含硅阻燃大分子相容剂的制备及其在无卤阻燃聚乙烯复合材料中的协效作用

为验证含硅大分子相容剂在无卤阻燃体系中的协效阻燃作用,首先,以马来酸酐、硅橡胶与聚乙烯为原料,通过熔融接枝共聚制备了新型含硅阻燃大分子相容剂;然后,利用氢氧化铝、氢氧化镁和含硅大分子相容剂复配协同阻燃聚乙烯复合材料;最后,探讨了含硅大分子相容剂对复合材料极限氧指数、锥形量热参数、拉伸性能以及微观结构的影响。结果表明:与聚乙烯接枝马来酸酐相比,含硅大分子相容剂含量为10wt%时可使无机阻燃剂在基体树脂中分散较好;随着大分子相容剂含量的增加,复合材料的拉伸强度上升而断裂伸长率下降,极限氧指数提高至34.0%,燃烧时的热释放速率峰值和热释放总量均明显下降,说明含硅大分子相容剂除了能够在该复合材料中起到良好的相容作用外,还可以发挥较好的协效阻燃作用。

Preparation of silicon-containing flame-retardant macromolecular compatibilizer and its synergistic effects on halogen-free flame-retardant polyethylene composites

In order to verify the synergistic flame-retardant effects of silicon-containing macromolecular compatibilizer in halogen-free flame-retardant systems, using maleic anhydride, silicone rubber and polyethylene as raw materials, a novel silicon-containing flame-retardant macromolecular compatibilizer was prepared by melting graft copolymerization firstly. Then the polyethylene composites were inflaming retarded synergistically by compounding of aluminium hydroxide, magnesium hydroxide and silicon-containing macromolecular compatibilizer. Finally, the effects of silicon-containing macromolecular compatibilizer on limiting oxygen index, parameters of cone calorimetry, tensile properties and microstructures of the composites were investigated. The results show that compared with polyethylene grafted maleic anhydride, when the silicon-containing macromolecular compatibilizer content is 10wt%, the inorganic flame-retardants are dispersed better in matrix resin. With the macromolecular compatibilizer content increasing, the tensile strength of composite increases but the elongation at break decreases. The limiting oxygen index increases to 34.0%, and the peak value of heat release rate and total heat release of burning decrease siginificantly, which means that the silicon-containing macromolecular compatibilizer can not only play a favorable compatible role in the composites, but also shows a better synergistic flame-retardant effect.