Phase Transformations 2,4,6-Tris(2,2,2-Trinitroethylnitramino)-1,3,5-Triazine

Thermal transformations of 2,4,6-tris(2,2,2-trinitroethylnitramino)-1,3,5-triazine (I) are studied in the temperature range 22–300°C with the use of methods of differential thermal analysis, powder X-ray diffractometry, and IR spectroscopy. At 120°C, the polymorphic transformation α-I → β-I, which is preceded by a sharp increase in the volume of the unit cell and amorphization of I, is recorded. The polymorphic transformation is accompanied by a significant increase in the rate of thermal decomposition of the compound I. Under normal conditions, the phase β-I is stable, but a reverse polymorphic transformation with the formation of a defect phase α-I can be realized at a pressure of 5 kbar.