Toward effective and tunable interphases in graphene oxide/epoxy composites by grafting different chain lengths of polyetheramine onto graphene oxide - Journal of Materials Chemistry A (RSC Publishing)
Interface design plays a crucial role in developing superior mechanical performance of graphene/polymer nanocomposites. Herein, we report a facile approach to fabrication of advanced polymeric nanocomposites of epoxy by incorporation of polyetheramine functionalized graphene oxide (PEA-f-GO). Two types of PEA molecules with different molecular lengths were used to synthesize the PEA-f-GO sheets. The chemical bonds being formed between the amine functional groups on the GO surface and the epoxy resin during curing provided strong sheet/matrix interfacial adhesion. Addition of PEA-f-GO was found to produce significant enhancements in mechanical properties of epoxy including elastic modulus, tensile strength, elongation at break and toughness. In particular, the PEA-f-GO sheets containing shorter PEA molecules produced higher improvement in strength but smaller increase in both ductility and toughness than those containing longer PEA molecules. For example, at 0.50 wt% filler loading, the two nanocomposites showed increases of 63% and 51% in the tensile strength and 90% and 119% in the toughness, respectively, as compared to the unfilled epoxy. Our results suggest that the interphases between the GO and the polymer matrix can be tuned by varying the molecular lengths of grafted modifiers, providing a new route for the rational design and development of the GO-based composite materials.
