Abstract:Several d-metal perchlorate complexes with 3-hydrazino-4-amino-5-R-1,2,4-triazoles as ligands (where R=H, CH₃, SH) were investigated. It was shown that SH-group inhibited radical processes of thermal decomposition and burning of the complexes and also increased the thresholds of their Q-switch IR-laser initiation compared with the salts where as R=H, CH₃-groups decreased the sensitivity of the metal complexes to laser initiation.

Abstract:The chemical structure parameters of trimethylolethane trinitrate (TMETN) were confirmed by analyzing the thermal decomposition characteristics of TMETN. The burning rates and pressure exponents of insensitive and low signature propellants containing TMETN were simulated. The relationship between TMETN content and combustion characteristics of insensitive and low signature propellant containing TMETN was given. And the effect of certain type of organic potassium salt used as flame suppressor (KD) on the burning rate was also discussed. The numerical simulation result shows that calculation results are basically in agreement with test results. The burning rate of insensitive and low signature propellant containing TMETN decreases and pressure exponent of this type of propellant decreases with TMETN content increasing. KD can improve the burning rate of this type of propellant and can help “Pb-Cu-CB” composite combustion catalyst to enhance plateau effect of this type of propellant.

Abstract:A new synthetic methodology has been developed for the synthesis of poly BAMO and poly BAMO-co-THF with controlled molecular weight and narrow molecular weight distribution. The synthesis of BCMO, the precursor of the BAMO monomer was accomplished using the reaction of Vilsmeir reagent with pentaerythritol. The BAMO monomer could be synthesized with an over all yield of 60% and polymerized using BF₃·Et₂O as the initiator and 1,4-butane diol as the co-initiator. Computational evaluation of the energy releasing properties of the poly BAMO derivatives was performed using Gaussian algorithm. The theoretically calculated values agreed very well with the experimentally determined ones.

Abstract:The energy characteristics of monopropellants and propellants with insensitive and minimum signature properties containing seven kinds of insensitivity materials, such as N,N′-dinitropiperazine (DNPZ), N-guanylureadinitramide (FOX-12), 1,1-diamino-2,2-dinitroethylene (FOX-7), insensitivity RDX (I-RDX), 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), nitroguanidine (NQ) and 1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin (TTNZ), are calculated by propellant energy calculation program. The calculation results show that the integrated energy characteristics of monopropellant, composite modified double base propellant and glycidyl azide polymer (GAP) base propellant containing I-RDX, FOX-7 and TTNZ respectively are excellent among seven materials above. The energetic properties of composite modified double base propellant containing I-RDX, FOX-7 and TTNZ, such as specific impulse, characteristic velocity, combustion temperature and heat of explosion at constant volume, increase with the mass fraction of the energetic additives increasing, while the oxygen coefficient and the relative molecular mass of products decrease with the mass fraction of three energetic additives increasing.

Abstract:By combining the ab initio molecular dynamics (AIMD) method and density functional theory (DFT), the thermal decomposition mechanism of s-tetrazine was studied. The dissociation channel was first simulated in a number of trajectories using the VASP package based on ab initio MD method, then further examined by Gaussian 98 at the B3LYP/6-311G(d,p) level to locate the minimum points and the transition structure. The high accuracy single point calculations were performed by B3LYP/6-311+G(2df,2p), G3MP2B3, G3B3, CCSD(T)/6-311G(d,p), CCSD(T)/ 6-311+G(2df,2p) and the rate constants were calculated by the microcanonical variational transition state theory (μVT). The studies suggest that s-tetrazine undergo concerted triple dissociation to form one N₂ and two HCN.

Abstract:B3LYP/6-31G(d, p), MP4(SDTQ)/6-31G(d, p) and G3MP2B3 methods were used to calculate the energy of the decomposition species of FOX-7. Based on the energy obtained by G3MP2B3 method, the rate constants of C—NO₂ cleavage and nitro-to-nitrite rearrangement were calculated in the temperature range of 250-3300 K. It is found that C—NO₂ cleavage is the dominant initial thermal decomposition step at high temperature which is consistent with the conclusion based on ab initio molecular dynamics simulation. The effects of NO₂ on the FOX-7 decomposition were investigated. Results show that the decomposition energy barrier becomes lower when NO₂ reacts with FOX-7.

Abstract:22 Tetrazine substituted by six-membered C—N heterocyclic derivatives have been investigated by density functional theory. Their optimized geometry structures, electronic structures, conjugation, molecular energies, heats of formation (HOF) and density (ρ) were calculated at the B3LYP/6-311G(d,p) level. The results show that most of the species keep a planar structure and exit considerable conjugation over the whole molecule, which enhances the stability of these derivatives. There is a good linear relationship between the molecular energies, density and N atoms in these species. The studies show most of the species have high HOFs and relative stabilities. The HOFs of these compounds are between 631.1 kJ·mol^-1 and 1465.6 kJ·mol^-1.

Abstract:7-Amino-6-nitrobenzodifuroxan (ANBDF) was synthesized from 3,5-dichloroaniline and chloroacetyl chloride through acetylation, nitration, azidation-denitrogenation and hydrolysis at mild conditions with high yields. The yields of acetylation, nitration, azidation-denitrogenation and hydrolysis were 97.7%, 70.0%, 82.5%, and 80.0% respectively. The denitrogenation was completed at 80 ℃ while others were finished from 0 ℃ to room temperature. The optimal reaction conditions of temperature, time, and ratio of substrate and other reactants were also studied. The structures of ANBDF and its precursors were characterized by means of ¹H NMR, FTIR, MS and elemental analysis. ANBDF is a stable and insensitive explosive with the melting point 204-205 ℃.

Abstract:5-Amino 3-nitro-1,2,4-triazole (ANTA) as well as its intermediate was synthesized from 3,5- diamino-1,2,4-triazole after diazotization, neutralization and reduction. Its structure was characterized by IR, MS, ¹H NMR and elemental analysis. In addition, the effects of reaction temperature on yield and purity were investigated. The synthetic procedures of ANTA were optimized with the overall yield to be 64%, and purity to be 98%.

Abstract:The single crystal of 3-amino-4-acylaminoximinofurazan (AAOF) was cultured using the mixed solvent of water and ethanol. The structure was characterized by 4-circle single-crystal X-ray diffraction analysis, IR and elemental analysis. The results indicate that the crystal belongs to monoclinic, space group P21/C with the crystallographcial parameters of a=0.7651(3) nm, b=1.1702(3) nm, c=1.9216(10) nm, M_r= 143.12, β=96.47 (4)°, V=1.7095(12) nm³, Z=4, D_c=1.668 g·cm^-3, F(000)=888. The AAOF molecule is good planar. There are inter- and intramolecular hydrogen bonds in the crystal.

Abstract:The compound of 3,6-bis(3′-aminofurazan-4-yl)-1,4-dioxa-2,5-diazacyclohexa-2,5-diyne (BADDD) was obtained and characterized. It is triclinic, P-1, and with parameters of a=0.48616 (10) nm, b=0.5237 (2) nm, c=0.97076 (19) nm, α=102.25(3)°, β=93.631(17)°, γ=101.88 (2)°, V=0.23489 (12) nm³, Z=1, D_c=1.783 g·cm^-3, λ (MoKα)=0.071073 nm, μ(MoKα)=0.153 mm^-1, F(000)=128, T=294 (2) k, R₁=0.0351 and wR₂=0.0875. The molecule consists of two aminofurazano rings and a 6-membered heterocycle formed by two O atoms, two N atoms and two C atoms, respectively. The molecule is centrally symmetrical.

Abstract:A new method for prediction of Gurney velocity of explosives is introduced in which energy output is correlated with the heat of detonation, the number of moles of gaseous products of detonation per gram of explosive and the average molecular weight of gaseous products. It is assumed that the CHNO explosive reacts to form products composed of N₂, CO, H₂O, CO₂, H₂, O₂ and C(s) as determined by the oxygen balance of the unreacted compound. Good agreement is obtained between measured and calculated values of Gurney velocity as compared to previous correlations which assumed the reaction products to consist of N₂, H₂O, CO₂ and either C(s) or O₂.

Abstract:PBX-2 explosive accelerated aging 180 days and 540 days at 55 ℃ were tested in Steven test by using a steel projectile of 2.0 kg. The pressure change was measured by pressure gauges, and ignition delay time was analyzed with high-speed motion pictures and pressure curves. The reaction overpressure was gained by blast pressure gauges. The test results of aged PBX-2 explosive were compared with pristine PBX-2. The results show that there is not obvious change for the reaction degree and pressure course of pristine and accelerated aged PBX-2 explosive in Steven test.

Abstract:High-nitrogen energetic compounds (HNECs) including tetrazines, high-nitrogen furazas and trizoles (or tetrazoles) have characteristics as higher positive heat of formation, better oxygen balance, higher density, and lower sensitivity. The usual synthesis methods of HNECs, and the synthesis route for typical HNECs，including BT, DAAzF and BHT are reviewed. And then some ideas to synthesize new HNECs from non-symmetrical molecular design direction are suggested, i.e. interlinkage between the tetrazine and the farazan, the tetrazine, the pyrazole.

Abstract:3,4-bisnitrofurazanfuroxan (DNTF) is a novel high energy density compound. This paper reviews its physicochemical and thermolysis properties. The physicochemical properties show that synthetical properties of DNTF are superior to that of HMX; The thermolysis properties of DNTF indicate that DNTF good thermal stability, the some common lead salts and cuprum salts can catalyze the thermolysis of DNTF. And some applications of DNTF in the explosive composition, CMDB and related item are also reviewed, and the feasibility of DNTF application in CMDB propellant is analyzed emphatically from the aspect of energy, stability and safety.Some problems of DNTF-CMDB propellant are pointed out.

Abstract:A high energetic explosive compound, 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazaisowurtzitane(TEX) synthesized by different routes is reviewed. The properties of TEX, such as explosive performance, thermal decomposition, friction sensitivity and impact sensitivity are summarized. It can be concluded that energy lever of TEX is higher than RDX, even exceeds TATB. Moreover, TEX is high solids pressable, extrudable explosive or simple castale explosive. It is expected that TEX has good potential applications in high performance, low sensitivity explosives.

Abstract:Fine AP particles are required to manufacture the AP-based composite propellants with a wide burning rate range for various applications, especially high burning rate propellants. However, it is difficult to prepare a fine AP safely. Some safe methods for preparing the fine AP particles are reported such as the spray-dry method and freeze-dry method. It is shown that the crystal habit modified AP particle is an effective oxidizer to enhance the burning rate.

Abstract:This review concentrates on development of the synthesis and performance research on new nitrogen heterocycles energetic compounds, such as furazan, trizole, trizine, tetrazole, tetrazine, polycyclic cage and all-nitrogen compounds etc. The disadvantages of these materials are described and the possible solutions for these problems are also provided.

Abstract:The characterizing methods of molecular structure and crystal phase of adamantane including XRD,FT-IR,MS,NMR,EMS,DMS,RAMAN,DSC, etc were introduced in order to foretell adamantane chemistry and its application prospect in energetic materials. The phase transition behavior of adamantane at different temperature or pressure conditions was discussed as well. Finally,the thermodynamic properties and solubility of adamantane in various of organic solvents were reviewed respectively. The latest research progress of polynitroadamantanes and polynitroazaadamantanes in HEDM molecular design were also illustrated.

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