Urea Nitrate as Stabilizer for AchIEving Phase Stabilization of Ammonium Nitrate

The present study has been aimed to investigate the stabilization effects provided by the addition of Urea Nitrate (UN) on the modification of phase (II) transition of Ammonium Nitrate (AN) and thus on its thermal decomposition behavior. Urea Nitrate was synthesized in the laboratory and was characterized to ascertain its structural ingenuity. Urea Nitrate was then co-crystallized with AN in three different weight percentages i.e. 3%, 6% and 10% for the preparation of Phase Stabilized Ammonium Nitrate (PSAN). The thermal decomposition patterns of virgin AN and prepared samples of PSAN were measured and compared using Differential Scanning Calorimetry (DSC) to detect the efficiency of UN as a potential stabilizer. The present study indicated that UN, in low weight percentages, was able to deliver a noteworthy postponement in the onset temperature range of near-room-temperature phase modification (III) of AN occurring at around 32°C–34°C. Also, co-crystallization of UN with AN significantly modified the hygroscopic tendency of the prepared co-crystals.

Keywords: Urea Nitrate, Ammonium Nitrate, Phase Stabilized Ammonium Nitrate (PSAN), Phase Transitions, Co-crystallization, Differential Scanning Calorimetry (DSC).