Achieving Improved Ablative Performance by Enhancing the Interfacial Interaction between Silicone Rubber and Carbon Fiber Reinforcements

In the aerospace and fire protection sectors, silicone rubber composites exhibit large deformability and outstanding thermal protection performance. However, the interface between silicone rubber and carbon fiber is easily destroyed under external tensile deformation, thereby leading to the formation of cracks that deteriorate thermal insulation and ablative performance. This study introduces an interfacial strengthening strategy that deposits a silica layer onto carbon fibers via polydopamine-assisted modification and modifies the silicone rubber matrix with epoxy resin, achieving an 11.86-fold enhancement in terms of interfacial shearing strength. The optimized interface between short-cut carbon fiber and vinyl silicone rubber matrix significantly reduces the mass ablative rate by 13% and lowers the back-face temperature by 54.7 °C during oxyacetylene ablation tests under 10% tensile strain. This work provides a strategy to simultaneously improve the ablative and mechanical properties of flexible thermal protection materials that have promising applications in industrial sectors.