莫来石纤维增强SiO2气凝胶复合材料的制备及性能研究

以正硅酸乙酯为硅源,采用溶胶-凝胶及超临界干燥技术制备了掺杂莫来石纤维的SiO2气凝胶复合材料,并对材料的热学性能和力学性能进行了测试,结果表明:SiO2气凝胶复合材料的热导率与其密度、温度和纤维添加量有关;添加莫来石纤维可以明显提高SiO2气凝胶的弹性模量和机械强度,改善材料的力学性能;莫来石纤维添加量控制在3%左右可以使SiO2气凝胶材料保持较低的热导率和较高的机械强度.

Study on preparation and performance of SiO2 aerogels composites reinforced by mullite fiber

SiO_2 aerogels composites were prepared via sol-gel process and super drying technique using tetraethoxysilane(TEOS)as precursor,and the thermal and mechanical properties of the composites were tested.The results show that the thermal conductivity of the composites was related with density,temperature and the quantity of adding fiber,adding mullite fiber can increasd the elastic modulus and mechanical strength of SiO_2 aerogels composites markedly,and as a result the mechanical property of the composites was improved,controlling the quantity of the adding mullite fiber at 3% or so can make SiO_2 aerogels composites keeping low thermal conductivity and high mechanical strength.