In our previous work, a hybrid shish kebab structure, with polyethylene (PE) crystal lamellae periodically decorated on the surface of an inorganic whisker (SMCW) and aligned approximately perpendicular to the long axis of the whisker, has been observed in the injection molded bar of PE/SMCW composites. To investigate the effect of the molecular weight of the PE matrix on the formation of the hybrid shish kebab structure and the corresponding physical properties of HDPE/SMCW composites, in this work, three types of PE with different molecular weights were used to prepare the composites. They were first melt blended and then subjected to dynamic packing injection molding (DPIM), in which the prolonged shear was exerted on the melt during the solidification stage. An obvious hybrid shish kebab (HSK) structure, with PE crystal lamellae closely packed on the surface of the SMCW, was found in the samples with a low molecular weight PE (LMW-PE) matrix and a medium molecular weight PE (MMW-PE) matrix. However, in samples with a high molecular weight PE (HMW-PE) matrix, an incomplete HSK structure with PE crystal lamellae loosely decorated on the surface of the SMCW was observed. Furthermore, DSC results indicated that SMCW served as a good nucleating agent only for the composite with a LMW-PE matrix and the nucleation efficiency decreased with increasing PE molecular weight. Correspondingly, the tensile strength of the PE/SMCW composites was significantly improved by adding SMCW for the samples with a LMW-PE or MMW-PE matrix. Especially for samples with a LMW-PE matrix, the tensile strength was remarkably enhanced by the presence of only 1 wt % SMCW. For the composites with a HMW-PE matrix, the addition of SMCW had almost no reinforcing effect on the composites. The molecular weight dependence of the formation of HSK and property enhancement was discussed on the basis of the chain mobility and crystallization capability of the PE matrix.
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机译：在我们以前的工作中，在注射成型的试条中观察到一种混合烤肉串结构，在无机晶须（SMCW）的表面上定期装饰有聚乙烯（PE）晶体薄片，并大致垂直于晶须的长轴排列。 PE / SMCW复合材料。为了研究PE基质的分子量对混合烤肉串结构的形成以及HDPE / SMCW复合材料的相应物理性能的影响，在这项工作中，使用了三种不同分子量的PE来制备复合材料。首先将它们熔融共混，然后进行动态填充注射成型（DPIM），其中在凝固阶段将延长的剪切力施加到熔体上。在具有低分子量PE（LMW-PE）基质和中等分子量PE（MMW-PE）的样品中发现了明显的杂种烤肉串（HSK）结构，PE晶体薄片紧密堆积在SMCW的表面上）矩阵。但是，在具有高分子量PE（HMW-PE）基质的样品中，观察到不完整的HSK结构，在SMCW表面上松散地装饰有PE晶体薄片。此外，DSC结果表明，SMCW仅作为具有LMW-PE基体的复合材料的良好成核剂，且成核效率随PE分子量的增加而降低。相应地，通过为具有LMW-PE或MMW-PE基体的样品添加SMCW，可以显着提高PE / SMCW复合材料的拉伸强度。特别是对于具有LMW-PE基体的样品，仅存在1 wt％的SMCW，抗拉强度显着提高。对于具有HMW-PE基体的复合材料，SMCW的添加几乎对复合材料没有增强作用。基于PE基质的链迁移率和结晶能力，讨论了HSK形成的分子量依赖性和性能增强。
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