Significantly improved ablation properties under high heat flux environment based on carbon fiber reinforced Zr-doped silicone rubber

In order to improve the ablative properties of silicone-rubber (SR) based ablative coatings under high heat flow, firm char layer required to be formed during ablation. Herein, Zr-doped SR composites with significantly improved ablation properties were prepared by co-blending synthesized zirconium-doped polydimethylsiloxane and short-cut carbon fibers (Zr-PDMS-CF). Compared to carbon fiber modified pure polydimethylsiloxane (PDMS-CF) and ZrO2-modified PDMS-CF (ZrO2 @PDMS-CF), the mass ablation rates were decreased by 28.96% and 28.53%, respectively, and the linear ablation rates were decreased by 47.88% and 38.20%, respectively. Compared to PDMS-CF and ZrO2 @PDMS-CF, the compressive strength of char layer of Zr-PDMS-CF was also significantly enhanced. In addition to the well distribution of t-ZrO2 crystals in the char layer of Zr-PDMS-CF, the homogeneous distribution of zirconium elements was also beneficial to protect CFs skeleton from severe oxidation. The char layer of Zr-PDMS-CF thus possessed the ability to resist erosion under high heat flow, protecting underneath materials from further oxidation and erosion.

Automated summary

Zr-doped silicone-rubber (SR) ablative coatings with improved ablation properties were prepared by blending synthesized zirconium-doped polydimethylsiloxane and short-cut carbon fibers (Zr-PDMS-CF). Compared to carbon fiber modified pure polydimethylsiloxane (PDMS-CF) and ZrO2-modified PDMS-CF (ZrO2 @PDMS-CF), Zr-PDMS-CF showed decreased mass and linear ablation rates and enhanced compressive strength of the char layer. The distribution of t-ZrO2 crystals and zirconium elements in the char layer contributed to the improved resistance against oxidation and erosion.