Enhanced properties of poly(vinyl alcohol) composite films with functionalized graphene

Abstract

Three types of poly(vinyl alcohol) (PVA) composite films containing graphene oxide (GO), reduced graphene oxide (RGO) and novel sulfonated graphene oxide (SRGO) as a filler were successfully prepared by a simple solution casting. The structure and properties of graphene-based PVA composites films were investigated. The results showed that the properties of the polymer composites films were sensitive to the structure of graphene. GO acted as the best reinforcing filler to enhance the mechanical property of PVA because it has many oxygen functional groups which could enhance the interfacial interactions through the formation of hydrogen bonds with PVA chains. The tensile strength and modulus of the resulting PVA/GO composites could reach 280 MPa and 13.5 GPa, respectively. RGO could improve the dielectric properties of PVA and the electrical conductivities were increased by ∼10¹¹ orders of magnitude in the composites with 50 wt% of filler loadings as compared to that of neat PVA. SRGO could enhance the mechanical and dielectric properties of PVA simultaneously. The mechanical properties of PVA could be efficiently improved due to the strong interaction between the –SO₃H groups on the SRGO sheets and PVA chains. The tensile strength and modulus of the resulting PVA/SRGO composites could reach 252 MPa and 8.5 GPa, respectively. Although the conductivity values of PVA/SRGO composites were less than those of the PVA/RGO composites, they were still increased by ∼10¹⁰ orders of magnitude in the composites with 50 wt% of filler loadings as compared to that of neat PVA. These results demonstrated that PVA films with enhancement in the mechanical and electronic properties can be fabricated with proper modified graphene.