| Thermal analysis is a necessary means to assess the stability and compatibility of energetic materials. An initial synthesis of the new graphene modified lead styphnate-- primary explosive, provides a new path of development for the traditional primary explosives. But its thermal decomposition process had not yet been analyzed, whether other nano-carbon material can be used for modification of energetic materials also have not been studied. Therefore, we needed the research on preparation of lead styphnate modified with nano-carbon materials and use a scientifically reliable thermal analysis technology to achieve the study of the thermal decomposition process of the series of energetic materials. In this paper, the thermal decomposition rules and thermal properties of the new lead styphnate modified with nano-carbon material were studied through Dynamic Pressure-measuring Thermal Analysis(DPTA), thermal gravimetric analysis(TG) and differential scanning calorimetry analysis(DSC). The main research works and innovation achievements are as follows:1) Based on built-in miniature pressure and temperature sensor, the original DPTA test system was miniaturized. It achieves a "dynamic" monitoring for release air pressure and temperature of system vacuum thermal decomposition, removed redundant portions of the original system, and configure real-time monitoring software and data processing software to obtain decomposition process data, reaction thermodynamics and reaction mechanism.2) According to the preliminary synthetic methods of lead styphnate modified with graphene nanosheets, a variety of lead styphnate modified with the nano-carbon materials are developed with a wide range application prospects for the first time. Scanning electron microscopy, X-ray powder diffraction and Raman spectroscopy among showed that fullerenes, carbon nanotubes, graphene could form stable complexes with lead styphnate crystals, respectively. It has an important academic and application values for improving the antistatic, heat resistance lead styphnate.3) There kinds of lead styphnates modified with fullerenes, carbon nanotubes, graphene were thermal analyzed by DPTA, TG and DSC. Primary thermal decomposition law and the net gas volume from thermal decomposition of three modified primary explosive have been obtained, and the kinetic parameters and mechanism function were also calculated.4) The research on the whole thermal decomposition process laws and thermal properties of lead styphnate modified with nano-carbon materials are completed by TG and DSC methods. TG and DSC method tests determined the whole process of thermal decomposition of the samples to obtain the critical temperature of thermal explosion, activation enthalpy, the activation entropy and Gibbs free energy of activation, and calculated the total activation energy and pre-exponential factor.5) The effects of nano-carbon materials for thermal performances of lead styphnates were explored. For lead styphnates, there are the presence of catalytic effect of three types of nano-carbon material. The fullerenes can change the crystal morphology and thermal decomposition process; as modified materials, graphenes can either catalyzed the decomposition reactions or significantly increased thermal stabilities of lead styphnates; due to the excellent thermal conductivity and electrical conductivity of carbon nanotubes, it can control the output modes of energy.6) By the experiments, the best ratio of addition amount of fullerene C60, carbon nanotubes and graphenes should be 3%, 2%, 1%, respectively. C60 maintained the thermal stability of LS; when the content of CNTs is larger, it can improve the thermal stability of LS; graphene reduced the possibility of thermal decomposition reaction of LS, and improved the thermal stability of LS. LS is most compatible with carbon nanotubes, followed by fullerene C60, the last is graphene, but they all are compatible with LS. |
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