Chen Peng, Zhao Yunliang, Wang Wei, Zhang Tingting, Song Shaoxian
School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China.
Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China.
Polymers (Basel). 2019 Jan 26;11(2):213. doi: 10.3390/polym11020213.
Polymer⁻clay membranes constructed via the layer-by-layer (LbL) assembly, with a nanobrick wall structure, are known to exhibit high flame retardancy. In this work, chitosan⁻montmorillonite nanosheet (CH⁻MMTNS) membranes with different thickness of MMTNS were constructed to suppress the flammability of flexible polyurethane (FPU) foam. It was found that a thinner MMTNS membrane was more efficient in terms of reducing the flammability of the FPU foam. This was because such MMTNS membrane could deposit cheek by jowl and form a dense CH⁻MMTNS membrane on the foam surface, thus greatly limiting the translation of heat, oxygen, and volatile gases. In contrast, a thicker MMTNS constructed a fragmentary CH⁻MMTNS membrane on the coated foam surface, due to its greater gravity and weaker electrostatic attraction of chitosan; thus, the flame retardancy of a thick MMTNS membrane was lower. Moreover, the finding of different deposition behaviors of MMTNS membranes with different thickness may suggest improvements for the application of clay with the LbL assembly technology.
通过层层（LbL）组装构建的具有纳米砖壁结构的聚合物-粘土膜具有很高的阻燃性。在这项工作中，构建了具有不同蒙脱石纳米片（MMTNS）厚度的壳聚糖-蒙脱石纳米片（CH-MMTNS）膜，以抑制柔性聚氨酯（FPU）泡沫的可燃性。结果发现，较薄的MMTNS膜在降低FPU泡沫可燃性方面更有效。这是因为这种MMTNS膜可以紧密堆积并在泡沫表面形成致密的CH-MMTNS膜，从而极大地限制了热、氧气和挥发性气体的传递。相比之下，较厚的MMTNS由于其更大的重力和壳聚糖较弱的静电吸引力，在涂覆的泡沫表面构建了破碎的CH-MMTNS膜；因此，厚MMTNS膜的阻燃性较低。此外，不同厚度的MMTNS膜具有不同沉积行为的发现可能为粘土在LbL组装技术中的应用改进提供思路。
