Abstract:The thermal decomposition processes of PETN and GI-920 explosives were studied by DSC-TG at heating rates of 5,10 and 20 K·min-1,respectively. The thermal decomposition kinetic parameters and the mechanism function of PETN and GI-920 explosives were obtained by Ozawa′s method and the integral isoconversional non-linear method. The results show that the thermal decomposition mechanism of PETN and GI-920 explosives is classified as random nucleation and growth. The initial temperatures of the thermal decomposition of GI-920 explosive are approximately the same on TG curves with the different heating rates. DSC curve of the GI-920 explosive reveals an endothermic melting peak and an exothermic decomposition peak. The GI-920 explosive have good thermal stability below 130 ℃. The activation energy,pre-exponential factor and mechanism function of the thermal decomposition process of GI-920 explosive are 156.02 kJ·mol-1，1.934×1017 s-1 and f(α)=4/3(1-α)［-ln(1-α)］1.-4,respectively. The thermal decomposition kinetic equation is dα/dt=2.579×1017×(1-α)［-ln(1-α)］1.-4exp(-1.876×104.-T).

Abstract:The thermal behaviors in the incident shock waves of aluminum nano-particles with average diameter about 75 nm reacting with propylene oxide were studied. The ignition delay time （about 8 μs) of aluminum nano-particles reacting with propylene oxide in the incident shock wave,was experimentally investigated by spectral technology. The reacting temperature was determined to be 3189 K with AlO(B²Σ⁺-X²Σ⁺) strength obtained by the calibrated ICCD. The morphology of the products was studied by the scanning electron microscopy(SEM) image. The results indicate that the reaction products consist mainly of spherical particles. The average diameter is about 70 nm for the sintered products,while a small part of the products are larger than 100 nm as the agglomerating products.

Abstract:The continuous specific heat capacities at constant pressure (C_p) of energetic materials of mono-substituted potassium (K₁TNPG), di-substituted (K₂TNPG) and tri-substituted (K₃TNPG) trinitrophloroglucinate were measured by differential scanning calorimeter (DSC) method. The change of enthalpy and entropy were calculated at an interval of 5 ℃ in the range of 50-100 ℃. The least square method is applied to treat experimental data. The temperature dependence of C_p was determined as quadratic equation: C_p=a+bT+cT². The correlation coefficients (R) of measured results of K₁TNPG, K₂TNPG and K₃TNPG are 0.987, 0.999 and 0.993, respectively. The deviation analysis indicates that DSC method is effective and can be used to measure the specific heat capacity of other energetic materials.

Abstract:The thermal decomposition behaviors of single-base propellants stored with different humidity were studied by using microcalorimetry with sealed and open glass test-tube. The experimental results show that under the same humidity condition,the temperature of initial accelerating thermal decomposition of single-base propellant under the sealed condition,Ｔ_０,is larger than that under the open condition. The temperature corresponding to maximum decomposition rate of single-base propellant under the sealed condition,Ｔ_Ｐ２,reduces obviously with humidity increasing,but that under the open condition does not. The process and reaction accelerating extent of the decomposition reaction of single-base propellant under the sealed condition are greater than those under the open condition.

Abstract:The non-isothermal crystallization of 3,4-dinitrofurzanfuroxan（DNTF） in RDX was studies by DSC. The results show that RDX reduces the super-cooling degree and eliminate heating-self. On the basis of Avrami and Avrami-Ozawa equations,the Avrami exponent n and Ozawa exponent m are obtained to be 3.12 and 2.48,respectively. The kinetic parameters E_a of DNTF non-isothermal crystallization is obtained by Kissinger equation to be -378.19 kJ·mol^-1. Moreover,the behaviors of non-isothermal crystallization of DNTF in RDX and HMX were compared.

Abstract:The dynamic mechanical properties of NEPE propellant with minimum signature and its binder film were measured by dynamic mechanical analyzer. The results show that the mechanical loss (loss tangent and loss module) curves of the propellant and its binder film consist of α and β relaxations,which are caused by motion of the binder molecules and motion of plasticizer molecules associated with binder sidegroups,respectively. It is found that the magnitudes of tan δ (loss tangent) and loss modules of two relaxation processes of the propellant are obviously higher than those of the binder film because of the addition of nitramine in propellant. It is also found that viscoelastic coefficients from WLF equation and activation energy from relaxation processe of the propellant are lower than those of the binder film,which gives proofs that nitramine increases the free volume of the binder system and weakens the interactions of the molecular chains,further explains why the mechanical loss,tan δ,of the propellant is higher than that of the binder film.

Abstract:The ultrasonic parameters,such as amplitude and wave shape and ultrasonic velocity were monitored during explosive cast process with the heat preservation and natural cooling by using ultrasonic transmission test. The results show that the ultrasonic amplitude at the bottom position of explosive is obviously greater than that at the middle and top positions,indicating the quality of cast explosive at bottom is the best. The ultrasonic amplitude of explosive with heat preservation is larger than that with the natural cooling at the same position,indicating that heat preservation technique is effective to control cast quality.

Abstract:To investigate the mechanism of toughening and reinforcement, ATR-FTIR and TEM were used to analysis chemical and morphology structures of HBPE/HTPB polyurethane interpenetrating polymer network (IPN). Results show H-bond between the two network and phase separation enhance the mechanical properties of IPNs. When the HBPE is used as dispersed phase and its domain size is about 1 μm, the mechanical properties of IPN reach the maximum.

Abstract:In order to study the mechanical property of explosive crystals with different qualities,two recrystallized and a commercial grade RDX and HMX particles were selected and tested by compressive stiffness method. The Kawakita equation is applied in fitting the compressive curves. The fitting constant of the equation,which is of the reciprocal dimension of modulus,can be used to evaluate the mechanical property of energetic crystalline particles. For RDX,the fitting results are respectively 13.08,12.16 and 5.51,corresponding to the two recrystallized samples and the commercial grade one. And the values for HMX turn out to be 11.43,12.57 and 10.05 respectively. However,the results of the fragmentation stage in compression are reduced to 9.53,7.86,4.36 for RDX,and 6.13,6.48,5.56 for HMX. The study proves that the fitting constants can be used to evaluate the mechanical property of energetic crystalline particles,and it also shows that the results based on the fragmentation processes describe the real mechanical behaviors better.

Abstract:reasonable model of plastic bonded exploisve (PBX) substantiated by creep property is useful for finite element simulation of machining PBX components. Modified time hardening theoretical (MTHTT) model,which has compact form and less undetermined parameters,is promoted in this paper to describe creep behavior of PBX. A HMX based PBX is employed to conduct compressive creep tests. The model parameters are determined and the corresponding fitting details are discussed for validating the model. Meanwhile,finite element software is used to simulate the creep deformation of cylinder specimens subjected to the experimental stresses. Theoretical analysis and the simulation show that the model agrees well with the results of creep test and it could be used in simulating the deformation of PBX components during the machining process.

Abstract:The initial residual stress of the polymer bonded explosive based on TATB and its distribution were tested by blind-hole drilling method. The effects of hole depth and time of strain record on the testing result and the effects of heating treatment on residual stress relaxation were studied. The results show that 3 mm hole depth and 10 min time of strain records are suitable experimental parameters. The residual stress reduces to about 50% and tends to be steady by heating treatment at 75 ℃ for 3 days.

Abstract:Using Konjac glucomannan as the raw material,energetic glucomannan (EKGM) was synthesized in the mixture of fuming nitric acid,concentrated sulfuric acid and phosphoric anhydride,and was characterized by elementary analysis,FTIR,SEM,XRD and TG-DSC. The results indicate that the nitrogen content of EKGM is 13.59% due to the presence of —ONO₂，and crystallinity is higher than that of original KGM because of a loose network structure and the decomposition temperature is 161 ℃ with a high exothermic peak.

Abstract:Keto-RDX was obtained by one-step method with a certain amount of RDX as by-product. The effects of various parameters on high yield were studied. A simple analytical method was also introduced to determine simultaneously Keto-RDX/RDX mole ratio. Some important theoretical characterizations of Keto-RDX such as detonation performance at maximum nominal density and shock sensitivity were determined by new methods and compared with RDX.

Abstract:By nitration of ethyl malonate,ethyl 2,2-dinitroacetate was synthesized. The condensation with acetaldehyde in presence of N_aN₃ gave 4-methyl-5-nitro-1,2,3-trazole. 4-Amino-5-nitro-1,2,3-trazole (ANTZ) was finally synthesized by the process of oxidation,esterifies and recomposition. Their structures were confirmed by IR,NMR,DSC and elemental analysis. The best condition of oxidation reaction is 100 ℃,90 min,1：2 ratio of K₂CO₃ to 4-methyl-5-nitro-1,2,3-trazole.

Abstract:3,3′-Diamino-4,4′-azofuroxan (DAAFO) was synthesized by a two-step process,with 4-amino-3-azidocarbonylfuroxan as precursor which was synthesized by a three-step process with ethyl acetoacetate as starting material. The DAAFO and mediate products were characterized by DSC-TG,elemental analysis,IR and MS. And the sensitivity and DSC analysis of DAAFO were carried out and compared. The results show that 4-amino-3-azidocarbonylfuroxan is more sensitive than diaminofurazan and HMX. The peak decomposition temperature of DAAFO is 208.17 ℃,lower than that of 3,3′-diamino-4,4′-azofurazan (DAAF) and 3,3′-diamino-4,4′-azoxyfurazan (DAOAF).

Abstract:RDX was coated with hyantoin/triazines composite bonding agent and the effects of the processing parameters,including reaction time, reaction temperature and bonding agent mass on the coating degree were studied by means of water-solution suspending method in the L₉(3⁴) orthogonal experiment. The coated RDX was characterized by X-ray photoelectron spectroscopy(XPS), scanning electron microscope(SEM), Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC） and impact sensitivity (H₅₀). The optimum conditions are as follows: 10.0 g RDX, reaction time 90 min，reaction temperature 50 ℃, 0.3 g composite bonding agent (CBA), and stirring speed 700 r·min^-1. Accordingly,coating degree is up to 87%. It is found that surface of the coated RDX is covered by clear film with a thickness of about 0.2 μm. In FTIR spectra, NO₂ group absorption peak has a 22 cm^-1 red shift to 1510 cm^-1and the absorption band widened. Thermal decomposition peak temperature is enhanced 0.4 ℃. The characteristic height of impact sensitivity (H₅₀) is increased by 4.5 cm.

Abstract:ε-HNIW was respectively coated with Impranil DLF® polyurethane and melamine-formaldehyde resin by demulsification and in-situ condensation polymerization. The mechanical properties and morphology of NEPE propellants containing the coated ε-HNIW were characterized. The results show that compared with the propellant containing uncoated ε-HNIW,the ε_m and the ε_b of the propellant containing ε-HNIW coated with melamine-formaldehyde resin increases by 75.2% and 62.16% respectively,and the ε_b/ε_m ratio decreases to 1.03. The dewetting problem is improved significantly,and the ε-HNIW was bonded on the propellant surface firmly. The ε_m and the ε_b of the propellant containing ε-HNIW coated with Impranil DLF® polyurethane increases a little, the ε_b/ε_m ratio is 1.10 and some ε-HNIW crystals shed from the propellant surface.

Abstract:The catalytic activities of potassium dihydrogen phosphate for nitrations of toluene were studied． Effects of catalyst dosage，reaction condition and recovered catalyst on the regioselectivities of toluene were investigated． The result shows high regioselectivity when 0.6 g potassium dihydrogen phosphate catalyst is used with 95% nitric acid as nitrating reagent in the presence of acetic anhydride,in 60 min at 55 ℃. The ortho-paro isomer ratio is 0.96,lower than 1.67 with sulfonitric acid as catalyst. The yield of product is 95.1%. The catalyst is reutilized up to five times with little change in activity.

Abstract:The compatibilities of ammonium dinitramide (ADN) with five kinds of the binders including hydroxyl terminated polybutadiene (HTPB),3,3-azidomethyl-3-methyloxetane-tetrahydrafuran (BAMO-THF),nitroglycerine/nitrocellulose (NG+NC),polyethylene glycol (PEG) and poly(epoxy ethane tertrahydrafuran) (PET),were studied by vacuum stability test (VST). Meanwhile the compatibilities of ADN with three kinds of the binders were studied by DSC and LAWA techniques. The results show that the systems of PEG and (NG+NC) with ADN have strong reactivity and is rated to be incompatible using three methods. The system of PET with ADN is judged to be incompatible by VST,while to be compatible by DSC and LAWA. The reasons causing different conclusion from different methods were discussed.

Abstract:The stabilities of the blend nitrate ester and the high energetic binder containing 70% blend nitrate ester were studied by adding some impurities. The results indicate that the stability of nitrate ester is decreased with the addition of Fe³⁺，Cl^-,and particularly NO₃^-. The effects of Fe₂(SO4)₃，FeCl₃，Fe(NO₃)₃，BaCl₂ decreases in sequence on the stability of high energetic binder containing 70% blend nitrate ester,and high concentration of impurity causes low stability. At three different storage temperatures, the safety storage time of the high energetic binder increases firstly and then decreases with the increase of pH value,reaches its longest point at a pH value of 7.08. And the water content decrease the safety storage period,too.

Abstract:α-Hydrazinium nitrate (HN)with high purity was synthesized by neutralizing hydrazine and hydrazine dinitrate,and its crystallogram were obtained by X-ray powder diffraction. Results show that the average crystal size of HN is 185.3 nm,and the cell unit is in good order in the crystal,and the density is 1.688 g·cm^-3. The crystal parameters of HN are as following: monoclinic,P 21/n,a=0.8015 nm，b=0.5725 nm，c=0.8156 nm，β=92.3，V =0.374 nm³，D_c=1.688 g·cm^－3,Z=4.

Abstract:In order to restrain or prevent AN phase transition,six kinds of polymers were added to AN samples and the effects of polymers on AN phase transition were studied by differential scanning calorimetry (DSC) method. The results show that sodium p-ethylene benzenesulfonate-acrylic acid polymer has little effect on AN phase transition,while sodium p-ethylenebenzene sulfonate-dodecyl acrylate polymer prevents the transition of Ⅳ-Ⅲ effectively. And sodium p-ethylene benzenesulfonate polymer,dodecyl acrylate,sodium p-ethylenebenzenesulfonate-N,N-dimethyldiallyl ammonia chloride polymer and sodium p-ethylenebenzenesulfonate-dodecyl acrylate-N,N-dimethyldiallyl ammonia chloride polymer prevent the transition of Ⅲ-Ⅱ effectively. The effect of polymer on AN phase transition results from that polymer strengthens the hydrogen-bond network and baffle the turn of NO₃^-.

Abstract:The specific heat capacity of four carbohydrazide nitrate energetic coordination compounds ［M(CHZ)₃］(NO₃)₂,(M=Mn,Co,Zn,Ni) were determined by differential scanning calorimeter (DSC) under a temperature range,and regression equations for the specific heat capacity changing with temperature were obtained by Origin 7.0. The equations of Ni(CHZ)₃(NO₃)₂ and Mn(CHZ)₃(NO₃)₂ are functions of sixth degree,second degree and third degree in some range of temperature,equations of the others mostly are functions of fourth degree or fifth degree,where the relative coefficient square is more than 0.987,and standard deviation is smaller than 0.017. Except Zn(CHZ)₃(NO₃)₂,the specific heat capacity of the compounds changes more,and one or more peaks appear in the curves of the specific heat capacity. TG and FTIR were carried through. At 200 ℃,only Co(CHZ)₃(NO₃)₂ loses 8.64% of its mass. As FTIR spectra are not same at different temperature,it is possible that the crystal transformation results in the change of the specific heat capacity.

Abstract:The oblate propellant with micropores（MPOP） was prepared by chemical foamed process,and the effects of the materials and inner-structure on its electrostatic spark sensitivity were studied by adjusting the distance of discharging and the way of loading. Results show that the lower the bulk density of these oblate propellants is,the higher electrostatic spark sensitivity is. And the smaller the grain diameter of the oblate propellants is,the higher its electrostatic spark sensitivity is. The electrostatic spark sensitivity of MPOP with the bulk density not more than 0.3 g·cm^-3 is apparently higher than nitrocellulose. It is feasible to test the electrostatic spark sensitivity of low-density materials with micropores using this improved method.

Abstract:The test theory,design procedure and data analysis of Langlie method and up-and-down method were analyzed,and the experimental results of impact sensitivity of certain explosive HMX were compared. The results show that Langlie method is almost insensitive to the initial estimate,while up-and-down method is sensitive to that. In addition,according to the experimental data,the fire probability of samples was attained at the same stimulus with two different methods. The sensitivity distribution curves were obtained from fitting the experimental data. When the safety and reliability of explosive is calculated on the basis of counting process method,the estimate value of Langlie method is more optimistic than that of up-and-down method. When the 0.001 responses is evaluated,the stimulus relative error of Langlie method is about 16% higher than that of up-and-down method,when the 0.999 responses is evaluated,the stimulus relative error of Langlie method is about 21% lower than that of up-and-down method.

Abstract:A quantitative structure-property relationship (QSPR) model with 4 variables was established with electrotopological state (E-state) indices,and was used to analyze the impact sensitivity of 20 kinds of nitroaromatics. The correlation coefficient and standard deviation of the model are 0.929 and 0.079. The model possesses better reliability and correlation. Results show that the main structural factors influencing the impact sensitivity of m-nitroaromatics are the 4 sub-structures such as saCa，N，—CH₂— and —O—,which indicate that the electrical condition of atoms is an important factor affecting the impact sensitivity.

Abstract:Based on analyzing characteristics of five kinds of energetic materials including nitratoethylnitramine（NENA），hexanitrohexaazaisowurtzitane（CL-20），furazan compounds，zole nitrogen-rich compounds and hydrogen storage alloy，energetic level of NEPE solid propellant composed of normal(or energetic) binder/energetic plasticizer/high energy density material/metal incendiary agent was calculated with the code based on the minimum free energy method. The technical routes and consideration of novel high energy solid propellants were explored. The effects on energetic properties resulted from these approaches were discussed. Eight methods of forming high energy propellant were supplied.

Abstract:Based on the one-dimensional energy criterion of explosives shock initiation,considering the shock propagation of projectile impacting covered explosives,the relation formula of threshold velocity is obtained as V_w≈0.8 V_Fe between tungsten and steel in the same size. The formula is validated using LS-DYNA numerical program.

Abstract:Recent advances of clean nitration of aromatic compounds,including liquid-phase nitration with solid acid,nitration in liquid acid/nitrate salt system,vapor-phase nitration with solid acid,liquid-phase nitration with Lewis acid,nitration in ionic liquid system,are reviewed. Their specific features and reaction mechanism are described,and the perspectives of the clean nitration are prospected.

Abstract:Empirical, quantum mechanical and artificial neural network methods are three usual methods in recent years that were used to predict sensitivity of different classes of high explosives. Some recent developments in predicting sensitivity by various methods are reviewed and discussed for various classes of energetic materials.

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