Improved interfacial strength and ablation resistance of carbon fabric reinforced phenolic composites modified with functionalized ZrSiO₄ sol

The using performance of carbon fabric reinforced phenolic composites in the aerospace industry is determined by the fibre/matrix interfaces performance and ablation resistance. To enhance these properties, a functionalized ZrSiO₄ sol was prepared and sprayed onto carbon fabric, and then the coated fabric was impregnated with resin to fabricate the composite. The ablation resistance and interlaminar shear strength of the composite were investigated. Results showed that the functionalized ZrSiO₄ sol had positive effect on composite modification. Due to the improved interfacial adhesion between the carbon fabric and resin, the shear strength of the functionalized ZrSiO₄ sol modified composite increased by 11% compared to the unmodified composite. Furthermore, the mass ablation ratio of the functionalized ZrSiO₄ sol modified composite was 30% lower than that of the unmodified composite. The surface ceramic layer with a main phase composition of ZrO₂ provided an oxygen insulating effect and protected the inner material from serious oxidative ablation. These results confirm that the interlaminar shear strength and ablation resistance of the composite were both significantly enhanced, making this composite be suitable for more severe ablation environments.