含碳纳米管上浆剂的制备及对碳纤维/环氧树脂复合材料界面的影响

Fabrication of Sizing Agent Containing Multi-Walled Carbon Nanotubes and Effect on Carbon Fibers / Epoxy Resin Composite Interface

首先采用"Friedel-Crafts"酰化反应制备羧基化多壁碳纳米管(MWCNTs)并将其与环氧树脂、丙酮混合制成含MWCNTs的上浆剂,然后用该上浆剂浸渍碳纤维制备碳纳米管/碳纤维多尺度增强纤维。采用扫描电镜研究了上浆处理对碳纤维表面形貌的影响,采用短臂梁剪切测试方法研究了含碳纳米管的上浆剂对碳纤维/环氧树脂复合材料层间剪切强度(ILSS)的影响。结果表明,碳纳米管在上浆剂中的分散状态直接影响纤维表面碳纳米管分布的均匀性;与未浸渍的碳纤维相比,含碳纳米管上浆剂浸渍后的碳纤维/环氧树脂复合材料的ILSS提高了34.33%。通过上浆剂红外光谱表征、纤维束表面浸润性测试及ILSS试样端口形貌的观察,分析了层间增韧机理。研究表明,碳纤维束表面浸润性的提高以及碳纤维/环氧树脂界面处化学键合作用增强,是ILSS提高的主要原因。

Carboxylic multi-walled carbon nanotubes(MWCNTs) were prepared through 'Friedel-Craft'acylation.On the basis of MWCNTs functionalization,the sizing agent containing MWCNTs,epoxy resin and acetone was prepared,in which carbon fibers were sized to fabricate carbon nanotubes / carbon fiber hybrid fiber.The effect of sizing progress on the surface micrograph of carbon fiber was studied by SEM.The influence of sizing agent on the interlaminar shear strength(ILSS) of carbon fiber / epoxy resin composites was investigated through short-beam shear tests.The results show that the dispersion of carbon nanotubes in the sizing agent has direct effect on the uniform distribution of carbon nanotubes on the surface of carbon fiber.The ILSS of MWCNTs containing sizing agent sized carbon fiber / epoxy resin composites is increased by 34.33% compare to the unsized ones.The interlaminar reinforcing mechanism was investigated by FT-IR spectra,the wettability test of the carbon fiber,and fractographic observation of cross-sections of the ILSS specimen.The results indicate that the main reason for increase of ILSS is attributed to the enhanced wettability of the carbon fiber and chemical bonding at the interface of carbon fiber / epoxy composites.