In this contribution, the impact of graphene oxide (GO) with different oxidation degrees on the cryogenic mechanical properties of GO/epoxy nanocomposites is investigated. GO samples with varied oxidation degrees were prepared using a modified Hummers’ method. It was found that GO exhibited better dispersion in the matrix and improved interfacial interactions with epoxy resin as its oxidation degree increased. Resultantly, GO/epoxy nanocomposites showed increased tensile properties at room temperature (RT) and liquid nitrogen temperature (LNT) as GO oxidation degree increased and reached the idealist performance with appropriate GO oxidation degree. Under low GO loading of 0.10 wt% GO/epoxy nanocomposites exhibited the highest tensile strength of 78.0 MPa at RT and 123.2 MPa at LNT, 31% and 14% higher than that of neat epoxy, respectively. Based on the fractured surface investigation, toughening mechanisms of GO for epoxy nanocomposites at RT and LNT were analyzed, between which there existed significant differences.

在此贡献中，研究了氧化度不同的氧化石墨烯（GO）对GO /环氧纳米复合材料的低温机械性能的影响。使用改进的Hummers方法制备具有不同氧化度的GO样品。发现GO随着其氧化度的增加而表现出更好的分散在基质中并且改善了与环氧树脂的界面相互作用。结果，随着GO氧化度的增加，GO /环氧纳米复合材料在室温（RT）和液氮温度（LNT）下显示出增加的拉伸性能，并在适当的GO氧化度下达到了理想的性能。在低GO负载下，0.10 wt％的GO /环氧纳米复合材料在室温下的最高拉伸强度为78.0 MPa，在LNT下的最高拉伸强度为123.2 MPa，分别比纯环氧树脂高31％和14％。