Crosslinked acetylacetonated poly(vinyl alcohol-co-vinyl acetate) nanocomposites with graphene oxide and reduced graphene oxide: a new way to modify the property of nanocomposites

Many researches have been done on polymer/graphene nanocomposites due to their unique properties. How to better disperse graphene oxide (GO) and reduced graphene oxide (rGO) into nanocomposites has been widely studied because the dispersion of graphene into polymer matrix determines the property enhancements. In this study, acetoacetyl group was introduced into the poly(vinyl alcohol) (PVA) polymer chain, endowing PVA with the property of self-crosslinking. Significant increases in mechanical properties were shown in films prepared from crosslinked nanocomposites compared with those prepared from un-crosslinked. Covalent linkages between PVA chains which preferred better and firmer dispersion of nanofillers are responsible for the property improvement. A 300% improvement of tensile strength and a over 50 times increase of Young's modulus were observed relative to neat polymer with the addition of 2% GO. Considering excellent mechanical strength of graphene nano-layers, although better and more stable dispersion of GO was achieved in the crosslinking matrix, the maximum increase of mechanical property in the resultant nanocomposites was obtained with the addition of 1% rGO.