First Example of 1,2,5-Oxadiazole-Based Hypergolic Ionic Liquids: A New Class of Potential Energetic Fuels

The development of liquid energetic fuels with improved properties is an important topic in space propulsion technologies. In this manuscript, a series of energetic ionic liquids incorporating a 1,2,5-oxadiazole ring and nitrate, dicyanamide or dinitramide anion was synthesized and their physicochemical properties were evaluated. The synthesized compounds were fully characterized and were found to have good thermal stabilities (up to 219 & DEG;C) and experimental densities (1.21-1.47 g cm(-3)). Advantageously, 1,2,5-oxadiazole-based ionic liquids have high combined nitrogen-oxygen contents (up to 64.4 %), while their detonation velocities are on the level of known explosive TNT, and combustion performance exceeds those of benchmark 2-hydroxyethylhydrazinium nitrate. Considering the established hypergolicity with H2O2 in the presence of a catalyst, and insensitivity to impact, synthesized ionic liquids have strong application potential as energetic fuels for space technologies.

Automated summary

Liquid energetic fuels with improved properties, synthesized in this study, were evaluated for their physicochemical properties. The results showed that the synthesized compounds had good thermal stabilities and experimental densities. Particularly, the 1,2,5-oxadiazole-based ionic liquids exhibited high combined nitrogen-oxygen contents, detonation velocities comparable to TNT, and better combustion performance than the benchmark compound 2-hydroxyethylhydrazinium nitrate. Due to their hypergolicity with H2O2 in the presence of a catalyst and insensitivity to impact, these synthesized ionic liquids have great application potential for space technologies.