Combination of Nitrogen-Rich Skeleton and Coordination Group:Synthesis of a High-Energy Primary Explosive Based on 1H-Tetrazole-5-Carbohydrazide

The high energy coordination compounds Cu(TZCA)_(2)(ClO_(4))_(2)(ECCs-1) was prepared by 1H-tetrazole-5-carbohydrazide(TZCA) with a high energy skeleton and a strong coordination ability group.At the same time,the reaction activity of the ligand was explored,and the single crystal structure of it and intermediate were obtained.The structures of all substances were characterized by IR and EA.And the structure and composition of ECCs-1 are confirmed by ESP,AC,SEM and ICP-OES.Physical and chemical properties tests show that ECCs-1 has an acceptable thermal stability(T_(d)=177℃) and extremely sensitive mechanical stimulation(IS=1 J,FS=5 N).The comprehensive performance test results show that ECCs-1 has excellent initiation ability.In addition,the decomposition mechanism of ECCs-1 is explored from two aspects of experiment and theoretical calculation.

Deflagration to detonation transition in weakly confined conditions for a type of potentially novel green primary explosive:Al/Fe_(2)O_(3)/RDX hybrid nanocomposites

The properties of the combustion and deflagration to detonation transition(DDT)of Al/Fe_(2)O_(3)/RDX hybrid nanocomposites,a type of potentially novel lead-free primary explosives,were tested in weakly confined conditions,and the interaction of Al/Fe_(2)O_(3)nanothermite and RDX in the DDT process was studied in detail.Results show that the amount of the Al/Fe_(2)O_(3)nanothermite has a great effect on the DDT properties of Al/Fe_(2)O_(3)/RDX nanocomposites.The addition of Al/Fe_(2)O_(3)nanothermite to RDX apparently improves the firing properties of RDX.A small amount of Al/Fe_(2)O_(3)nanothermite greatly increases the initial combustion velocity of Al/Fe_(2)O_(3)/RDX nanocomposites,accelerating their DDT process.When the contents of Al/Fe_(2)O_(3)nanothermite are less than 20 wt%,the DDT mechanisms of Al/Fe_(2)O_(3)/RDX nanocomposites follow the distinct abrupt mode,and are consistent with that of RDX,though their DDT processes are different.The RDX added into the Al/Fe_(2)O_(3)nanothermite increases the latter's peak combustion velocity and makes it generate the DDT when the RDX content is at least 10 wt%.RDX plays a key role in the shock compressive combustion,the formation and the properties of the DDT in the flame propagation of nanocomposites.Compared with RDX,the fast DDT of Al/Fe_(2)O_(3)/RDX nanocomposites could be obtained by adjusting the chemical constituents of nanocomposites.

Recent advances in the synthesis and energetic properties of potassium-based potential green primary explosives

Primary explosives are utilized as a reliable initiator for secondary explosives in an extensive range of military and civilian operations. Heavy-metal-based primary explosives are moderate performing, more sensitive, and environmentally hazardous, posing a direct and indirect threat to health and safety.Therefore, heavy-metal-based primaries have been replaced by environment-friendly metal-based primary explosives, such as potassium complexes. This review presents not only a summary of the current progress of new-generation potassium-based primary explosives and their methods of preparation, energetic properties, and applications, but also a further comparison with traditional primary explosives. In addition, this work discusses the necessity of heavy metal-free primary explosives and the major challenges faced in replacing traditional primary explosives.

Synthesis and properties of potassium 5,5'-azobis(1-nitraminotetrazolate)：A green primary explosive with superior initiation power

Potassium 5,5＇-azobis（1-nitraminotetrazolate）,（K2ABNAT）, a new green primary explosive, was synthesized via a safe and convenient synthetic procedure based on methylcarbazate and cyanogen azide. The compound was characterized by single-crystal X-ray diffraction, IR spectroscopy, Raman spectroscopy, multinuclear NMR spectroscopy, elemental analysis, and differential scanning calorimetry（DSC）. With the calculated（CBS-4M） heat of formation（617.0 kJ/mol） and the room temperature X-ray density（2.11 g/cm^3）, impressive values for the detonation parameters such as detonation velocity（8367 m/s） and pressure（31.5 GPa） were computed using the EXPLO5 program. The superior calculated energetic performance show it could serve as a green replacement for the widely used primary explosive,lead（II） azide, which contains toxic ingredient.

Metal-organic framework templated synthesis of copper azide as the primary explosive with low electrostatic sensitivity and excellent initiation ability

Subject Code:F05With the support by the State Key Laboratory of Explosion Science and Technology,the research team led by Prof.Yang Li(杨利)and Prof.Wang Bo(王博)of Beijing Institute of Technology,applied MOFderived porous carbon materials with well-distributed metal source in the in-situ synthesis of primary explosive(MOFT-CA),which was published in Advanced Materials(2016,28:5837—5843).

Synthesis of energetic coordination polymers based on 4-nitropyrazole by solid-melt crystallization in non-ionization condition

Based on the theory of crystallization,a solvent-free solid-liquid phase crystallization method called solid-melt crystallization was designed to prepare energetic coordination polymers.Two target compounds[Cu(NPyz)_(4)NO_(3)]·NO_(3)(ECPs-1)and Cu(NPyz)_(4)(ClO_(4))_(2)(ECCs-2)were prepared through programmed heating and cooling by using 4-nitropyrazole(NPyz),(Cu(NO_(3))_(2)·5H_(2)O and Cu(ClO_(4))_(2)·5H_(2)O) as raw materials.In addition,crystallization pre-experiments and annealing experiments also verified the feasibility of the method.Their structures were confirmed by IR,elemental analysis,single-crystal X-ray diffraction and powder X-ray diffraction.The physicochemical properties and sensitivity test results showed that ECCs-2 has better thermal stability(T_(d)=221℃),while ECPs-1 is less sensitive to mechanical stimuli(IS=12 J,FS=240 N).Calculations based on EXPLO5 and the Kamlet-Jacobs equation showed that ECCs-2 has more considerable detonation performance(P=25.2 GPa,D=7.5 km/s).In comparison,the more intuitive results from the HN test,flame test,thermal resistance test and lead plate explosion test revealed that ECCs-2 has an“acceptable”detonation performance.The laser detonation test also showed that ECCs-2 is a promising excellent laser detonation material(E=408 mJ,P=24 W,τ=17 ms).

Research Progress of Nano Copper Azide

The development trend of miniaturization, chipization, integration, and intelligence of new energetic devices has put forward higher requirements for primary explosives, and the toxicity of lead-containing initiating explosives has also caused increasing concerns. Nano copper azide, due to its green and high-energy characteristics, has attracted increasing interest from researchers in recent years. The research progress of Nano copper azide energetic materials is summarized from the design and preparation of composite energetic materials, and the analysis of sensitivity changes. On this basis, the key points to realize its application prospects are discussed: Develop the preparation method of carbon material modification and the combination of processing and forming to prepare new composite materials to make up for their overly sensitive defects, while giving full play to their advantages of high energy density. By comparing the existing research progress of Nano copper azide, we can understand its performance parameters more systematically, and guide the further application of Nano copper azide. .