Microbeam two-dimensional small-angle X-ray scattering investigating the effects of reduced graphene oxide on local microstructures of high-density polyethylene/reduced graphene oxide nanocomposite bars

It has reported that the introduction of reduced graphene oxide (RGO) can enhance the crystallization and orientation of high density polyethylene (HDPE) matrix and thus improve the mechanical properties of HDPE/RGO nanocomposites. Herein, the local microstructures and orientations in different regions of HDPE/RGO bars with varied RGO contents were further explored by two dimensional small angle X-ray scattering (2D SAXS) using a microbeam technique. It is unveiled that the orientation orderings of every positions are all intensified with increasing RGO amount, and of particular interest is the observation of the quite slight change of the ordering degrees in diverse zones of HDPE/RGO nanocomposite bars, implicating that RGO imposes a uniform enhancing effect upon HDPE matrix within different areas and consequently reflects an effective increase of mechanical properties of HDPE/RGO nanocomposites.已有研究表明，引入还原氧化石墨烯（reduced graphene oxide, RGO）可提升高密度聚乙烯（high density polyethylene, HDPE）基体的结晶能力与取向程度，进而改善HDPE/RGO纳米复合材料的力学性能。本文采用微束技术结合二维小角X射线散射（two dimensional small angle X-ray scattering, 2D SAXS）手段，对不同RGO添加量的HDPE/RGO棒材各区域的局部微观结构与取向情况进行了进一步探究。研究结果显示，随着RGO添加量的增加，各位置的取向有序度均有所增强；尤为值得关注的是，HDPE/RGO纳米复合棒材不同区域的有序度变化极小，这表明RGO对HDPE基体在各区域均起到了均匀的强化作用，从而有效提升了HDPE/RGO纳米复合材料的力学性能。