Influence of size of graphene oxide on interfacial properties of carbon fiber/epoxy resin under damp and heat conditions

Abstract

Two different sizes of graphene oxide (GO) produced by the Hummers method had been incorporated into epoxy resins and used to fabricate GO modified carbon fiber reinforced epoxy resin composites (GO/CF/EP) by compression molding method, and the composite material was processed under damp and heat conditions. The modification effects of dry and wet composite materials were investigated through interlayer shear performance, dynamic thermomechanical properties and microscopic morphology. The results indicate that GO has a good improvement on the interlaminar shear strength and glass transition temperature of composite materials. In the dry state at room temperature, two sizes of GO have basically the same improvement effect on the interlaminar shear strength of the composite. With the increase of GO content, the small size of GO makes the hygrothermal interlaminar shear strength of composites decrease faster. When the GO content is 0.1%(mass fraction, the same as below), the improvement of the interlaminar shear performance of the composite material is better, however, the glass transition temperature of the composite material is better when the GO content is 0.2%. With the increase of GO content, the exothermic peak of the GO-EP composite resin matrix shifts to low temperature, and the small size of GO shortens the gel time of the composite resin. The micro-morphology analysis shows the presence of GO is beneficial for increasing the crack propagation path during the failure of composite material, thereby more conducive to the dissipate the crack tip energy by the material.

Keywords

• graphene oxide
• carbon fiber
• epoxy resin
• interface property