Nanocomposites from biobased epoxy and single-wall carbon nanotubes: synthesis, andmechanical and thermophysical properties evaluation

Abstract

The synthesis, and thermophysical and mechanical properties of anhydride-curedbiobased epoxy containing diglycidyl ether of bisphenol F (DGEBF) epoxy andepoxidized linseed oil (ELO) reinforced with fluorinated single-wall carbon nanotubes(FSWCNT) are reported. Sonication was used to disperse FSWCNT in thebiobased glassy epoxy network, resulting in great improvement of the modulus ofnanocomposites containing extremely small amounts of FSWCNT. The glasstransition temperature of the obtained nanocomposites decreased by approximately30 °C after the addition of 0.20 wt% (0.16 vol%) FSWCNT, without adjusting the amount of theanhydride curing agent. This was because of the non-stoichiometry of the epoxy matrix,caused by the fluorine on the single wall carbon nanotubes. The adequate amount ofthe anhydride curing agent needed to achieve stoichiometry was experimentallydetermined by dynamic mechanical analysis (DMA). The storage modulus of theepoxy at room temperature, which is below the glass transition temperature of thenanocomposites, increased up to 0.44 GPa with the addition of only 0.24 wt% (0.20 vol%) ofFSWCNT, representing an up to 14% improvement from the modulus of the biobasedELO neat epoxies. The fracture toughness of the neat biobased ELO epoxies wasalso improved by approximately 43% upon addition of FSWCNT. The excellentimprovement of the modulus was achieved without sacrificing the fracture toughness.