作者：Fushi Li, Na Zhang, Yunbao Gao, Nan Yan, Jing Jin, Zhaohui Su, Wei Jiang
关键字：脆韧转变, 核壳橡胶粒子, 聚丙烯复合材料, 刚性, 韧性
论文来源：期刊
具体来源：Polymer Engineering & Science, 2022, 62(12), 4090-4099
发表时间：2022年

摘要：用单相冲击改性剂增韧热塑性塑料通常会导致刚度显著降低，而核壳橡胶改性剂具有核刚性和壳柔性等额外结构参数，通过控制这些参数可更好平衡复合材料的刚度和冲击韧性。本文分别采用三种不同刚度的聚乙烯（PE），通过熔融共混制备聚丙烯/乙烯-丙烯橡胶/聚乙烯（PP/EPR/PE）三元复合材料，其中EPR与PE比为1:1。原子力显微镜-红外（AFM-IR）和扫描电镜（SEM）结果表明，原位形成了以PE为核、EPR为壳的核壳橡胶粒子并均匀分散在PP基体中。力学测试表明，在相同改性剂含量下，用这些核壳橡胶粒子增韧的PP复合材料比单独使用EPR具有更高的韧性和刚度，且PE核越刚，效果越明显。这些结果与近期理论模型定量一致，为该模型提供了坚实实验证据。此外，该工作展示了用更便宜的PE部分替代EPR增韧PP的经济方法。

Abstract：Toughening of thermoplastics with a one-phase impact modifier generally results in significant reduction in stiffness, whereas core-shell rubber modifiers have extra structural parameters such as core rigidity and shell flexibility, by controlling which the stiffness and impact toughness of their composites can be better balanced. In this study, three kinds of polyethylene (PE) with different rigidity are used respectively to prepare polypropylene/ethylene-propylene rubber/polyethylene (PP/EPR/PE) ternary composites by melt blending, in which the EPR-to-PE ratio is 1:1. Atomic force microscopy-infrared (AFM-IR) and scanning electron microscopy (SEM) results indicate that core-shell rubber particles with a PE core and an EPR shell are formed in situ and uniformly dispersed in the PP matrix. Mechanical measurements show that at the same modifier content the PP composites toughened with these core-shell rubber particles exhibit higher toughness and stiffness than that with EPR alone, and the more rigid the PE core, the greater the effects. These results are in quantitative agreement with a recent theoretical model, providing solid experimental evidence in support of the latter. Furthermore, this work demonstrates an economical approach to toughening PP by partial substitution of the EPR with the much cheaper PE for better performance.

论文链接：https://doi.org/10.1002/pen.26169