Microwave-absorption properties of SiOC ceramics derived from novel hyperbranched ferrocene-containing polysiloxane

Abstract

In this contribution, we design a novel strategy to synthesize SiOC ceramics by pyrolysis of hyperbranched ferrocene-containing polysiloxane (HBPSO-VF) which are synthesized by the reaction of polysiloxane (PSO) with 1,1′-Bis(dimethylvinylsilyl)ferrocene (VF). This SiOC ceramics show much lower crystallization temperature because of the capability of HBPSO-VF to incorporate metallic iron into the backbone of PSO. The usage of HBPSO-VF offers enhanced ceramic yield of 83wt% at 1200°C due to the deep cross-linking of hydrosilylation. Nano-sized SiC and turbostratic carbons are separated from amorphous SiOC phase when it is annealed at 1100°C, while crystallization temperature is 1400°C when PSO is used as polymer precursors. The minimum reflection coefficient (RCmin) of this nanocrystal-containing ceramic reaches −46dB, exhibiting a promising prospect as a kind of electromagnetic wave (EMW) absorbing materials. This method also can be further extended to develop other functional Si-based polymer derived ceramic (PDC) systems for EMW absorption and shielding applications.