EVA插层复合材料的取向结构对阻燃性能的影响

利用蒙脱土(MMT)特殊的片层结构,采用挤出工艺、熔融插层法制备了乙烯醋酸乙烯脂/蒙脱土(EVA/MMT)和乙烯醋酸乙烯脂/有机蒙脱土(EVA/OMMT)纳米复合材料,用锥形量热仪测试并分析了材料的燃烧性能。结果表明,添加OMMT的复合材料具有阻燃作用;复合材料中蒙脱土片层的(横、纵)取向影响材料的阻燃性;横向取向的EVA/OMMT复合材料有更低的热释放速率和质量损失速率,具有较好的阻燃性。通过扫描电镜(SEM)表征不同取向材料燃烧后炭渣的形貌,表明形成的炭层也为横、纵取向,解释了插层复合材料的横、纵取向对材料阻燃性的影响。

Orientation of Effect of Intercalated Structure on Flame Retardancy of EVA/Montmorillonite Composites

EVA/OMMT nano-composites with different orientation of intercalated structure were prepared by melt intercalation approach.The cone calorimeter was used to assess the flammability of EVA/OMMT nano-composites.The results demonstrated that the EVA/OMMT nano-composites reduced the flammability of EVA polymer.It was found that the layer orientation(horizontal or vertical) would affect the flammability of the compositesl.The composites with horizontal layer orientation gave less heat release and lessmass loss,and therefore had a lower flammability.The detailed structure of layer orientation in the composites was observeded with the SEM technique,which provides some fundamental explanation for flame retardancy of polymers by intercalation approach.