Reinforcing epoxy resin through covalent integration of functionalized graphene nanosheets

Abstract

A chemically converted graphene/epoxy (EP) resin nanocomposite has been developed through the use of the functionalized graphene nanosheets (FGNs). The FGNs were prepared via the reaction of amines with alkylcarboxyl groups attached to the graphite oxides in the course of a dicarboxylic acid acyl peroxide treatment. FGNs/EP composites were prepared by dissolving the FGNs in organic solvent followed by mixing with EP and curing agent. In this composite, the FGNs were able to create molecular entanglement with EP matrix by taking advantage of the reactions between amine groups of FGNs and EP groups of EP, thus the FGNs could be covalently integrated into the EP matrix and became part of the cross-linked network structure rather than just a separated component. Great enhancement in the mechanical properties of the epoxy composite, such as the ultimate tensile strength and toughness, had been achieved with small loading (0.1 wt%) of FGNs by 17.0% and 262.2%, respectively. However, the FGNs reinforced EP composites showed a slight decrease in glass transition temperature (Tg).

Fabrication of graphene oxide–alumina hybrids to reinforce the anti-corrosion performance of composite epoxy coatings

“…Two peaks were detected in the N1s of GO-Al 2 O 3(Fig. 4d)at 399.7 and 401.4 eV that corresponded to C-N and N-H, respectively[40,42]. These abovementioned XPS results further demonstrated a reaction between the oxygen functional group and amine group.Combining the FT-IR and XPS analysis, we can confirm that the APTS attached to the surface of Al 2 O 3 , and GO-Al 2 O 3 has been successfully synthesized.…”

Effects of facile amine‐functionalization on the physical properties of epoxy/graphene nanoplatelets nanocomposites

“…The nanocomposites with the FGNPs 1.5 phr showed slightly lower T g compared to the nanocomposites with the same amount of the GNPs. This suggests that the FGNPs act as reactive plasticizers, when added over 1.0 phr, that reduce slightly the cross‐linking density of the cured epoxy matrix, thus improving slightly the flexibility of chain segments of the cross‐linked epoxy matrix …”

Epoxy/graphene nanocomposites – processing and properties: a review

“…It has been vastly reported that graphene reduces the glass transition or thermal degradation temperature of epoxy matrix and there is no unanimous agreement for this negative trend. Some research groups like Saurín et al 165 , Liu et al 166 , and Guo et al 91 reported that graphene acts as reactive plasticizer and has a plasticizing effect on epoxy resin, thus increasing the flexibility of chain segments of the epoxy matrix. Graphene sheets are stiffer than epoxy matrix which could lead to significant confinement on the polymer chains.…”