纤维增强气凝胶柔性隔热复合材料的制备  

Preparation of Flexible Fiber-Reinforced Aerogel Composites for Thermal Insulation

作　　者：冯军宗[1] 冯坚[1] 王小东[1] 高庆福[1] 武纬[1] 

机构地区：[1]国防科技大学航天与材料工程学院CFC国防科技重点实验室,湖南长沙410073

出　　处：《稀有金属材料与工程》2008年第A02期170-173,共4页Rare Metal Materials and Engineering

摘　　要：以正硅酸乙酯(TEOS)为原料,酸碱催化两步法配制溶胶,浸渍柔性纤维毡后进行超临界干燥制备柔性隔热复合材料。研究表明,随着超临界干燥溶胶之前老化时间的延长(1h～7d),复合材料在600℃下的抗拉强度变大(0.13～0.21MPa),红外光谱分析确定是由于其水解程度变大。复合材料中的纯气凝胶比表面积为209.8m2/g,平均孔径为18.8nm。场发射扫描电镜照片表明气凝胶很好地填充于纤维之间,避免了纤维与纤维的接触。从而柔性复合材料具有低热导率,120、500℃下分别为0.019、0.054W/m.K。Flexible fiber-reinforced SiO2 aerogel composites were prepared by forming SiO2 aerogel interstitially within a flexible fiber matrix, using tetraethoxysilane （TEOS） precursor by two-step acid-base catalyzed sol-gel process followed by soaking and supercritical drying. It has been observed that the tensile strength increased from 0.013 to 0.21 MPa at 600 ℃ with the increase in the aging time before drying the sol from l h to 7 d due to the various extent of hydrolyzation analyzed by FT-IR. The surface area of the aerogel was 209.6 m2/g and the average pore diameter was 18.Snm. Fiber-fiber contact was substantially avoided and the aerogel finely filled in the porous fiber matrix as shown by FE-SEM. So the flexible composites have a low thermal conductivity such as 0.019, 0.054 W/m.K at 120 ℃ and 500 ℃, respectively.

关 键 词：SIO2气凝胶 柔性 隔热材料 溶胶-凝胶 

分 类 号：TB332[一般工业技术—材料科学与工程]