Preparation method of silicon dioxide-phenolic resin aerogel felt for bridge fire resistance

The invention discloses a preparation method of a silicon dioxide-phenolic resin aerogel felt for bridge fire resistance, which comprises the following steps: (1) fully mixing raw materials sodium silicate, aluminum silicate, ethanol and water in a container at room temperature, stirring for about 15 minutes, and adding acetic acid to obtain sol; (2) putting the sol and phenolic resin mixed solution into a reaction container to form gel; coating a supporting material with the gel to form a silicon dioxide-phenolic resin aerogel felt precursor; and (3) soaking the gel felt in ethanol so that the gel felt absorbs moisture and is softened. And finally preparing the fire-resistant flexible silicon dioxide-phenolic resin aerogel felt through a vacuum freeze drying method. 本发明公开了一种桥梁抗火用二氧化硅-酚醛树脂气凝胶毡的制备方法，包括以下步骤：(1)在室温下将原材料硅酸钠、硅酸铝以及乙醇和水比充分混合于容器，搅拌约15min，加入醋酸，得到溶胶。(2)将溶胶与酚醛树脂混合液放入反应容器，形成凝胶体。将凝胶体涂覆在支撑材料，形成的二氧化硅-酚醛树脂气凝胶毡前驱体。(3)将凝胶毡置于乙醇中浸润使凝胶毡吸湿柔化。而后通过真空冷冻干燥的方法，最终制备出抗火用柔性二氧化硅-酚醛树脂气凝胶毡。