Recrystallized Ammonium Perchlorate Decomposition—A TGA-FTIR-MS Study

Thermogravimetric analysis (TGA) of evolved gases was utilised in conjunction with Fourier transform infrared (FTIR) spectroscopy and electron ionisation (EI) mass spectrometry (MS) to investigate the effect of recrystallization on ammonium perchlorate decomposition. Particle size has only a minor effect on recrystallized AP decomposition, according to TGA and DTG plots. In contrast, particle size has a significant impact on the decomposition of original AP samples. The FTIR and mass spectra revealed the following species: O2 Cl2, N2O, NO2, HNO3, H2O, HCl, ClO, HOCl, and m/z 30. When recrystallized AP was compared to AP, these species concentrations decreased in the LTD stage and increased in the HTD stage. This supported the TGA findings because the DTG peak of recrystallized AP is lower in the LTD stage but higher in the HTD stage when compared to the DTG peaks of the original AP. To understand the ageing behaviour of different AP samples, the Kissinger–Akahira–Sunose iso-conversional method was used, which shed more light on the effect of recrystallization on both the LTD and HTD stages. The reaction constant (k) value in the LTD stage shows that AP recrystallization accelerates sample ageing. Nonetheless, recrystallized AP has no change in effect on AP burn rate behaviour.