Interfacial properties of phosphorous acid modif iedKevlar f iber reinforced epoxy resin composites

The Kevlar fibers were t reated by phosphorous acid ( PA) solutions of different concent rations. Thesurface properties of the t reated Kevlar fiber and the interfacial properties of the fiber/ epoxy resin composites wereinvestigated. The result s show that the amount of the oxygenous functional groups on the surface reaches a maximum af ter being t reated with 20 wt % PA solution. The amount of the oxygenous functional groups and the surfaceroughness decrease as the concent ration of PA solution increases , but the filament st rength rises. Af ter beingt reated with 20 wt % PA solution , the interlaminar shear st rength ( ILSS) of Kevlar fiber/ epoxy composites reaches62 MPa and the interfacial shear st rength ( IFSS) of Kevlar fiber/ epoxy composites increases by 18 %. The amount ofthe functional groups on the fiber surface and the surface roughness are the crucial factors to improve interfacialproperties of Kevlar fiber/ epoxy composites .