碳纤维表面重氮化接枝氧化石墨烯用于碳/环氧界面增强

The interfacial adhesion between carbon fibers and epoxy resin is pretty poor due to the inert nature of carbon fiber surfaces. The recent literatures and our preliminary research results show that the coating of grapheme oxide (GO) onto carbon fiber surfaces will be able to significantly improve the interfacial bonding properties. However, the poor physical interactions between the carbon fibers and the coated GO sheets limits the strengthening extent of the interfacial adhesion. This proposal aims to covalently graft GO sheets onto carbon fiber surfaces by diazo-reactions. This proposal is explore the mechanism of diazo-functionalization of carbon fiber surfaces, to realize the electric-field induced self-assembly of GO sheets onto carbon fibers, and to clarify the factors that affect the grafting structures and morphology of GO sheets on carbon fiber surface; and also, the effect of the grafting of GO sheets on interfacial bonding between fibers and epoxy resin will also be discussed. The innovation of this work is to develop a no-losing tensile strength of carbon fibers, covalent bonding between GO and carbon fibers, and potentially industrialble methods for preparation of GO/carbon fiber hybrids. This study is expected to help solving the problem of “how to make better use of domestic carbon fibers” in China.

聚丙烯腈基碳纤维的表面呈惰性，与环氧树脂间的界面粘合力弱。最近的文献报道和我们的初步研究结果显示：碳纤维表面涂覆氧化石墨烯可显著改善碳纤维与树脂基体间的界面粘合性能。然而，氧化石墨烯与碳纤维之间较弱的物理结合力导致界面粘合性能难以显著提高。本项目设计通过重氮化反应将氧化石墨烯通过共价键偶合接枝在碳纤维表面，探讨碳纤维表面的重氮化修饰机理；阐明氧化石墨烯在碳纤维表面的自组装机理；明确重氮化接枝对氧化石墨烯沉积结构、形貌的影响机制；在此基础上探讨氧化石墨烯对碳纤维/环氧树脂界面粘合性能的作用机制。本项目的创新点在于发展一种无损碳纤维力学性能、氧化石墨烯与碳纤维之间牢固结合且可工业化的新型复合增强体，为解决我国碳纤维“用得好”的问题提供新工艺和新材料。

聚丙烯腈基碳纤维表面呈惰性，与环氧树脂间的界面粘合力弱。碳纤维表面构筑氧化石墨烯纳米结构可显著改善碳纤维与树脂基体间的界面粘合性能。然而，纳米结构与碳纤维之间较弱的物理结合力导致界面粘合性能很难显著提高。本项目提供了一种同时改善界面性能和纤维力学性能的方法。采用重氮化电化学还原的方法制备了氧化石墨烯/碳纤维复合增强体，研究了电化学还原的反应机理，验证碳纤维与氧化石墨烯通过共价连接，结合强度较高；采用不同原料和工艺路线，最终选定最佳合成路线，通过调节工艺参数实现表面形貌可控，为高性能碳纤维复合材料的研制提供了改性方法和理论指导。在此基础上，进一步研究了碳纤维表面重氮化接枝碳纳米管的制备工艺、结构与性能表征及界面增强机理。本研究制备的氧化石墨烯/碳纤维和碳纳米管/碳纤维复合增强体可改善碳纤维增强树脂基复合材料的界面性能，同时保持纤维表面晶体结构不被破坏，弥补表面缺陷，提升纤维力学性能。反应速率较快、设备简单，使用原料和反应介质清洁环保，具有工业化应用前景。