电化学氧化处理对PAN基炭纤维表面浸润性的影响

以硫酸铵为电解质,对炭纤维进行连续电化学氧化处理,利用反气相色谱(IGC)研究电化学氧化处理前后的表面能变化,并联系SEM、AFM、XRD、Raman、XPS等测试结果综合分析电化学氧化处理对炭纤维表面性能的影响。研究表明,经电化学氧化处理后,纤维沿轴方向表面沟槽加深加宽,薄弱层被剥除,晶格择优取向遭到破坏;纤维表面活性官能团增多,氧和氮含量分别增加了180%和65%,提高了纤维与树脂的粘结性;纤维表面能提高了3.1倍,与树脂的浸润性得到改善;电化学氧化处理后其复合材料的ILSS达109MPa,已可充分满足实际应用需求。

Study on Wettability of Electrochemically Oxidized PAN-based Carbon Fibers

The surface of polyacrylonitrile(PAN)-based carbon fibers(CFs) were continuously electrochemically oxidized in ammonium sulphate.The morphology,structure,chemical composition and surface energy were investigated by SEM,XRD,Raman,XPS,TG and inverse gas chromatography(IGC).The potential relationships between the microstructure and the surface properties of carbon fibers were analyzed.Results showed that compared with untreated carbon fiber,the treated carbon fibers showed wider and deeper grooves and some weak layers were removed.The electrochemical oxidation increased functional groups on the surface of carbon fibers,which was confirmed from the fact that the contents of O and N are increased by 180% and 65% respectively.In addition the surface energy of the treated carbon fibers was increased by 310% compared with the untreated fibers,which means the wettability to epoxy resin of carbon fibers increased.Consequently,the cohesiveness between the fibers and resin matrix is improved and the interlaminar shear strength(ILSS) of CFRP can be up to 109MPa under an appropriate oxidative treatment,which fully meets the practical application.