Facile synthesis of lithium containing polyhedral oligomeric phenyl silsesquioxane and its superior performance in transparency, smoke suppression and flame retardancy of epoxy resin
Facile synthesis of lithium containing polyhedral oligomeric phenyl silsesquioxane and its superior performance in transparency, smoke suppression and flame retardancy of epoxy resin
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DOI：
10.1016/j.compscitech.2020.108004
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发表时间：
2020-03
影响因子：
9.1
通讯作者：
Xinming Ye;Wenchao Zhang;Rongjie Yang;Jiyu He;Jiarong Li;F. Zhao
中科院分区：
文献类型：
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作者：
Xinming Ye;Wenchao Zhang;Rongjie Yang;Jiyu He;Jiarong Li;F. Zhao
燃烧过程中有毒挥发物和烟雾的大量释放是环氧树脂复合材料面临的最大问题之一，因此，获得一种既能提高阻燃性能又能减少烟雾和有毒气体释放的阻燃剂仍然是一个巨大的挑战。本文通过苯基三乙氧基硅烷在LiOH·H2O存在下的水解缩合反应，合成了一种新型的含锂多面体低聚苯基倍半硅氧烷(Li-Ph-POSS)。通过FTIR、核磁共振和MALDI-TOF-MS对Li-Ph-POSS的结构进行了表征，结果表明它是由不完全缩合的Si-OH和Si-O-Li基团组成的七苯基POSS。通过扫描电子显微镜和透射电子显微镜观察到Li-Ph-POSS在EP/Li-Ph-POSS纳米复合材料中具有良好的相容性和分散性。用锥形量热仪、烟密度和极限氧指数法研究了EP/Li-Ph-POSS纳米复合材料的有效抑烟和阻燃性能。与纯EP相比，添加4wt%Li-Ph-POSS的EP的放热率峰值(p-HRR)、总释热率(THR)、产烟率峰值(p-SPR)和CO产生率峰值(p-COP)分别降低了61%、36%、44%和72%。这项工作为使用无磷无卤金属POSS降低EP的火灾危险性提供了新的策略。
Massive release of toxic volatiles and smoke during combustion is one of the biggest problems facing epoxy resin composites, therefore, it is still a huge challenge to obtain a flame retardant that can simultaneously improve the flame retardancy and reduce the evolution of smoke and toxic gases. Herein, a novel lithium containing polyhedral oligomeric phenyl silsesquioxane (Li-Ph-POSS) has been prepared via hydrolysis condensation of phenyltriethoxysilane in the presence of LiOH·H2O. FTIR, NMR, and MALDI-TOF-MS were used to identify the structure of Li-Ph-POSS, which indicate that it is a hepta-phenyl POSS comprised of incompletely condensed Si–OH and Si–O–Li groups. The excellent compatibility and dispersion of Li-Ph-POSS in EP/Li-Ph-POSS nanocomposites were detected by SEM and TEM. The effective smoke suppression and flame retardancy of EP/Li-Ph-POSS nanocomposites were investigated using cone calorimeter, smoke density and limited oxygen index measurements. Compared with pure EP, the EP with 4 wt% Li-Ph-POSS made the peak of heat release rate (p-HRR), total heat release (THR), peak of smoke production rate (p-SPR) and peak of CO production rate (p-COP) reduce by 61%, 36%, 44%, and 72%, respectively. This work provides a new strategy of mitigating the fire hazard of EP using phosphorus- and halogen-free metal-POSS.