• In-Situ Raman Spectroscopic Studies and Density Functional Theory Calculations of the TDI Curing Reaction

  HONG Tian-jiao, KANG Yan, TIAN Peng-fei, XUAN Fu-zhen

  Online:March 25, 2025  DOI: 10.11943/CJEM2025009

  Abstract(13) HTML(86) PDF(1.41 M)( 75)

  Abstract:To explore the application of in-situ spectroscopy for monitoring the curing reaction of energetic materials by using toluene diisocyanate （TDI） as curing agent， both in-situ Raman and infrared （IR） spectroscopy were employed to study the spectral changes before and after the curing reaction of 3，3-bis（azidomethyl）oxetane-tetrahydrofuran co-polyether （PBT）-TDI system. The Raman bands suitable for quantitative monitoring of the curing process were analyzed， and the results were evaluated. The vibrational modes of the Raman bands of reactants and products were identified using the density functional theory （DFT） method. The correlation between the curing reaction results obtained from IR and Raman spectroscopy was also discussed. Results show that the peak of 1534 cm^-1 in Raman spectroscopy of the PBT-TDI system exhibits a low signal-to-noise ratio， making it unsuitable for quantitative analysis. The reaction degree calculated from the peak of 1743 cm^-1 in Raman spectroscopy is significantly higher than that derived from the peak of 2269 cm^-1 in IR spectroscopy. The peak of 1505 cm^-1 in Raman spectroscopy is associated with the stretching vibration of the isocyanate （NCO） group. The difference in the degree of reaction between Raman and IR is due to the number of individual NCO groups in the TDI molecules that participate in the reaction. The two methods play complementary roles in monitoring the curing process.

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• Synthesis and Characterization of 4，4，8，8-Tetranitro-2，6-dioxaadamantane

  LI Huan, ZHOU Qi, HOU Tian-jiao, WANG Gui-xiang, LUO Jun

  Online:March 13, 2025  DOI: 10.11943/CJEM2025012

  Abstract(53) HTML(140) PDF(1.38 M)( 149)

  Abstract:A novel cage-like energetic compound， 4，4，8，8-tetranitro-2，6-dioxaadamantane， was synthesized via four steps involving oxidative cyclization， oxidation， oximation and gem-dinitration by using 9-oxabicyclo［3.3.1］nona-2，6-diene as raw material. Its structure was characterized by nuclear magnetic resonance（NMR）， Fourier transform infrared spectroscopy （FT‐IR） and elemental analysis （EA）， and single crystal X-ray diffraction （SC-XRD）was adopted to further confirm its crystal structure. The thermal stability was investigated by differential scanning calorimetry‐thermogravimetry（DSC‐TG）analysis， and detonation parameters were predicted by EXPLO5. Results show that 4，4，8，8-tetranitro-2，6-dioxaadamantane has a crystal density of 1.75 g·cm^-3 and belongs to monoclinic system， space groups P2₁/c. Its thermal decomposition temperature is 190.6 ℃， theoretical detonation velocity is 7705 m·s^-1， and detonation pressure is 25.75 GPa.

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• Preparation and properties of surface-modified boron and its composite powder

  WU Jun-ying, WANG Jian-yu, LIU Xin-hang, HU Liang, SHANG Yi-ping, LIU Dan-yang, Chen Lang

  Online:March 13, 2025  DOI: 10.11943/CJEM2024290

  Abstract(69) HTML(172) PDF(1.77 M)( 171)

  Abstract:Boron powder is often used as a combustible agent in energetic materials due to its high calorific value， volume calorific value and clean combustion products. However， the surface oxide layer of boron powder makes it difficult to ignite and brings low combustion efficiency. In order to improve the ignition and combustion performances， boron powder was wetly milled in hot acetonitrile to remove the surface oxide layer for obtaining pre-treated boron powder with high activity， according to the good solubility of boron oxide in acetonitrile solvent. Acetonitrile and n-hexane were used as a dual control agent， and then the pretreated boron powder and highly active aluminum were performed a secondary ball milling to finally prepare the boron-aluminum composite powder with surface-activated boron. The morphological characteristics， thermogravimetric， ignition and combustion characteristics of boron and composite powder were studied. The results showed that the content of surface boron oxide of boron powder was reduced after pretreatment with acetonitrile， pretreatment boron powder was easier to react with oxygen when heated in air， and the percentage of mass increase was 25.6% more than that of untreated boron powder. After pretreatment with hot acetonitrile， the surface boron oxide content decreased， the active boron content increased， and the ignition and combustion performances were significantly improved. The mass of composite powder with boron-aluminum mass ratio of 60/40 increased by 93% when heated in air， the ignition temperature was 738.1 ℃ at low heating rate， and the particle combustion time was 11.2 ms.

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• e-mail：luming@njust.edu.cn Developing Energetic Materials with High Hydrogen Content， Nitrogen Rich and High Enthalpy of Formation

  LU Ming, YANG Feng, WANG Xian-feng

  Online:January 20, 2025  DOI: 10.11943/CJEM2024272

  Abstract(167) HTML(204) PDF(531.46 K)( 420)

  Abstract:

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• Process Parameters of Single-Layer Stacking Process through 3D Printing of Solid Propellants

  WANG Jia-wei, SHI Hong-bin, LIU Xuan-jie, SONG Shi-xiong, SHI Jia-wei, WANG Qi-hu

  Online:January 03, 2025  DOI: 10.11943/CJEM2024210

  Abstract(148) HTML(76) PDF(2.22 M)( 556)

  Abstract:The process parameters have a direct impact on the 3D printing quality of solid propellant grains. To more reasonably adjust the 3D printing process parameters and improve printing quality， based on the single-layer stacking process， a numerical simulation method was employed to conduct an orthogonal experimental study on three influencing factors： extrusion speed， printing height， and printing temperature. The degree of influence of each factor was calculated through variance and range analysis. The grey relational analysis method was adopted for comparison， and the optimal combination of process parameters was selected after comprehensively considering the printing accuracy of special points. A method for calculating the printing line spacing based on single-line cross-sectional data was proposed for the first time， and simulation and experimental verification were conducted. The results indicated that the extrusion speed had the greatest impact on printing quality. When the extrusion speed was set to 12 mm·s^-1， the nozzle height was 1.2 mm， and the printing temperature was 55 ℃， the printed part exhibited optimal quality. After parameter adjustment， the tensile strength of the specimen increased from 0.21 MPa to 0.43 MPa， and the density rose from 1.43×103 kg·m^-3 to 1.65×103 kg·m^-3. Single-layer printing simulations and experiments demonstrated a significant improvement in molding quality after parameter adjustment.

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• Reaction Characteristics of Perfluoropolyether-Functionalized Micro/Nano Aluminum in Hexanitrohexaazaisowurtzitane

  WU Cheng-cheng, SUN Sen, LI Shi-wei, GUO Xue-yong

  Online:December 27, 2024  DOI: 10.11943/CJEM2024230

  Abstract(142) HTML(64) PDF(3.43 M)( 431)

  Abstract:In order to investigate the reaction characteristics of oxidizer-fuel composite materials with different particle sizes in constant-volume combustion， laser ignition and detonation environment of high energy explosive hexanitrohexaazaisowurtzitane （CL-20）， three particle sizes of perfluoropolyether-functionalized micro/nano aluminum （nAl_150@xPEPE， μAl_1@xPEPE and μAl_5@xPEPE， where x=2.5%， 5.0%， 7.5%） was constructed by particle suspension method， and CL-20 based aluminized explosive was prepared by kneading granulation method. The pressure-time curve， laser-induced ignition process， energy release rate and efficiency of samples in CL-20 were studied by means of closed constant-volume explosive device， laser ignition， detonation velocity and detonation heat test equipment， respectively. The results showed that with the increase of PFPE mass fraction， the peak pressure and pressurization rate of nAl_150@xPEPE samples and μAl_1@xPEPE samples increased gradually， while the peak pressure of μAl_1@7.5%PEPE sample reached 4138.4 kPa and its pressurization rate reached 0.216 MPa·ms^-1. However， when the PFPE mass fraction exceeded 5.0%， the pressurization rate seemed to slow down. At the same time， with the increase of PFPE mass fraction， the burning rate of PFPE-functionalized micro/nano aluminum in CL-20 increased gradually. When x=7.5%， the burning rate of all the three samples with different particle sizes in CL-20 increased by 2.1 cm·s^-1， 1.8 cm·s^-1 and 2.3 cm·s^-1， respectively. In addition， four kinds of fuel-rich CL-20 based aluminized explosives were designed. Among them， the measured detonation velocity of JWL-3 explosive （62% CL-20/32% μAl_1@5.0%PEPE/6% binder） was 8125 m·s^-1， the measured detonation heat was 8049.8 kJ·kg^-1， and the energy release efficiency reached 86.10% （measured by detonation heat）.

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• Synthesis and Properties of 6-Amino-4-（trinitromethyl）-2-carbonyl-1H-1，3，5-triazine

  ZHANG Tong-wei, XU Yuan-gang, LU Ming

  Online:December 12, 2024  DOI: 10.11943/CJEM2024239

  Abstract(188) HTML(212) PDF(1.41 M)( 494)

  Abstract:A novel high-energy compound， 6-Amino-4-（trinitromethyl）-2-carbonyl-1H-1，3，5-triazine， was synthesized in one step. The crystal structure of this compound was characterized by X-ray single crystal diffraction. Its structure and properties were characterized by ¹H and ¹³C NMR， FT-IR and DSC. The detonation performance was calculated by EXPLO5. The sensitivity testing was performed according to the BAM standard method.The compound crystallizes in orthorhombic space group C 2/c， a=10.183（4） ?， b=9.388（3） ?， c=21.324（8） ?， V=2005.9（13） ?³， α=90°， β=100.246（10）°， γ=90°， Z=8. The calculated detonation velocity and pressure for compound 1 are 8167 m·s^-1 and 27.6 GPa， respectively， with measured impact sensitivity of 6 J and friction sensitivity of 210 N.

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• Thermal Behavior and Decomposition Mechanism of 2，2-Azobi［4，5-bis （tetrazole-5-yl）］-1，2，3-triazole

  LIU Shu-liang, CAI Tao, ZHANG Li-nan, QI Yuan, MA Hui-chao, LIN Qiu-han

  Online:November 27, 2024  DOI: 10.11943/CJEM2024229

  Abstract(164) HTML(210) PDF(1.93 M)( 428)

  Abstract:To study the thermal decomposition behavior of 2，2-azobi［4，5-bis（tetrazole-5-yl）］-1，2，3-triazole （NL24）， the structure， morphology and thermal decomposition characteristics of NL24 were studied by means of scanning electron microscopy， thermogravimetric analyzer， differential scanning calorimeter and thermogravimetric infrared mass spectrometry. The kinetic parameters such as apparent activation energy and pre-exponential factor were calculated by Kissinger， Ozawa and ?atava-?esták method， and the thermal decomposition mechanism of NL24 was speculated. Results show that NL24 has two main weight loss stages at the heating rate of 10 ℃·min-1 . The first weight loss stage occurs at about 180 ℃， which belongs to the volatile endothermal process of dimethyl sulfoxide. The violent thermal decomposition of NL24 occurs at the second weight loss stage between 270 ℃ and 300 ℃， which has not only rapid gas generation rate， but also belongs to autocatalytic reaction. The main gaseous products are N2， HCN， HN3， etc. The apparent activation energy and pre-exponential factor of the decomposition process are 174.69 kJ·mol-1 and 1016.60 s-1 ， respectively. The reaction model of thermal decomposition stage of NL24 is random nucleation and subsequent growth.

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• Synthesis and Properties of N²，N⁶-Dimethyl-N²，N⁴，N⁶，3，5-Pentanitro-2，4，6-Pyridinetriamine

  ZHANG Rong-zheng, LU Ming, XU Yuan-gang

  Online:November 21, 2024  DOI: 10.11943/CJEM2024211

  Abstract(141) HTML(148) PDF(1.56 M)( 443)

  Abstract:A pyridine energetic molecule， N²，N⁶-dimethyl-N²，N⁴，N⁶，3，5-pentanitro-2，4，6-pyridinetriamine （NNDP）， has been synthesized in two steps from 4-amino-2，6-dichloropyridine. The process was found to be effective and simple. The structure of this compound is characterized by ¹H and ¹³C NMR， FT-IR and DSC. The crystal structure of this compound is characterized by X-ray single crystal diffraction. Results shows that compound NNDP belongs to the monoclinic space group P 2₁/c， a=16.3215（17） ?， b=7.9819（8） ?， c=13.1954（13） ?， V=1712.3（3） ?³， α=90（6）^o， β=95.093（3）^o， γ=90（7）^o， Z=4. The presence of multiple nitro and nitramine groups contributes to a low decomposition temperature. Its detonation performance was predicted using EXPLO5， and sensitivity testing was conducted using the BAM standard method.It was found that the detonation performance and impact sensitivity of NNDP（D=8762 m·s^-1， p=34.5 GPa， IS=7.7 J） are comparable to those of RDX.

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• Theoretical Study of the Electronic Structure， Bonding properties and Aromaticity of Hexazine Anion ［N₆］^4-

  JIANG Shuai-jie, ZHANG Guang-yuan, XU Yuan-gang, WANG Peng-cheng, LU Ming

  Online:November 13, 2024  DOI: 10.11943/CJEM2024205

  Abstract(107) HTML(140) PDF(1.86 M)( 404)

  Abstract:To understand the properties of the novel polynitrogen compound hexazine anion ［N₆］^4-， computational chemical methods were used to study the electronic structure， bonding properties and aromaticity of N₆， ［N₆］^2- and ［N₆］^4-. The M06-2X method combined with the def2-TZVP basis set was used to optimized the structures and calculated the electronic structure features， such as bond length， bond angle， dihedral angle， molecular size and so on. Subsequently， multiple bond orders were calculated， using the atoms-in-molecules （AIM） theory to calculate multiple bond properties， and drawing the electron deformation density map to directly show the bond behavior. Finally， various aromatic indices were calculated to show the aromatic characteristics of three hexazine rings. The calculation results show that by comparing with the electronic structure optimized by CCSD， the M06-2X method in the common DFT method is suitable for studying the current system. Mayer bond order shows that the N—N bond has a certain degree of σ bond characteristics. The aromaticity study shows that the［N₆］^4- is aromatic， with the aromatic harmonic oscillator model （HOMA） value at 0.96 and the nuclear independent chemical shift （NICS_ZZ（1）） at -18.97 ppm. The IR， Raman and UV-Visible spectra of ［N₆］^4- were simulated to provide reference for experimental detection.

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• Synthesis and Performance of 5-Nitro-3-（trinitromethyl）-1H-1，2，4- triazole Nitrogen-Rich Energetic Ionic Salts

  WANG Xian-feng, YANG Feng, XU Yuan-gang, LU Ming

  Online:September 18, 2024  DOI: 10.11943/CJEM2024224

  Abstract(219) HTML(116) PDF(2.31 M)( 597)

  Abstract:To further balance the energy and safety of 5-nitro-3-（trinitromethyl）-1H-1，2，4-triazole， four nitrogen-rich energetic ionic salts were synthesized using 2-（5-amino-1H-1，2，4-triazole-3-yl） acetic acid as a starting material through a silver salt substitution reaction. The structures of all new compounds were characterized using nuclear magnetic resonance， Fourier transform infrared spectroscopy， differential scanning calorimetry， thermogravimetric analysis， and single crystal X-ray diffraction. The results indicate that the ammonium salt， hydrazine salt， and guanidine salt of 5-nitro-3-（trinitromethyl）-1H-1，2，4-triazole exhibit higher initial decomposition temperature than that of the precursor. Moreover， the hydrazine salt and guanidine salt belong to the different crystal systems with distinct crystal packing arrangements and densities. However， they share consistent characteristics in terms of intermolecular weak interactions， with the H…O interaction being the predominant contributor. With the decreasing of the ratios of N…O and O…O interactions， the sensitivity of the nitrogen-rich energetic ionic salts to mechanical stimuli decreases. Finally， the analysis of the distribution of molecular electrostatic potential supplements the explanation for the change in impact sensitivity of 5-nitro-3-（trinitromethyl）-1H-1，2，4-triazole after salt formation. Among the four ionic compounds， the hydrazine salt exhibits outstanding detonation performance （D=8634 m·s^-1， p=30.2 GPa， I_sp=263.5 s） with relative high sensitivity. In contrast， the triaminoguanidine salt demonstrates excellent overall performance. It has a detonation velocity comparable to that of the hydrazine salt （D=8627 m·s^-1）， a heat of formation nearly 1.4 times greater than that of the precursor （ΔH_f=0.644 kJ·g^-1）， and a low mechanical sensitivity （IS=10.3 J， FS=150 N）.

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Vol, 33, No.3, 2025    

>Explosion and Damage

• Research on Combustion Characteristics and Injury Effects of Methane Vapor Clouds in Tunnels

  GU Lin-lin, XU Yong-hang, ZHU Huang-hao, WANG Zhen

  2025,33(3):213-224, DOI: 10.11943/CJEM2024155

  Abstract(11) HTML(7) PDF(2.33 M)( 13)

  Abstract:In order to explore the propagation patterns and characteristics of methane vapor cloud combustion waves in tunnels， the CE/SE （space-time conservation element and solution element） method in LS-DYNA software was employed to establish a pre-mixed explosion model of methane and air in the tunnel， which was validated through experimental data. In this paper， typical combustion waveforms of methane vapor cloud with a concentration 9.5% in different test positions were demonstrated by numerical simulation. The propagation and evolution law of overpressure and temperature was analyzed. The injury effects of overpressure and thermal radiation on human in tunnel were investigated. It was revealed that the combustion pressure wave along the tunnel can be divided into four stages： free expansion， reflection dissipation， wall acceleration， and Mach propagation. The pressure variation presented three characteristics： wall impact rise， reflective decay， and stable propagation. The pressure wave presented a sort of periodical reflection propagation mode radially， while the intensity was declining according to the consumption of methane. The temperature field evolved symmetrically from the ignition point to the tunnel entrance and the peak temperature decayed rapidly along the path. The temperature field radiated from the ignition point to the bottom of the tunnel， leading to a gradual convergence of in a certain section and decreased slowly over time. For the injury effects caused by a combination of combustion overpressure and thermal radiation， the fatal distance was 13.51m， the severe injury distance was 13.51-23.51 m， the moderate injury distance was 23.51-160 m while the concentration of methane vapor cloud was 5%. For the methane vapor cloud with a concentration 6.5%， those distances were 16.46 m， 16.46-45.36 m and 45.36-160 m respectively. As for a concentration 9.5%， the fetal distance was 20.58m and the severe injury distance was 20.58-160 m.

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• Explosion Characteristics of Hydrogen-Methane-Air in a Closed Vessel

  MEI Liang, GUO Jin, HUANG Shi-kai, WANG Jin-gui

  2025,33(3):225-235, DOI: 10.11943/CJEM2024186

  Abstract(10) HTML(2) PDF(3.30 M)( 7)

  Abstract:In order to guide the application of hydrogen/methane mixture as fuel， explosion experiments were carried out using a cylindrical closed vessel with an inner diameter and length of 300 mm. The effects of hydrogen fraction （X_H2） from 0 to 100% and equivalence ratio （Φ） from 0.6 to 1.4 on the flame evolution and explosion pressure were investigated. Meanwhile， CHEMKIN software was introduced to analyze the laminar burning velocity and sensitivity coefficient of the H₂-CH₄-air premixed gas. The results showed that， for a certain Φ， the maximum explosion pressure （p_max）， the maximum pressure rise rate （（dp/dt）_max）， the explosion index （K_G）， and the laminar burning velocity increased monotonically with the increase of X_H2. The duration to reach p_max and （dp/dt）_max ， named t_A and t_B， respectively， decreased gradually. After ignition， the flame surface gradually transformed from a smooth structure to a honeycomb flame lattice structure. With a constant Φ and an increasing X_H2， the duration from ignition to the termination of the explosion decreased dramatically. Meanwhile， at the same moment the flame radius increased but the fold on the flame surface increased. The simulation results showed that the elementary reactions R35 and R52 had the most significant influence on the laminar burning velocity. The maximum molar fractions of the key radicals （H， O， and OH） had a positive correlation with the laminar burning velocity， and the increase of X_H2 lead to a significant increase in the maximum molar fractions of the key radicals. The primitive reactions R38 and R84 were the dominant reactions affecting the rate of production （ROP） of key radicals.

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• Design and Optimization of Multi-layer Composite Structure under Combined Loading of Shock Wave and Fragments

  ZHOU Meng, LIANG Min-zu, CHEN Rong, LIN Yu-liang, ZHANG Yu-wu

  2025,33(3):236-245, DOI: 10.11943/CJEM2024175

  Abstract(7) HTML(7) PDF(2.27 M)( 14)

  Abstract:To effectively mitigate the combined impulsive and fragmentary loads exerted by near-field explosion， a multi-layer composite protective structure has been developed， incorporating an anti-penetration layer， a coordinated support layer， and a cushioning energy-absorption layer. A finite element analysis model was established and validated through near-field explosion experiment. Utilizing the outcomes of finite element simulations， a response surface approximation model for the composite protective structure was constructed. With the areal density and overall thickness of the composite protective structure as the optimization targets， a multi-objective optimization of the thickness distribution was conducted under the individual and combined effects of fragments and shock waves using the Non-dominated Sorting Genetic Algorithm II （NSGA-II）. And the Pareto optimal solution set was obtained. The findings demonstrate that， in comparison to the initial design， the areal density of the optimized composite protective structure subjected to the individual action of fragments can be decreased by up to 19.2%， with a maximum thickness reduction of 10.0%. Under the individual action of shock waves， the areal density can be reduced by up to 34.9%， and the thickness by up to 27.5%. Under the combined action of shock waves and fragments， the areal density can be reduced by up to 19.2%， and the thickness by up to 10.0%. For application scenarios where the thickness is constrained to no more than 40 mm， the optimized composite protective structure exhibits an approximately 17.5% reduction in areal density and a 9.1% reduction in total thickness compared to the initial design. It was noted that the Pareto optimal solution sets obtained from the individual fragment action and the combined action are nearly identical， indicating that the composite protective structure significantly diminishes the influence of shock waves on the subsequent fragment impact， thereby effectively mitigating the combined effects of shock waves and fragments.

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>Preparation and Property

• Combustion Characteristics of Ternary Reactive Metal Fuels Al/B/Mg and Al/B/MgH₂

  CHENG Zhi-peng, XIA Yu, LUO Yi-min, MA Teng, XU Fei-yang, ZHANG Yu, WU Xing-liang, XU Sen

  2025,33(3):246-255, DOI: 10.11943/CJEM2024100

  Abstract(11) HTML(4) PDF(2.42 M)( 15)

  Abstract:To investigate the combustion characteristics of ternary active metal fuels Al/B/Mg （ABM） and Al/B/MgH₂ （ABM-H）， the heat of combustion and minimum ignition energy were studied by using an oxygen bomb calorimeter and a Hartmann tube， respectively. The sub-transient process of flame propagation and the spatiotemporal distribution characteristics of temperature fields were determined by using a high-speed camera system and a high-speed infrared camera system. The results indicate that the calorific values of ABM and ABM-H are 34.1 and 32.2 MJ·kg^-1， respectively， exhibiting increases of 14.4% and 8.1% over pure Al （29.8 MJ·kg^-1）. The minimum ignition energies of ABM， ABM-H， and Al are 160-170， 100-110， and 20-30 mJ， respectively. Compared to pure Al， the combustion duration of ABM and ABM-H increase by 65.5%， 34.5% and the peak flame propagation velocities increase by 12.6%， 23.0%， respectively， at a mass concentration of 625 g·m^-3. At a mass concentration of 500 g·m^-3， ABM-H and ABM exhibit the largest peak flame propagation velocities by 45.05， 38.7 m·s^-1， and the maximum temperatures peak of flame surface by 1856， 1717 ℃， respectively， where ABM-H shows a 7.6% improvement on temperatures peak of flame surface and a faster heating-rate compared to ABM. It suggests that the ABM and ABM-H formulations significantly reduce the explosion risk of the dust/air mixture， and significantly improving the combustion performance. ABM demonstrates superior thermal effects in calorific value and duration of combustion， whereas ABM-H exhibits higher reactivity in terms of minimum ignition energy， flame propagation speed， and temperature rise rate.

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• Plasma Characteristics of Typical Nitrogen-containing Compounds in Nitrogen Atmosphere

  LIU Hai-qing, XIANG Shu-jie, FANG Pu-yixing, LI Chun-tian, SHEN Rui-qi, ZHANG Wei

  2025,33(3):256-265, DOI: 10.11943/CJEM2024101

  Abstract(9) HTML(0) PDF(3.36 M)( 10)

  Abstract:Nitrogen-containing compounds， acting as nitrogen donors， directly influence the types of high nitrogen compounds formed under laser irradiation. To understand the impact of various nitrogen-containing compounds on the formation of high-nitrogen compounds， three representative compounds NaN₃， Si₃N₄ and P₃N₅ were ablated using a pulsed Nd： YAG laser in a nitrogen atmosphere. The plasma characteristics and the evolution of the transient intermediates generated by laser sputtering were investigated by transient spectrometer. The findings indicate that the laser ablation of NaN₃ yields the highest number of nitrogen atoms （NⅠ）， monovalent nitrogen ions （NⅡ）， and trivalent nitrogen ions （NⅢ）， with the longest duration of nitrogen plasma. The lifetimes of NⅠ， NⅡ， and NⅢ reached 39，400 ns， 39，400 ns， and 19，450 ns， respectively. Among the three nitrogen donors， the laser ablation of NaN₃ in a nitrogen atmosphere is most likely to result in the formation of high-nitrogen or all-nitrogen compounds.

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>Analysis and Testing

• Using BDD Electrode for Electrochemical Treatment of Nitrogen in Real Energetic Material Wastewater

  YOU Jia-jun, WANG Bing, XIONG Ying, WANG Jian

  2025,33(3):266-276, DOI: 10.11943/CJEM2024092

  Abstract(7) HTML(0) PDF(1.98 M)( 8)

  Abstract:The pilot-scale energetic material wastewater is a kind of wastewater which is extremely difficult to degrade， containing high concentrations of various nitrogen-containing compounds， such as ammonia nitrogen （NH₃─N）， nitrite （NO₂^-）， nitrate （NO₃^-）， and other organic pollutants . To realize the efficient and directional removal of these nitrogen-containing compounds， boron-doped diamond （BDD） electrodes were prepared by the hot-filament chemical vapor deposition （HFCVD） method and utilized to degrade the wastewater. The effects of electrolyte composition and concentration， modified electrode type， and electrolysis device structure on the degradation efficiency were investigated. It demonstrated that adding 0.1 M sodium chloride （NaCl） electrolyte to energetic material wastewater could improve the selectivity of NH₃─N direct conversion to nitrogen （N₂）. Using Cu/BDD and Ni/BDD cathodes accelerate the conversion process of high-valent nitrogen to NH₃─N. Under the dual electrolysis cell structure system， employing Cu/BDD and Ni/BDD electrodes as anodes improve the degradation rate of NH₃─N conversion to N₂. Therefore， the approach utilizes metal-modified BDD electrodes as anodes， is expected to be a highly effective method in the rapid and selective degradation of energy material wastewater， especially when using 0.1 M NaCl as electrolyte.

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• Initial Thermal Aging Behavior of PNIMMO Studied by Isothermal Gasometric Method

  GONG Xue-ling, GUAN Jian, LIU Hong-ni, MO Hong-chang, ZHANG Qing-yuan, PENG Ru-fang, JIN Bo

  2025,33(3):277-283, DOI: 10.11943/CJEM2024157

  Abstract(8) HTML(3) PDF(1.03 M)( 10)

  Abstract:The initial isothermal aging behavior of poly （3-nitratomethyl-3-methyloxetane） （PNIMMO） was studied. The aging kinetic parameters and thermal aging mechanism of PNIMMO at 100-120 ℃ were investigated using an isothermal gas measuring device. The storage life of PNIMMO was determined by the Berthelot equation. The results indicate that the activation energy （E_a） is 156.42 kJ·mol^-1 and the logarithm of the pre-exponential factor （lgA） is 16.86 s^-1 when the aging depth of PNIMMO reaches 0.1%. Conversely， at an aging depth of 0.5%， E_a is measured at 156.05 kJ·mol^-1 and lgA at 16.03 s^-1， as derived from the Arrhenius equation. According to the mode matching method， the thermal aging of PNIMMO at 100-120 ℃ conforms to the mechanism function No.28， that is， the reaction order n=1/4， E_a=154.33 kJ·mol^-1. Using an aging depth of 0.1% as the evaluation criterion， PNIMMO can be stored at room temperature for 51.6 years. During the initial phase of thermal decomposition， the side chain ─O─NO₂ bond undergoes cleavage followed by hydrogenation， subsequently leading to gradual degradation of the main chain into stable polyaromatic compounds.

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>Calculation and Simulation

• Simulation Study on the Anisotropy Rule of Impact Sensitivity of ε-CL-20

  LIANG Lin, WANG Ya-jun, GAN Qiang, ZHANG Wen-bo, REN Shu, LI Gen, FENG Chang-gen

  2025,33(3):284-294, DOI: 10.11943/CJEM2024121

  Abstract(18) HTML(2) PDF(3.65 M)( 21)

  Abstract:To investigate the anisotropy of impact sensitivity of the cage-like energetic material hexanitrohexaazaisowurtzitane （ε-CL-20），this work used the ReaxFF-lg reactive force field and molecular dynamics method， multiscale impact loading simulations were performed on six typical crystallographic planes： （0 1 0）， （1 1 0）， （2 0 ）， （0 1 1）， （1 1 ）， and （0 0 1）. The correlation between stress， temperature， chemical reactions， and the direction of impact was analyzed. Results indicate a pronounced anisotropy in the impact sensitivity of ε-CL-20， with the sensitivity ranking of the planes as （0 1 0）>（1 1 0）>（2 0 ）≈（0 1 1）>（1 1 ）>（0 0 1）. The system exhibits the strongest thermo-mechanical and chemical responses when impacted perpendicular to the （0 1 0） plane， implying the highest sensitivity. In contrast， the weakest responses and lowest sensitivity occurs when impacted perpendicular to the （0 0 1） plane. Based on these findings， for planar layered energetic materials， impacts parallel to the molecular layers yield the highest sensitivity， while the impacts perpendicular to the molecular layer opposite result in low sensitivity.

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• Solubility and Thermodynamic Modeling of 3-Nitro-l，2，4-triazole-5-one （NTO） in Different Binary Solvents

  GUO Hao-qi, YANG Yu-lin

  2025,33(3):295-303, DOI: 10.11943/CJEM2024184

  Abstract(11) HTML(1) PDF(885.73 K)( 18)

  Abstract:Using a dynamic laser monitoring technique， the solubility of 3-nitro-l，2，4-triazole-5-one （NTO） was investigated in two different binary systems， namely hydroxylamine nitrate （HAN）-water and boric acid （HB）-water ranging from 278.15 K to 318.15 K. The solubility in each system was found to be positively correlated with temperature. Furthermore， solubility data were analyzed using four equations： the modified Apelblat equation， Van’t Hoff equation， λh equation and CNIBS/R-K equations， and they provided satisfactory results for both two systems. The average root-mean-square deviation （10⁵RMSD） values for these models were less than 13.93. Calculations utilizing the Van’t Hoff equation and Gibbs equations facilitated the derivation of apparent thermodynamic properties of NTO dissolution in the two systems， including values for Gibbs free energy， enthalpy and entropy. The %ζ_H is larger than %ζ_TS， and all the %ζ_H data are ≥58.63%， indicating that the enthalpy make a greater contribution than entropy to the ΔG_soln^Θ.

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>Reviews

• 3D Printing Technology in the Manufacturing of Solid Propellant Grain： A review of Applications and Prospects

  SONG Shi-xiong, REN Quan-bin, WANG Jia-wei, PANG Ai-min, TANG Min

  2025,33(3):304-315, DOI: 10.11943/CJEM2024129

  Abstract(17) HTML(3) PDF(2.80 M)( 27)

  Abstract:3D printing technology has the characteristics of customization， mold free， and flexibility， which can provide an effective approach for the shaping of special structure solid propellant grains in multi-thrust or multi -pulse solid rocket motors. At present， research on 3D printing of solid propellant grain has been conducted both domestically and internationally. This article focuses on the application of typical 3D printing processes such as binder jetting， photopolymerization curing， and material extrusion in the formation of heterogeneous solid propellant grains with contained complex structures， gradients， and multi material integration. It summarizes the key issues that exist in the 3D printing of these three types of solid propellant grains. The future research directions were prospected， and it was emphasized that the future manufacturing of heterogeneous solid propellant grains should focus on low sensitivity specialized solid propellant slurries， printing equipment for large grain forming， and insulation coating printing technology.

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