• Effect of Air Gap in Borehole on Directional Penetration of Shaped Charge with/without Metal Liner

  CAI Jing-jing, XU Xuan, CHEN Zhan-yang, YANG Jun

  Online:December 07, 2023  DOI: 10.11943/CJEM2023196

  Abstract(320) HTML(224) PDF( 1154)

  Abstract:In order to explore the influence of the radial air gap in the hole on the directional penetration effect of shaped charge with/without metal liner and the detonation energy transfer process of explosive， ANSYS/LS-DYNA software was used to carry out the numerical simulation study when the air gap of the charge in the hole was 6， 8， 10， 12， 14 cm. The process of centralized release of energy from the shaped charge with metal liner forming an EFP and without metal liner forming concentrated detonation product flow as well as the depth of directional penetration into the borehole wall， was analyzed. The results show that when the air gap is less than 10 cm， the penetration depth of concentrated detonation product flow into the hole wall is increased by 53% （6 cm） and 29% （8 cm）， respectively， compared with the average penetration depth of EFP. When the air gap was greater than 10 cm， the average penetration depth of EFP increased by 26% （12 cm and 14 cm） compared with the concentrated detonation product flow. The kinetic energy of EFP and concentrated detonation product flow per unit area through the hole wall on the shaped energy axis was calculated， it is found that when the air gap is small， the energy dissipation of concentrated detonation product flow in the air is less than that of EFP plastic deformation， and the penetration effect of concentrated detonation product flow on the hole wall is better. When the air gap is large， the density and kinetic energy at the axis of the concentrated detonation product flow are significantly reduced due to the spatial expansion of detonation products， while the EFP has high density and incompressibility， small energy dispersion and slow decay of kinetic energy， so the penetration effect of EFP on the hole wall is better than that of the concentrated detonation product flow.

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• Influence of Barrel Parameters on the Velocity of the Transducer Flyer

  WANG Wei, DONG Xiao-fen, WANG Duan, LI Qian, LI Si-yu, GUO Yu-xuan

  Online:June 14, 2024  DOI: 10.11943/CJEM2023254

  Abstract(83) HTML(66) PDF( 242)

  Abstract:The velocity of the flyer is a key factor in determining the reliability of initiating exploding detonators. In order to investigate the influence of barrel parameters on the flyer velocity， the factors affecting the flyer velocity were analyzed through both experimental and numerical simulation methods. A TiW/Ni/Au composite film exploding foil with a film thickness of 0.5/0.5/2 μm and dimensions of 0.15 mm×0.15 mm was designed and prepared using magnetron sputtering technology. Under excitation conditions of 0.1 μF and 1200 V， a polyimide flyer with a density of 1.45 g·cm^-3 and a thickness of 25 μm was selected， and the flyer velocities with different barrel parameters were measured using photon Doppler velocity testing technology. The research results indicate that， under the same diameter conditions， the flyer velocity initially increases and then decreases with increasing barrel thickness， reaching a peak at 0.4 mm. When the barrel diameter are 0.15，0.23，0.3，0.35，0.45 mm， the flyer velocity decreases as the diameter increases， with the highest velocity observed at a diameter of 0.15 mm. Furthermore， under the same thickness and diameter conditions， the velocities obtained from polyimide and ceramic barrel tests exhibit similar trends and values， with polyimide demonstrating higher strength and toughness and lower cost， making it a viable alternative to ceramic as a barrel material. Furthermore， a numerical simulation method was used to re-fit the empirical formula for flyer velocity applicable to the TiW/Ni/Au composite thin film， and the verification results show that the deviation between the calculated results and experimental data is within 2.5%.

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• Research Progress and Prospect of Branched Glycidyl Azide Polymer

  YAN Yi-teng, SUN Shan-hu, LIU Shan, JI Ying-xu, BAI Sen-hu

  Online:April 08, 2024  DOI: 10.11943/CJEM2023262

  Abstract(274) HTML(206) PDF( 380)

  Abstract:Branched glycidyl azide polymer （BGAP） has higher relative molecular mass， wider adjustment range of hydroxyl functionality （f）， higher heat of formation and lower viscosity than linear glycidyl azide polymer （GAP）. It can increase the energy level， and improve the processing and mechanical properties of the composite solid propellant. Therefore it has become a hot research topic in the field of the azido polyether binder. However， the essentially important key to obtain high quality BGAP energetic binder is how to control and regulate some structural parameters such as hydroxyl functionality， molecular weight and molecular weight distribution. This paper illustrates two synthetic methods and processes of BGAP， proposes the possible reaction mechanism， and summarizes the progress in performance research. Some problems and deficiencies are pointed out. Finally， the development prospects of BGAP in the field of synthesis and performance research are forecasted. It is concluded that optimizing the extraction procedure after reaction， improving the throughput per run， and strengthening the studies in fundamental performance and application will be the focuses in future researches.

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• Research Progress of Trace Detection Technology of Organic Gunshot Residue in Firearms

  NAN Ce, ZHAO Peng-cheng, ZHANG Zhi-yue, WANG Yi-fei, WANG Zong-xing

  Online:May 22, 2024  DOI: 10.11943/CJEM2024011

  Abstract(118) HTML(116) PDF( 293)

  Abstract:Gunshot residue （GSR） is an important concomitant product of gun firing， and the analysis of GSR is of great significance in the investigation and litigation of gun-related cases. The traditional GSR test mainly focuses on the inorganic substances produced by primer， but neglects the organic gunshot residue （OGSR） from the propellant. Due to the widespread presence of metal particles in the environment and the production and application of non-heavy metal ammunition， conventional detection methods are prone to false positive or false negative problems. The trace detection technology of OGSR is becoming a research hotspot. The research progress of trace OGSR detection in recent years was reviewed. The advantages and limitations of Raman spectroscopy， mass spectrometry， liquid chromatography-mass spectrometry and electrochemical method in OGSR detection were discussed. The application of chemometrics in trace OGSR detection was introduced. Among them， liquid chromatography-mass spectrometry （LC-MS） is a simple pre-treatment method for OGSR detection with low detection limit and high sensitivity. In the future， the focus of research is to combine the large amount of data obtained based on liquid chromatography-mass spectrometry with the data processing technology of chemometrics to build a detection technology with rapid analysis and identification of OGSR samples.

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• Initial Velocity Calculation of Eccentric Initiation Warhead Fragment based on Infinitesimal Method

  LIU Heng-yan, LIANG Zheng-feng, RUAN Xi-jun, CHENG Shu-jie

  Online:April 17, 2024  DOI: 10.11943/CJEM2024023

  Abstract(165) HTML(170) PDF( 364)

  Abstract:The distribution of initial fragment velocity in the aim direction is one of the important factors for evaluating the power of the directional warhead. Therefore， the calculation method of the initial fragment velocity in the whole domain on the directional side of the warhead under the eccentric double-line initiation and the kinetic energy gain compared with the central initiation are studied. Based on the infinitesimal theory， the calculation method of the initial fragment velocity in different circumferential position on the directional side was derived， and the static explosive experiment of the warhead was carried out to compare with the theoretical result. Combined with the numerical result of the warhead， the axial velocity correction function was fitted， and the universality of the algorithm was verified according to the existing research. It is shown that the proposed formula is suitable for the warhead with eccentric double-line initiation， and the error between theoretical calculation and test results is within 4.80%， calculation result is consistent with actual situation. The fitting correction function can predict the initial velocity of the fragments in different axial direction. The algorithm still has good universality when the warhead parameters change and the calculation error is less than 7.11%. Compared with central initiation， the eccentric double-line initiation mode with an angle of 60° can increase the total kinetic energy of the fragments in the range of -30°-30° from the center of the directional side by 34.9%.

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• The Method and Mechanism of TATB Purification Based on Green Solvent

  ZUO Yi-wen, CHEN Jian-bo, LIU Xiao-feng, LIU Yu, SUO Zhi-rong

  Online:May 24, 2024  DOI: 10.11943/CJEM2024046

  Abstract(127) HTML(336) PDF( 328)

  Abstract:Traditional methods are difficult for the purification of TATB due to its poor solubility. Green deep eutectic solvent （CS-1） displays good solubility toward TATB， so CS-1 was used as the solvent with water as back extractant to develop a new purification method for TATB in this study. The difference between this method and other methods were investigated for the purification of TATB. Purification conditions including the amount of back extractant， washing times and drying methods were comprehensively optimized to improve the purity of TATB. Finally， a new method has been established for highly efficient separation and green purification of TATB. Through this method， high-purity TATB was obtained with the purity of （99.7±0.2）% and good recovery of 92.5%. Further， spectroscopic monitoring was combined with theoretical simulation to study the kinetics of the purification of TATB， and then a purification mechanism has been proposed， which is based on the dissociation of TATB’s complexes through the competition of hydrogen bonding between CS-1 and water.

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• Molecular Dynamics Simulation on the High Temperature Thermal Decomposition of Derivatives of Isowurtzitane

  GAN Qiang, ZHANG Wen-bo, WANG Ya-jun, LIANG Lin, REN, Shu, LI Gen, HE Jia-jun

  Online:June 03, 2024  DOI: 10.11943/CJEM2024063

  Abstract(89) HTML(106) PDF( 197)

  Abstract:Isowurtzitane derivatives are currently one of the most potential cage energetic compounds.In order to systematically study the high temperature thermal decomposition law of isowoodsane derivatives and clarify their detonation mechanism， in this work， the thermal decomposition properties of hexanitrohexaazaisowurtzitane （ε-CL-20）， 4，10-dinitro-2，6，8，12-tetraoxa-4，10-diaztetracyclododecane （TEX） and 4，10-diazomethyl-2，6，8，12-tetranitrohexaazaisowurzane （BATNIW） under high temperature were studied by molecular dynamic simulations with ReaxFF-lg reactive force field and molecular dynamics method. The results show that the denitro and ring opening are the main initial reactions of ε-CL-20， TEX and BATNIW， in which the ring opening mainly occurs at the C─N bonds or C─O bonds of the five membered rings. Among the decomposition products， the yields of CO₂ and H₂ change significantly under different temperature， while content of N₂ are similar at temperature higher than 3000 K. The decomposition of BATNIW produced N₂ with the highest reaction rate and the maximum yield. During the thermal decomposition of TEX， clusters could easily be produced， and glyoxal could be regarded as its characteristic product. The order of thermal decomposition activation energy of the three derivatives is TEX > BATNIW > ε-CL-20， which suggests TEX shows the best stability. This work preliminarily reveals the relationship between the molecular structure and thermal decomposition of three isowurtzitane derivatives.

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• Anti-hygroscopic Technology for Ammonium Dinitramide （ADN） Based on Its Cationic Regulation Strategy

  PENG Pan-pan, QU Wei-chen, DU LI Xiao-song, SHI Shu-jing, ZHAO Xin-yan, LI Lei, DU Fang, TAO Bo-wen, LI Hong-xu

  Online:May 16, 2024  DOI: 10.11943/CJEM2024081

  Abstract(279) HTML(2) PDF( 345)

  Abstract:Ammonium dinitramide （ADN）， as a highly promising new oxidant， is still difficult to achieve large-scale applications due to its strong hygroscopicity. Numerous studies show that the strong hygroscopicity of ADN is mainly attributed to the formation of hydrogen bonds between NH₄⁺ cations and water molecules in air. In this work， a novel dinitramide energetic ionic salt （DBDN） containing divalent cation was synthesized by a simple， safe and efficient one-pot reaction using terephthalaldehyde （TPA）， aminoguanidine hydrochloride （AGC） and ADN as raw materials through Schiff base reaction and ion exchange reaction. The product was characterized by elemental analysis， infrared spectroscopy， and nuclear magnetic spectroscopy. Its physical and chemical properties were tested by thermal analysis， mechanical sensitivity testing， and theoretical calculations. In addition， the hygroscopicity of ADN and DBDN was studied by using the desiccator equilibrium method. The impact sensitivity （IS）， friction sensitivity （FS） and thermal decomposition temperature （T_d） of DBDN are >40 J， 16% and 225 ℃， respectively. The stability of DBDN is much better than that of ADN （5 J， 76% and 198 ℃）. Under the conditions of 25 ℃ and relative humidity （RH） of 66% and 75%， after 9 days， the saturated hygroscopic rates of the ADN are 24.1% and 39.5%， respectively， while those of DBDN are only 0.26% and 0.48%， showing non-hygroscopic properties of DBDN.

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• Research on the simulation method based on CT image modeling for the ultrasonic detection of TATB-based PBX

  LI Zhi-feng, LIN Li, ZHANG Wei-bin, ZHAO Wen-xia, MA Zhi-yuan, LI Hai-ning

  Online:June 20, 2024  DOI: 10.11943/CJEM2024089

  Abstract(118) HTML(182) PDF( 252)

  Abstract:In order to break through the current limitation of simulation accuracy for the ultrasonic detection of TATB based PBX and to realize the structure-performance relationship based nondestructive ultrasonic testing and characterization， an ultrasonic simulation method based on CT image modeling （MBCT） was proposed. Using the significant difference of gray-level distribution between the particle phase and the binder phase in CT images， the structural morphology and features of the sample were extracted. A two-dimensional geometric structure model containing molding powder particles and boundary morphology was obtained by processing the CT slice image with noise reduction， binarization and boundary optimization. Then， the model was used for finite element simulation of ultrasonic propagation， and the differences between MBCT and conventional Voronoi model were quantitatively compared. Results show that the MBCT can effectively and precisely describe the random complex structure characteristics of TATB particles and boundary morphology， which makes the ultrasonic simulation results have better consistency with the experiment ones. The errors of sound velocity， attenuation， frequency domain amplitude and apparent integrated backscattering （AIB） coefficient were 0.32%， 1.14%， 0.92% and 1.55%， respectively （within 2%）. Compared with Voronoi model（2.77%、35.93%、20.70%、13.68%）， the error is greatly reduced， and the simulation accuracy is significantly improved.

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• Prediction of the Crystal Growth of Energetic Materials by a unified Kinetic Three-dimensional Partition Model

  SONG Liang, CHEN Bo-cong, ZHANG Yong, SU Hao-long, Hou Fang-chao, YE Jing, SHE Chong-chong

  Online:June 20, 2024  DOI: 10.11943/CJEM2024098

  Abstract(120) HTML(88) PDF( 352)

  Abstract:In order to describe the characteristics of the crystal morphologies of hexogen （RDX）， octogen （HMX）， and hexanitrostilbene （HNS）， the unified kinetic three-dimensional partitioning method was used to simulate the real-time growth morphologies of these three energetic material crystals. The influence of crystal growth conditions on crystal morphology and the topology of crystal face were studied. The research results show that the predicted crystal shape of RDX is rhombus-like， with the main crystal faces being （0 1 0）， （1 0 0）， and （1 1 0）. The crystal morphology of HMX exhibits a columnar shape， with the main crystal faces including （0 1 1）， （0 1 0）， and （1 1 -1）. The crystal morphology of HNS has a flake-like shape， with the （1 0 0） face having the largest exposed area. The predicted crystal morphologies of energetic materials are consistent with experimental results. When RDX， HMX， and HNS crystals exhibit 2D nucleation and growth modes， a higher driving force （Δμ=418.59 kJ·mol^-1） causes the molecular layers of the crystal to continuously stack， resulting in layered growth. When the temperature is low， growth units first attach to the crystal faces in the platform area， gradually forming "island-like" agglomerations， followed by epitaxial growth. When the crystal face is sufficiently large， multiple "island-like" structures of different sizes may appear， gradually merging over time. At lower driving force （Δμ=27.21 kJ·mol^-1）， HNS crystals exhibit spiral dislocation growth， where the （1 0 0） crystal face triggers lamellar growth through a spiral axis， resulting in "terraced" crystal face. Adsorption ability analysis reveals that the kink sites and step surfaces of the helix have strong adsorption ability， while the sites on the face have weak adsorption ability.

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Vol, 32, No.6, 2024     Innovation of Nitrogen-Rich Polycyclic Energetic Compounds

>Editorial

• Editorial：Innovation of Nitrogen-Rich Polycyclic Energetic Compounds

  张文全

  2024,32(6):570-570, DOI:

  Abstract(88) HTML(40) PDF(1.06 M)( 200)

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>Energetic Express

• Energetic Express--2024No6

  张文全

  2024,32(6):571-572, DOI:

  Abstract(96) HTML(38) PDF(1.12 M)( 177)

  Abstract:

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>Preparation and Property

• Machine Learning Assisted High-Throughput Design of ［5，6］ Fused Ring Energetic Compounds

  PAN Lin-hu, WANG Rui-hui, FAN Ming-ren, SONG Si-wei, WANG Yi, ZHANG Qing-hua

  2024,32(6):573-583, DOI: 10.11943/CJEM2024055

  Abstract(108) HTML(36) PDF(1.94 M)( 203)

  Abstract:Compared with the research and development model guided by experience and calculations， machine learning-assisted high-throughput virtual screening technology for energetic molecules has shown obvious advantages in terms of molecular design efficiency and quantitative analysis of structure-activity relationships. In view of the fact that nitrogen-rich fused ring energetic compounds usually show better energy-stable balance properties， this study uses machine learning-assisted high-throughput virtual technology to conduct chemical space exploration of ［5，6］ nitrogen-rich fused ring energetic molecules. Based on the ［5，6］ all-carbon skeleton， this study obtained 142，689 ［5，6］ fused ring compounds through combined enumeration and aromatic screening. At the same time， a machine learning algorithm was used to establish and optimize an energetic molecular property prediction model （including density， decomposition temperature， detonation velocity， detonation pressure， impact sensitivity and enthalpy of formation）. The effects of nitrogen and oxygen atoms on the fused ring and functional groups on the molecule on the performance of energetic compounds were analyzed. The research results show that the structure-activity relationship of the generated fused ring compounds is consistent with the general correlation between energy and stability of energetic compounds， verifying the rationality of the prediction model. Taking detonation velocity and decomposition temperature as the criteria for energy and thermal stability， five molecules with outstanding comprehensive properties were screened， and the quantum chemical calculation results were in good agreement with the machine learning prediction results， which further verified the accuracy of the prediction model.

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• Synthesis and Properties of 3-（1H-Tetrazol-5-yl）-7-（trifluoromethyl）-1，2，4-triazolo［5，1-c］-1，2，4-triazin-4-amine

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

  2024,32(6):584-590, DOI: 10.11943/CJEM2024053

  Abstract(77) HTML(30) PDF(1.09 M)( 207)

  Abstract:A trifluoromethyl-containing fused triazole-triazine energetic molecule， 3-（1H-tetrazol-5-yl）-7-（trifluoromethyl）-1，2，4-triazolo［5，1-c］-1，2，4-triazin-4-amine （2）， was synthesized in two steps from 5-（trifluoromethyl）-1，2，4-triazol-3-amine. The crystal structure of this compound was characterized by X-ray single crystal diffraction. Its structure and properties were characterized by ¹H and ¹³C Nuclear Magnetic Resonance Spectroscopy （NMR）， Fourier Transform infrared spectroscopy （FT-IR） and differential scanning calorimetry （DSC）. The detonation performance of compound 2 was predicted by EXPLO5 and and sensitivity testing was performed according to the BAM standard method. Results show that compound 2 belongs to the triclinic space group Pī， a=4.9035（10） Å， b=10.219（2） Å， c=15.194（3） Å， V=720.4（3） ų， α=107.163（6）°，β=92.486（7）°，γ=96.4438（7）°， Z=2. The theoretical detonation velocity and pressure of compound 2 are 6933 m·s^-1 and 17.1 GPa， respectively. Its measured impact sensitivity is more than 40 J and the friction sensitivity is larger than 360 N.

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• Synthesis， Crystal Structures and Properties of Tetrazole Based Polycyclic Self-Assembled Energetic Compounds

  YANG Ya-lin, QIN Yi-feng, XIA Jiang-lu, DU Hui-ying, LI Xin-yu, WU Bo, MA Cong-ming

  2024,32(6):591-600, DOI: 10.11943/CJEM2024006

  Abstract(89) HTML(65) PDF(2.40 M)( 180)

  Abstract:Polycyclic energetic compounds with high nitrogen content have attracted much attention owing to their distinctive advantages in constructing novel energetic molecules with low mechanical sensitivity， good thermal stability and high density. The construction of polycyclic skeletons involves the incorporation of tetrazole into fused heterocycle， serving as high-energy organic fuel and hydrogen bond donors. Three self-assembled non-hydrated energetic compounds， namely 7-amino-6-（2H-tetrazol-5-yl）-pyrazolo［1，5-a］pyrimidine （1）， 7-diamino-6-（2H-tetrazol-5-yl）-［1，2，4］triazolo［1，5-a］pyrimidine perchlorate （2）， and 2，7-diamino-6-（2H-tetrazol-5-yl）-［1，2，4］triazolo［1，5-a］pyrimidine perchlorate （3）， were synthesized through noncovalent self-assembly of polycyclic skeleton with the oxidizing structural unit HClO₄ rich in hydrogen bond acceptors. The structural characterization employed nuclear magnetic resonance （NMR） spectroscopy and single crystal X-ray diffraction， while thermal behaviors and mechanical sensitivities were determined by differential scanning calorimetry-thermogravimetry and BAM methods. Detonation performances were predicted utilizing the Gaussian 09 program and EXPLO5 V6.05.02. The results show that three compounds exhibit high crystal densities （ρ： 1.75-1.86 g·cm^-3）， good thermal stabilities （decomposition temperature （onset）： 184-260 ℃）， and good detonation performances （detonation velocity： 7343-7570 m·s^-1； detonation pressure： 21.1-22.8 GPa）， surpassing those of traditional explosives trinitrotoluene （TNT）. Both compound 1 （impact sensitivity （IS） > 40 J， friction sensitivity （FS）=216 N） and compound 3 （IS=25 J， FS=240 N） exhibit low mechanical sensitivity.

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• Synthesis and Charaterization of 3，5，7-Triamino［1，2，4］triazolo［4，3-a］［1，3，5］triazine Pentazolate Salt

  JIANG Shuai-jie, QIN Ya-qi, XU Yuan-gang, LU Ming, WANG Peng-cheng

  2024,32(6):601-607, DOI: 10.11943/CJEM2024028

  Abstract(135) HTML(76) PDF(1.47 M)( 209)

  Abstract:A novel nonmetallic salt， 3，5，7-triamino［1，2，4］triazolo［4，3-a］［1，3，5］triazine pentazolate （4）， was synthesized through a metathesis reaction by employing AgN₅ as precusor with 3，5，7-triamino［1，2，4］triazolo［4，3-a］［1，3，5］triazine hydrochloride. The structural characterization were carried out by X-ray single crystal diffraction， infrared spectroscopy （IR）， elemental analysis （EA）， nuclear magnetic resonance （NMR）， and thermal decomposition behavior were determined by thermogravimetric analysis （TG） and differential scanning calorimetry （DSC）. The enthalpy of formation of compound 4 was calculated using atomization method， the detonation performance was predicted using EXPLO5， and sensitivity was tested using BAM testing method. The results show that compound 4 exhibits a monoclinic crystal structure with a crystal density of 1.644 g·cm^-3 and belongs to the P2₁/n space group. This compound has a nitrogen content of 77%， a thermal decomposition temperature of 113.8 ℃， and an enthalpy of formation of 491.5 kJ·mol^-1. Furthermore， its detonation velocity was calculated at 7913 m·s^-1， detonation pressure at 19.6 GPa； The impact sensitivities measured were >40 J， and friction sensitivity >360 N.

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• Synthesis and Performance Adjustments of 5-amino-2H-pyrazol-3，4-dione-3-oxime-4-hydrazone and Its Energetic Salts

  HU Li-jing-cao, SUN Huan-yu, AN Zi-wei, ZHAO Zi-chang, HUANG Wei, LIU Yu-ji

  2024,32(6):608-614, DOI: 10.11943/CJEM2023270

  Abstract(60) HTML(32) PDF(852.81 K)( 153)

  Abstract:5-amino-2H-pyrazol-3，4-dione-3-oxime-4-hydrazone （3） and its perchlorate （4）， nitrate （5） and 5，5′-dinitramino-3，3′-azo-1，2，4-oxadiazolate salts （6） were prepared from 4-chloro-3，5-dinitro-1H-pyrazole via amination and substitution/reduction reactions. The single crystals of 3 and 4 were obtained by solvent evaporation method and the crystals were characterized by single crystal X-ray diffraction. The structures of energetic compounds 3-6 were characterized by nuclear magnetic resonance spectroscopy and infrared spectroscopy. Moreover， the capacities of those compounds were confirmed by gas pycnometer， differential scanning calorimetry， impact and friction sensitivity testers. Their enthalpies of formation and detonation parameters were estimated using theoretical calculation methods. The results show that 3 has a planar molecular configuration. The ketone oxime and ketone hydrazone have unique double bond characteristics， reducing the conjugation of the pyrazole ring and making it easier to form salts. After salt formation， different anions have various effects on the performance of the neutral compound. Among those examined anions， the perchlorate anion not only improves the oxygen balance， but also increases the density， resulting in the detonation velocity and pressure of 4 （8499 m·s^-1 and 30.2 GPa） higher than 3 （8072 m·s^-1 and 22.5 GPa）. In addition， 5，5′-dinitramino-3，3′-azo-1，2，4-oxadiazole significantly increases the decomposition temperature of 3， rising from 135 ℃ to 285 ℃. These results indicate that a rational combination of anions and cations can effectively regulate the performances of target energetic compound.

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• Synthesis and Properties of Two 1，2，5-Oxadiazole based Energetic Salts with Nitrogen-Rich Fused Ring Skeleton

  LI Tao, YI Wen-bin, YU Qiong

  2024,32(6):615-622, DOI: 10.11943/CJEM2024039

  Abstract(74) HTML(33) PDF(1.42 M)( 172)

  Abstract:Two nitrogen-rich energetic salts， 5，5''-（hydrazine-1，2-diyl）bis（5，7-dihydro-［1，2，5］oxadiazolo［3，4-e］［1，2，4］triazolo［4，3-a］pyrimidine-8（4H）-one） perchlorate （2） and 5，5''-（diazene-1，2-diyl）bis（［1，2，5］oxadiazolo［3，4-e］［1，2，4］triazolo［4，3-a］pyrimidine-8（7H）-one） nitrate （3） were accomplished from the raw material of 5，6-diamino-［1，2，5］oxadiazolo［3，4-b］pyrazine （1）. Structure characterization of energetic ionic salts 2 and 3 were achieved through various techniques， including Nuclear Magnetic Resonance Spectroscopy （NMR）， Fourier Transform infrared spectroscopy （FTIR）， elemental analysis （EA） and X-ray single crystal diffraction （XRD）. Their thermal decomposition behaviors were investigated using differential scanning calorimetry （DSC） method， while their friction and impact sensitivities were identified according to BAM standard test methods. Moreover， their detonation performances were predicted based on the combination of Isodesmic Reactions and EXPLO5 software. The results prove that compounds 2 and 3 crystallize in the monoclinic system， belonging to space groups Pn and P2₁/n， respectively. The cationic parts of their crystal structures show good planarity and intensive hydrogen bonds in the crystal packing are observed. The thermal decomposition temperatures of compounds 2 and 3 are 154 ℃ and 130 ℃， respectively. Their theoretical detonation velocities are 7722 m·s^-1 and 8008 m·s^-1， while their theoretical detonation pressures are 26.3 GPa and 28.4 GPa， respectively. Their friction sensitivities are both 360 N， and impact sensitivities are greater than 40 J. Compounds 2 and 3 outperform traditional explosives TNT in terms of detonation performance， friction sensitivity， and impact sensitivity.

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• Synthesis and Properties of Nitrogen-rich Polycyclic Energetic Ionic Salts

  WANG Zhe, YIN Ping, PANG Si-ping

  2024,32(6):623-630, DOI: 10.11943/CJEM2024056

  Abstract(82) HTML(25) PDF(1.11 M)( 172)

  Abstract:A coupling reaction using hydrochloric acid and potassium permanganate as oxidizing agents was carried out to synthesize compound 1 from the polyamino fused heterocyclic compound 5-（6，7-diamino-3-imino-3H-［1，2，4］triazolo［4，3-b］［1，2，4］triazolo-2（7H）-yl）tetrazole. Subsequent displacement reaction in perchloric acid gave the perchlorate 2. The structure and thermal performance of compound 2 were characterized by X-ray single crystal diffraction， Fourier Infrared spectroscopy， Nuclear Magnetic Resonance， elemental analysis， differential scanning calorimetry （DSC） and thermogravimetry analysis （TG）. Additionally， the heat of formation was computed using Gaussian software， and the detonation properties of compound 2 were calculated using EXPLO5 software. The results showed that compound 2 crystallizes in the monoclinic crystal system， possessing a crystal density of 1.750 g·cm^-3 with four molecules per unit cell. The onset thermal decomposition temperature of compound 2 is 232.6 ℃， its theoretical detonation velocity and pressure are 8373 m∙s^-1 and 29.05 GPa， respectively. Remarkably， compound 2 exhibited insensitivity to external mechanical stimuli， evidenced by an impact sensitivity of 40 J and a friction sensitivity of 360 N， indicative of its robust performance overall.

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• Synthesis of Pentazolate Salts Based on Methenamine Cage-like Cations

  JIANG Tian-yu, LIU Tian-lin, WANG Kang-cai, XIA Hong-lei, ZHANG Wen-quan

  2024,32(6):631-640, DOI: 10.11943/CJEM2024091

  Abstract(78) HTML(24) PDF(1.87 M)( 173)

  Abstract:Based on two urotropine cage-like cationic structures， two new pentazolate salts， urotropine pentazolate salt （C₆H₁₃N₉， 1） and methylated urotropine pentazolate salt （C₇H₁₅N₉， 2）， were synthesized. The synthesized pentazolate salts were structurally characterized by X-ray single crystal diffraction， infrared spectroscopy （IR）， mass spectrometry （MS） and nuclear magnetic resonance （NMR）， and were analyzed by thermogravimetric analysis （TG） and differential scanning calorimetry （DSC） to evaluate their thermal decomposition behaviors. The formation enthalpy of compound 1 and 2 was calculated using the atomization method， the detonation performance was predicted using EXPLO5， and the impact sensitivity and friction sensitivity were tested using the BAM method. The results show that compound 1 belongs to the monoclinic crystal system （P2₁/c）， and the crystal cell parameters are a=13.6795（2） Å， b=11.6892（1） Å， c=12.5941（2） Å， V=1937.53（5） ų， α=γ=90°， β=105.822（1）°， Z=8， D_c=1.448 g·cm^-3； compound 2 belongs to the monoclinic crystal system （P2₁/m）， and the crystal cell parameters are a=6.9025（5） Å， b=7.6042（5） Å， c=10.6808（9） Å， V=538.50（7） ų， α=γ=90°， β=106.148（8）°， Z=2， D_c=1.389 g·cm^-3. The thermal decomposition temperature of compound 1 is 90.0 ℃， and 82.8 ℃ for compound 2. The detonation velocity and pressure of compound 1 and 2 are 8291 m·s^-1 and 20.33 GPa， 7862 m·s^-1 and 17.41 GPa， respectively. While the measured impact sensitivity and friction sensitivity of compound 1 and 2 are 5 J and 288 N， 3 J and 86 N， respectively.

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• Intriguing Fluorine Effect： An Important Factor for Effective Construction Insensitive Energetic Materials

  YU Pei-dong, LIU Qiang-qiang, Ding Xiao-yong, LIU Ying-le, GAO Hai-xiang

  2024,32(6):641-650, DOI: 10.11943/CJEM2024061

  Abstract(83) HTML(26) PDF(1.57 M)( 177)

  Abstract:The compound 5，7-bis（trifluoromethyl）-2-（dinitromethyl）-［1，2，4］triazolo［1，5-a］pyrimidine （1） was designed， synthesized， and thoroughly characterized. Thermal properties were determined using Differential Scanning Calorimetry （DSC）， while Gaussian 03 and EXPLO5 v6.05 programs were employed to calculate the heat of formation and detonation properties of compound 1， respectively. In addition， a comparative analysis of Hirschfeld surface， 2D fingerprint and electrostatic potentials （ESP） was conducted between compound 1 and other known dinitromethyl-containing compounds in this study. The result demonstrate that compound 1 exhibits exceptional insensitivity （IS > 40 J， FS > 360 N） toward external stimuli compared to other dinitromethyl-containing compounds. Furthermore， the presence of halogen bonding （C—F⋅⋅⋅X） effectively disrupts the formation of O…O interactions in energetic materials and leads to a favourable distribution of electrostatic potentials. This finding provides valuable insights for the development of novel insensitive energetic materials.

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• Synthesis and Internal Plasticization of （Azidofurazan-ether based Oxetane）-HTPE Copolymer

  WEN Yu-jia, ZHANG Jing, DOU Jin-kang, TAN Bo-jun, LIU Ning

  2024,32(6):651-659, DOI: 10.11943/CJEM2024022

  Abstract(47) HTML(22) PDF(1.52 M)( 176)

  Abstract:Migration and leaching of plasticizers will severely affect the physical and mechanical properties of polymers. In this study， two new monomers， 3-（4-nitrofurazan-3-oxy-methyl）-3-bromomethyl oxetane （BrNFMO） and 3，3-bis（4-nitrofurazan-3-oxy-methyl） oxetane （BNFMO）， were synthesized by the combination of 3-nitro-4-hydroxy-furazan and dibromomethyl oxetane （BBMO）. Using hydroxy-terminated polyether （HTPE） as macromolecular initiator， three block copolymers containing azide groups were synthesizd by polymerization of BrNFMO， BNFMO and BBMO under the catalysis of boron trifluoride ether followed by azidation process. Then the detonation performance of the designed monomer structure was evaluated by quantum chemistry. Besides， the copolymerization process was optimized by the control variate method， and better copolymerization conditions were obtained. The results show that this series of novel energetic copolymers can further improve the energy level of the binders， and the intramolecular plasticizing strategy can result in energetic polymers with lower glass transition temperature （T_g） and viscosity by introducing azide groups into the polymer through the structure of azidofurazan ether， compared with directly introducing azide groups into the polymer. T_g can be reduced by 5.27 ℃， viscosity can be reduced by 4.90 Pa·s， and its thermal stability is also improved （thermal decomposition temperature （T_d） can be increased by 7.3 ℃）.

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>Reviews

• Research Progress of Nitrogen Heteropolyclic Energetic Materials Based on Data-driven

  LIU You-hai, HUANG Shi, ZHANG Wen-quan, YANG Fu-sheng

  2024,32(6):660-671, DOI: 10.11943/CJEM2024088

  Abstract(92) HTML(18) PDF(4.12 M)( 190)

  Abstract:The development of energetic materials faces many challenges， and the traditional trial-and-error research model often results in long development cycles and low efficiency. With the advancement of data science and artificial intelligence （AI） technologies， a data-driven research model has emerged as a new path for the development of energetic materials. Polycyclic energetic compounds are currently a hot topic in the field of energetic materials， among which nitrogen-containing polycyclic frameworks， due to the presence of π electrons for delocalized resonance and multiple modifiable sites， exhibit enhanced molecular structural stability. At the same time， the presence of energy groups ensures the energy level of the molecules， achieving a good balance between energy and stability， overcoming the inherent contradiction between them. This study briefly introduces the workflow of data-driven development of novel energetic materials， outlines the latest research progress of data-driven methods for the development of nitrogen-containing polycyclic energetic compounds， and finally proposes prospects for the application of data-driven methods in the development of novel energetic materials. Future directions should consider supplementing data volume through means such as data augmentation and governance to improve the accuracy and generalization ability of model predictions. Machine learning models can be used to predict the molecular synthetic feasibility by establishing chemical reaction conditions and synthetic pathways， thereby accelerating the development of novel nitrogen-containing polycyclic energetic compounds.

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• Research Progress in Electrochemical Synthesis of Azo Bridged Nitrogen-Containing Heterocyclic Energetic Compounds

  LIU Lei, WANG Ze-tao, LIU Yu-ji, TANG Yong-xing, HUANG Wei

  2024,32(6):672-682, DOI: 10.11943/CJEM2024031

  Abstract(80) HTML(25) PDF(1.52 M)( 159)

  Abstract:Azido-bridged nitrogen-rich heterocyclic energetic compounds have high heat of formation and low mechanical sensitivity， making them widely applicable in the field of energetic materials. However， traditional preparation methods often involve oxidative coupling， which poses high safety risks and severe environmental pollution. In contrast， the electrochemical synthesis method is favored by researchers for its efficiency， controllability， and environmental friendliness. By adjusting the electrochemical reaction conditions， selective synthesis of azido-bridged nitrogen-rich heterocyclic energetic compounds with different structures can be achieved， opening up new possibilities for their synthesis. This study reviews the electrochemical synthesis methods， effects of electrolytes and electrodes， and possible reaction mechanisms of azido-bridged nitrogen-rich heterocyclic energetic compounds such as furazan， pyrazole， 1，2，4-triazole and tetrazole. Additionally， future research directions are proposed， including the electrochemical preparation of energetic molecules that cannot be synthesised by traditional methods， the construction of nitrogen-nitrogen bonds， carbon-nitrogen bond through electrochemical method， and the synthesis of various fused/bis-heterocylcic energetic compounds. Furthermore， the scaled-up synthesis of these compounds via the electrochemical method is also discussed. The study provides a reference for the research and development of electrochemically synthesized azido-bridged rich nitrogen-containing energetic molecules.

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