基于常压协同射流等离子体改性国产高强中模碳纤维表面的研究

Research on the Surface Modification of Domestic High Strength and Medium ModulusCarbon Fiber Based on Atmospheric Pressure Collaborative Jet Plasma

国产高强中模碳纤维性能优异,但其表面活性低,与树脂基体的结合能力较差。为了改善国产高强中模碳纤维表面活性,提高其与环氧树脂的界面性能,采用常压脉冲放电与射频放电协同的射流等离子体放电形式,对碳纤维表面进行改性处理,并系统研究了改性前后碳纤维的表面形貌、单丝强度、与环氧树脂的接触角、表面O/C比、含氧活性基团含量、复合材料层间剪切强度(ILSS)等参量。结果发现:等离子体处理3次时(约为120 s)碳纤维表面性能最佳,与原样相比,其接触角降低了21.3%,O/C比提升了53.3%,C1s峰上的C-O和COOH含量分别提高了95.61%与179.37%,复合材料的层间剪切强度提高了64.49%,说明其界面性能得到了大幅度提升。此外,常压协同射流等离子处理对纤维本体未造成明显损伤,且一定程度上起到修复纤维表面疵点的作用,增加了表面粗糙度,有效提高了碳纤维对树脂的浸润性能。

The properties of domestic high strength and medium modulus carbon fiber are excellent,but it has poor surface activity and binding ability with resin matrix.In order to improve the surface activity of domestic high-strength and medium modulus carbon fiber and increase the interface properties between carbon fiber and epoxy resin,the surface modification of carbon fiber was carried out by atmospheric pressure pulse discharge and radio frequency discharge.The surface morphology,monofilament strength,contact angle with epoxy resin,sur-face O/C ratio,content of oxygen-containing active groups and interlaminar shear strength(ILSS)of carbon fiber before and after modification were systematically studied.The results showed that the surface properties of carbon fi-ber treated by plasma for three times(about 120s)were the best.Compared with the original carbon fiber,the con-tact angle reduced by 21.3%,the O/C ratio increased by 53.3%,the contents of C-O and COOH on C1s peak in-creased by 95.61%and 179.37%respectively,and ILSS of the composite increased by 64.49%,which indicated that the interfacial properties were improved greatly.In addition,the treatment of atmospheric pressure collaborative jet plasma did not cause obvious damage to the fiber body,and repaired the fiber surface defects to a certain ex-tent,which increased the surface roughness and effectively improved the wettability of carbon fiber to resin.