Relationship between surface characteristics and interlaminar shear strength of oxyfluorinated carbon fibers in a...

In this work, a direct oxyfluorination method was used to study the effect of oxygen content on surface and mechanical interfacial characteristics of oxyfluorinated carbon fibers in an epoxy matrix system. The changes of surface functional groups, chemical compositions, and structures of the carbon fibers were characterized by Fourier transform infrared spectrometer, X-ray photoelectron spectroscopy, and X-ray diffraction measurements. Also, the mechanical interfacial properties of the composites were evaluated by means of interlaminar shear strength tests. The results indicated that graphitic carbon was the major carbon functional component on the carbon fiber surfaces and other functional groups were also present, such as Cz.sbnd;O, Cz.dbnd;O, HOz.sbnd;Cz.dbnd;O, Cz.sbnd;F(x), after oxyfluorination of carbon fibers. No large changes of structure were found with the content of oxygen. Consequently, these introductions of oxygen functional groups onto the carbon fiber surfaces led to an improvement of the ILSS of the composites.