High-temperature behavior of silicon oxycarbide glasses in air environment

Silicon oxycarbide glasses (SiOC) have been produced by siloxane resin under flowing argon at 1000 °C and then their evolutions in air from 800 to 1700 °C were investigated. Those glasses annealed at various temperatures were characterized by X-ray diffraction, 29Si MAS NMR, Raman spectroscopy, and chemical element analysis. It can be found that oxidation reactions of the SiOC glasses occurred at above 1000 °C; carbothermal reduction was indiscernible at temperature below 1600 °C but almost finished at 1700 °C; and the decomposition of SiOxC4−x network was complete at 1400 °C.