阳极氧化及上浆过程中PAN基碳纤维表面形态结构的演变

Surface structure transformation of PAN-based carbon fibers in the process of anode oxidation and sizing treatment

采用阳极氧化法对PAN基碳纤维的表面进行改性,然后使用上浆剂对纤维表面进行上浆处理。使用扫描电镜、原子力显微镜、X射线光电子能谱仪等分析了处理过程中碳纤维表面形态结构的变化,研究了阳极氧化及上浆处理对碳纤维的拉伸强度及其与环氧树脂间界面剪切强度(IFSS)的影响。结果表明:阳极氧化处理后,碳纤维表面平均粗糙度从48.0 nm增大到90.5 nm,而上浆后碳纤维平均粗糙度下降到32.3nm;经阳极氧化处理后,碳纤维表面碳(C)元素含量降低,氧(O)、氮(N)元素含量增加,—OH基团含量由14.43%增加到39.32%,而上浆后纤维表面—OH基团含量变化不大;在阳极氧化过程中随着氧化程度的提高,碳纤维的拉伸强度逐渐降低,但其IFSS逐渐升高;上浆对碳纤维拉伸强度影响不大,但上浆剂中较高的活性基团使得其IFSS进一步提高。

The surface of PAN-based carbon fibers was modifed by anode oxidation prior to sizing process.The surface structure transformation during the treatment were analyzed by scanning electron microscopy,atomic force microscopy,X-ray photoelectron spectrometry.The effects of anode oxidation and sizing treatment on the tensile strength of carbon fiber and interfacial shear strength（IFSS） of carbon fiber-reinforced expoxy resin composites were also studied.The results showed that the average surface roughness of carbon fiber increased from 48.0 nm to 90.5 nm after anodic oxidation,but decreased to 32.3 nm after sizing treatment; the content of element carbon（C） dropped,elements oxygen（O） and nitrogen（N） rose,and—OH group on the surface of carbon fiber increased from 14.43%to 39.32%after anode oxidation and did not change greatly after sizing treatment;the tensile strength of carbon fiber gradually decreased and the IFSS gradually increased with the increase of oxidation degree during the anode oxidation;and the sizing treatment did not affect the tensile strength of carbon fiber greatly,but the groups with relatively high activity in sizing agent produced a further increase of IFSS.