Tensile properties of carbon nanotubes-sheets/carbon fibers/epoxy and carbon nanotubes-grafted carbon fibers/epoxy hybrid composites

An interesting technique for modifying the carbon fiber reinforced polymer matrix composites is hybridizing with carbon nanotubes (CNT). CNT-sheets/carbon fibers and CNT-grafted carbon fibers offer potential benefits of nanoscale reinforcement to the well-established fibrous composites by creating multiscale hybrid micro-nano composites. However, the mechanical properties of polymer matrix composites reinforced with the CNT-sheets/carbon fibers and CNT-grafted carbon fibers have not been evaluated. It is important to clarify the tensile properties of polymer matrix composites reinforced with the CNT-sheets/carbon fibers and CNT-grafted carbon fibers. In this study, the tensile properties of carbon fiber reinforced polymer matrix composites incorporating CNT-sheets (CNT-sheets/carbon fibers/epoxy hybrid composites) and CNT-grafted carbon fibers (CNT-grafted carbon fibers/epoxy hybrid composites) were investigated. For the CNT-sheets/carbon fibers/epoxy hybrid composites, the tensile modulus of hybrid composites was higher than that in the as-received state. The tensile strength of CNT-sheets/polyacrylonitrile (PAN)-based carbon fibers/epoxy hybrid composite was lower than that in the as-received state and the tensile strength of CNT-sheets/pitch-based carbon fibers/epoxy hybrid composite was higher than that in the as-received state. On the other hand, for the CNT-grafted carbon fibers/epoxy hybrid composites, the tensile modulus of hybrid composites was higher than that in the as-received state and tensile strength of hybrid composites was almost similar to that in as-received state.