Dynamic vacuum stability test (DVST) method (IV): Thermal decomposition of HMX

The thermal decomposition process of HMX was studied by dynamic vacuum stability test (DVST) method. The activation energy and pre-exponential constant of thermal decomposition reaction of HMX were obtained by universal integral method and differential method. The results show that the mechanism functions of thermal decomposition reaction of HMX at different isothermal temperatures are different. The thermal decomposition process of HMX obeys Ginstling-Brounshtein equation with 3D mechanism in the temperature range of 100-110°C, parabola rule with 1D mechanism in the temperature range of 120-140°C and Valensi equation with 2D mechanism at 150°C. Reaction rate constant (k) of the thermal decompositionreaction of HMX increases with temperature, but it does not accord with the Van't Hoff rule. The amount of decomposition gases of HMX below 150°C obtained by DVST are less than 2.0 mL·g ^-1, showing that HMX has a good thermal stability. The Semenov equation obtained by the time(t) required to decompose 0.1% HMX at different temperature(T) is lnt _T=12157.95/T-19.0052. The effective storage life needed to consume 0.1% HMX at 25°C deduced by this equation is 90.6 a.