Effect of polymorphic phase transitions on stability of energetic compounds. Thermal transformations of 2,4,6-tris(2,2,2-trinitroethylnitramino)-1,3,5-triazine

The kinetics of thermal transformations of the energetic compound 2,4,6-tris(2,2,2- trinitroethylnitramino)-1,3,5-triazine (1) and products of this reaction were studied by differential scanning calorimetry, thermogravimetry, IR spectroscopy, single-crystal X-ray diffraction, and powder X-ray diffraction. The kinetic and activation parameters of the decomposition of compound 1 were determined. The polymorphic phase transformation α-1 → β-1 was observed at 105 °C. The kinetics of the solid-state thermal decomposition of compound β-1 was found to be described by the same Arrhenius equation as the decomposition kinetics of 1 in the melt, i.e., the inhibitory effect of the crystal lattice is absent. The factors responsible for this anomaly are discussed.