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

The synthesis, and thermophysical and mechanical properties of anhydride-cured biobased epoxy containing diglycidyl ether of bisphenol F (DGEBF) epoxy and epoxidized linseed oil (ELO) reinforced with fluorinated single-wall carbon nanotubes (FSWCNT) are reported. Sonication was used to disperse FSWCNT in the biobased glassy epoxy network, resulting in great improvement of the modulus of nanocomposites containing extremely small amounts of FSWCNT. The glass transition temperature of the obtained nanocomposites decreased by approximately 30 °C after the addition of 0.20 wt% (0.16 vol%) FSWCNT, without adjusting the amount of the anhydride 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 of the anhydride curing agent needed to achieve stoichiometry was experimentally determined by dynamic mechanical analysis (DMA). The storage modulus of the epoxy at room temperature, which is below the glass transition temperature of the nanocomposites, increased up to 0.44 GPa with the addition of only 0.24 wt% (0.20 vol%) of FSWCNT, representing an up to 14% improvement from the modulus of the biobased ELO neat epoxies. The fracture toughness of the neat biobased ELO epoxies was also improved by approximately 43% upon addition of FSWCNT. The excellent improvement of the modulus was achieved without sacrificing the fracture toughness.