Polymorphism has attracted significant
attention in the area of
pharmaceutical chemistry and materials chemistry. For energetic materials,
polymorphism may affect their physical performances such as energy,
sensitivity, thermal stability, etc. 4,4′,5,5′-Tetranitro-1H,1′H-[2,2′-biimidazole]-1,1′-diamine
(DATNBI) exhibits high density (d: 1.93 g cm–3), superior detonation performance (D: 9063 m s–1) and comprehensive sensitivity (IS:
15 J), suggesting it is a nonsensitive-high-energy material (NSHEM)
compared with HMX as a sensitive-high-energy material (SHEM). In this
work, a new polymorph of DATNBI was discovered for the first time.
To elucidate its phase transformation behavior and morphology-performance
relationship, single X-ray diffraction (SXRD), variable temperature
powder X-ray diffraction (VT-PXRD), Raman spectroscopy, differential
scanning calorimetry-thermal gravity (DSC-TG), and scanning electron
microscopy (SEM) were characterized thoroughly. Solvation and temperature
effects on the polymorph formation of DATNBI were also investigated.