with a mask. The bridge surface was smeared by 15-20 mg lead styphnate (LTNR). The current safety testing,antistatic testing and the bridge wire comparative testing were used to study its properties of safety and ignition. Infrared thermal imaging technology was used to verify the heat distribution of the thin film bridge. The results show that the metal film bridge has good antistatic,ignition and mechanical performances. The heat is concentrated in the narrowest part of the center.

Abstract:The effect of radiofrequency on three different hotbridge electric explosive devices was studied by experiment and calculation. The sensitive frequency were measured using conduction method,and the radiofrequency sensitivity was tested and calculated in the condition of sensitive frequency based on the updown method. The sensitive frequencies are 0.4 GHz through detection test of 30 samples for each electric explosive device; the fire powers are 2.818 W,0.428 W and 0.897 W at 50% fire/no fire through radiofrequency sensitivity test of 30 samples for each electric explosive device,and the radiofrequency sensitivity decreases along with the increase of electric resistance of hotbridge.

Abstract:Reliability test information entropy of passfail product and particularity of high reliability product with margin were studied. Results show that reliability test information entropy is equivalent to reliability test information quantity under the condition of zero failure. The assessment results of 20 kinds of initiating devices with GJB6478 are consistent with those with rundown method.

Abstract:By Monte Carlo,the equivalence between GJB376 method and variablesattributes assessment method was studied. According to reliability assessment rule,it is required that the maximum error of receptance between two methods is less than 1%. Twenty kinds of qualified and unqualified products assumed artificially were assessed with variablesattributes method and rundown method respectively. The conclusions from two methods are consistent. Results show that variablesattributes assessment method is equivalent to GJB376 method and the variablesattributes method is feasible for assessing high reliability of initiating explosive devices with small samples.

Abstract:A new analysis method of reliability tests for explosive initiator was proposed to improve the analysis of reliability tests for explosive initiator with small sample size. The reliability data were collected by Langlie test,and then were processed to be order restricted with the isotonic regression. The new parameters estimates were obtained from the order restricted data. The simulation was used to compare the efficiency of the new estimates with the traditional estimates,and the result shows that the new estimate of location parameter is better. The present method was used to assess the high reliability of one initiating device with small sample size. And the feasibility and applicability are validated, compared with the rundown method.

Abstract:A firing reliability design method for hot bridgewire electroexplosive device was put forward. Firstly,the temperature rising model of bridgewire and temperature distribution model of explosive were constructed; secondly,the critical firing energy of explosive was calculated based on energybalance equation and selected parameters; finally,margin of firing reliability of initiator was calculated. If the margin can not meet the reliability requirement of product,parameters would be adjusted and margin of firing reliability would be calculated again. By using the method above and adjusting the design parameters,the critical firing voltage of an electroexplosive actuated device is 4.75 V and its margin is 1.2. The calculation result shows that the product can meet the reliability requirements.

Abstract:The changes of current,voltage and light intensity of semiconductor bridge (SCB) with discharge time under capacitor energy supply excitation were conducted. The electroexplosion energy conversion processes and phase changes for SCB were analyzed based from the electric energy input and enthalpy change theoretical calculation. Results show that melting ratio,vaporizing ratio and ionizingratio of SCB are 61.1％,14.5％ and 70.3％ at 2.18 μs,3.48 μs,and 17.60 μs respectively when the capacitance is 22 μF and the charging voltage is 45 V.

Abstract:Structures of pyrazole compounds were constructed and their energetic properties were studied theoretically. For 9 pyrazole compounds,their geometry and electronic structures were analyzed by means of natural bond orbital (NBO) theory; their reactivity was analyzed by electrostatic potential distributions,heats of formation and Bader density were also calculated. After that,detonation velocities and ChapmanJouguet pressures of these compounds were given by means of VLW equation. Results show that there is some aromaticity in the ring of pyrazole compounds,also there is some linear relationship between total energy,density and the number of amine groups respectively. Calculated detonation velocities of these compounds are more than 8.0 km·s^-1,which indicate that these compounds are very good potential energetic materials.

Abstract:Density functional method was applied to the study of the isomers of the primary explosive of tetrazene. The geometrical structures of the three isomers of tetrazene molecule which had been proposed formerly were fully optimized at the B3LYP/6311+G^** level of theory. The results show that the total energy of (Ⅲ) is less than that of (Ⅰ) and (Ⅱ),indicating that (Ⅲ) is the most stable structure,which is in agreement with the fact that tetrazene molecules in its crystal adopt structures similar to (Ⅲ). The computational results of the IR vibration of the three isomers show that there is no imaginary frequency,which indicates that all of them are possibly existent structures. The NBO charges of the atoms of the three isomers show that the arrangement of atoms of (Ⅲ) facilitates the charge distribution better than (Ⅰ) and (Ⅱ). It can be concluded from the frontier molecular orbital analysis that N(8) is the most active atom of tetrazene,and bond N(8)—N(12) will break first when it is activated.

Abstract:Guanidine dinitramide (［(NH₂)₂CNH₂］+N(NO₂)₂-, GDN) was prepared by mixing ammonium dinitramide (ADN) and guanidine hydrochloride in water, and its structure was firstly determined by singlecrystal Xray diffraction. The crystal is triclinic, space group P1 with crystal parameters of a=0.8332(5) nm, b=0.9306(6) nm, c=0.9878(6) nm, α=84.659(11)°, β=69.213(12)°, γ=67.451(12)°, V=0.6605(7) nm³, Z=4, μ＝0.159 mm^-1, F(000)=344, and D_calc=1.671 g·cm^-3. The thermal behavior of GDN was studied with DSC and TG/DTG methods, and its thermal decomposition process can be divided into four stages, and the third stage is an intense exothermic decomposition process. The apparent activation energy and preexponential constant of the exothermic decomposition reaction are 118.75 kJ·mol^-1 and 10^10.86 s^-1, respectively. The critical temperature of thermal explosion is 164.09 ℃. GDN presents higher thermal stability than ammonium dinitramide (ADN).

Abstract:Guanidinium azotetrazolate(GZT) was synthesized from 5-aminotetrazole (5-AT) by oxidation-reduction reaction and chemical combination reaction. The effects of reaction temperature,reaction time,molar ratio of reactants and NaOH concentration on the reaction were discussed. The proper technological conditions were identified as follows: based on 0.1 mol of 5-AT,NaOH concentration 1.5 mol?L^-1,n(5-AT)n(KMnO₄)=33,reaction temperature 80 ℃,reaction time 60 min. Under the known optimum conditions,scale-up test is made and the yield is more than 80%. The structure and characterization of the compound were characterized by element analysis,IR,¹H-NMR and TG-DTA technology.

Abstract:Tetrazene was analyzed by electric spray ionization mass spectrometry (ESIMS) to study its fragmentation pathways and mechanism. Fragments and structurally informative spectra of tetrazene were obtained. Results show that the atom N is most likely to dissociate in neutral fragment forms of NH₂,HCN,HCN₂,N₃ and N₄,while the fragmentation mechanisms are the cleavage of C—N and N—N and the rearrangment. The relatively stronge peak at m/z 68.9 indicates that tetrazole cycle is stable in the molecule. The presence of stronge peaks at m/z 68.9 and m/z 95.8 suggests that the cleavages of C(5)—N(1) bond and N(2)—N(3) bond are ready to form tetrazole radical,aminoguanidinyl radical and molecular nitrogen.

Abstract:Carbon nanomaterials is a new kind of materials with good qualities such as small dimension,light weight,good characteristic of electrical conductivity and electromagnetic wave absorption etc. To explore the applications of carbon nanomaterials on interference the imaging IR guidance weapons,using large smoke chamber,the shielded extinction performance for IR images of carbon nanotubes,carbon nanofibers,nanographite were tested in the wavelength range of 8-12 μm. Results show that carbon nanomaterials smoke has excellent far infrared extinction capacity,the minimum and the maximum of far infrared extinction coefficients are 0.8884 m²·g^-1 and 2.6226 m²·g^-1 respectively.

Abstract:Infrared extinction ability and application of tiny graphite powder in combustible antiinfrared smoke screen were studied. Results show that infrared extinction ability of dispersed graphite is stronger when its granularity is smaller. The graphite can burn when it is used in combustible antiinfrared smoke screen. When graphite is added from 20% to 5% respectively,its burning loss is accordingly increased from 31.6% to 57.6% in formula containing organic combustible and from 44.6% to 80.5% in formula containing metal combustible. In order to make use of graphite effectively,5% carbon black is added into combustible antiinfrared aerosol containing oxidant,organic combustible and 20% graphite. Compared to the original formula,the use of carbon black can effectively prevent combustion of graphite and improve infrared extinction of smoke screen containing graphite.

Abstract:The CuAg coating was deposited on the surface of carbon fiber fabric by electroless plating process to make a new millimeter wave passive countermeasure materials. The surface microcosmic appearance,resistances and the Radar cross section(RCS) values of CuAg deposited carbon fiber fabric were measured. Results show that CuAg deposited carbon fiber fabric has better uniformity,luster,adhesion and conducting ability. The RCS values increase with the increasing of conducting ability of metal deposited carbon fiber fabric and the RCS value of CuAg deposited carbon fiber fabric is 92.3% of the caculated value. The CuAg deposited carbon fiber fabric would be an efficient materials to interfere millimeter wave.

Abstract:The extinction performance of 30 g nano-Ni powder smoke to 1.06 μm and 10.6 μm laser were tested in 20 m³ smoke chamber. Its mass extinction coefficient is 1.542 and 1.078 m²?g^-1respectively, and the sedimentation rate is 1.035×10^-3 m?s^-1. Compared with the smoke performance of conventional materials such as HC, RP, oil, graphite, carbon black, nano-Ni powder smoke has better extinction capability to 1.06 μm and 10.6 μm laser and possesses the better suspending characteristic in the air.

Abstract:In order to investigate one kind of new underwater acoustical passive jamming materials,the underwater burning of pyrotechnic composition having pulsating combustion effect was studied. The acoustic frequency characteristic formatted from the underwater burning of pyrotechnic composition was also studied with the testing system for underwater acoustic. The reasons for its formation were discussed. Results show that 15 g pyrotechnic composition having pulsating combustion effect can form the sound pressure as high as 340 Pa. Its corresponding acoustic pressure level is 51 dB. The time of burning can last 18.5 s.The acoustic frequency is mainly between 0-2000 Hz in the band of lowfrequency.

Abstract:To improve the safety of potassium chlorate in pyrotechnics,the method of liquid phase separation was adopted to coat potassium chlorate. XPS and SEM were used to test the coating results,and ARC,impact sensitivity and friction sensitivity apparatus were used to analyze the safety properties of the coated potassium chlorate. The results show that the coating degree of potassium chlorate by using PVB can be 95.13%; compared with uncoated potassium chlorate,the initial exothermic temperature of coated potassium chlorate is increased by 36.08 ℃,maximal pressure produced by unit mass decreased by 0.63 MPa·g^-1,friction sensitivity decreased by 64%,and impact sensitivity decreased by 72% respectively.

Abstract:In order to explore the relationship between structure and properties of hydroxyalkyl cellulose ether nitrate，molecular structures of nitrate ester of hydroxylethyl cellulose ether (NHEC),nitrate ester of hydroxylpropyl cellulose (NHPC) and nitrate ester of cellulose glycerol ether (NGEC) with molar substitution (MS) of 1 were simulated by using Synthia module of Materials Studio,and their performances of nitrogen content,glass transition temperature and Young′s modulus were predicted. The titled etherified products with MS of 1 and nitrates with maximum nitrification degree were synthesized,and the conditions of synthesis were determined. The mass ratio of HNO₃ to organic solvent is 50 to 50 in nitrification system,and the mass ratio of cellulose ether to nitrification system is 1 to 50,and the reaction temperature and time are 22 ℃ and 30 min respectively. Some relevant properties of the products were measured by elemental analysis,tensile test and dynamic mechanical thermal analysis. Although there are some deviation between the results estimated by Synthia and the measured besides the larger error on the prediction of Young′s modulus,the results show that performances trends E_{0(NGEC )}＞E_{0 (NHPC)}＞E_{0 (NHEC)} predicted by Synthia module have agreements with experiments. It indicates that the molecular simulation by Synthia module is qualitative in analysis of the system.

Abstract:Using prepolymerized glycidyl azide polymer （GAP） as soft segments,4,4′-diphenylmethane diisocyanate （MDI） and 1,4-butanediol（BDO） as hard segments for the purpose of insensitive high energy propellants,an energetic thermoplastic elastomer(ETPE) was synthesized by melt-prepolymerization,and was characterized by FTIR,TG,tensile strength test and DMA. The results show that the reaction time and aging time for ETPE synthesization are 2 h and 3 d respectively. And the tensile strength (δ) of the ETPE is 6.12 MPa,and the elongation(ε) is 71% when hard segment is 40% in weight and the mole ratio of —NCO to —OH （R） is 0.98. After adding plasticizer BDNPF／A(A3) in the ETPE,δ is invariability,but the elongation decreases.

Abstract:In order to develop a method to break the aircrafts canopy, a miniature detonating cords (MDC) of 1 mm in diameter were manufactured and its detonation properties were studied. MDC in a heavy lead confinement were also manufactured and were examined for breaking of organic glass plates. Results show that MDC in lead confinement with 1 g plastic explosive per metre, cuts organic glass plate 10 mm thick.

Abstract:The factors influencing delay time of detonation wave of superfine insensitive HMX in limited corner channel were analyzed. The dimension analysis method was adopted to induce the theory formula,and the delay time was tested by valid experiments in the limited corner of 0.8 mm×0.8 mm and 0.6 mm×0.6 mm channel. Results show that the delay time of detonation wave is longer in the channel d=0.6 mm than d=0.8 mm with similar corner,and the propagation of detonation wave will be failure when α=2π/3. Based on the theory formula and the testing results,the semiexperimental equation is given by Least Square Method,and the undetermined coefficients k and m are 365.8 and 4.75.

Abstract:In order to study the electrical ignition properties of HAN-based liquid propellant,an experimental device of electrical heating ignition of liquid propellant droplet was designed. By using high speed camera system,the ignition properties of LP1846 single droplet was observed at different electrical heating rates. The results show that when the LP1846 droplet is electrified,it goes mainly through four characteristic processes,i.e. evaporization process,periodic expansion and contraction process,stronger thermal decomposition process,and ignition and combustion process. When peak load voltage is from 80 V·s^-1 to 140 V·s^-1,the ignition delay time of LP1846 droplet is linearly shorten from 0.82 s to 0.62 s,but the flame is lighter.

Abstract:To study the transient combustion performance of igniter for base bleed unit under rapid depressurization,a semiclosed bomb and a high speed digital video camera were used to simulate and record the combustion phenomena. Results show that the combustion of igniter is disturbed violently by the rapid depressurization. The antijamming ability of igniter depends on the charge in the igniter. The combustion of the igniter charged with barium nitrate and those charged with magnesium powder and PTFE is stable,while the igniter charged with zirconium hydride and lead oxide is unstable. The standard error of duration of the third kind of igniter flame is 523 ms,and also its nozzle hole is blocked seriously.

Abstract:Recent developments of experiments,mechanism and modeling research on the plasma ignition of propellants were introduced. The feasibility of plasma ignition technology in the application of insensitive high energy propellants was discussed. The concepts,frames,keynotes and related research tactics in plasma ignition of insensitive high energy propellants were proposed. The plasma ignition research of insensitive high energy propellants should benefit from the research fruits of plasma ignition in electrothermal chemical gun. Based on the interaction between the plasma and special formulations in insensitive high energy propellants,the plasma energy output power adjustment and structural design of igniter can be carried out.

Abstract:Several effective routes to decrease the ignition energy of semiconductor bridge(SCB) were summarized based on the analysis of the characteristics of SCB,the ignition mechanism,the properties of charge and the charge conditions. These routes will be: (1) choosing small size SCB (23 μm(L)×67 μm(W) ×2 μm(t)); (2) choosing lead 2,4,6-trinitroresorcinate(LTNR) as ignition charge of SCB; (3) controlling the size of granule below 5 μm; (4) pressing the charge at a pressure above 30 MPa; (5) adding the fine Zr powder; (6) using G10 as the shell material of charge.

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