Polymer-Derived SiOC/ZrO_2 Ceramic Nanocomposites with Excellent High-Temperature Stability

摘要

Polymer-derived SiOC/ZrO_2 ceramic nanocomposites have been prepared using two synthetic approaches. A commercially available polymethylsilsesquioxane (MK Belsil PMS) was filled with nanocrystalline zirconia particles in the first approach. The second method involved the addition of zirconium tetra(n-prop-oxide), Zr(O~nPr)_4, as zirconia precursor to polysilsesquioxane. The prepared materials have been subsequently cross-linked and pyrolyzed at 1100℃ in argon atmosphere to provide SiOC/ ZrO_2 ceramics. The obtained SiOC/ZrO_2 materials were characterized by means of X-ray diffraction, elemental analysis, Raman spectroscopy as well as transmission electron microscopy. Furthermore, annealing experiments at temperatures from 1300° to 1600℃ have been performed. The annealing experiments revealed that the incorporation of ZrO_2 into the SiOC matrix remarkably increases the thermal stability of the composites with respect to crystallization and decomposition at temperatures exceeding 1300℃. The results obtained within this study emphasize the enormous potential of polymer-derived SiOC/ZrO_2 composites for high-temperature applications.