Tracking Thermal Decomposition Chemistry in Secondary Solid Explosives with X-ray Diffraction.

We present an approach for measuring thermal decomposition kinetics in crystalline solids using X-ray diffraction to track the loss of crystallinity that accompanies condensed phase decomposition chemistry. We apply this method to systems for which extracting thermodynamic parameters has been historically difficult: organic molecular crystals that thermally decompose below their melting points, such as solid explosives. To demonstrate this method, we measured the rate of solid, thermal decomposition versus temperature in three different secondary solid explosives and the sugar fructose. In all cases, we observed an acceleration in the thermal decomposition rate with increasing temperature, which forms a vertical asymptote, a phenomenon known as