纤维增强聚苯并[口恶]嗪-SiO2气凝胶复合材料阻燃隔热性能

Flame retardant and thermal insulation properties of polybenzoxazine-silicon aerogels composites with reinforced fiber

以正硅酸乙酯为硅源,与苯并[口恶]嗪单体(BO)在酸催化条件下共聚,制备聚苯并[口恶]嗪(PBO)-SiO2气凝胶。将PBO-SiO2气凝胶与纤维复合,在常温常压条件下制备纤维增强PBO-SiO2气凝胶复合材料。通过现代分析方法研究气凝胶和纤维增强气凝胶复合材料的结构特征,并采用Hot Disk热常数分析仪和石英灯单面加热测试纤维增强PBO-SiO2气凝胶复合材料的常温热导率和高温隔热性能,采用数显氧指数仪测试材料的极限氧指数(LOI)。结果表明:制备的复合材料密度为0.30 g/cm3,常温热导率为0.042 W/(m·K),LOI为37.5。复合材料具有良好的力学性能,弯曲强度为0.90 MPa,5%形变的压缩强度为0.24 MPa。热面温度为800℃,加热1000 s,材料的冷面温度仅为221℃,石英灯单面加热测试前后复合材料的形状保持不变。

Polybenzoxazine(PBO)-SiO2 aerogels were prepared by copolymerizing tetraethoxysilane as a silicon source and benzoxazine monomer(BO)under acid-catalyzed conditions.The PBO-SiO2 aerogels were compounded with fibers,and the fiber-reinforced PBO-SiO2 aerogels composites were prepared under normal temperature and pressure conditions.The structural characteristics of the aerogels and fiber-reinforced aerogels composites were investigated by modern analysis methods,the thermal conductivity at room temperature and thermal insulation at high temperature of fiber-reinforced PBO-SiO2 aerogels composites were tested using Hot Disk thermal constant analyzer and quartz lamp single-sided heating thermal measurement,the limiting oxygen index(LOI)was tested using digital oxggen index instrument.Results showed that the density of the prepared composite was 0.30 g/cm3,the thermal conductivity at room temperature was 0.042 W/(m·K),and LOI was 37.5.The composites had excellent mechanical properties,with a bending strength of 0.90 MPa and compressive strength of 5%deformation of 0.24 MPa.When the hot surface temperature was 800℃,heating for 1000 s,the cold surface temperature of the materials was only 221℃,and the shape of the composites before and after the single-sided heating test of the quartz lamp remained unchanged.