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

Abstract

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.