TATB thermal decomposition: An improved kinetic model for explosive safety analysis

We investigate and model the cook-off behavior of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) to understand the response of explosive systems in abnormal thermal environments. Decomposition has been explored via conventional ODTX (one-dimensional time-to-explosion), PODTX (ODTX with pressure-measurement), PyGC-MS (pyrolysis gas chromatography mass spectrometry), TGA (thermo-gravimetric analysis), DSC (differential scanning calorimetry), and IR (infrared spectroscopy) experiments under isothermal and ramped temperature profiles. The data were used to fit rate parameters for proposed reaction schemes in a MATLAB thermo-chemical computational model. These parameterizations were carried out utilizing a genetic algorithm optimization method on LLNL's high-performance computing clusters, which enabled significant parallelization. These results include a multi-step reaction decomposition model, identification of likely autocatalytic gas-phase species, accurate high-temperature sensitization, and prediction of confined system pressurization. This model will be scalable to several applications involving TATB-based explosives, like LX-17, including thermal safety models of full-scale systems.