The surface chemistry and structure of multiwalled carbon nanotube (MWCNT) plays an important role in MWCNT/epoxy nanocomposites. In this contribution, oxidized multiwalled carbon nanotube (OMCNT) with tunable oxygen‐containing groups is prepared by finely controlling oxidation time and centrifugal speeds. Effects of oxygen‐containing group content on mechanical properties of the OMCNT/E51 epoxy nanocomposites at 77 K are investigated in detail. It reveals that oxygen‐containing groups on the OMCNT surface contribute to significant increases in tensile strength and impact resistance of the OMCNT/E51 epoxy nanocomposites compared with those of the pristine MWCNT/E51 nanocomposites. A positive correlation between the oxygen‐containing group content and interfacial properties of OMCNT and epoxy matrix is demonstrated by thermogravimetric analysis and fracture morphology, and homogeneous dispersion of the OMCNT in epoxy matrix is obtained with the increase of oxygen‐containing groups on surface of the OMCNT. However, proper content of oxygen‐containing groups is essential to OMCNT/E51 nanocomposites because excessive oxidation tends to make sever structural defects on the OMCNT and has a side effect on cryogenic mechanical properties of OMCNT/E51 nanocomposites.

中文翻译：

---

表面具有可调含氧基团的多壁碳纳米管改性环氧纳米复合材料的低温力学性能和破坏机理

多壁碳纳米管（MWCNT）的表面化学和结构在MWCNT /环氧纳米复合材料中起着重要作用。在此贡献中，通过精细控制氧化时间和离心速度，制备了具有可调含氧基团的氧化多壁碳纳米管（OMCNT）。详细研究了含氧基团含量对OMCNT / E51环氧纳米复合材料在77 K下的力学性能的影响。结果表明，与原始MWCNT / E51纳米复合材料相比，OMCNT表面的含氧基团显着提高了OMCNT / E51环氧纳米复合材料的拉伸强度和抗冲击性。通过热重分析和断裂形态证实了含氧基团含量与OMCNT和环氧基体的界面性质之间呈正相关，并且随着碳纳米管表面含氧基团的增加，OMCNT在环氧基体中均匀分散。 OMCNT。但是，适当的含氧基团含量对于OMCNT / E51纳米复合材料至关重要，因为过度氧化往往会在OMCNT上造成严重的结构缺陷，并对OMCNT / E51纳米复合材料的低温机械性能产生副作用。