Improving the interfacial shear strength of polypropylene/carbon fiber nonwoven composite by three different methods

Abstract

This paper introduces three different methods to improve the interfacial shear strength (IFSS) of PP/CF nonwoven composites: (A) mixing maleic anhydride-grafted-PP (MAPP) powder into polypropylene/carbon fiber (PP/CF) nonwoven preform, (B) grafting MAPP onto polydopamine-coated-CF (PCF) utilizing esterification reaction, and (C) coating ethylene–glycidyl methacrylate (E-GMA) copolymer onto CF through solution dipping. First, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectra, and X-ray photoelectron spectroscopy (XPS) results over modified CFs show that the MAPP and E-GMA were delivered onto CF. Surface Chemistry analysis validated the esterification between MAPP and PCF. Second, the tensile test and SEM observation of composites’ tensile fracture region confirmed the improved interfacial adhesion. Tensile strength was improved by 42.5%, 44.6%, and 49.8% by Method A, B, and C, respectively. Finally, the Bowyer-Bader methodology estimated the IFSS improvement of 352%, 161%, and 136% produced by Method A, B, and C, respectively.