PP／EPDM共混物的力学性能及形貌研究

对PP／EPDM共混物的力学性能进行了研究，并用扫描电子显微镜（SEM）观察了共混物的形貌特征。结果表明，随EPDM含量增加，拉伸强度、拉伸弹性模量、弯曲强度、弯曲弹性模量均下降，但冲击强度在EPDM含量约为30％时出现极大值。除了分散相球粒的粒径和粒间距外，分散相在基体中的形状对共混物的冲击强度也有很大影响。同时，SEM结果表明，EPDM参与了PP的结晶过程。

On Impact Strength of PP/EPDM Blend

PP(Polypropylene) is inexpensive and widely used, but one factor limiting its use in China is its low impact strength. One mechanical method for ameliorating this limitation is blending EPDM (ethylene -propylene terpolymer) with PP. This mechanical method is both inexpenshe and easliy implementable. Our research has succeeded in improving this mechannd method further. The improvement came from SEM (scanning electronic microscope)study of morphology of EPDM in PP/EPDM blend. We found that the impact strength of PP/EPDM blend peaked at 30% of EPDM (lowest part of Fig.1). Scrutinizing Fig. 2, we discovered that much anisotropic structure of dispersed phase was formed at 30% EPDM.We deem that the appreciable increase in impact strength comes from a large increase in toughness of blend while still maintaining a certain amount of rigidity at 30% EPDM.