Insights into the large-size graphene improvement effect of the mechanical properties on the epoxy/glass fabric composites

In this study, we investigated how the chemical structural properties, mechanical properties, and morphology of large-size graphene platelets (LGPs) doped glass fabric (GF)/epoxy composites are affected by varying loading amounts of LGPs. Scanning electron microscope results revealed that the dispersion and filling effect of LGPs can improve the flowability of the resin, reducing the aggregation and shrinkage of the resin on the glass fabric surface, thereby facilitating better resin infiltration and coverage of the glass fabric surface. From the spectrum analysis, the binding of LGPs with epoxy resin was the physical combination, without new chemical groups generated during the curing process. The addition of LGPs improved the ratio of the crystalline phases in the composites, from 30.00% of the GF/epoxy to 57.50% of the GF/epoxy@2.2LGPs. Mechanical properties indicated that the composites exhibited greater tensile strength than pure GF, which progressively increased with increasing LGPs content until it reached 1.5 wt%, then the tensile strength starts to decrease. And the GF/epoxy@1.5 LGPs exhibited 136% enhancement in tensile strength compared to other carbon fillers reinforced composites, which achieved a satisfactory enhancement under relatively low loading content.