Abstract:A novel dinitramine compound， 5，5''''-Bis（trinitromethyl）-2，2''''-dinitramide-3，3''''-bi（1，2，4-triazole） （3）， was synthesized via N-amination and subsequent nitration of the starting material 3，3′-bi（1H，1′H-1，2，4-triazole）-5，5′-bis（trinitromethyl） （1）. The structure of compound 3 was confirmed by X-ray single-crystal diffraction （XRD） and further characterized by infrared spectroscopy （IR）， elemental analysis （EA）， and nuclear magnetic resonance （NMR） spectroscopy. The enthalpy of formation for compound 3 was calculated using the isodesmic reaction method， while its detonation performance was predicted using the EXPLO5 code. Results indicate that compound 3 crystallizes in the monoclinic space group P2₁/n. The crystal density of the dihydrate （3·2H₂O） is 1.937 g·cm^-3 at 100 K. It exhibits an initial decomposition temperature of 92.6 ℃ and a calculated enthalpy of formation of 680.5 kJ·mol^-1. Furthermore， its predicted detonation velocity and pressure are 8926 m·s^-1 and 34.1 GPa， respectively， with a specific impulse of 257.7 s. Its integrated performance suggests its potential for use as an energetic oxidizer.

Abstract:Stereoisomerism plays a unique role in tuning the structures and performances of energetic molecules. Photochemical reactions feature mild conditions and precise configurational regulation， thus bearing important theoretical and practical significance for realizing stereoisomeric transformation of energetic molecules. （E）-Potassium 5，5''''-azotetrazolate （E-PZT） was employed as the substrate in this work. Systematic condition screening was conducted to determine the optimal parameters for the photochemical synthesis of （Z）-potassium 5，5''''-azotetrazolate （Z-PZT）. The molecular structure of Z-PZT was fully characterized. The half-life of Z-PZT was measured to be 49 min at room-temperature. Theoretical calculations are highly consistent with the experimental phenomena and results of the photoinduced isomerization reaction. The predicted excitation wavelengths and corresponding spectra obtained from theoretical calculations are highly consistent with the experimental phenomena and results of the photoinduced isomerization reaction. The successful preparation of the target product Z-PZT is further verified by these theoretical results. The isomerization energy barrier was calculated， and a rational photochemical reaction mechanism was accordingly proposed to elucidate the metastable characteristic of Z-PZT and the intrinsic origin of its relatively short half-life. Reliable experimental and theoretical support is provided by this work for the investigation of photoinduced isomerization regulation in energetic molecules.

Abstract:To investigate the regulatory mechanism of amino and nitro substituents on the thermal stability of TYX series heat-resistant explosives， two novel heat-resistant explosives based on the bis（triazolo）tetrazine backbone-fully amino-substituted 2，7-diaminobis（［1，2，4］triazolo）［1，5-b：1''''，5''''-e］［1，2，4，5］tetrazine-5，10-diium-3，8-diide （TYX-1） and mono-nitro mono-amino substituted 2-amino-7-nitrobis（［1，2，4］triazolo）［1，5-b：1''''，5''''-e］［1，2，4，5］tetrazine-5，10-diium-3，8-diide （TYX-3）-were selected in this study. Their thermal decomposition behaviors were systematically compared using differential scanning calorimetry （DSC） and thermal decomposition kinetic methods， while the decomposition processes were comprehensively analyzed by thermogravimetry-infrared-mass spectrometry （TG-FTIR-MS）. The results show that the difference in substituents exerts a decisive influence on their thermal stability and decomposition pathways. TYX-1 exhibits a single high-temperature decomposition process with a peak temperature of 477.56 ℃ （at a heating rate of 20 ℃·min^-1）， and its decomposition mechanism conforms to the random two-dimensional nucleation growth model （A2）， consistent with the layered stacking structure promoted by amino groups and the resulting controlled two-dimensional energy release pathway. In contrast， TYX-3 shows a significantly lower decomposition temperature and multi-step decomposition characteristics： the initial stage follows a two-dimensional diffusion model （D2）， followed by a multi-reaction competitive stage， and finally transitions to a skeletal fracture process dominated by the one-dimensional chemical reaction model （F1）. Gas product analysis shows that the main decomposition products of TYX-1 are N₂， CO₂， N₂O， and HCN， while additional products including NO， HCNO， NH₂， and H₂O are detected for TYX-3， confirming that the nitro group， as a strong oxidizing moiety， induces an unconventional decomposition pathway and promotes the oxidative cleavage of the parent ring skeleton.

Abstract:To investigate the evolution of the mechanical sensitivity of the energetic oxidizer ammonium dinitramide （ADN） under varying moisture and temperature conditions， standard tests specified by the Federal Institute for Materials Research and Testing （BAM） were carried out in combination with the Langlie–D optimization method. The impact and friction sensitivities of ADN samples with moisture contents of 0， 5%， 10%， and 15% were quantitatively evaluated at 25， 50， and 75 ℃. The results show that both impact and friction sensitivities decrease significantly with increasing moisture content， although the variation is not simply linear and instead exhibits a distinct stagewise pattern. At 25 ℃， the limiting impact energy increased from 4 J for anhydrous ADN to 30 J at 5% moisture content and exceeded 50 J when the moisture content reached 10% or higher. Meanwhile， the minimum friction load increased progressively from 56 N and surpassed the upper measurement limit of the apparatus at 15% moisture content. Further analysis indicates that increasing temperature gradually weakens the desensitizing effect of moisture. At a given moisture content， both the limiting impact energy and the minimum friction load at 50 and 75 ℃ are generally lower than those at 25 ℃， while the corresponding impact and friction ignition-probability curves shift continuously toward lower stimulus levels. Among them， friction sensitivity shows a stronger dependence on temperature. These results suggest that the coupled effects of moisture content and temperature are reflected not only in single threshold values， but also in systematic shifts of the entire ignition-probability curve and the corresponding low-probability risk boundary.

Abstract:In order to reduce the hygroscopicity of ammonium dinitramide （ADN）， a double-layer coating strategy was developed to fabricate a double-layer coated composite ADN@18C6@HTFVP via a one-pot method， using 18-crown-6 （18C6） as intermediate tuning layer ADN fluorine-containing polymer HTFVP as outer hygroscopic-resistant layer. Besides， ADN， ADN@18C6， ADN ADN@18C6@HTFVP were characterized ADN analyzed by Scanning Electron Microscopy-Energy Dispersive Spectroscopy （SEM-EDS）， thermogravimetry-differential scanning calorimetry （TG-DSC）， ADN X-ray photoelectron spectroscopy （XPS）. The laser response characteristics of ADN， ADN@18C6， ADN ADN@18C6@HTFVP were investigated via laser ignition tests. The apparent decomposition activation energies of ADN， ADN@18C6， ADN ADN@18C6@HTFVP were calculated via Kissinger ADN Ozawa equations. Results show that the hydrophobic double-layer 18C6@HTFVP structure is uniformly coated on the ADN surface. The thermal decomposition temperature of ADN@18C6@HTFVP increases from 181.46 °C of ADN to 183.79 °C， the impact sensitivity is enhanced from 8 J to 16 J， ADN the friction sensitivity is improved from 80 N to 140 N. Under the conditions of 25 °C， 55% RH， ADN 72 h， the moisture absorption rate of ADN@18C6@HTFVP is 0.38%， which is 94.6% lower than that of ADN （7%）. Calculations reveal that the decomposition reactivity of ADN@18C6@HTFVP is higher than that of ADN. Moreover， ADN@18C6@HTFVP exhibits favorable laser response ADN can be ignited by laser.

Abstract:To elucidate the energy deposition mechanism of electro-chemical coupled explosion and provide a scientific basis for parameter optimization and precise control of related devices， an experimental platform was established to systematically investigate the effects of aluminum wire diameter （0.1-0.4 mm） and initial charging voltage （25-40 kV） on the detonation of HMX driven by electrical wire explosion. The results reveal that the electro-chemical coupled explosion comprises four characteristic stages： wire vaporization and plasma expansion， HMX ignition， HMX detonation， and disintegration of the detonation-product conductive channel. A quantitative criterion system for identifying mechanism transitions was established by defining the energy fraction in the HMX detonation stage （η_Ⅲ=E_Ⅲ/E_total） and the power peak ratio （γ=P_p2/P_p1）. When η_Ⅲ > 90% and γ > 0.5， the system operates in the HMX-dominated “electro-chemical coupled explosion” mode； when η_Ⅲ decreases to 70%-80% and γ <0.2， it transitions to the Al-dominated “electrical explosion” mode； when η_Ⅲ≈0， γ≈0， and current oscillations disappear， it enters the resistance-dominated “capacitive discharge” mode. The wire diameter governs the fundamental transition of energy deposition mechanisms by controlling the effective vaporized and ionized mass fraction of aluminum. As the diameter increases from 0.1 mm to 0.4 mm， the energy release mechanism sequentially undergoes the three modes described above. The initial charging voltage regulates the intensity and efficiency of the coupled explosion through a power density enhancement mechanism. Increasing the voltage from 25 kV to 40 kV boosts the first power peak by 3.2 times， shortens the ignition delay by 62%， increases the energy deposited in the HMX detonation stage by 3.0 times， and raises the total deposited energy by 3.3 times. This study demonstrates that enhancing the efficiency of electro-chemical coupled explosion requires a combined strategy of reducing the wire diameter and increasing the initial charging voltage. The established quantitative criterion system and synergistic regulation laws provide a critical scientific basis for parameter optimization and precise control of electro-chemical coupled explosion technology.

Abstract:To explore a new process for mixing composite solid propellant slurry and address the safety assessment issues related to the process of mixing HTPB-based propellant two-component slurry in a static mixer， a low-burning-rate HTPB propellant with 85% solid content was selected as the research object. The limiting impact energy and limiting friction load of the binder slurry， curing agent slurry， and their mixed slurry were determined using BAM impact and friction sensitivity tests. Through force analysis and calculations during the pipeline transportation of the slurry and the mixing process in the static mixer， the driving pressure and friction force exerted on the slurry were compared with its limiting impact energy and limiting friction load， thereby obtaining safety assessment results. The results show that at 25 ℃， the limiting impact pressure sustainable by the curing agent slurry， binder slurry， and mixed slurry are 363 MPa， 363 MPa， and 325 MPa， respectively； the limiting friction loads sustainable are 128 N， 168 N， and 144 N， respectively. When the slurry inlet pressure is in the range of 0.4-0.5 MPa， and the temperature ranges from 25-45 ℃， the maximum driving pressures experienced by the binder slurry and curing agent slurry during pipeline transportation are 0.024 MPa and 0.046 MPa， respectively， and the maximum friction forces experienced are 6.11 N and 17.10 N. The maximum driving pressure experienced by the mixed slurry in the static mixer is 0.44 MPa， and the maximum friction force is 77.88 N. The binder and curing agent slurries are safe and reliable during pipeline transportation with a large safety margin； the mixed slurry exhibits good safety during the static mixer mixing process with a certain safety margin.

Abstract:To elucidate the influence mechanism of the mass ratio of ammonium perchlorate （AP） to octogen （HMX） on the combustion performance of nitrate ester plasticized polyether （NEPE） propellants， multiple testing methods including the underwater acoustic emission method， micro-thermocouple technique， coaxial digital holography and condensed-phase product collection method were adopted in this study. The effects of AP/HMX mass ratio （13/50-19/44） on the burning rate， combustion wave structure and condensed-phase product characteristics of NEPE propellants were systematically investigated. The results show that with the increase of AP/HMX mass ratio， the burning rate of propellants increases from 11.4 mm·s^-1 to 12.3 mm·s^-1， the explosion heat rises from 6820 kJ·kg^-1 to 7107 kJ·kg^-1， the thickness of condensed-phase preheating zone decreases from 317.3 μm to 183.6 μm， the burning surface temperature rises from 336 ℃ to 494 ℃， the maximum temperature of gas-phase flame zone increases from 2934 ℃ to 3017 ℃， the median diameter of aluminum agglomerates decreases from 275.86 μm to 209.77 μm， and the active aluminum content in condensed-phase products decreases from 2.55% to 0.86%. The combustion performance of NEPE propellants can be regulated by adjusting the AP/HMX mass ratio via the synergistic action of thermodynamics and kinetics.

Abstract:To reveal the curing reaction characteristics of polyurethane-crosslinked energetic composite slurry， this study derived the curing kinetic equations for the HTPB/IPDI system based on the evolution of characteristic functional groups monitored by in-situ ATR-FTIR spectroscopy during the curing process. The evolution of characteristic groups was monitored at 45 ℃， 50 ℃， 55 ℃， 60 ℃ and 65 ℃. Using the derived equations， kinetic curves for the slurry curing reaction were constructed， and the apparent activation energy was determined. The results indicate a two-stage curing process. The first stage corresponds to the pre-gelation period， with an apparent activation energy （E_a1） of 69.83±5.54 kJ·mol^-1. The second stage corresponds to the post-gelation curing period， with an apparent activation energy （E_a2） of 71.31±4.45 kJ·mol^-1. The apparent activation energy for the HTPB/IPDI energetic composite slurry is significantly higher than that of a homogeneous HTPB/IPDI mixture.

Abstract:In order to explore the effect of aromatic compounds on the combustion performance of CMDB propellant， 2，2''''-（propane-1，1-diyl）bis（4-（tert-butyl）phenol） （PDBP） was used to prepare HMX-CMDB propellant， and the combustion performance of HMX-CMDB propellants with different PDBP contents was studied using the target line method. The results showed that with the increase of PDBP content， the burning rate and pressure index of HMX-CMDB propellant significantly decreased. For HMX-CMDB propellant containing 7% PDBP， the burning rate at 16 MPa decreased to 8.55 mm·s^-1， and the pressure index decreased to 0.217. Compared with the sucrose octaacetate （SOA）， HMX-CMDB propellant containing the same mass of PDBP exhibited almost unchanged burning rate in the low-pressure region （8-10 MPa）， a further reduced burning rate in the high-pressure region （12-16 MPa）， resulting in a lower pressure index. In addition， after replacing SOA with 1% PDBP， the detonation heat of HMX-CMDB propellant was reduced by only 20 kJ·kg^-1. Based on chemical structure analysis， the mechanism of PDBP''''s burning rate inhibition effect is as follows： the aromatic molecule decompose to form protons and structurally stable radical molecules with conjugated π bonds， and the active protons can react with the active radicals released from the decomposition of energetic molecules in the HMX-CMDB propellant， forming stable structures that mitigate the autocatalytic effect of free radicals， thereby reducing the burning rate.

Abstract:To achieve one-step determination of component contents in hydroxylammonium nitrate-based propellants （HAN-based propellant） and address issues like complex procedures and long analysis cycles of existing methods， molecular spectroscopy multivariate calibration technology was employed to develop the analytical method for such propellants. Near-infrared （NIR） spectra of prepared HAN-based propellant samples were acquired. Using partial least squares （PLS）， the optimal spectral pretreatment methods， spectral regions， and number of principal components （NPC） were selected， and outliers were eliminated. Separate NIR quantitative analysis models were established for the four main components in the propellant： hydroxylammonium nitrate， nitrate A， additive B and additive C. All established models exhibit excellent performance. The correlation coefficients of the calibration set （RC） are all above 0.997， and those of the validation set （RP） are all above 0.990. The standard error of calibration （SEC） is below 0.06 for all models， and the standard error of prediction （SEP） is below 0.09. Additionally， the ratio of SEP to SEC is less than 2 for each model. The results show that the NIR method has good consistency with manual titration and gas chromatography （GC）. The test deviations of the four components are all less than 0.10%. The NIR method also demonstrates high precision. The standard deviations （SD） of repeated tests for hydroxylammonium nitrate and nitrate A are less than 0.10%. For additive B and additive C， the SD of repeated tests are less than 0.03%. The established quantitative analysis models and method enable simple， rapid and one-step determination of component contents in HAN-based propellants.

Abstract:The inherent conflict between high energy density and low mechanical sensitivity represents a central challenge in the field of energetic materials. Although traditional nitramine compounds such as RDX， HMX， and CL-20 have significantly enhanced energy levels， they remain constrained by this trade-off. To explore new pathways for overcoming conventional performance limitations， researchers have proposed a strategy centered on rigid， planar fused-ring frameworks， leading to the development of nitrogen-rich fused-ring compounds. This review systematically outlines the evolution of this field， from the design of monocyclic systems （e.g.， azoles， azines， and 1，2，5-oxadiazoles） to the integrated design of binary fused-ring systems. It highlights the conceptual design of representative molecules， key advances in synthetic methodologies—ranging from oxidative nitration to controlled rearrangement reactions—and the regulatory mechanisms of intermolecular interactions such as hydrogen-bonding networks and π-π stacking on material performance. This progression illustrates a paradigm shift from empirical trial-and-error to rational design and function-oriented customization. Finally， addressing the synthetic bottlenecks that constrain practical application， this review proposes that future breakthroughs require synergistic efforts across three dimensions： design， preparation， and application. This includes developing design methods that balance performance with synthetic feasibility， promoting synthetic technologies with improved safety profiles， and expanding the application scope of fused-ring energetic materials， thereby facilitating the transition from molecular design to practical implementation and providing a foundation for next-generation high-performance energetic materials.