Li Meng-En, Wang Shui-Xiu, Han Lin-Xuan, Yuan Wen-Jie, Cheng Jin-Bo, Zhang Ai-Ning, Zhao Hai-Bo, Wang Yu-Zhong
Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China.
Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, China.
J Hazard Mater. 2019 Aug 5;375:61-69. doi: 10.1016/j.jhazmat.2019.04.065. Epub 2019 Apr 22.
Polyurethane foam (PUF) is widely used in building insulation field but highly flammable. In an effort to develop an efficient way to reduce flammability and smoke release of PUF without sacrificing its inherent merits, a novel strategy has been proposed to decorate silica aerogels onto the surface of PUF to fabricate hierarchically porous SiO/PUF composites. Due to the unique hierarchically porous structure, the resultant composites showed superior thermal insulation with a lower thermal conductivity of 0.0282 W/(m K). The introduction of silica aerogels also effectively improved the compressive strength, almost 220% of that of neat PUF. Notably, the SiO/PUF composites were rendered self-extinguishing in vertical burning tests and had a high limiting oxygen index (LOI) value of 32.5%. Cone calorimetry (CC) tests revealed that the peak heat release rate (PHRR) and peak smoke production release (PSPR) of the SiO/PUF composites were reduced by 40.4% and 45.6%, respectively. Particularly, the specific optical density (Ds) of the composites displayed as 55.7% reduction in the smoke density chamber tests, showing excellent smoke-suppression. The mechanism analysis suggested that a compact silica-rich hybrid barrier formed, preventing thermal degradation products and energy transfer during combustion. These results indicate SiO/PUF composites have enormous potential as building insulation materials.
聚氨酯泡沫（PUF）在建筑保温领域广泛应用，但易燃。为了开发一种在不牺牲其固有优点的情况下降低PUF可燃性和烟雾释放的有效方法，人们提出了一种新颖的策略，即在PUF表面装饰二氧化硅气凝胶以制备具有分级多孔结构的SiO₂/PUF复合材料。由于独特的分级多孔结构，所得复合材料表现出优异的保温性能，热导率低至0.0282W/（m·K）。二氧化硅气凝胶的引入还有效提高了抗压强度，几乎是纯PUF的220%。值得注意的是，SiO₂/PUF复合材料在垂直燃烧试验中具有自熄性，极限氧指数（LOI）高达32.5%。锥形量热法（CC）测试表明，SiO₂/PUF复合材料的峰值热释放速率（PHRR）和峰值烟雾产生速率（PSPR）分别降低了40.4%和45.6%。特别是，在烟雾密度室测试中，复合材料的比光密度（Ds）降低了55.7%，显示出优异的抑烟性能。机理分析表明，形成了致密的富含二氧化硅的混合阻隔层，在燃烧过程中阻止了热降解产物和能量传递。这些结果表明，SiO₂/PUF复合材料作为建筑保温材料具有巨大潜力。
