低密度酚醛树脂基热防护复合材料的制备及性能

Preparation and Properties of Low Density Phenolic Resin Based Thermal Protection Composites

烧蚀热防护是目前最成熟且应用最广泛的一种卫星再入防热措施。本工作以酚醛树脂为基体,加入固体填料(空心玻璃微球、空心二氧化硅微球及空心酚醛微球)及纤维(石英纤维、碳纤维)制成一种低密度酚醛树脂基烧蚀热防护复合材料,并通过抗弯和压缩强度测试,隔热测试,烧蚀测试等方法对复合材料的性能与组分配比的关系及复合材料的烧蚀机理进行了分析。对比力学性能、隔热性能及抗烧蚀性能发现,复合材料密度的提高以及碳纤维含量的提高有助于提升复合材料的综合性能,最佳配比为密度0.6 g/cm^(3)、5%石英纤维+5%碳纤维。对比烧蚀前后的成分发现,酚醛树脂在高温下炭化后会与SiO_(2)反应生成SiC,有助于提升复合材料的抗烧蚀性能。

Ablative thermal protection is the most mature and widely used thermal protection measure for satellite re-entry at present.In this work,a low-density phenolic resin based ablative thermal protection composite was prepared by taking phenolic resin as the matrix,adding solid fillers(hollow glass microspheres,hollow silica microspheres and hollow phenolic microspheres)and fibers(quartz fibers and carbon fibers).The relationship between the properties of the composites and the component distribution ratio and the ablation mechanism of the composites were analyzed through relevant characterization.Comparing the mechanical properties,thermal insulation and ablation resistance,it is found that the increase of the density and carbon fiber content of the composite is helpful to improve the comprehensive properties of the composite.The best ratio is 0.6 g/cm^(3)density,5%quartz fiber+5%carbon fiber.Comparing the components before and after ablation,it is found that phenolics resin will react with SiO_(2)to form SiC after carbonization at high temperature,which is helpful to improve the ablation resistance.