Improving the interfacial property of carbon fibre/epoxy resin composites by grafting amine‐capped cross‐linked poly‐itaconic acid

Abstract

To improve the interfacial properties of carbon fibre‐reinforced polymer composites, a surface treatment was used to cap cross‐linked poly‐itaconic acid onto carbon fibres via in‐situ polymerization after itaconic acid grafting. The chemical composition of the modified carbon fiber (CF) surface was characterized by X‐ray photoelectron spectral and Fourier‐transform infrared spectroscopy. Scanning electron microscopy and atomic force microscopy images showed that the poly‐itaconic acid protective sheath was uniformly capped onto the CF surface and that the surface roughness was obviously enhanced. Chemical bonds also played a key role in the interfacial enhancement. The results showed that the interfacial shear strength of the composites with poly‐itaconic acid on the carbon fibres (72.2 MPa) was significantly increased by 89.5% compared with that of the composites with pristine CF (38.1 MPa). Moreover, the poly‐itaconic acid sheath promoted a slight increase in mono‐fibre tensile strength. In addition, the interfacial mechanisms were also discussed. Meanwhile, the mechanical property of the functionalized CF/epoxy resin composites was also significantly improved.