Structural characterization and thermal oxidation resistance of silicon oxycarbides produced by polysiloxane pyrolysis

Oxycarbides were produced by pyrolysis of polysiloxanes with different contents of methyl/phenyl groups at 1000 °C under nitrogen atmosphere. The structure of the three silicon oxycarbides was studied by elemental analysis, spectroscopy, and X-ray diffraction. The free carbon phase was concentrated by treatment with hydrofluoric acid. The sp2 graphene planes merged in sp3 structures form the free carbon phase. Its content and location in the SiOC network and its structural pattern reflects the sp2/sp3 ratio of the source polysiloxanes.