二氧化硅气凝胶/硅酸铝复合纤维纸的制备及其耐热与力学性能研究

Preparation,heat resistance and mechanical properties of silica aerogel/aluminum silicate composite fiber paper

硅酸铝纤维作为一种传统的隔热材料,高温后结构易坍塌,力学性能下降明显。本文以硅酸铝纤维纸作为结构框架,在其纤维表面利用溶胶凝胶法构建二氧化硅(SiO_(2))气凝胶,得到SiO_(2)气凝胶/硅酸铝复合纤维纸,复合后纤维纸耐热温度从800℃提高到1100℃,直到1100℃煅烧后,拉伸强度由9.01 MPa提升至20.41 MPa,断裂伸长率由2.36%提升到3.52%。并且对比了不同碱性pH(8,9,10)环境下制备出的复合纤维纸的微观形貌,发现pH为8时,SiO_(2)气凝胶颗粒与硅酸铝纤维纸之间的复合效果最好。

Aluminosilicate fiber paper is a traditional kind of thermal insulation material.When it is used at a relatively high temperature,its structure easily collapses,resulting in the significantly deteriorated mechanical properties.In this paper,silica(SiO_(2))aerogel/aluminum silicate composite fiber papers were prepared on the structure of aluminum silicate fibers with SiO_(2) aerogel by a sol gel process.The heat resistance of the as-prepared composite fiber papers was obvious increased from 800℃to 1100℃,and their structures began to collapse until 1100℃.The tensile strength of the SiO_(2) aerogel/aluminum silicate composite fiber papers was increased from 901 MPa to 2041 MPa,and the elongation at break was increased from 236%to 352%.By comparing the micro morphology of the composite fiber papers prepared under different pH(8,9 and 10),the combination between the SiO_(2) aerogels and aluminum silicate fiber was the best at pH of 8.