Preparation of SiC ceramic fiber from a photosensitive polycarbosilane

Curing treatment is essential for ceramic precursors to maintain their shape during pyrolysis. In this study, a photosensitive SiC ceramic precursor was synthesized by chlorinating partial Si–H groups of polycarbosilane (PCS) with Cl 2 followed by reacting with hydroxyethyl acrylate. According to 1 H NMR and element analysis , about 10% structural unit of PCS was grafted with the acrylate group. After mixing with photo-initiator, the acrylate-grafted PCS transformed from soluble and fusible state to insoluble and non-fusible state under UV light. Its curing rate with related ceramic yield and oxygen content were compared with PCSs cured by the traditional air oxidation and electronic radiation. By electrospinning synchronized with UV illumination and pyrolyzing the acrylate-grafted PCS, one-dimensional continuous SiC fibers were prepared. The effects of pyrolysis temperature on the morphology, crystallographic structure and elemental composition were also characterized and discussed.