ИСТИНА

Derivatives of mesionic heterocycle azasydnone (oxatriazolium-5-olate derivatives) may be of interest not only as medications, but also as energetic materials. In order to determine the possible applications of a new class of energetic compounds, it is necessary to determine the thermal stability, the combustion behaviors, and other properties of representatives of this chemical class. The goals of the work are to study the thermal decomposition and combustion of energetic azasydnone derivatives. The thermal stability of the substances was studies by DSC analysis under non-isothermal conditions and by means of gas evolution method (in Burdon glass manometers) under isothermal conditions. Combustion behavior of pressed samples was investigated in a constant-pressure bomb in a wide pressure interval, and the flame structure was studied with the help of thin tungsten-rhenium thermocouples. Investigation of the thermal stability of the simple derivatives of azosidones showed that the heterocycle possesses satisfactory stability. The decomposition of molecules begins with the decomposition of the azasydnone ring, and there is a strong dependence of the thermal stability of azosidones on the nature of the substituent. The thermal effect of decomposition of the azasydnone ring consists of 16-20 kcal/mol of the enthalpy of formation and the heat of oxidation of the carbon atom adjacent to the cycle. It is shown that the introduction of mesionic heterocycle in nitropyrazoles leads to an increase in the burning rate and a decrease in the exponent in the combustion law. It turned out that the decomposition reaction with activation energy about 30 kcal/mol and less in the condensed phase controls the burning rate of these compounds.