The preparation method of precursor for SiC was improved. Polyborazine-polymethylsilane(PBN-PMS) was obtained by reaction of PMS with 1%(mass fraction) PBN; and then soluble polymeric precursor PBN-PCS-PMS was prepare...The preparation method of precursor for SiC was improved. Polyborazine-polymethylsilane(PBN-PMS) was obtained by reaction of PMS with 1%(mass fraction) PBN; and then soluble polymeric precursor PBN-PCS-PMS was prepared by hybridization of the PBN-PMS with a suitable amount of PCS(polycarbosilane). Silicon carbide material was obtained by pyrolysis of the PBN-PCS-PMS in inert atmosphere at 1 400 ℃. XRD, elemental analysis, 29Si and 13C MAS NMR indicated it is a near-stoichiometric β-SiC when the mass ratio of PCS to PBN-PMS is 0.25∶1.00.展开更多
文摘The preparation method of precursor for SiC was improved. Polyborazine-polymethylsilane(PBN-PMS) was obtained by reaction of PMS with 1%(mass fraction) PBN; and then soluble polymeric precursor PBN-PCS-PMS was prepared by hybridization of the PBN-PMS with a suitable amount of PCS(polycarbosilane). Silicon carbide material was obtained by pyrolysis of the PBN-PCS-PMS in inert atmosphere at 1 400 ℃. XRD, elemental analysis, 29Si and 13C MAS NMR indicated it is a near-stoichiometric β-SiC when the mass ratio of PCS to PBN-PMS is 0.25∶1.00.
