【作者】 李红霞；

【导师】 张立群；

【作者基本信息】 北京化工大学 ， 材料加工工程， 2007， 硕士

【摘要】 聚烯烃类高分子材料制作的电线电缆，在高压、热源等条件下容易引起火灾。含卤阻燃剂具有优良的阻燃性能，曾被广泛应用。但是，火灾发生时，这类含卤阻燃材料会产生大量的烟雾和有毒的腐蚀性卤化氢气体，造成“二次危害”。为此，开发新的阻燃体系，研究燃烧时发烟量小，不产生有毒、腐蚀性气体的无卤阻燃烯烃是很有必要的。无卤阻燃添加剂主要以金属氢氧化物和磷系化合物为主。这两类化合物，燃烧时不挥发、不产生腐蚀性气体，被称为无公害阻燃剂，在国内外已得到深入的研究和广泛应用。本课题主要研究氢氧化镁及其阻燃增效剂对EVA及POE复合材料力学性能和阻燃性能的影响，研制出高性能的无卤阻燃电缆料。本文首先选用形貌、粒径尺寸及分布相近的两种无机阻燃剂氢氧化铝（Al（OH）₃）和氢氧化镁（Mg（OH）₂），研究了二者用量对乙烯-醋酸乙烯酯共聚物（EVA）复合材料的力学性能和阻燃性能的影响，并比较了添加红磷的复合材料的力学性能和阻燃性能。研究表明：随着Al（OH）₃和Mg（OH）₂用量的增加，复合材料的阻燃性能提高，拉伸强度增加，但断裂伸长率下降；通过锥形量热仪数据看出：Al（OH）₃的点燃时间短，最大热释放速率和平均热释放速率低，火行为指数大，阻燃效果比Mg（OH）₂好；红磷的加入对复合材料力学性能影响不大，而对阻燃性能影响较大。Mg（OH）₂与红磷复配能提高复合材料的氧指数，而从水平和垂直燃烧角度考虑，Al（OH）₃与红磷之间的阻燃协效效果更好。但是Mg（OH）₂的烟密度小，对阻燃有利。综合比较本文确定氢氧化镁作为体系的主阻燃剂。本文还考察了Mg（OH）₂的用量对聚烯烃弹性体POE复合材料力学性能、阻燃性能、耐热性能、结晶性能和加工性能的影响。发现Mg（OH）₂用量的增加能够提高复合材料的氧指数，改善其水平燃烧和垂直燃烧效果，但只有在阻燃剂填充量为65％时才能达到最佳的阻燃效果。阻燃协效剂红磷阻燃增效Mg（OH）₂／POE复合材料并没有达到预期的效果。大量填充未改性Mg（OH）₂会导致复合材料力学性能的急剧恶化，适当的表面改性则可在很大程度上提高复合材料的力学性能。Mg（OH）₂能够显著降低复合材料的热变形率，提高其耐热性能。复合材料的熔融结晶数据表明，Mg（OH）₂加入后对POE具有异相成核作用。Mg（OH）₂的加入会导致复合材料加工粘度明显提高，特别在高填充量下，复合材料的储能模量和粘度都显著提高。本文研究了红磷、可膨胀石墨等阻燃增效剂对氢氧化镁的协同阻燃作用，确定了红磷和可膨胀石墨对氢氧化镁起增效作用的最佳用量。同时筛选出了一组最佳阻燃配方，并对其阻燃性能以及力学性能进行了研究。更多还原

【Abstract】 Polyolefin Cable can easily conflagate in heat and high pressure. Halogen flame retardant which have excellent flame retardant properties have been used widely. But they give birth to many smog and noxious gas. Accordingly, to develop non-halogenated flame-retardant system becomes an attractive and emergent subject.Among non-halogenated flame retardants, hydroxid and phosphorus-based flame retardants which was called no-social effects of pollution have been widely used in various polymeric materials. Because they can not produce noxious gas.This article study effect of Mg（OH）₂ and synergistic additives on EVA or POE composite mechanical properties and flame retardant properties. And develop good halogen-free flame retardant cable.Al（OH）₃ and Mg（OH）₂ powder, which had similar shape and particle size and distributing, were chosen as two kinds of halogen-free flame retardants for EVA. The effect of the amount of two flame retardants on the mechanical and flame retardant properties of the composites were discussed and compared with the composites incorporated with red phosphorus. The results showed that these effects were similar, which included the improvement of flame retardant properties and tensile strength, and the decrease of elongation at break as the increase of flame retardant. Shown by the results of cone calorimeter, the ignite time of Al（OH）₃ was short, the most and mean rate of heat release was low, and the flame performance index was high, the flame retardant properties was better than Mg（OH）₂. The effect of amount of red phosphorus was slight on the mechanical properties of composites, but its effect was larger on the flame retardant properties. Although the limit oxygen index of the composites of EVA increased with the increase of Mg（OH）₂ and red phosphorus, the general flame retardant properties of the composites of EVA with Al（OH）₃ and red phosphorus was better, considering the level and vertical flame.Magnesium Hydroxide as halogen-free flame retardant was used to study effect of its amount on composite mechanical flame retardant heat-resistant crystal and rheology properties. The results showed that LOI of composite increase with the increase of Mg（OH）₂. Vertical flame can achieve FV-0 when the amount of flame retardant is 65%. Anticipate purpose can not achieve when red phosphorus add to Mg（OH）₂/POE system. Filling of many uncoated Mg（OH）₂ can lead to the rapidly decreasing of composite mechanical properties which could be improved when Mg（OH）₂ is coated. Heat-resistant properties can increase with adding Mg（OH）₂.The dates of melt and crystal indicate that the flame retardant exerts an obvious heterogeneous nucleation in preparation of the POE. Composites G’ and viscosity remarkable enhance with adding many Mg（OH）₂.We study effect of Mg（OH）₂/EG,Mg（OH）₂/RP on polymer materials flame retardant properties. And find Mg（OH）₂ and EG or RP optimal dosage. Study their mechanical properties and flame retardant properties.更多还原