A study on the thermal decomposition, ignition and combustion of core-shell structured Al@ADN/PVDF energetic composites

This study successfully fabricated core-shell structured Al@ADN/PVDF energetic composites through electrostatic spraying, with nano-aluminum (n-Al) cores encapsulated by an ammonium dinitramide (ADN)/polyvinylidene fluoride (PVDF) composite shell. The morphology and structure were systematically characterized using scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thermal decomposition behavior was investigated through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), with corresponding kinetic parameters calculated. Combustion processes were monitored via high-speed imaging, while ignition and combustion performance were evaluated under both ambient and confined environments. The results show that n-Al particles are uniformly encapsulated by a continuous ADN/PVDF composite shell. Compared to physically mixed mixture, the Al@ADN/PVDF composites exhibit a 6.7% reduction in the PVDF decomposition stage mass loss and demonstrate a 24% reduction in decomposition activation energy. Furthermore, Al@ADN/PVDF composites demonstrate superior combustion characteristics, including 102% higher maximum pressure, 128% faster pressurization rate, 19% shorter ignition delay time and 17% shorter burning time. The core-shell Al@ADN/PVDF architecture provides an innovative approach for optimizing the energetic potential of aluminum in both solid propellant and pyrotechnic applications.