Synthesis and Characterization of SiC(Ti) Ceramics Derived from a Hybrid Precursor of Titanium-Containing Polycarbosilane
- 化学化工－已发表论文 
A hybrid precursor of titanium-containing polycarbosilane is prepared by blending hyperbranched polycarbosilane (HBPCS) and tetrabutyl titanate (TBT), and then crosslinking at 160 A degrees C, followed by pyrolyzing at high temperatures to afford SiC(Ti) ceramics. The crosslinking reaction of HBPCS-TBT hybrid precursor is investigated by FT-IR, solid state (29)Si MAS NMR, and GPC. The results indicate that the crosslinking reaction takes place via condensation between the Si-H bond of HBPCS and butoxy group in TBT leading to the formation of Si-O-Ti bonds. The thermal properties and structural evolution of crosslinked hybrid precursor and the crystallization behavior and composition of final ceramics are investigated by TGA, FT-IR, Raman spectroscopy, XRD and energy dispersive elemental analysis. The ceramic yield of hybrid precursor is significantly enhanced by introduction of TBT. The ceramic yield at 1,400 A degrees C is 83% for HBPCS-TBT-5 as measured by TGA. The Ti-content in the ceramic is controlled by varying the TBT content in the feed. The SiC(Ti) ceramic is amorphous at 900 A degrees C. The characteristic peaks of beta-SiC and TiC appear until 1,600 A degrees C. The growth of SiC crystals is inhibited by the formation of TiC.
CitationJOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS，2011,21（3）：412-420