Integrated ternary bionanocomposites with superior mechanical performance via the synergistic role of graphene and plasma treated carbon nanotubes

Herein, we prepared an integrated ternary bionanocomposite based on polylactic acid (PLA) as a host polymer and two different forms of carbon fillers, i.e. graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs), used simultaneously at extremely low concentrations, relying on the synergistic effect of CNT and graphene nanoreinforcement and a novel, multi-step procedure to achieve a high level dispersion. The results indicated that this multi-step approach allows stiffness increments up to +66%, with simultaneous enhancement of tensile strength (up to +44%), and elongation at break (up to +36%) with respect to neat PLA, by adding an extremely low content (0.5 wt%) of a hybrid combination of CNTs and GNPs. The development of a multistep strategy to achieve molecular level dispersion of multifunctional nanoparticles integrated in a fully renewable polymer matrix allows the premise of industrial-scale production of advanced bionanocomposites with outstanding properties at extremely low loadings.