Bi-phase fire-resistant polyethylenimine/graphene oxide/melanin coatings using layer by layer assembly technique: Smoke suppression and thermal stability of flexible polyurethane foams
Bi-phase fire-resistant polyethylenimine/graphene oxide/melanin coatings using layer by layer assembly technique: Smoke suppression and thermal stability of flexible polyurethane foams
复制标题
采用层层组装技术的双相阻燃聚乙烯亚胺/氧化石墨烯/黑色素涂层：软质聚氨酯泡沫的抑烟和热稳定性
DOI：
10.1016/j.polymer.2019.03.008
复制
发表时间：
2019-04-29
期刊：
影响因子：
4.6
通讯作者：
Kuang, Tairong
中科院分区：
文献类型：
--
作者：
Shi, Xingxing;Yang, Peng;Kuang, Tairong
为了实现软质聚氨酯(PU)泡沫塑料的高效防火涂层，在PU泡沫塑料表面构建了聚乙烯亚胺(PEI)、氧化石墨烯(GO)和合成黑色素纳米颗粒(SMNPs)的层层组装技术。SMNPs优异的自由基清除能力和高温热稳定性使其可用作后续涂层工艺的阻燃剂。扫描电子显微镜(SEM)照片表明，所制备的PEI/GO/SMNPs涂层沿泡沫塑料的胞壁均匀沉积在PU泡沫塑料表面。热重分析(TGA)结果表明，与纯泡沫塑料和双层包覆(BL包覆)PU泡沫塑料相比，三层包覆(TL包覆)泡沫塑料具有更好的热氧稳定性和较低的热解速率。在火炬燃烧实验中，仅包覆一层PEI/GO/SMNPs的PU-1TL泡沫塑料的火焰能够自动熄灭，并且完整地保持了整个泡沫塑料的原始形状。锥体比色仪测试表明，涂层泡沫能有效地抑制热和烟的释放，高石墨化炭层的形成有利于阻燃性能的提高。此外，热重分析/红外光谱(TG-IR)结果表明，SMNPs有效地抑制了有机气体和有毒气体在气相中的挥发，这归因于SMNPs对GO的层状屏蔽和自由基捕获效应。这些结果表明，合成黑色素材料是一种很有前途的阻燃聚合物添加剂，而PEI/GO/SMNPs涂层在气固相中起到了改善PU泡沫阻燃的作用。
In an effort to achieve a high-efficient fire-resistant coating for the flexible polyurethane (PU) foams, a layer-bylayer assembly technique of polyethylenimine (PEI), graphene oxide (GO) and synthetic melanin nanoparticles (SMNPs) was constructed on the surface of PU foams. The preeminent radical scavenging capacity and high-temperature thermal stability of SMNPs enable it to be applied as a flame retardant for the subsequent coating process. Scanning electron microscope (SEM) images indicate that the as-fabricated PEI/GO/SMNPs coatings are uniformly deposited on the PU foam along the cell walls. In contrast with pure and bilayer-coated (BL-coated) PU foams, thermogravimetric analysis (TGA) reveals that the trilayer-coated (TL-coated) foam exhibits a better thermos-oxidative stability and a lower pyrolysis rate with the deposition of PEI/GO/SMNPs nanocoating. In the torch burn test, the flame of PU-1TL foam coated with only one-trilayer PEI/GO/SMNPs is able to self-extinguish and the original shape of the entire foam is intactly preserved. Cone colorimeter tests indicate that the release amount of heat and smoke can be effectively suppressed in the coated foam, and the formation of the highly graphitized char is beneficial to the improvement of the fire-resistant performance. In addition, thermogravimetric analysis/infrared spectrometry (TG-IR) results demonstrate that the volatilization of organic and toxic gases in gas phase are effectively restrained, which can be attributed to the lamellar shield of GO and radical trapping effect of SMNPs. These results illustrate that synthetic melanin material is one of the promising candidates as efficient additive in fire-resistant polymers, and the PEI/GO/SMNPs coatings play a part in gas-solid phase to improve the flame retardancy of PU foams.