Synthesis and Thermal Behavior of New Hypergolic Imidazolium Cation- Dicyanamid Anion Based Ionic Liquids

A hypergolic bipropellant consist of fuels and oxidizers that can ignite rapidly upon mixing without external ignition devices. This self –ignition technology makes the engine ignition more reliable with the repeated use. Recently، ionic liquids with the dicyanamide anion showing good hypergolic properties when contacted with common oxidizer (such as concentrated nitric acid)، have attracted a lot of attentions. In this study، two new hypergolic ionic liquids with imidazole cations and energetic dicyanamide anions have been designed and synthesized. The synthesized ionic liquids was characterized by 1H-NMR and FT-IR، and their thermal properties were investigated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results suggested that these ionic liquids have good thermal stability (approximately up to 200 °C without significant weight loss) and phase change curves shown good agreement with the changes in weight loss by increasing temperature. In addition، hypergolic properties of synthesized ionic liquids were investigated by drop test in the presence of concentrated nitric acid following which، they shown spontaneous ignition in contact of oxidizer surface.