Physico-chemical properties and combustion behavior of new oxygen-rich pyrazolyltetrazoles

摘要

Physico-chemical characterization of new oxygen-rich N-[3-nitro-1-(trinitromethyl)-1H-pyrazol-4-yl]-1H-tetrazole and N- [I-(fluorodinitromethyl)-i-nitro-1H-pyrazol-4-yl]-1H-tetrazole has been conducted, including studies on the thermal decomposition, burning behavior, and flame structure. It was found that the trinitromethyl group and the tetrazole substituent have a close thermal stability and decompose simultaneously under the nonisothermal conditions. The fluorodinitromethyl fragment is more stable than the trinitromethyl group, the decomposition of this substituent and the tetrazole ring proceeds at different temperature intervals under the conditions of DSC tests. It turned out that pyrazolyltetrazoles have high burning rates. The structure of the combustion wave of fluorodinitromethyl compound was determined with the help of thin thermocouples. Combustion of the investigated substances obeys the combustion model with the leading reaction in the condensed phase. In the case of trinitromethyl compound, the leading reaction is the decomposition of the trinitromethyl group and the tetrazole moiety, but in the case of the other compound, the combustion rate is determined by the decomposition kinetics of the more stable but more energy-rich fluorodinitromethyl group, since rapid release of heat upon the tetrazole moiety decomposition is insufficient to maintain combustion.