Synthesis of Iron-Containing Preceramic Polymer and Preparation of Fe/Si/C Ceramics via Precursor-Derived Method

Iron-containing SiC ceramics have low specific resistivity and excellent electromagnetic properties. In this work, hyperbranched polyferrocenylsilane as the precursor of Fe/Si/C ceramics was prepared by the reaction of ferrocenyl dilithium, dichlorodimethylsilane and trichloromethylsilane. The ceramization process of the preceramic polymer from organic to inorganic was then investigated. Precursor microspheres were prepared by emulsion method, which were then pyrolyzed to obtain Fe/Si/C ceramic microspheres.The composition, structure and morphologies of the precursor and ceramics were characterized by 1H-NMR, FT-IR, TG-MS, XRD, SEM and EDS. Experimental results showed that the hyperbranched precursor was successfully synthesized, the pyrolytic process of which started at 350 °Cand almost completed above 600 °C. There was crystalline transformation from Fe5Si3 to Fe3Si as the sintering temperature increased from 1000 °C to 1400 °C. Moreover, the crystalline phase of β-SiC appeared at 1400 °C. Precursor microspheres were prepared by emulsion method. Porous ceramic microspheres were obtained after the precursor microspheres being sintered at 1400 °C, which can be applied in gas adsorption and catalyst supports.