Preparation and characterization of poly(vinyl alcohol) / starchcomposite films reinforced with graphene and graphene oxide

Abstract

The main objective of this research is to characterize the graphene oxide (GO) prepared by using modified Hummer‟s method with some modifications which was then used in the poly(vinyl alcohol) (PVA)/starch blends biocomposite film. Results from Fourier transform infrared, scanning electron microscopy-electron dispersive x-ray and x-ray diffraction analyses showed the presence of oxygen functional groups which confirmed the transformation of graphene (G) to GO. PVA/starch film was prepared via casting method at room temperature. The G and GO were added into PVA/starch film with different loadings from 0.5 to 4.0 wt% to determine the best optimum loading that would give the best result of mechanical, thermal and morphological properties. From the scanning electron microscopy, PVA/starch/GO film showed a smoother surface due to the GO filler being more uniformly dispersed in the matrix of PVA/starch film compared to G. The thermal properties, tensile strength, elongation at break and Young‟s modulus of PVA/starch/G and PVA/starch/GO films showed improvement with increasing filler loading until 2.0 wt%. However, PVA/starch/GO showed better improvements compared to PVA/starch/G. Water barrier properties analysis showed that PVA/starch/GO film had better water resistance than to PVA/starch/G film. From the soil burial test, the biodegradability of films showed that G and GO filler do not gave any significant influence on the biodegradability of film. The addition of 2.0 wt% of filler loading was found to be the best loading to improve the properties of the films, with PVA/starch/GO showed better properties compared to PVA/starch/G film.