1,2,4-triazole-3-one (TO) and guanidine nitrate (GN) have the potential to be used as alternative gas-generating agents. To
obtain a better understanding of thermal decomposition properties of TO/GN mixtures, sealed cell differential scanning calorimetry,
thermogravimetry–differential thermal analysis–infrared spectroscopy (TG–DTA–IR), and thermogravimetry–differential thermal
analysis–mass spectrometry (TG–DTA–MS) were carried out. The endothermic peak and onset temperatures of TO/GN mixtures were
lower than those of individual TO and GN. TG–DTA–IR and TG–DTA–MS showed that the mass of TO/GN mixtures decreased with heat
generation and N2 evolved as the major gas during thermal decomposition. The interaction between TO and nitric acid from the dissociation of
GN is proposed for the thermal decomposition of TO/GN mixtures.