碳纳米材料表面改性碳纤维及在环氧树脂中的应用

以N,N-二甲基甲酰胺为溶剂,通过超声的方法分别制备含多壁碳纳米管(MWCNTs)或石墨烯纳米片(GnP)的碳纳米材料表面改性剂,采用浸渍法对预处理碳纤维(CF)(去浆CF)进行改性使碳纳米材料均匀涂覆在纤维表面上,然后采用手糊成型及热压成型工艺制备环氧树脂(EP)/改性CF复合材料,利用扫描电子显微镜和电子万能试验机分析碳纳米材料表面改性剂制备条件对CF表面形貌、复丝拉伸性能的影响,在此基础上,选择各自的最佳表面改性剂制备条件,对比了含MWCNTs或GnP的表面改性剂改性CF对复合材料力学性能的影响。结果表明,碳纳米材料在表面改性剂中的分散状态直接影响CF表面碳纳米材料分布的均匀性和复合材料的性能。超声时间为2h的含MWCNTs表面改性剂和GnP质量分数为0.5%的含GnP表面改性剂对CF的改性效果较好,相应复丝的拉伸强度与去浆CF复丝相比分别提高了59.4%和70.2%,而相应复合材料的弯曲强度相对于EP/去浆CF复合材料分别提高了11.2%和41.1%,层间剪切强度分别提高了35.8%和71.3%。

Carbon Fiber Surface Modified by Carbon Nanomaterials and Its Application in Epoxy

Taking N,N-Dimethylformamide as solvent,surface modifying agents based on carbon nanomaterials containing multi-walled carbon nanotubes(MWCNTs)or graphene nanoplatelet(GnP)were prepared respectively by sonication.Pretreatment carbon fiber(desizing CF)is modified with the surface modifying agents by impregnation method,so that carbon nanomaterials could be uniformly coated on the surface of fiber,and then the epoxy resin(EP)/modified CF composites were prepared by hand lay-up molding and hot pressing process.The effects of preparation conditions of the surface modifying agents on the surface morphology of CF and tensile properties of multifilament are investigated by scanning electron microscopy and electronic universal testing machine.On the basis,each optimal preparation conditions of the surface modifying agents were selected and the influences of the CF modified by the agents containing MWCNTs or GnP on the mechanical properties of the composites were compared.The results show that the dispersion state of carbon nanomaterials in the surface modifying agents directly affects the distribution of carbon nanomaterials on the surface of CF and mechanical properties of the composites.There have better modifying results when CF are modified by the surface modifying agent containing MWCNTs with ultrasonic time of 2 h or the agent containing 0.5%(mass fraction)GnP,the tensile strength of corresponding multifilaments increase by 59.4%and 70.2%respectively compared with the desizing CF,the flexible strength of corresponding composites increase by 11.2%and 41.1%respectively and the interlaminar shear strength increase by 35.8%and 71.3%respectively compared with the EP/desizing CF composite.