5,5-Dimethylhydantoin (DMH) is one of the most important and widely used derivatives of hydantoin, including in the preparation of pharmaceutical compounds, disinfectants and in the preparation of bonding agents for composite propellants. In this research, the synthesis conditions of this compound were optimized on a laboratory scale from available industrial raw materials. The 1,3-diglycidyl5,5-dimethylhydantoin derivative was also synthesized as a bonding agent for composite propellants. The synthesized compounds were analyzed and identified by FT-IR and NMR techniques. Finally, in order to investigate the effect of 5,5-DMH as a thermal stabilizer and phase transfer of ammonium nitrate, its compositions with different percentag of ammonium nitrate
was evaluated using DSC-TGA technique. The DSC results showed that composition (AN / DMH) (0.9: 0.1) and (AN / DMH) (0.8: 0.2) had positive effects on the reduction and elimination of phase transitions in the temperature range of 50-100 ° C, thermal stability as well as the melting point reduction of ammonium nitrate.