Experimental and numerical investigation on the mechanical characteristics of polyethylenimine functionalized graphene oxide incorporated woven carbon fibre/epoxy composites

The synergistic effects of polyethyleneimine functionalized graphene oxide (PEI-FGO) on the static and dynamic mechanical properties of the carbon fibre reinforced epoxy composites were investigated in detail. The functional groups of PEI-FGO, especially the NH2, experienced strong molecular interaction with the epoxy resin, and increased the load carrying capacity of the matrix, and the corresponding overall mechanical strength of the composites. The tensile and flexural strength of the 0.3 wt% PEI-FGO incorporated CF/epoxy composites was improved by ∼ ((58-62) and (65-70)) %, respectively as compared to the base CF/epoxy composites. The numerical analysis via Finite Element Method of the prepared composites was carried out to validate the experimental results. The numerical models showed linear behavior in the stress-strain diagram, whereas the experimental results expressed non-linear behavior, due to the fibre-matrix de-bonding. The effects of temperature and frequency on the dynamic mechanical properties of the prepared composites were meticulously studied. The broadening of the tan δ curve with increasing frequency also signified that PEI-FGO affects the molecular motions of the epoxy network.