The effect of graphene nanofiller on the crystallization behavior and mechanical properties of poly(vinyl alcohol)

Abstract

Abstract The effect of graphene on the crystallization behavior of graphene/poly(vinyl alcohol) ( PVA ) nanocomposites is investigated in terms of the heterogeneous nucleation effect using Fourier transform infrared spectroscopy and differential scanning calorimetry. Nanometer‐sized graphenes with disc‐type shape are successfully fabricated by transversal cutting of platelet carbon nanofibers, and the graphene/ PVA nanocomposites are prepared by varying the concentration of graphene using a solution‐casting method. The graphene/ PVA nanocomposites exhibit an enhanced degree of crystallization, increasing to 18.8% at a graphene concentration of 0.5 wt%. The graphene acts as an effective nucleating agent during the crystallization process, enhancing the degree and rate of crystallization. In addition, the graphene/ PVA nanocomposites with a high graphene content have markedly improved mechanical properties. Mechanical properties, including hardness and elastic modulus, of the prepared graphene/ PVA nanocomposites are analyzed using an atomic force microscopy nanoindentation method. The graphene plays a key role in increasing the crystallinity by acting as an effective nucleating agent at low concentrations (<1.0 wt%) and in enhancing the mechanical properties by acting as a nanofiller at high concentrations (>1.0 wt%).