Abstract：
Lightweight ablative thermal protection materials (TPMs), which can resist long-term ablation in an oxidizing atmosphere, are urgently required for aerospace vehicles. Herein, carbon fabric/phenol-formaldehyde resin/siloxane aerogels (CF/PFA/SiA) nanocomposite with interpenetrating network multiscale structure was developed via simple and efficient sol-gel followed by atmospheric pressure drying. The ternary networks structurally interpenetrating in macro-, micron-, and the nanoscales, chemically cross-linking at the molecular scale, and silica layer generated by in situ heating synergistically bring about low density (∼0.3 g cm-3), enhanced mechanical properties, thermal stability, and oxidation resistance, and a low thermal conductivity of 81 mW m-1 K-1. More intriguingly, good thermal protection with near-zero surface recession at 1300 °C for 300 s and remarkable thermal insulation with a back-side temperature below 60 °C at 20 mm thickness. The interpenetrating network strategy can be extended to other porous components with excellent high-temperature properties, such as ZrO2 and SiC, which will facilitate the improvement of lightweight ablative TPMs. Moreover, it may open a new avenue for fabricating multifunctional binary, ternary, and even multiple interpenetrating network materials.
摘要：
轻质烧蚀热防护材料（TPM），可以抵抗氧化气氛中的长期消融，是航空航天飞行器迫切需要的。在这里，通过简单高效的溶胶-凝胶，然后进行常压干燥，开发了具有互穿网络多尺度结构的碳织物/酚醛树脂/硅氧烷气凝胶（CF/PFA/SiA）纳米复合材料。三元网络结构在宏观中互穿，micron-,和纳米尺度，分子尺度的化学交联，和原位加热产生的二氧化硅层协同产生低密度(~0.3gcm-3)，增强的机械性能，热稳定性，和抗氧化性，和81mWm-1K-1的低热导率。更有趣的是，良好的热保护，在1300°C下接近零的表面凹陷持续300s，并且在20mm厚度下具有低于60°C的背面温度的显着隔热。互穿网络策略可以扩展到其他具有优异高温性能的多孔组件，如ZrO2和SiC，这将促进轻质烧蚀TPM的改进。此外，它可能会为制造多功能二进制文件开辟一条新途径，三元，甚至多种互穿网络材料。
