The pyrotechnics technology is the key device and device for the initial energy of the propellant system. The primary explosive is directly charged as an initial charge or mixed with an oxidant, a reducing agent, etc., and then charged in an explosive product, to directly control the sensitivity, power, and various effects of the pyrotechnic or pyrotechnic system. United States, Russia, Germany, United Kingdom, and other countries have never stopped the development and research of new explosives, and they have been continuously exploring and searching for new explosives with better performance, safety, and stability.
Professor Li Yang at SKLEST cooperated with Prof. Bo Wang, and for the first time innovatively achieved the use of copper-containing organic frameworks (MOFs) as precursors, which were prepared by high temperature carbonization and gas-solid azide reaction to produce a type of electrostatic blunt Sensitive Carbon-Azide Copper Composite. The proposed method effectively uses the structural features of the MOFs. The arrangement of organic ligands and metal ions or clusters has obvious directionality and can form different framework pore structures. The copper-ion-containing MOFs were selected as the substrate, and the atoms in the ligand structure were converted into carbon atoms by carbonization. The structure still maintained the ordering of atoms and the existence of porous properties in the original structure. The great advantage of this porous property is that it makes the compound more complete in the azidation reaction, avoiding part of the non-occurrence of azidation reaction that retains the copper atom itself and affects the detonation of the copper azide, and also avoids the azide produced during the azidation process, which increases the unsafe factors of the primer. The atomic ordering in the original structure effectively segregates the copper azide molecules and reduces their sensitivity to weak external stimuli.
Figure 1 Synthesis of Carbon-Azide Copper Composites
The carbon-nitride copper composite material has insensitive electrostatic spark sensitivity, and 50% electrostatic ignition energy is 1.6 mJ, which is significantly higher than conventional high energy such as copper azide (0.2 mJ) and lead stephenic acid (0.5 mJ). Priming drugs have obvious advantages such as simple synthesis, safety and stability. At the same time, the carbon-azide nitride composite material 10 mg obtained through this method can independently complete the ignition of HRX, with a smaller limit dose, and has a great potential application in the fields of aerospace, , and civil blasting equipment.
2 Sensitivity of Carbon-Azide-Copper Nitride Composites
At present, the results are published online in the international top journal "Advanced Materials" (impact factor 17.43) with the title of "Metal-Organic Framework Templated Synthesis of Copper Azide as the Primary Explosive with Low Electrostatic Sensitivity and Excellent Initiation Ability". The reviewer gave high evaluation: “The use of a new type of porous matrix material to obtain high-energy sensible initiating explosives through simple methods effectively improves the sensitive and unsafe characteristics of high-energy primary explosives. This idea has been proposed to break the use of complex organic synthesis. The traditional method of preparing energetic materials is a new design method and a major breakthrough in the basic research of energetic materials in recent years. This paper was recommended as a VIP article for the first time.”
This work was mainly completed by Ganyou Wang, a doctoral student directed by Professor Li Yang, and was funded by the independent project fund of the State Key Laboratory of Explosive Science and Technology.
Paper link: http://onlinelibrary.wiley.com/doi/10.1002/adma.201601371/full
