不同阴离子插层的ZnMgAl层状双氢氧化物对聚氨酯弹性体阻燃抑烟性能的影响

摘要

NO3--and Mo7O246-intercalated ZnMgAl ternary layered double hydroxide (NO3-ZnMgAl LDHs,MoZnMgAl LDHs) was prepared by the hydrothermal method and ion exchange,respectively.The flame retardancy and smoke suppression of polyurethane elastomer (PUE) composites were studied by adding two ternary LDHs with different proportions.Both the cone calorimeter combustion and smoke density tests show that the peak heat release rate (PHRR) and maximum smoke density (D) of the pure PUE are 920 kW/m2 and 452,respectively.When the mass fraction of NO3-ZnMgAl LDHs is up to 7wt％,the PHRR and D are 377 kW/m2 and 216,respectively.With the same loading of Mo-ZnMgAl LDHs,the PHRR and D are 343 kW/m2 and 190,respectively.Both ternary LDHs possess notable flame retardancy and smoke suppression effects on PUE composites.LDHs/PUE composites have better flame retardancy and smoke suppression with Mo-ZnMgAl LDHs.TGA measurement confirms that the addition of two ternary LDHs can both promote the charring formation of LDHs/PUE composites and improve the char residue rate.LRS and XPS confirm that they could improve the graphitization degree of the char residue which can in turn enhance the thermal oxidation resistance of the char layer.Furthermore,the Mo-ZnMgAl LDHs can raise the char residue and graphitization degree and strengthen the thermal oxidation resistance,which could effectively protect the substrate material from heat radiation,and consequently oxygen could be isolated,meanwhile,the volatilization of combustible gas could be restrained.%分别以水热法及离子交换法制备了NO3-和Mo7O246-插层的ZnMgAl三元层状双氢氧化物(NO3-ZnM-gAl LDHs,Mo-ZnMgAl LDHs),并分别将制得的两种LDHs添加到聚氨酯弹性体(PUE)中,研究了不同阴离子插层的LDHs对PUE阻燃抑烟性能的影响.锥形量热仪和烟密度仪研究表明,纯PUE的热释放速率峰值(PHRR)及最大烟密度值(Ds,max)分别为920 kW/m2和452,当NO3-ZnMgAl LDHs、Mo-ZnMgAl LDHs的质量分数为7wt％时,LDHs/PUE复合材料的PHRR和Ds,max分别降低至377 kW/m2、343 kW/m2和216、190,两种LDHs对PUE均有较好的阻燃抑烟效果,Mo-ZnMgAl LDHs的效果更显著.LDHs/PUE复合材料的TGA、残炭的拉曼光谱和XPS研究证实,两种LDHs的加入都能够促进LDHs/PUE复合材料催化成炭,提高残炭率,并且能够提高炭层的石墨化程度,使炭层的抗热氧化能力增强;另外,与NO3-ZnMgAl LDHs相比,Mo-ZnMgAlLDHs的引入能够使Mo-ZnMgAl LDHs/PUE复合材料残炭率和炭层的石墨化程度更高,抗热氧化能力更强,有效地保护基体材料避免受热辐射,隔绝氧气,抑制可燃性气体的挥发.