摘要
Differential scanning calorimetry(DSC)was used to investigate the thermal decomposition and thermal safety characteristics of Shuangfang-3(SF-3)gun propellant.The kinetic calculation of the DSC curve was carried out by Kissinger and Friedman models,and the time to the maximum rate under adiabatic conditions and the self-accelerating decomposition temperature were calculated by using the AKTS thermal analysis software in combination with the heat balance equation.The thermal history experiment was carried out to further analyze the autocatalytic properties of SF-3.The results show that the initial decomposition temperature,decomposition peak temperature,and decomposition completion temperature of SF-3 all move to the high temperature direction with the increase of heating rate,and the average decomposition heat is 1521.4 J/g.The kinetic model showcased that SF-3 has different reactions in different reaction stages,and its apparent activation energy is 168.2 kJ/mol.When the times to maximum rate under adiabatic conditions are 2.0 h,4.0 h,8.0 h,24.0 h,respectively,the corresponding temperatures are 130.7℃,124.8℃,119.2℃and 110.5℃,respectively.When the masses are 5.0 kg,15.0 kg,25.0 kg,50.0 kg,100.0 kg,respectively,the corresponding self-accelerating decomposition temperatures are 110.0℃,105.0℃,102.0℃,99.0℃and 96.0℃,respectively.As the packaging mass increases,it is more difficult to exchange the liberated heat into the surrounding environment and its safety would be further reduced.The thermal history experiment demonstrates that the thermal decomposition of SF-3 is an n-stage reaction and does not have autocatalytic properties.Therefore,the size and ventilation conditions of the sample have a certain impact on the storage stability of SF-3.In the actual production,usage,storage and transportation,sample size and ventilation conditions should be controlled,and practical and effective measures should be taken according to the actual situation.
基金
Key Research and Development Project of Shanxi Province(No.201903D121028)。
