Kinetic study by TGA of the effect of oxidation inhibitors for carbon-carbon composite

The corrosion by air oxidation of the carbon fiber reinforced carbon composites can be inhibited by adding glass-forming particles to the matrix during the impregnation process. The effectiveness of the inhibition is related to the formation, wetting and spreading of the glass on the carbon matrix. The glass acts as a blockage onto the carbon active sites forming a thin protection barrier against oxygen diffusion. This work intends to evaluate the influence of the reactivity of the composite components on the inhibition effectiveness obtained by the addition of boron carbide and amorphous boron to the carbon matrix. Bi-directional composites were obtained with carbon matrix derived from phenolic resin using both carbonized and graphitized carbon fibers. The oxidation resistance of the composites was carried out by a weight loss in a thermogravimetric analyzer and activation energy calculation through Arrhenius plot for oxidation in air. The inhibition effectiveness depended on the reactivity of the individual components of the composite. (C) 2003 Elsevier Science B.V. All rights reserved.