Influence of bio-resource-derived graphene oxide on the mechanical and thermal properties of poly(vinyl alcohol) nanocomposites

Abstract

The present study reports on an environment-friendly and economically viable method of synthesizing graphene oxide (GO) using agricultural waste, specifically oak (Quercus ilex) fruit. The agricultural waste-derived GO (AGO) is further used as a reinforcing filler in the fabrication of poly(vinyl alcohol) (PVA) polymer nanocomposites by employing a solution-mixing process. A series of characterization methods have been used to assess the interactions between AGO and PVA, including, Raman spectroscopy, FT-IR, field emission scanning electron microscopy (FESEM), and energy-dispersive x-ray (EDX). The thermal and structural properties have been studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)analysis, and a universal testing machine (UTM). The strong H-bonding interaction between the PVA interface and AGO considerably enhanced interfacial dispersion and adhesion. As a result, the addition of 5 wt% AGO to the PVA polymers significantly improved their mechanical and thermal properties, including tensile strength which rose by 117%, melting temperature (Tm) by 7.02°C, and crystallization temperature (Tc) by 9.06°C. The thermal decomposition temperatures such as T5%, T10% and T50% were increased by 53.68°C, 68.49°C, and 57.37°C, respectively. The results show that a small loading of nanofillers causes substantial increases in the thermal and mechanical properties of PVA, thus making it a promising material for structural applications.