Establishing a coating of ferrocene-based hyperbranched polymer on ammonium perchlorate: Enhancing the anti-migration and catalytic performance

Ferrocene-based catalyst is one of the most widely used burning rate catalysts for ammonium perchlorate (AP) based propellants. However, its application is limited due to the defect of easy migration. Herein, the hyperbranched polymers with a large number of amide groups and high Fe content were employed to construct rAP/HFc composites by a solvent-antisolvent method to improve their anti-migration and catalytic performance. The 1H NMR, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscope, powder X-ray diffraction and inductively coupled plasma mass spectrometry were used to characterize the prepared samples. The surface coating technology enabled ferrocene-based catalysts to be distributed evenly on the surface and between the gaps of rAP, and no migration of the catalysts was observed after 28 days of the aging test. The thermal decomposition temperature of rAP coating with 5wt % 0.5HFc was decreased from 404 to 335 °C. Moreover, the hydrophobicity test showed that the water contact angles of prepared composites increased to 50°, indicating good anti-caking performance.