Iranian Scientific Association of Energetic Materials

In this research, the thermal stability and decomposition kinetics of pentaerythritol tetranitrate (PETN) and Pentastite explosives have been studied experimentally using non-isothermal differential thermal analysis (DTA) and thermo-gravimetric (TG) methods at heating rates of 4.0, 6.0, 8.0 and 10.0 °C/min. The kinetic parameter of activation energy (E_a) and critical ignition temperature for thermal decomposition of these explosives have been evaluated by the model-free methods proposed by the International Confederation for Thermal Analysis and Calorimetry (ICTAC). The Vyazovkin isoconversional method was used  without need for the Arrhenius factor and reaction mechanism.  The  mechanisms of the reactions and mass loss route of the samples in different temperatures were predicted and compared with the results of advanced kinetics and technology solutions (AKTS) software. The mean kinetic parameter of activation energy of exothermic decomposition of the PETN and Pentastite explosives as calculated by the Kissinger, Ozawa, Ozawa-Flynn-Wall and KAS methods were 129.1 kJ/mol and 161.9 kJ/mol, respectively. These results were used to estimate  the mass loss and predict the lifetime of the explosives. , and also they were statistically compared to experimental accelerated aging and AKTS results and  showed satisfactory outcomes at > 100.0 °C.