Reduction in the Thermal Stability of Nitro-Containing Compounds due to Cross-Catalyzed Autocatalytic Decomposition Caused by Nitro-Containing Impurities

Testing performed by ramped and isothermal differential scanning calorimetry has demonstrated a previously unreported effect wherein the thermal stability of nitro-containing compounds can be significantly reduced by the presence of low levels of a secondary nitro-containing compound, where the impurity is of lower thermal stability than the bulk material. This effect is believed to be due to the autocatalytic decomposition of nitro-containing species being catalyzed by a common catalyst, such that the catalyst generated from an impurity can cross-catalyze the decomposition of the bulk material. Accordingly, this effect does not occur when the impurity is of similar or greater thermal stability than the bulk. This effect reiterates the importance of performing thermal stability testing on samples whose impurity profile is representative of that to be utilized or produced.