Improving the ceramic yield of polycarbosilane by radiation cross‐linking in the presence of multifunctional monomers

An interesting method for radiation cross‐linking polycarbosilane (PCS) at high efficiency and low cost was developed by adding multifunctional monomers (trimethylolpropane trimethacrylate (TMPTMA) or divinylbenzene (DVB)). The effect of multifunctional monomers on the radiation cross‐linking and ceramic yield of PCS was investigated. The results revealed that the addition of a small amount of multifunctional monomer can substantially improve the ceramic yield and reduce the absorbed dose by promoting cross‐linking. The ceramic yields of radiation cross‐linked “PCS/2%DVB (300 kGy)” and “PCS/2%TMPTMA (300 kGy)” were 74 wt% and 78 wt%, respectively, while that of the radiation cross‐linked “PCS (300 kGy)” was only 64 wt%. The presence of double bonds in multifunctional monomers stimulated the combination reactions of free radicals in PCS induced by γ‐ray irradiation and subsequently enhanced the efficiency of cross‐linking. Furthermore, it was found that the incorporation of a small amount of multifunctional monomer hardly affected the chemical composition and crystallization behavior of the final SiC ceramics.