改性SiO_(2)气凝胶隔热材料的制备及其性能

Preparation and properties of modified SiO_(2) aerogel thermal insulation materials

为提高二氧化硅气凝胶材料的综合性能,采用酸-碱两步法成功制备改性二氧化硅气凝胶,并以芳纶纤维毡为骨架支撑体与二氧化硅气凝胶进行复合。利用红外光谱、X射线衍射、扫描电镜及能谱等对其进行表征,测试并分析其疏水性能、整体热防护性能及阻燃性。结果表明,改性二氧化硅气凝胶属于疏水型材料(接触角为133.89°),其热防护值(TPP)、辐射热传导指数(RHTI 24)和对流热传导指数(CHTI 24)依次为645.46±54.38 kW·s·m^(-2)、12.5 s、9.1 s。阻燃性能测试结果显示试样的损毁长度为40 mm,未出现阴燃、续燃、熔融、滴落等现象。参照行业标准,改性二氧化硅气凝胶材料的关键指标达到隔热材料的要求,其在航空航天、化工、建筑、消防等领域具有潜在的应用前景。

In order to improve the comprehensive performance of silica aerogel material,modified silica aerogel was successfully prepared via acid-base two-step method.The aramid fiber felt was used as the skeleton support body which compounded with silica aerogel.The composite was characterized by infrared spectrum,X-ray diffraction,scanning electron microscope and energy spectrum.The hydrophobicity,overall thermal protection,and flame retardancy of the composite were tested.The results show that the modified silica aerogel belongs to hydrophobic material.The contact angle is 133.89°.The thermal protection value(TPP),radiative heat transfer index(RHTI 24) and convective heat transfer index(CHTI 24) are 645.46±54.38 kW·s·m^(-2),12.5 s and 9.1 s,respectively.Flame retardant test shows that the damaged length of the sample is 40 mm,and there is no smouldering,secondary combustion,melting,dripping and other phenomena.According to industry standard,the key indicators of modified silica aerogel material meet the requirements of heat insulation material.It has potential application prospects in the field of aerospace,chemical industry,construction,and fire protection.