Non-isothermal Studies on the Thermal Decomposition of C4 Explosive Using the TG/DTA Technique

Abstract

The thermal behaviour of energetic materials is very important for their safe production, storage, handling and even demilitarization. In this work, the thermal behaviour and decomposition kinetics of conventional C4 plastic explosive has been studied experimentally by a non-isothermal thermogravimetric (TG)/differential thermal analysis (DTA) technique at different heating rates (2, 4, 6 and 8 °C·min-1). The kinetic triplet of activation energy, frequency factor and model of thermal decomposition of this compound has been evaluated via model-fitting and model-free methods. The results show a single thermal decomposition process for C4, with the model of integral function (g(α)) of [(1−α)-1/3 −1]2 and differential function (f(α)) of [(1−α)2/3(3α−3)/2(1−α)1/3−2], indicating a 3-dimensional diffusion mechanism. In addition, Ea values of 207.1 ± 17.3, and 241 kJ·mol-1, by using the isoconversional model-free modified Kissinger-Akahira-Sunose (KAS) and the Kissinger method, respectively, were obtained for the conversion interval of 0.3-0.7. The C4 matrix shows a significant effect on the activation energy distribution of pure RDX