Investigating the effect of a zeolitic imidazolate framework, ZIF-8, on the phase transition and thermal decomposition of ammonium nitrate

Abstract

Ammonium nitrate (AN) is a well-known energetic material that is used as a chlorine-free oxidizer for substituting the ammonium perchlorate in composite and gas generators propellants. In this work, the phase transitions and the thermal decomposition of AN was investigated under the influence of a zeolitic imidazolate framework (ZIF-8). Different percentages of AN/ZIF-8, i.e., 0.95:0.05, 0.9:0.1, and 0.85:0.15, were prepared by the solvent and mechanical methods, and their phase transition and thermal decomposition have been studied by TG-DSC. To investigate the interactions between AN and ZIF-8, the UV–Vis-DRS, XRD, and FT-IR techniques were used. Accordingly, ZIF-8, despite its low weight percentage, stabilized the AN up to 125°C and improved its thermal decomposition behavior. In addition, the catalytic combustion of AN/ZIF-8 species showed exothermic peaks. Moreover, the results showed that ZIF-8, due to its Lewis acid-base sites as well as the porous structure, could be stated as an excellent catalyst that improves the AN thermal decomposition and removes its inappropriate phase transitions.