One-step synthesis of polynitropyridine-based thermostable and low sensitive energetic materials

Abstract

In this study, two energetic compounds based on a 3,5-dinitropyridine backbone linked by hydrazine and imine bridges were synthesized and fully characterized using elemental analysis, NMR (1H, 13C), IR, and differential scanning calorimentry (DSC). The crystal structures of 1,2-bis(3,5-dinitropyridin-2-yl)hydrazine (2) and N-(3,5-dinitropyridin-2-yl)-6,8-dinitro-[1,2,4]triazolo[1,5-a]pyridine-2-amine (3) were further determined using X-ray diffraction. Compounds 2 and 3 possess high thermal stability, with Td of 274 ​°C and 290 ​°C, respectively, both of which are higher than 250 ​°C. In addition, both compounds have desirable insensitive properties IS ​> ​40 ​J, FS ​> ​360 ​N) and are more insensitive than HNS and PYX (HNS: IS ​= ​5 ​J, FS ​= ​240 ​N; PYX: IS ​= ​10 ​J, FS ​= ​360 ​N). Moreover, the detonation properties of compounds 2 and 3 (2: vD ​= ​7862 ​m·s−1, p ​= ​25.4 ​GPa; 3: vD ​= ​8024 ​m·s−1, p ​= ​26.9 ​GPa) are both higher than that of HNS (vD ​= ​7612 ​m·s−1, p ​= ​24.3 ​GPa). These results indicate that both compounds have promising prospects as thermostable and insensitive explosives.

Keywords

• Pyridine
• Insensitivity
• Nitrogen-rich heterocyclic
• Thermostable energetic materials