可加工气凝胶复合隔热材料的制备及性能表征

针对中高温领域热防护需求,以正硅酸乙酯作为硅源,通过溶胶-凝胶(sol-gel)工艺结合超临界干燥技术制备了可加工高效气凝胶复合隔热材料。对气凝胶复合隔热材料的微观结构、热物理性能及力学性能进行了表征和分析。结果表明:气凝胶纳米粒子均匀分布在复合材料中,组成三维网络结构,孔径在70nm以下,比表面积在800-1000m2/g。热学性能显示,气凝胶复合材料在300℃的导热系数为0.03W/mK,800℃/20min,线收缩1%;力学性能显示,压缩强度为0.2MPa。此外,复合材料具有优异的加工性能。

Preparation and Characterization of Machinable Airgel Composite Insulation Materials

In view of thermal protection requirements in the high temperature field, composite aerogel materials were fabricated by sol-gel method and supercritical drying technique. The thermal physical properties and microstructure, properties of aerogel composite insulation materials were characterized and analyzed. The results show that： aerogel nanoparticles were uniformly distributed in the composite materials, which constituted infinite through channels and the hole diameter is below 70nm. Otherwise, the specific surface area is 800-1000m^2/g. Thermal conductivity of aerogel is 0.03W/InK, line shrinkage is below 1% at 1200℃/20min. Composite aerogel materials＇compression strength is 0.2MPa, and possess excellent machining.