A detailed fracture analysis of polypropylene/ethylene–propylene–diene monomer rubber/nano-silica (PP/EPDM/SiO2) ternary blend-nanocomposites was conducted through using both Izod impact and quasi-static fracture tests. The phase morphology and the fractured surfaces were evaluated using scanning electron microscopy. Morphological observations revealed that the SiO2 nanoparticles were mainly located either around the EPDM particles or at the PP/EPDM interface. A synergistic effect was observed between the soft EPDM rubber particles and rigid SiO2 filler on activation of different toughening micro-mechanisms, so that the impact strength of the ternary systems was significantly higher than that of corresponding binary blends. This effect was much more significant for percolated morphologies. The concept of the essential work of fracture (EWF) was used to analyze the fracture behavior and toughening/deformation mechanisms of the samples. The percolated structure of the EPDM particles and the SiO2 nanoparticles exhibited superior fracture resistance under EWF fracture tests. Formation of multiple void-fibrillar structures dissipated further energy and significantly improved fracture resistance under EWF tests. It was demonstrated that the toughness and stiffness could successfully be balanced via controlling the microstructure of the ternary systems.

中文翻译：

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PP/EPDM/SiO2三元共混纳米复合材料断裂韧性及变形微观机理研究

通过使用悬臂梁式冲击和准静态断裂试验，对聚丙烯/乙烯-丙烯-二烯单体橡胶/纳米二氧化硅 (PP/EPDM/SiO2) 三元共混物-纳米复合材料进行了详细的断裂分析。使用扫描电子显微镜评估相形态和断裂表面。形态观察表明，SiO2 纳米颗粒主要位于 EPDM 颗粒周围或 PP/EPDM 界面处。观察到软质三元乙丙橡胶颗粒和硬质SiO2填料对不同增韧微观机制活化的协同作用，使得三元体系的冲击强度显着高于相应的二元共混物。这种效果对于渗滤形态更为显着。断裂基本功（EWF）的概念用于分析样品的断裂行为和增韧/变形机制。EPDM 颗粒和 SiO2 纳米颗粒的渗滤结构在 EWF 断裂试验中表现出优异的抗断裂性。在 EWF 测试中，多个空隙纤维结构的形成进一步耗散了能量并显着提高了抗断裂性。结果表明，通过控制三元体系的微观结构可以成功地平衡韧性和刚度。在 EWF 测试中，多个空隙纤维结构的形成进一步耗散了能量并显着提高了抗断裂性。结果表明，通过控制三元体系的微观结构可以成功地平衡韧性和刚度。在 EWF 测试中，多个空隙纤维结构的形成进一步耗散了能量并显着提高了抗断裂性。结果表明，通过控制三元体系的微观结构可以成功地平衡韧性和刚度。