Study On The Interfacial Modification And Properties Of Carbon Fiber/PEK-C Thermoplastic Composites

In this paper, the effect of low temperature oxygen plasma modification on the carbonfiber surface was investigated in order to improve the interface bonding property of thecarbon fiber/containing phenolphthalein of polyaryletherketone （PEK-C） comwposites. Theinfluence of oxygen plasma treatment on the surface properties of carbon fibers wereinvestigated by X-ray photoelectron spectroscopy （XPS） and atomic force microscopy （AFM）,and the effect of plasma modification on the mechanical properties of the T700/PEK-Ccomposites were also studied. The interlaminar shear strength as well as the flexuralproperties of the composite was significantly improved after modification, which increasedfirstly and then decreased. The results indicated that the composites achieved the best resultswhich using the carbon fibers treated in the200plasma power for12.5min or300plasmapower for5min. The fracture morphology of scanning electron microscope （SEM）photographs showed that the destruction mode of composites was changed after the carbonfibers were treated by oxygen plasma.The prepreg was made by online solution impregnation, and the continuous carbonfiber/PEK-C composite was produced through in-situ consolidation winding process. Theeffects of processing temperature and nano-TiO₂on the mechanical properties of the windingproducts were studied. The results showed that the NOL ring had a good mechanical propertyunder a certain processing temperature range. Moreover, a proper amount of Nano-TiO₂could improve the interface bonding property between fiber and resin as well as theinterlaminar shear strength of composite.The effect of plasma modification on the hygrothermal properties of composite wasstudied. The results showed that the water absorption of composites was initially consistentwith the Fick second low. Compared with the composite without plasma treatment, themoisture absorption rate of the composite after treatment was low, and the equilibriummoisture absorption rate was also lower than the former. After the moisture absorption, the mechanical properties of the composites decreased, the interlaminar shear strength retentionof the treated composite was higher than that of treated ones. SEM fracture morphologyanalysis showed that the interface bonding property of the PEK-C composites was good, thusthe ability of resisting aging was enhanced.