Controlled synthesis and ceramization of well-defined Fe/Si/C ceramic precursors by living anionic polymerization

Two kinds of iron-containing ceramic precursors, PFS and PS-b-PFS, were synthesized via living anionic polymerization by using ferrocenyldimethylsilane and styrene as the monomers. The structures, elemental compositions and molecular weights were characterized by FT-IR, NMR, EDS and GPC, respectively. The homopolymerization of ferrocenyldimethylsilane was simulated using computational chemistry method. The copolymerization between ferrocenyldimethylsilane and styrene was investigated by altering the ratio between monomers and initiator (n-butyllithium). The experimental results indicated that the Mn, Mw and PDi of homopolymer PFS were 6.91×103 g/mol, 8.29×103 g/mol and 1.20, respectively. Moreover, the molecular weight, structure and composition of block copolymers PS-b-PFS, were successfully controlled by changing the ratio of styrene, n-butyllithium and ferrocenyldimethylsilane. Subsequently, using such iron-containing polymers as precursors, Fe/Si/C ceramics were obtained after sintering at 1400°C. The microstructures, morphologies and elemental compositions of ceramics were characterized by SEM and EDS. The results implied the controllable preparation of spherical Fe/Si/C ceramics was achieved via the self-assembly of precursors.