In-Situ Reduced Graphene Filled Epoxy NanoComposite With Highest Storage Modulus

Abstract

Reduced graphene fillers were integrated into epoxy nanocomposites by solvent exchange of GO solution to acetone, ethanol and DMF, and subsequent in-situ thermal reduction and curing. The comparative fracture specimens of neat epoxy, acetone-rGO/epoxy, and DMF-rGO/epoxy showed ethanol-rGO/epoxy had greater load transfer by bonding and functionalization of the rGO surface with polymer chains from the epoxy via the solvent. The TGA and DTG showed marginal drop in the stability of the nanocomposites behind the neat epoxy, and DSC heat loss magnitude showed superior chemical bonding within ethanol-rGO/epoxy. The modulus increased with rGO content from 0, 0.05, 0.1, 0.2, 0.3 and 0.4 wt%, while the highest tensile strength was at 0.2 wt%. Thereafter, the dynamic and viscoelastic mechanical characteristics of rGO-epoxy nanocomposites: while the 0.4 wt% of rGO in ethanol-rGO/epoxy exhibited the highest storage modulus of 4144 MPa 0.91 tan delta, and a marginal decrease in glass transition temperature, Tg, while highest Tg was 115 ⁰C at 0.05 wt%. The dynamic mechanical storage moduli were fairly constant with increased amplitude from 0 to 4 µm, while loss moduli and tan delta only reduced at lower amplitudes from 0-4 µm.