Enhanced thermal and mechanical properties of poly (vinylidene fluoride) nanocomposites reinforced by liquid-exfoliated graphene

Abstract

We report the preparation and enhanced thermal and mechanical properties of poly (vinylidine diflouride) (PVDF) nanocomposites reinforced by few-layer graphene flakes which are produced by the direct liquid-phase exfoliation of pristine graphite. Graphene flakes are found to homogeneously disperse in PVDF, reduce the bubble defects and thus the porosity of PVDF, and change PVDF's crystallinity. Thermogravimetric analysis indicates that graphene can accelerate the fracture of hydrogen bond connecting PVDF and N-Methyl pyrrolidone molecules. 1.5 wt% graphene loading leads to around 20 °C enhancement in the melting temperature of PVDF. The mechanical properties like Young's modulus (EIT), yield stress (σy), and hardness (H) of the nanocomposites are investigated by nanoindentation technique. A 1.0 wt% loading of graphene is found to increase EIT, σy, and H of PVDF by ∼337%, ∼102%, and ∼228%, respectively.HighlightsFew-layer graphene was produced by liquid-phase exfoliation.Graphene were added to PVDF to enhance thermal and mechanical properties of polymer.Mechanical properties of PVDF/graphene composite films were investigated by nanoindentation.