Enhancing the yield of polycarbosilane synthesis via recycling of liquid by-product at atmospheric pressure

Abstract Polycarbosilane (PCS) is a typical ceramic precursor for the fabrication of SiC fibers and SiC matrix composites. However, it is still costly and not widely employed in industry, mainly due to its low yield by typical chemosynthesis methods. In this work, we reported for the first time a novel method to significantly increase the PCS yield from 51.3% to 62.8% by recycling the liquid by-products (LBP), which was mainly made up of low-molecular-weight PCS, as revealed by FT-IR, GPC, and NMR analysis. The results showed that recycling LBP did not alter the chemical structure of the PCS products, making it very promising for mass production and application of PCS at the industrial scale.