Low-combustible, high-strength, and thermally stable bio-blended epoxy-based bio-nanocomposite using reduced graphene oxide as a strengthening agent

Firms choose to maximize the use of natural resources when producing new generations of polymer composites. The incorporation of carbon-based nanoparticles into the polymer matrix resulted in substantial enhancements in strength qualities. In this work, a set of bio-nanocomposites was fabricated using reduced graphene oxide (rGO) at several weight %s (0, 0.25, 0.5, 0.75, and 1 wt.%) in a bio-blended epoxy thermoset matrix generated from adding cashew nut shell liquid (CNSL) as an additive in a commercial grade bisphenol-A-based unmodified liquid epoxy resin. Thermal and mechanical properties, morphology analysis, XRD analysis, flammability, and limiting oxygen index (LOI) were used for characterization. The mechanical properties of the bio-nanocomposite containing 0.75 wt.% of rGO were investigated, resulting in the observation of enhanced flexural strength by 43.97%, compression strength by 58.08%, tensile strength by 39.84%, impact energy by 47.05%, and shore-D hardness by 21.26% compared to neat epoxy. The thermal stability of a bio-nanocomposite containing 0.75 wt.% of rGO is not compromised while demonstrating a 44.71 % residual mass at 550°C compared to neat epoxy. The cured bio-blended epoxy has a 23.38% lower combustion rate than epoxy resin and shows slow burning rate.