Thermal decomposition mechanism of 1,3,5-trinitroperhydro-1,3,5-triazine: Experiments and reaction kinetic modeling

This study investigates the thermal decomposition of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) based on combined thermogravimetric (TG) and chemical reaction neural network (CRNN). Two compact kinetic models for RDX are introduced, with one consisting of three substances and a single global reaction (one-step model) and the other consisting of three substances and four reactions (3–4 model). In the one-step model, the calculated activation energy is 193.67 kJ mol⁻¹, which agrees with the experimental value. As for the 3–4 model, the substances and reactions are assigned based on a skeleton mechanism involving reactions of N-N and C-N bond rupture and HONO elimination. This work presents the first application of the CRNN to obtain a reaction mechanism of RDX decomposition, which is further validated against experiments. Furthermore, effects of sublimation and vaporization phenomena are also included in the model. Extension of the CRNN to kinetic modeling of other energetic materials is anticipated in future studies.