Oxidation behavior of carbon materials derived from a carborane- and silicon-incorporated polymer

摘要

The oxidation behavior and oxidation mechanism of carbon materials containing silicon and boron elements (C-Si-B materials) were investigated at different high temperatures in air. The carbon materials were prepared by oxidative pyrolysis of the polymer precursor, carborane-incorporated poly(dimethylsilylene-ethynylenephenyleneethynylene) (CB-PSEPE), at 800, 1000, or 1200 °C for 1 h under static air. Homogeneous dispersion of silicon and boron components in the carbon matrix could be achieved in the carbon materials after the pyrolysis. The oxidation behavior of the C-Si-B materials during the oxidation process was studied. The evolution of elemental composition and morphology of the surface layers of carbon materials was monitored by X-ray photoelectron spectroscopy and scanning electron microscopy, respectively. The results imply that the formation of protective borosilicate layer in the surface is the main mechanism to provide remarkable oxidation resistance of the carbon materials. The obtained borosilicate layer with a self-healing property can withstand oxidation at 1000 °C in air.