Аннотация:Burn rate characteristics of monopropellant combustion of furazan derivatives, an endothermic five-membered ring, and their N-oxides, furoxans, were studied. For the furazan compounds without active oxygen in the substituents, thermocouple-aided measurements showed results well below calculated adiabatic combustion temperatures. Nitrile-containing compounds formed during decomposition of the heterocycle in the absence of an oxidizer is assumed to remain unreacted among combustion products and to be responsible for incomplete energy release. For combustion of compounds of this type, the main source of heat release is suggested to be isomerization of the nitriloxide formed during heterocycle decomposition to isocyanate rather than an oxidation reaction. At combustion of furoxan derivatives in most cases, even at low pressures, all energy accumulated in heterocycle is released that is well agree with the known channel of furoxan decomposition to nitriloxides. The significant distinction furazans and furoxans in thermal stability results in that the majority of mononuclear furazan derivatives burn by gas-phase combustion mechanism, while furoxans obey condensed-phase combustion mechanism.