A propellant is used in military application and consists of an oxidizer, fuel, plasticizer, hardening agent and crosslinking agents. The commonly used oxidant is ammonium perchlorate. But its combustion products are dangerous for the environment. Nowadays, ammonium nitrate is gaining popularity in the propellant field as a great oxidizer. Ammonium nitrate is an inorganic compound used as a fertilizer, oxidant and also for other applications. AN combined with fuel can be used in gas generators. Ammonium nitrate extracted from demilitarized rocket engines can be used as an oxidizing agent in the hydrothermal oxidation of organic waste. It has seven phase transitions3. Phase Transition of Ammonium Nitrate IUPAC defined polymorphic transition as “a reversible transition from a solid crystalline phase at a certain temperature and pressure (the inversion point) to another phase of the same chemical composition with a different crystal structure".The crystal structure (II) turns out to be disordered tetragonal, space group P4͞ 21m, a = 5.7193, c = 4.9326 A0,,Z=2. The phase (IV) of AN is stable between the temperature -18 and 32.30C. It belongs to the orthorhombic structure of space group Pmmn. It has a coordination number of two. The IV-III transition takes place at a temperature close to 32 0C. it causes swelling, agglomeration and deterioration of stored ammonium nitrate particles. The IV-III transition only occurs in the presence of humidity and this transition is carried out by dissolution and recrystallization of the solid. During the recrystallization process, salt bridges form between the crystallites. This phase transition is followed by a change in volume. This also leads to...... middle of paper ......the specific binding to metal molecular cations. 18-crown, 6- and 15-crown ethers are used for recrystallization of AN from non-aqueous solvents. Crystals formed by this method showed a decrease in hygroscopicity. T. Lee et al. used crown ethers to minimize the polymorphic transition near room temperature. The phase transition at room temperature is minimized by forming a 1:1 co-crystal of AN-benzo-18-crown-6 with a melting point of 125–129 °C. A disadvantage of this phase-stabilized AN is that it reduces the propellant burn rate. Organic compounds, those that have a crystallographic structure close to the AN crystal structure, are also used as phase stabilizers. N. Galavina et al. The phase stabilization of AN was studied using organic compounds containing planar unsaturated N-heterocycles substituted with carbonyl, amine or imine groups.A