Enhanced interfacial adhesion between polypropylene and carbon fiber by graphene oxide/polyethyleneimine coating

In order to improve the interfacial properties in polypropylene/carbon fiber (PP/CF) composites, graphene oxide and brached polyethyleneimine were coated onto the surface of carbon fiber by layer-by-layer assembly in this work. Compared with the origin PP/CF composite, the composites reinforced by PP/CF–GO showed significant enhancement not only in tensile strength but also in elongation at break. The improved fiber–matrix adhesion was proved by fracture morphology observation of scanning electron microscopy and almost unaffected mechanical properties of the fiber itself during the coating process. The optimal assembly time was found to be 10 for enhancing the overall composite mechanical performance.