An isothermal decomposition dynamics research instrument and its application in HMX/TNT/Al composite explosive

An isothermal decomposition dynamics research instrument that uses a pressure sensor with the ability to withstand high temperatures for investigating sublimated samples was established. The isothermal decomposition of HMX/TNT/Al (HTA) composite explosive was investigated by this instrument, and the corresponding thermal decomposition kinetic parameters were obtained with the method of isothermal decomposition dynamics research. Arrhenius equation and model-fitting method were used to calculate the thermal decomposition kinetic parameters based on the experimental data obtained by the improved instrument. Results of the Arrhenius equation and model-fitting method were consistent with an average E-a of 146.56 kJ mol(-1) and lnA of 13.29 s(-1). The model-fitting method further proved that the mechanism of thermal decomposition of HTA composite explosive was controlled by 3D diffusion. The instrument was also used to predict the storage life of HTA. Results showed that the effective storage life of HTA at ambient temperature (25 degrees C) is 229 years, whereas the extent of reaction reached 0.5%.