Phase Stability of Ammonium Nitrate with Organic Potassium Salts

A study has been undertaken on the effect of additives on the phase transition of ammonium nitrate(V) (AN). Results obtained using Differential Scanning Calorimetry (DSC) showed that organic compounds and potassium salts of organic compounds have an effect on the phase transition behavior of AN. The samples were further analyzed using infrared (IR) and powder X-ray diffraction (XRD). The mechanism of phase stabilization of AN by compounds of this kind was examined. The present study showed that the influence of additives on the phase transition of AN occurs through the polar groups that are involved in intermolecular interactions of orbital and electrostatic types that form new hydrogen bonds. AN exists in only one phase in the temperature range from 30 °C to +100 °C, when a potassium salt of organic compounds was added. However, with organic compounds, the III→II phase transition was changed. IR and XRD of composites are characterized by new intermolecular interactions. Compacted samples of AN containing potassium salts of organic compounds exhibited better stability than AN containing organic compounds to multiple cyclic changes within a temperature range. This we named ‘freezing and thawing analysis’. Additives have two functions on the AN phase transition. First, solid solutions of AN mixture were formed for K+ replacement of NH4+. Second, hydrogen bonds formed, which caused AN and salts of organic compounds to interact intimately.