Hybrid bio-based composites from nano-reinforced bio-petro polymer blends and natural fibers

Natural fiber composites or biocomposites have recently gained much attention due to their low cost, environmental friendliness, and their potential to compete with glass-fiber composites. However, the use of all-natural resins is limited due to performance concern, and hence the blending bio-resins in petroleum resins has gained importance due to their improved toughness and environmental friendliness. Nevertheless, addition of bio-resins generally compromises stiffness, barrier and thermal properties. The enhancement of polymer stiffness and barrier properties with small concentrations of layered silicates is well established. With this context, the paper presents the development and thermo-physical characterization of a hybrid composite material with increased environmental friendliness that can retain stiffness without sacrificing toughness, barrier and thermal properties. Hybrid biocomposites were made from bio-based resins (blends of unsaturated polyester and epoxidized soya bean oil) reinforced with organo-nanoclays and natural fibers (unprocessed industrial hemp). Results show that an optimum material design that maximizes the synergy of the constituents is possible and provide an initial benchmark in identifying such balance.