Thermal Decomposition Kinetics and Decomposition Mechanism of (Dinitropyrazolyl)Azoxyfurazanes

ABSTRACT The decomposition of azoxy derivatives of dinitropyrazole and furazan, the first example in which an azoxy group is coupled to a pyrazole ring nitrogen, has been studied in detail using DSC, TGA, isothermal TGA, and manometry methods. The studies showed that the degradation of azoxy compounds starts with the cleavage of the bond between the N(O) atom of the azoxy group and the furazan cycle. It was found that under conditions of decomposition product removal, this stage can occur without heat release or with heat release without a pronounced peak. The insignificant heat effect of the initial decomposition stage of azoxy compounds makes it difficult to determine the true kinetic parameters using the standard DSC method, as the observed heat effect is actually due to the decomposition of intermediates. At the same time, decomposition under closed conditions can increase the decomposition rate constants by a factor of 10 or more. A possible mechanism for the decomposition of azoxy compounds has been proposed based on the kinetic data obtained and the analysis of the decomposition products.