Investigation of Thermal Decomposition Kinetics of Some RDX Based Material

The aim of the current study is to compare thermal decomposition kinetics of three 1, 3, 5-trinitro-1, 3, 5-triazinane (RDX) based explosives, containing A4, H6, and PBXW-108 using TGA/DSC experimental techniques and analytical methods. The experimental part of the study performed non-isothermally at 1, 2, 5, 10, 15, and 20‌ °C min-1 heating rates. A complementary approach which is a combination of model free isoconversional methods and model fitting methods was carried out to achieve more accurate results for the kinetic parameters. Moreover, Arrhenius parameters were determined by non-isoconversional Kissinger’s method. The values of the self-accelerating decomposition temperature (TSADT)and the critical ignition temperature (Tb) were also calculated. The results indicated that PBXW-108, a plastic bonded explosive, in comparison to H6 and A4 has the highest pre-exponential factor and activation energy of decomposition. Moreover, TSADT and Tb of PBXW-108 are higher than those of A4 and H6. Therefore, PBXW-108 can be introduced as a safer alternative to traditional A4 and H6 explosives. According to the obtained results, the contracting area model (R2) is the best choice for describing both PBXW-108 and H6 decompositions, while the F1/3 model is the suitable one for A4.