Studies On The Preparation Of High Energy Low Sensitivity Primary Explosives Based On Metal-Organic Frameworks

With the development of weapon systems and aerospace systems in the direction of miniaturization and intelligence,higher output power and higher security are demanded in explosive system.In particular,the application of Micro-Electro-Mechanical System(MEMS)in the technology of explosive system,the traditional primary explosives cannot meet the requirements of the output power and the charging way of explosives.Therefore,it is necessary to carry out research on high-energy primary explosives which is compatible with MEMS devices.We design and prepare a series of high-performance primary explosives based on metal-organic frameworks(MOFs).A MOFs templated copper azide(MOFT-CA)was prepared for the first time.MOFT-CA has excellent electrostatic safety and good detonation ability.We also study on the processing method of MOF-based primary explosives,and obtain a copper azide-carbon fiber film(CA-film@PF)which can meet the different charging forms.This research content consists of the following four parts.(1)Starting from commericially available dialkyl dicarboxylate as raw material,N,N'-azodihydrazide(BHCH)and 3-amino-1,2,4-triazole-3,5-diketone(ADTO)were prepared.Six energetic materials were obtained based on these two compounds.Their sensitivity,thermodynamic and explosive properties were studied.3D MOF Cd-ATDO has shown good thermal stability and excellent explosive performance.The decomposition temperature of Cd-ATDO is 445.87°C,and the calculated detonation velocity and detonation pressure are10070 m?s^-1 and 49.4 GPa,respectively.(2)Cu-based MOFs were prepared by using highly symmetric organic ligands.Two new structures,Cu-BDC-BP and Cu-BTC-BP were obtained,though these two non porous MOFs are not suitable for preparation of copper azide.Cu-BTC with high surface areas was obtained and was used as a precursor to synthesis Cu-C composites.We have studied on pyrolysis condition and confirmed that the optimum condition of preparing porous Cu-C composite is400°C under nitrogen atmosphere.The characterization of phase structure,morphology and thermal properties of MOFT-CA reveals the homogeneous element distribution of MOFT-CA.The decomposition temperature is above 200°C.(3)The impact sensitivity,friction sensitivity,flame sensitivity,electrostatic sensitivity and explosive performance of MOFT-CA were tested.The results show that MOFT-CA is very sensitive to the friction and impact.MOFT-CA is simultaneously achieving low electrostatic sensitivity,good flame sensitivity and excellent initiation ability.Importantly,10 mg of MOFT-CA can detonate RDX to bore through the lead plate acting as powerful as30 mg LS/LA composite in the identical initiation tests.The ignition energy and detonation ability of MOFT-CA were tested in the explosive chips,in which the low ignition energy of MOFT-CA was observed,and the CL-20 can be detonated.(4)Perfluorinated materials modified with copper azide-carbon film(CA-film@PF)was obtained in five steps.The impact sensitivity,friction sensitivity,flame sensitivity,electrostatic sensitivity and explosive performance of CA-film@PF were carefully examined.The results show that CA-film@PF are very sensitive to the friction and impact.CA-film@PF has excellent electrostatic sensitivity,extremely low electrostatic accumulation,acceptable flame sensitivity and superhydrophobicity properties.Only 10 mg of CA-film@PF can detonate RDX to bore through the lead plate.The CL-20 could be detonated by CA-film@PF in explosive chips.The composite detonating film with high safety and good detonating performance is expected to be used in micro weapon systems and MEMS systems.