Effect of MoO3 on mechanical interfacial behavior and anti-oxidation of carbon fibers-reinforced composites

In this study, the effect of MoO3 content on the mechanical interfacial properties and the anti-oxidation behaviors of carbon–carbon (C/C) composites were investigated. The MoO3 content was varied to 0, 5, 10, 20, and 30 wt% of the resin matrix. These composites were prepared by a one-direction filament winding method, and were subjected to carbonization (heat-treatment at 1100 °C). As a result, the anti-oxidation behavior and mechanical interfacial properties improved with increasing MoO3 content at respective heat-treatment temperatures. This is because MoO3 penetrated the composites through the cracks or pores formed during the manufacturing of the C/C composites and preferentially reacted with oxygen, thereby decreasing the rate of oxidation. This disturbed the carbon active species in the composites, increasing the physical cohesion between the interfaces of the carbon fibers and matrices, and improving thermal stability.