Effect of molecular chain length on the properties of amine-functionalized graphene oxide nanosheets/epoxy resins nanocomposites

Amine-functionalized graphene oxide nanosheets (D400-GOs and D2000-GOs) were prepared by linear poly(oxyalkylene) amines with two different molecular weights, 400 and 2000 (D400 and D2000), attached onto the surface of graphene oxides via the reactions of amines with alkylcarboxyle groups. By mixing the amine-functionalized graphene oxide nanosheets, the epoxy resins (EPs) and curing agent, the amine-functionalized graphene oxide nanosheets/EPs nanocomposites were subsequently fabricated. In these nanocomposites, the amine-functionalized graphene oxide nanosheets could covalently integrate into EPs matrices via the reactions between the amine groups of the chemically converted graphene oxide nanosheets and epoxy groups of EPs, thereby causing these graphene oxide nanosheets to become part of the heavily cross-linked network. The mechanical and thermal properties of these nanocomposites are investigated in detail. The effect of the molecular chain length of the grafted polymers on the properties of the chemically converted graphene oxide nanosheets/EPs nanocomposites are thoroughly discussed. This study provides a new route to design and develop chemically converted graphene oxide nanosheets/polymer nanocomposite materials by varying the chain length of polymers grafted onto the surface of graphene oxide nanosheets and then tuning the interphases between graphene oxide nanosheets and polymer matrices.