Synthesis and characterization of a novel polyborosilazane for SiBNC ceramic

A novel polyborosilazane (PBSZ) for preparing SiBNC ceramics was successfully synthesized via co-condensation approach using tetrachlorosilan (SiCl₄), trichloride (BCl₃) and propylamine (C₃H₇NH₂) as starting materials. After pyrolysis of these precursors, amorphous SiBNC ceramics were obtained. The chemical composition, structure and thermal stability of the synthesized PBSZ precursor and SiBNC ceramics were analyzed by using FT-IR, NMR, TGA and XRD methods. The results indicated that the PBSZ contained the major framework of –Si-N-B- and six-membered boron-nitrogen rings. The PBSZ precursor had an approximately ceramic yield of 63 wt% prolyzed at 900°C in nitrogen atmosphere. The SiBNC ceramics shows excellent oxidation resistance and maintained amorphous up to 1600°C. (paper)