含能材料CL-20的热安全性测试分析

CL-20是一种高能量、高性能的炸药。为了研究CL-20的热分解性能,分别采用DSC-TG、DSC-TG-QMS联用系统和高压型差示扫描量热仪(DSC 204 HP)对CL-20的热安全性进行了测试分析,并计算了CL-20的热力学参数和动力学参数。结果表明,CL-20固体炸药在不同升温速率下的TG曲线基本相似,都只有一个台阶。在升温速率为10 K/min时,CL-20在放热峰温处的活化焓、活化熵和活化自由能分别是177.26 k J/mol、52.61 J/(K·mol)和149.7 kJ/mol。CL-20热分解后的气体产物主要有NO、CO、CO_2和H_2O,离子流强度约为10-9A,其中H_2O的离子流强度最大。不同压力时CL-20热分解的过程不同,在压力高的情况下CL-20分解放热更多,反应过程越剧烈,热安全性越差。与常压下相比DSC放热峰值温度降低。

Test and analysis for the thermal safety of the energetic material known as CL-20

This article intends to make a detailed study of the thermal decomposition performance of the high-performance explosive known as CL-20.For the given purpose,we have first of all made an analysis and test of the thermal safety of CL-20 by using the DSC-TG thermal analyzer,the simultaneous DSC-TG -QMS system and DSC 204 HP testing system.At the same time,we have also calculated the thermodynamic parameters and kinetic parameters of CL-20.The conclusion that we have made can be stated as follows:The TG curves of the solid CL-20 are basically similar at the various heating levels,though there is only one step in the TG curves,which turns out to be the steepest at the heating rate of 10 K/min.This implies that the mass loss of CL-20 tends to reach its maximum limit,in which the DSC peak temperatures of CL-20 at various heating rates (5 K/min,10 K/min,15 K/min and 20 K/min) should be 243.2 ℃,250.7 ℃,255.7 ℃ and 259.8 ℃.DSC characteristic values of CL-20 at the various heating rates and tend to increase gradually with the increase of the heating rates.Furthermore,in accordance with the DSC peak temperatures at various heating rates,the activation energy (E),the pre-exponential factor (A) and the rate constant (k) for CL-20 should account for 181.62 kJ/mol,1.661 6 × 1016 s-1 and 1.228 7 × 10-8 s-1,respectively.Specifically speaking,when the heating rate is 10 K/min,the enthalpy of the activation,the entropy of activation and the free energy of activation for the CL-20 decomposition reaction at the peak temperatures should be 177.26 kJ/mol,52.61 J/(K · mol) and 149.7 kJ/mol,correspondingly,with the main gaseous products from the thermal decomposition of CL-20 being NO,CO,CO2 and H2O.The ion current intensities should be set up at about 10-9 A,with the ion current intensity of H2O being the greatest,though the decomposition processes for CL-20 under different pressures may not be the same.As compared to the normal pressure,the heat release amount of CL-20 proves larger at high pressures whereas the decomposition reaction may take place more violently and the thermal safety may also turn to be the worse.And,simultaneously,the DSC peak temperatures of CL-20 may also reveal a slight declining tendency.