TATB (1,3,5-triamino-2,4,6-trinitrobenzene) crystals exhibit strong thermoelastic anisotropy, making crystallographic texture a key factor in the thermal-stress response of TATB-based polymer-bonded explosives (PBXs). In this study, computational micromechanics combined with statistical analysis is used to quantify thermal-expansion-induced internal stresses in TATB-textured PBXs at the mesoscale. The results show that the spatial distribution of internal stress is strongly influenced by grain misorientation between neighboring grains, with larger misorientations leading to more severe stress concentrations. Statistical analysis further reveals that the internal stress distributions are generally asymmetric and unimodal. As texture intensity increases, the probability density peak rises, whereas both the mode stress and the average stress decrease. The maximum-to-minimum ratios of these three statistical characteristics reach up to 5.8, 8.9, and 6.1, respectively, indicating that texture intensity can regulate the stress field over a broad range. Gaussian mixture modeling is further employed to characterize the probability distributions of three stress measures. The distribution of maximum principal stress can be adequately described using two Gaussian components, whereas the von Mises and Tresca stress distributions require three components. These findings provide a quantitative basis for understanding and mitigating thermoelastic internal stress in PBXs through texture tailoring.

Amorphous materials exhibit a unique combination of properties surpassing crystalline materials due to their disordered structure, opening new dimensions for numerous frontier fields. This state is introduced into energetic materials systems, where the challenge lies not only in constructing stable energetic molecular disordered frameworks; it also faces the dual challenge of coordinated safety and reactivity. Herein, we propose a hydrogen bond-driven molecular assembly strategy using 4,4 ',5,5 '-tetranitro-1H,1 ' H-[2,2 '-biimidazole]-1,1 '-diamine (DATNBI) and hexanitrohexaazaisowurtzitane (CL-20) as model systems. By constructing a 3D hydrogen bond network as a "molecular lock," the stable amorphous DATNBI/CL-20 (AEM-DC) was successfully synthesized. This hydrogen-bond framework effectively constrains molecular motion, forming a kinetic barrier that inhibits crystallization and elevates the crystallization temperature to 101.6 degrees C. The material maintains high reactivity while achieving reduced impact sensitivity (17.5 J) and friction sensitivity (112 N). The material exhibits a combustion duration one to three times shorter and peak pressure 1.5 times higher than crystalline DATNBI, demonstrating synergistically enhanced energy release performance to its crystalline analogues. This result confirms the potential of noncovalent molecular frameworks in stabilizing metastable functional materials, offering a promising strategy for advancing the performance of energetic materials.

Polycyclic energetic materials make up a distinctive class of conjugated structures that consist of two or more rings. In this work, 1,3-bis(3,5-dinitro-H-1-pyrazol-4-yl)-4,6-dinitrobenzene (BDPD) was synthesized and investigated in detail as a polycyclic heat-resistant energetic molecule that can be deprotonated by bases to obtain its anionic (3-5) salts. All compounds were thoroughly characterized by H-1 and C-13 NMR, infrared spectroscopy, high-resolution mass spectrometry, and elemental analysis. The structural features of BDPD and its salts were investigated by single-crystal X-ray diffraction and analyzed by different kinds of computing software, like Multiwfn, Gaussian 09W, and so on. In addition, their thermal decomposition temperatures were evaluated by differential scanning calorimetry to be 319.8-329.0 degrees C, revealing that they possessed high thermal stabilities. The results of impact sensitivity and friction sensitivity analysis confirm that these energetic compounds were insensitive. The detonation properties of neutral compound BDPD and all its nonmetallic salts were calculated by the EXPLO5 v6.05.04 program. The results revealed that their detonation performances were higher than those of the widely used heat-resistant explosive 2,2 ',4,4 ',6,6 '-hexanitrostilbene (HNS). Combining the above results, it is reasonable to suggest that these compounds have the potential to be heat-resistant energetic materials.

Accurately predicting reactive flow is a challenge when characterizing an explosive under external shock stimuli as the shock initiation time is on the order of a microsecond. The present study constructs a new Ignition-Growth reaction rate model, which can describe the shock initiation processes of explosives with different initial densities, particle sizes and loading pressures by only one set of model parameters. Compared with the Lee-Tarver reaction rate model, the new Ignition-Growth reaction rate model describes better the shock initiation process of explosives and requires fewer model parameters. Moreover, the shock initiation of a 2, 4-Dinitroanisole (DNAN)-based melt-cast explosive RDA-2 (DNAN/HMX (octahydro- 1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazoncine)/aluminum) are investigated both experimentally and numerically. A series of shock initiation experiments is performed with manganin piezoresistive pressure gauges and corresponding numerical simulations are carried out with the new Ignition-Growth reaction rate model. The RDA-2 explosive is found to have higher critical initiation pressure and lower shock sensitivity than traditional explosives (such as the Comp. B explosive). The calibrated reaction rate model parameters of RDA-2 could provide numerical basis for its further application.

C–C bridged pyrazole and benzene skeletons were used to design explosives 1c and 2c with high thermal stabilities, respectively.

Surfacestructures and properties are particularly importantforvarious materials, as they can transport to the bulk properties inspecial cases and affect the applications of materials. Thermal stabilityis one of the key factors that determine the engineering applicationsof energetic cocrystals (ECCs). Here, in situ morphology and crystalstructure characterization techniques were applied to investigatethe thermal decomposition of hexanitrohexoazaisowurtzitane/1-methyl-3,4,5-trinitro-1H-pyrazole(CL-20/MTNP), an important CL-20-based energetic cocrystal, underisothermal conditions. An unexpectedly low thermal stability was observedfor the CL-20/MTNP cocrystal. The decomposition temperature can beas low as 140 & DEG;C with the evolution of surface defects startingfrom 100 & DEG;C. After decomposition, the cocrystal transformed to & gamma;-CL-20 in a porous morphology. Based on the facet indexingresult, the surface model was also constructed for the cocrystal.In combination with the surface structure and channel-like crystalstructure, a surface-induced decomposition mechanism was proposed,which provides a new perspective on the thermal stability of ECCs,and will be valuable for the estimation of thermal/chemical stabilityfor other cocrystal materials. Based on insitu morphology and crystal structure characterizationtechniques, thermal decomposition of energetic cocrystal CL-20/MTNPwas observed at a much lower temperature than previously reported.A novel surface-induced decomposition mechanism was proposed basedon the experimental observation and crystal structure analysis, whichrefreshes the understanding of the thermal stability of energeticcocrystals.

Photocurable polymer provides fast curable properties via ultraviolet (UV) light for 3D-printed propellants. This work outlines the preparation and characterization of photocurable fluorinated polyether-based reactive inks. Acrylate-terminated poly-2-((2,2,3,3,3-pentafluoropropoxy)-methyl) ethylene oxide (P5F-AA) was synthesized as photocurable binder through the esterification of acrylic acid, and the terminal hydroxyl group of poly-2-((2,2,3,3,3-pentafluoropropoxy)-methyl) ethylene oxide (P5F), which was synthesized through cationic ring-opening polymerization of 2-((2,2,3,3,3-pentafluoropropoxy)methyl) oxy-ethane (PFEE) by using butane diol as initiator. In comparison with P5F, P5F-AA had a lower glass transition temperature (T-g) of -63.3 degrees C. A new type of photocurable resin, which may be used for additive manufacturing of energetic materials, was prepared via UV radiation in an LED UV curing tank by using P5F-AA as prepolymer, diphenyl (2,4,6-trimethyl benzoyl) phosphine oxide (TPO) as photo-initiator, and tri-fluoroethyl acrylate (3F-AA) and 1,6-hexanediol diacrylate (HDDA) as mono- and multifunctional diluents, respectively. When the mass ratio of P5F-AA/3F-AA/HDDA binder matrix was 1:1:0.5, the sample exhibited maximal mechanical strength of 6.56 MPa with elongation at break of 13.38%, which was due to the introduction of HDDA effectively increasing the "entanglement" between molecular chains. Thermogravimetric analysis (TGA-DTG) was utilized to evaluate the ability to decompose thermally of the binder matrix, and the results showed the initial degradation temperature started at nearly 181 degrees C and two consecutive stages in thermal decomposition. Overall, the obtained results from the different techniques suggested that P5F-AA/3F-AA/HDDA binder matrix may be a photocurable reactive ink for 3D-printed propellants, which would provide a certain reference value and guiding importance for design of reactive inks.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Polype ntafluoropropane glycidyl ether (PPFEE), a new random block hydroxyl-terminated polyfluoroether, was synthesized successfully by cationic ring-opening polymerization of 2-(2,2,3,3,3-pentafluoropropoxymethyl) oxirane, and its molecular structure was confirmed by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectrometry, and gel permeation chromatography. The PPFEE-based polyurethane elastomers featuring fluorine in their side chains were prepared using PPFEE as soft segments, polyisocyanate polyaryl polymethylene isocyanate as hard segments, and dibutyltin dilaurate as catalysts under different curing conditions. The microphase separation, mechanical performance, and thermal behavior of the elastomers were investigated by differential scanning calorimetry, uniaxial tensile test, and thermal gravimetric analysis, respectively. Based on the results, the percentage of hard segments dissolved into the soft segments of elastomers was opposite to the change in breaking strength. The PPFEE-based polyurethane elastomer cured with 20 wt% PAPI at the curing temperature of 50 °C displayed the maximum tensile elongation of 2.26 MPa with an elongation at break of nearly 150%. The increased contents of PAPI can effectively strengthen the tensile strength, and the maximum tensile elongation was 3.04 MPa with an elongation at break of nearly 90% when the content of PAPI was 26 wt%. In addition, the PPFEE-based polyurethane elastomers exhibited excellent resistance to thermal decomposition and a sharp weight loss temperature at around 371 °C. All the results demonstrated that the PPFEE may be a potential polymeric binder as one of the ingredients applied to future propellant formulations.

Investigations of the detonation characteristics of a new aluminized DNAN-based melt-cast explosive RMA-2X (containing 30 wt.% DNAN (2,4-dinitroanisole), 30 wt.% NTO (3-nitro-1,2,4-triazol-5-one), 10 wt.% HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane) and 30 wt.% aluminum) were undertaken, as well as a lithium fluoride (LiF) substituted explosive RMF-2X (containing 30 wt.% DNAN, 30 wt.% NTO, 10 wt.% HMX and 30 wt.% LiF). The interfacial velocity experiment was carried out to measure the reaction zone parameters (including the CJ pressure, the pressure at the Von Neumann spike, and the reaction zone length) of RMA-2X. The cylinder test was also performed, and employing the test data, the detonation velocity, the Gurney energy, and the detonation energy of RMA-2X were calculated. Investigation results are analyzed and some conclusions are drawn. The role of aluminum in the detonation characteristics are also discussed. Finally, parameters of the Jones-Wilkins-Lee equation of state of the detonation products were confirmed.

In order to study the morphology evolution of 1， 1‑diamino‑2， 2‑dinitroethylene （FOX‑7） particles under thermal stimulus and its influence on mechanical properties and mechanical sensitivities， four kinds of FOX‑7 particles with typical size and morphology differences were selected. By controlling heating time and temperature， the morphology， mechanical properties and mechanical sensitivities evolutions of FOX‑7 particles after heating were studied by scanning electron microscope， compressive stiffness experiment and mechanical sensitivities tests. The results show that the surface cracks of FOX‑7 particles appear after heating and returning to room temperature. With the increase of heating temperature or heating time， the surface cracks of large‑size particles （>100 μm） grow and break through ， thus the particles crack in layers and exfoliate. While， the surface cracks of small‑sized particles （<100 μm） do not grow with the increase of heating temperature or heating time. Kawakita equation was used to fit the compaction curves of FOX‑7 particles before and after heating. It is found that the modulus of FOX‑7 particles increase after heating， and the increase is even greater for small particle size. Under the condition of larger particle size， FOX‑7 has relatively low mechanical sensitivities， and still maintains low mechanical sensitivities after being heated and returning to room temperature. When the particle size is small， the mechanical sensitivities of FOX‑7 are relatively high， and after heating and returning to room temperature， the mechanical sensitivities increase significantly， which may be related to the greater increase of modulus.

Energetic complexes represent a crucial research direction for the design and synthesis of novel energetic materials. In this work, 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), a significant explosive compound with exceptional comprehensive properties, was selected as the ligand for coordinating with various metal ions. Four novel energetic complexes, Ni(C4H3N6O5)2·DMF (1), Co(C4H3N6O5)2·2DMF (2), Mn(C4H3N6O5)3·3/2DMF (3), and Cu3(C4H2N6O5)3·3DMF (4) were successfully synthesized, and their crystal structures were identified by a single-crystal X-ray diffraction technique. The structural analyses illustrated that LLM-105 can form either a mononuclear metal complex after the deprotonation of one amino group or a trinuclear metal complex after the deprotonation of two amino groups. Compound 1 exhibits a planar quadrilateral geometry, while both compounds 2 and 3 display distorted octahedral configurations. Compound 4 has three metal centers and exhibits two coordination configurations of distorted tetragonal pyramid geometry and planar quadrilateral geometry. The detonation performances of compounds 1–4 were also theoretically calculated, revealing their favorable explosive properties. These findings emphasize the diverse coordination modes of LLM-105 and the structural variability and adjustability of its complexes, offering valuable insights for regulating both the structure and performance of the LLM-105 complex as well as researching its deprotonation.

Heat-resistant energetic materials refer to a type of energetic materials that possess a high melting point,high stability and operational safety. By studying the structures of these energetic materials has showed that the thermal stability can be enhanced by introducing amino groups to form intra/inter-molecular hydrogen bonds, constructing conjugate systems and designing symmetrical structures. This article aims to review the physical and chemical properties of ultra-high temperature heat-resistant energetic compounds and provide valuable theoretical insights for the preparation of ultra-high temperature heatresistant energetic materials. We also analyze the selected 20 heat-resistant energetic materials with decomposition temperatures higher than 350℃, serving as templates for the synthesis of various highperformance heat-resistant energetic materials.

Coordinating energy and sensitivity of explosives is a common challenge in the research field of energetic materials. Cocrystallization technology has alleviated the conflict between the energy and safety of high-energy explosives to a certain extent and has aroused the interest of researchers. Cocrystal component screening is the primary challenge in the preparation of energetic cocrystals. In this study, we developed a similarity function for explosives based on the molecular structure, polarity, and solubility. By calculating the similarity between 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX)- and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20)-based cocrystal explosive components, the applicability of the similarity function was demonstrated, and six possible energetic cocrystal component formulations were preferentially selected from 18 new energy-containing ligands, which are HMX/3,6-diamino-1,2,4,5-tetrazine-1,4-dioxide (DATAD), HMX/1,3,3-trinitroazetidine (TNAZ), HMX/4-amino-3,5-dinitro-pyrazole (LLM-116), HMX/2-oxo-1,3,5-trinitro-1,3,5-triazacyclohexane (Keto-RDX), CL-20/TNAZ, and CL-20/Keto-RDX, respectively. The energetic supramolecular similarity function can achieve rapid screening of cocrystal explosive components and guide the experimental synthesis of energetic cocrystals.

The analysis of N-oxide based explosives is beneficial to avoiding explosive risk and toxic hazard to the public. Nowadays, multifunctional sensors are scarce for green extraction and analysis of N-oxide based explosives. Herein, we have designed and developed two-in-one sensing solvents (DSMs) based on deep eutectic solvents with dual functions of both extraction and detection toward N-oxide based explosives. Besides, as an extraction solvent, DSM-3 based choline chloride and urea also can detect N-oxide based explosives via color change from yellow to red. The sensing mechanism of DSM-3 toward 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) as a prototype of N-oxide-based explosives has been fully investigated by experimental analysis and theoretical calculations. The proposed mechanism is based on the formation of H-bonding complexes between urea of DSM-3 and N-oxide group of LLM-105, which induces the charge transfer from urea to LLM-105. Further, this assay exhibits high selectivity, sensitivity and good visualization for the determination of LLM-105. Therefore, our study provides novel two-in-one sensing solvent for green, convenient and on-site detection of N-oxide based explosives.

The aim of this study was to investigate the effects of agglomerated TATB on the mechanical and sensitivity properties of cast polymer-bonded explosives (PBXs).By introducing agglomerated TATB, cast PBXs with a high solids content can be obtained.The mechanical properties of TATB-based cast PBXs were evaluated by tensile and compression tests.The experimental results showed that the addition of the agglomerated TATB clearly enhanced the ductility and fracture toughness, but decreased the strength of the PBXs.However, the strength increased with the decreasing particle size of the agglomerated TATB.When TATBcrystal was replaced by agglomerated TATB in the cast PBXs, a significant drop in the initial modulus and stress were observed.Samples with a higher content of agglomerated TATB were less sensitive to impact stimuli.The desired mechanical and sensitivity characteristics may be achieved for TATB-based cast PBXs by introducing agglomerated TATB.

不敏感炸药是指对热刺激、机械刺激和冲击波等感度较低的一类炸药,包括不敏感单质炸药和混合炸药,是提高弹药安全性的关键材料.用于装填武器弹药的炸药通常是以单质炸药为主成分(填料)、以聚合物为连续相或以熔铸型含能化合物(如三硝基甲苯、二硝基苯甲醚等)或热熔型石蜡为载体的混合炸药.其中,聚合物粘结炸药(polymer bonded explosive,PBX)是当前发展不敏感混合炸药的主流产品,广泛应用于现代武器弹药.不敏感PBX的感度特性与其多尺度结构密切关联,主要包括单质炸药分子的结构与稳定性、炸药分子的堆积方式与晶体结构及晶体品质、混合炸药的组成结构等与感度的关系3个层面的多尺度问题.通过不敏感含能分子的设计与合成、晶体结构的设计调控与高品质晶体降感技术、基于力热耗散的高效协同降感技术及PBX构效关系,发展不敏感炸药多尺度系统设计与结构调控及制备,是获得高能不敏感PBX的主要途径.加强超分子单质炸药和共晶炸药的设计研发,及发展第三代单质炸药高品质晶体降感技术等研究,是发展高能不敏感炸药的重要方向.

Thermal stability is one of the key factors that determine the engineering applications of energetic cocrystals (ECCs). Herein, in-situ morphology and structure characterization techniques were adapted to investigate the thermal stability of hexanitrohexoazaisowurtzitane/1-methyl-3,4,5-trinitro-1H-pyrazole (CL-20/MTNP) cocrystal. The cocrystal structure was observed to completely decompose when heating at 140 o C for 180 min and 180 o C for 140 min, which are much lower than the decomposition temperature (220 o C) determined by non-isothermal differential scanning calorimetry (DSC) test. Due to the low temperature, CL-20/MTNP cocrystal gradually transformed to porous γ -CL-20 after thermal treatment. More importantly, an obvious morphology evolution was observed on the crystal surface even at the temperature low to 100 o C, which indicates an even much poorer thermal stability of the cocrystal surface. Combined the experimental observation and theoretically structure analysis, a novel surface-induced decomposition mechanism was proposed to explain the unexpectedly low thermal stability of the CL-20/MTNP cocrystal. These results provide a new perspective on the thermal stability of ECCs and will have significant impacts on the evaluation and application of ECCs.

A new explosive ink based on 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) was designed and prepared. The explosive ink was deposited into micro-size grooves by using direct ink writing (DIW) technology and its detonation properties in an explosive network were explored. The properties of impact sensitivity, detonation velocity and critical size of detonation were determined and analyzed. The results show that this explosive has a good impact safety. When the LLM-105 content is 88 % and the density is 95 % TMD, the detonation velocity and critical size of detonation values are 7,771 m/s and 0.5x0.5 mm respectively. Moreover detonation velocity results indicated the explosive ink in micro-size grooves loaded by DIW was uniform.