Effect of Hygrothermal Aging on the Decomposition Reactions of Magnesium/Teflon/Viton (MTV) Pyrotechnic

ABSTRACTMagnesium/Teflon/Viton (MTV) pyrotechnic compositions are widely used in various applications. Magnesium is known to oxidize under elevated humidity and temperature conditions. Consequently, the performance of MTV pyrotechnics degrades as they age. Accurate characterization of the aging process is necessary for the prediction of storage life and performance of MTV pyrotechnics. This study investigates the hygrothermal aging of an MTV pyrotechnic mixture using accelerated aging, thermogravimetry (TG), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). The kinetic parameters were obtained using the Friedman isoconversional method. Differential TG (DTG) curves were analyzed to identify the reaction steps occurring during the decomposition of pristine and aged MTV samples. Scanning electron microscope–electron‐dispersive spectroscopy (SEM–EDS) and Fourier transform infrared (FTIR) spectroscopy revealed changes in morphology and chemical composition. As expected, increased humidity caused significant degradation of the metallic fuel in the MTV pyrotechnic. Furthermore, the formation of unwanted compounds due to aging was clearly observed. The formation of these compounds, in addition to the depletion of the metallic fuel, was realized to be the cause of reduced the performance of aged MTV pyrotechnics.