Carbon/carbon composites derived from phenolic resin/silica hybrid ceramers Part I Oxidation resistance and morphological properties

A novel phenolic resin/silica hybrid ceramer fabricated via the sol-gel method was prepared. Hybrid systems with different inorganic contents were used as the matrix precursors to fabricate the silica containing carbon/carbon composites. Isothermal oxidation tests at temperatures ranging between 650°C and 750°C were employed to investigate how the oxidation resistance of the derived carbon/carbon composites is improved. Furthermore, the isothermal oxidation test results between 550°C and 615°C were used to calculate the activation energy of oxidation. Experimental results demonstrate that the silica containing carbon/carbon composites have a better oxidation resistance than those derived from pure phenolic resins. Meanwhile, morphological observations indicate that the oxidation of carbon fibers is retarded in the phenolic resin/silica hybrid derived carbon/carbon composites.