The properties of ammonium dinitramide (ADN): Part 1, basic properties and spectroscopic data

Abstract

Basic properties and spectroscopic data for the energetic oxidizer ADN (Ammonium dinitramide (NH4N(NO2)2)) are presented. The ADN used for this work was synthesized by a new efficient and environmentally friendly method. The method is based on a direct nitration of salts of sulfamic acid by ordinary mixed acid, followed by neutralization and separation of the ADN by the use of an adsorption column. The heat of formation was measured by burning in hydrogen atmosphere in an adiabatic bomb calorimeter and was found to be 148 kJ/mole ±10 kJ/mole. The melting point was determined using DSC technique and is 93.5°C. This paper reports drop weight, friction and bullet impact sensitivity data. The friction sensitivity of ADN is much lower than that of RDX. The impact sensitivity of ADN is of the same magnitude as that of RDX but varies a great deal with the morphology of the particles, e. g. prilled ADN is nearly twice as insensitive as RDX. The bulk density measured by powder X-ray diffraction and was found to be 1.82 gcm−3. ADN does not show any sign of phase transitions in the -150°C to +80°C temperature interval (measured by single crystal X-ray diffraction). FTIR and FT-Raman spectra are also presented. In the UV-VIS region, ADN is characterized by two absorption peaks at 214 and 284 nm. UV-VIS spectroscopy was also found to be the most useful method for quantitative routine analysis of ADN.