THERMAL DECOMPOSITION BEHAVIORS OF AMMONIUM NITRATE AND CARBON MIXTURES

The influence of the physical form of carbon on the thermal decomposition of ammonium nitrate (AN) and carbon mixtures was investigated by Raman spectroscopy, differential scanning calorimetry (DSC), and thermogravimetry-infrared (TG-IR) spectroscopy. The DSC results revealed that AN mixed with activated carbon and AN mixed with carbon nanotubes underwent a violent reaction after the AN melted. In contrast, AN mixed with graphite and AN mixed with fullerene had a relatively small exothermic peak, the same as that observed for pure AN. The TG-IR spectroscopy results revealed that more carbon dioxide was generated by AN mixed with activated carbon and AN mixed with carbon nanotubes than by the other two mixtures. Furthermore, DSC was performed for AN mixed with carbon blacks having different particle diameters. It is concluded that AN mixed with low-crystallinity carbon reacts violently after melting, whereas AN mixed with high-crystallinity carbon exhibits the same thermal decomposition behavior as pure AN. The thermal decomposition behaviors of mixtures of AN and activated carbon were investigated by performing thermochemical calculations, and the reaction mechanism is discussed.