Energetic ionic liquid propellants (EILPs) are expected to have applications in next-generation spacecraft propulsion, and ammonium dinitramide (ADN) is one of the most promising energetic materials for use in these propellants. The development of deep eutectic solvent systems, consisting of mixtures of two or more components, would allow the formulation of ADN-based EILPs that do not require traditional solvents. However, little is known regarding the effects of various additives on the melting point depression of ADN. In this study, the eutectic behaviors and melting points of small scale ADN mixtures with amide compounds or nitrate salts were investigated, using both visual inspection and differential scanning calorimetry (DSC). ADN/acetamide (AA) and ADN/monomethyl amine nitrate (MMAN) mixtures were found to be liquids at 60ºC, with the formation of a solid state at approximately 15ºC. Equimolar mixtures of ADN with AA, propionamide (PrA), MMAN and dimethyl amine nitrate (DMAN) each exhibited a eutectic point below 15ºC. The data show that equimolar mixing ratios are not ideal when formulating eutectic ADN compositions and that ADNbased EILPs have a tendency to supercool.
ammonium dinitramide, amide compounds, nitrate salts, ionic liquids, eutectic