Abstract :
Kinetic equations of decomposition of several nitrobenzene (NB) derivatives were developed from isothermal DSC data. The mechanism of decomposition of all chemicals appeared to be autocatalytic with a slow first-order initiation reaction. Reaction orders, activation energies, and frequency factors of both (autocatalytic and initiation) reactions were determined for all chemicals. It was demonstrated that:
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utilization of a kinetic model with two parallel reactions (first-order initiation reaction and autocatalytic reaction) that have different activation energies accounts for the change in chemical behavior sometimes observed at low temperatures;
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reaction orders of the autocatalytic reaction are directly associated with the isothermal DSC curve shapes;
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elevated temperature aging of chemicals that decompose autocatalytically results in small to very significant reductions in their subsequent thermal stability.
