Effect of graphene oxide surface treatment on the interfacial adhesion and the tensile performance of flax epoxy composites

Abstract

The high stiffness and damping properties of flax fibres promote the integration of biocomposites in structural applications. However, the strength of flax/epoxy composites is still limited compared to glass/epoxy composites. Graphene oxide (GO) has proved to be a promising building block for nanocomposites due to its high toughness, stiffness and tunable interfacial interactions with polymers. This study aims to understand the potential of GO-based surface treatment of flax fibres to modify the interfacial adhesion and tensile performance of flax fibre/epoxy composites. GO-modification improves the interfacial shear strength of elementary flax fibre/epoxy by 43%. The interfacial improvement is also established by the 40% higher transverse bending strength compared to untreated flax/epoxy composites. The tensile moduli of GO-modified flax/epoxy composites are on average 2 GPa higher than for untreated flax fibre/epoxy composites in all strain ranges. The quasi-static longitudinal tensile strength of unidirectional composites is not affected by GO-modification.