Thermal hazard and mechanism study of 5-(4-Pyridyl)tetrazolate (H4-PTZ)

Thermal decomposition experiment of 5-(4-Pyridyl)tetrazolate (H4-PTZ) was carried out. The heat flow curve and reaction rate data under different heating rates were obtained. The characteristic parameters were obtained. The apparent activation energy for each individual reaction was calculated by applying different methods. On this basis, the Malek method was used to predict the most probable mechanism function of thermal decomposition reaction of H4-PTZ. The thermal safety parameters, including self-accelerating decomposition temperature, hot spot fire temperature and thermal explosion critical temperature were also predicted. The activation enthalpy, activation entropy, and activation Gibbs free energy of H4-PTZ are calculated. Gaussian16 program was used to optimize the molecular structure, search the transition state and calculate the intrinsic reaction coordinates of H4-PTZ. The most probable decomposition path of H4-PTZ was found, and the activation energy calculated by experiment was compared with that calculated by the theory.