EPDM/PS交替多层复合材料的力学性能分析

用自行设计的微纳多层共挤出体系制备了三元乙丙橡胶/聚苯乙烯(EPDM/PS)交替多层复合材料。偏光显微镜和扫描电镜分析表明, 所制备的复合材料具有规则层状交替结构。与同组分的一般共混样品相比, 64层EPDM/PS交替复合材料表现出不同的拉伸断裂行为: 初期的PS断裂行为和后期的EPDM拉伸行为。EPDM和PS层保持了较好的连续性, 且EPDM层阻止了PS层裂纹向相邻PS层的发展, 使64层样品与同组分的一般共混样品相比具有较高的拉伸强度和杨氏模量。讨论了在PS相中加入相容剂苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)对64层EPDM/PS交替复合材料力学性能的影响, 发现SEBS的加入提高了PS相的韧性, 并且改善了EPDM层与PS层界面的相互作用。 

Mechanical properties of EPDM/PS alternative multilayer composites

EPDM/PS alternative multilayer composites were prepared by micro-or nano-layer coextrusion system designed in this lab. The results of polar light microscope (PLM) and scanning electrical microscope (SEM) analysis indicate that the composites have the alternative multilayer structure. Compared to conventional blends, the fracture behavior of EPDM/PS alternative 64-layer composites is much different, which includes two stages: the PS layers break first, followed by only the EPDM layers elongated. Because both PS and EPDM layers are continuous and EPDM layers prevent the cracks or crazes developing between the nearby PS layers, the tensile strength and the Youngs modulus of the 64-layer composites are higher than those of the corresponding conventional blends. The effects of SEBS as a compatibilizer added into PS phase on the mechanical properties of EPDM/PS alternative multilayer composites were investigated. The results indicate that the interfacial adhesion strength between EPDM layers and PS layers and the toughness of the PS layers are improved in the presence of SEBS.