Facile synthesis and decomposition kinetics of novel green energetic molecular perovskite based on nitrate group DAN-4 as an alternative for ammonium nitrate oxidizer

The accompanying health and environmental issues have prompted a renewed effort to find more environmentally friendly substitutes for ammonium perchlorate (AP) as a solid rocket propellant oxidizer. AP Propulsion's outstanding performance is complemented by environmental concerns, which search for greener options necessary. Ammonium nitrate (AN) has emerged as a viable alternative that provides cost-effectiveness, non-detectable and tractable properties to the adversary, and cleaner combustion products. Structural instability is one of the problems with AN-based propellants. This work aims to overcome this obstacle by creating green energetic molecular perovskite based on nitrate groups (NO₃^-). NH₄(C₆H₁₂N₂)(NO₃)₃ (DAN-4) was synthesized by molecular assembly technique. Scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transfer infrared (FTIR) were applied to characterize the structure and morphology of AP, AN, and DAN-4. Thermal decomposition of AP, AN, and DAN-4 were investigated using differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). The results show that DAN-4 has one exothermic peak at 201 °C with 1420 J/g heat evolved compared to AN which has two endothermic phase transitions at 54 °C, and 128 °C respectively, melting point at 170 °C, and thermal decomposition at 294 °C with no exothermic peak, and heat evolved. DAN-4 shows higher energy released than common oxidizer (AP) which evolved 836 J/g. Decomposition kinetics was investigated via isoconversional (model free) and model fitting. Kissinger, Kissinger-Akahira-Sunose (KAS), integral isoconversional method of Flynn-Wall-Ozawa (FWO). DAN-4 demonstrated an apparent activation energy of 211.1 ± 1.66 kJ/mol compared with 160.8 ± 1.07 kJ/mol for pure AP, and 143.82 ± 3.3 kJ/mol for pure AN. DAN-4 shows higher thermal stability than AP, and AN. This work could promote the application of DAN-4 in the field of composite solid rocket propellant.