Effect of Graphene Oxide as a Reinforcement in a Bio-Epoxy Composite

Abstract

Graphene oxide (GO) has gained interest within the materials research community. The presence of functional groups on GO offers exceptional bonding capabilities and improved performance in lightweight polymer composites. A literature review on the tensile and flexural mechanical properties of synthetic epoxy/GO composites was conducted that showed differences from one study to another, which may be attributed to the oxidation level of the prepared GO. Herein, GO was synthesized from oxidation of graphite flakes using the modified Hummers method, while bio-epoxy/GO composites (0.1, 0.2, 0.3 and 0.6 wt.% GO) were prepared using a solution mixing route. The GO was characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM) analysis. The thermal properties of composites were assessed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). FTIR results confirmed oxidation of graphite was successful. SEM showed differences in fractured surfaces, which implies that GO modified the bio-epoxy polymer to some extent. Addition of 0.3 wt.% GO filler was determined to be an optimum amount as it enhanced the tensile strength, tensile modulus, flexural strength and flexural modulus by 23, 35, 17 and 31%, respectively, compared to pure bio-epoxy. Improvements in strength were achieved with considerably lower loadings than traditional fillers. Compared to the bio-epoxy, the 0.6 wt.% GO composite had the highest thermal stability and a slightly higher (positive) glass transition temperature (Tg) was increased by 3.5 °C, relative to the pristine bio-epoxy (0 wt.% GO).

Green Carbon Nanostructures for Functional Composite Materials

“…Graphene derivatives, including graphene nanoplatelets (GNP) [7], graphene oxide (GO) [8], and reduced graphene oxide (rGO) [9], are suitable fillers for the development of polymer composites. However, synthesis challenges associated with difficulties to scale up turn the graphene derivatives expensive nanomaterials [10].…”

Recent Studies on Dispersion of Graphene–Polymer Composites

“…The highly dispersed rGO showed higher glass transition, and improved quasi-static fracture toughness were measured [ 160 ]. Compared to the pristine bio-epoxy, graphene–epoxy composites showed high thermal stability and a slight increase in the glass transition temperature [ 161 ]. Graphene platelets in polystyrene were prepared by two methods, a one-step process (solution compounding) and a two-step process (solution compounding and subsequent melt compounding).…”

Preparation and Characterization of Polystyrene Hybrid Composites Reinforced with 2D and 3D Inorganic Fillers

“…The parallel, tubular mesopores of SBA-15 with the characteristic hexagonal ordering can be seen in Figure 2a and the inset image respectively, while the foamlike structure of the spherical pores of MCF can be seen in Figure 2b. 1) Multi-point BET method using N 2 adsorption data at −196 • C. (2) At P/Po = 0.99. (3) Average mesopore pore diameter by BJH analysis using N 2 adsorption data.…”

“…It is well-known that SBA-15 comprises of tubular mesopores in an ordered hexagonal array, while MCF exhibits a cellular pore morphology of relatively larger size pores, giving a foam-like texture [28][29][30]. (1) Multi-point BET method using N2 adsorption data at −196 °C . (2) At P/Po = 0.99.…”

“…Different types of nano-reinforcement in combination with polymer find application in various areas of engineering and technology due to their exceptional properties, such as improved thermal stability, water and oxygen barrier, mechanical strength, flame retardancy, chemical resistance, optical, magnetic, and electrical properties [1][2][3]. For the development of polymer nanocomposites, various nanofillers have been used.…”