A binuclear ferrocene-based ionic complex as a highly efficient burning rate catalyst for ammonium perchlorate composite propellants

Precise control of solid propellant burn rate is critical for aerospace and defense applications. This study introduces a novel binuclear ferrocene-based ionic complex, DiFc-IC, synthesized via a facile ionic self-assembly approach, as a highly efficient burning rate catalyst for ammonium perchlorate (AP) composite propellants. DiFc-IC, designed to mitigate catalyst migration, was characterized using ¹H-NMR, UV-Vis spectroscopy, and thermogravimetric analysis (TGA), confirming its structure, electronic properties, and thermal stability. Comparative TGA and differential scanning calorimetry (DSC) analyses revealed that DiFc-IC significantly reduced the high-temperature decomposition (HTD) temperature of AP, exhibiting superior catalytic activity compared to the commercially available catocene. Optimal DiFc-IC loading was determined to be 5 wt%, yielding a substantial enhancement in AP decomposition kinetics. Furthermore, migration studies demonstrated that DiFc-IC exhibited significantly reduced migration within the propellant matrix compared to catocene, with a diffusion coefficient approximately 7.6% that of catocene. This enhanced migration resistance, attributed to the ionic nature and potential for stronger interactions within the propellant binder, positions DiFc-IC as a promising catalyst for next-generation solid propellant formulations, offering improved performance and stability.