Free radical-initiated crosslinking of activated polycarbosilane and its application in the preparation of SiC fibers

In the process of preparing SiC ceramic fiber based on the conversion of precursor polycarbosilane, the cross-linking process is a necessary condition for maintaining the fiber morphology and improving the ceramic yield. In this study, polycarbosilane (A-PCS) containing acrylate group was used as the raw material, and the cross-linking of the raw material was realized by introducing a free radical thermal initiator during the heating process of pyrolysis. Infrared spectroscopy (FT-IR) and differential scanning calorimeter (DSC) were used to study the influence of initiator content on the crosslinking degree, crosslinking rate and thermal degradation rate of A-PCS; thermal weight loss (TG), elemental The analyzer and X-ray diffractometer (XRD) analyzed the ceramic yield, ceramic product composition and the change of amorphous state with temperature. The research results show that the addition of free radical thermal initiator can increase the acrylate group in A-PCS...