روزنامه با شماره پیاپی سال 2002

13

371

383

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: • 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; • reaction orders of the autocatalytic reaction are directly associated with the isothermal DSC curve shapes; • elevated temperature aging of chemicals that decompose autocatalytically results in small to very significant reductions in their subsequent thermal stability.

Food Microbiology

2002

Food Microbiology