Remarkable enhancements in mechanical properties of epoxy composites through double reinforcing structure: Integrated structure of carbon fiber‐carbon nanotube instead of conventional reinforcing methods

An integrated structure of carbon fiber‐carbon nanotube (CF‐CNT) was introduced to epoxy composite to reinforce the matrix at both macro and nano scale. The CNTs were deposited on the surface of the CF filaments and radially aligned under applied high electric field due to the strong repulsion forces between the tubes. The CF‐CNT hybrid is believed to provide efficient stress transfer from the matrix to the CNT and subsequently CF filaments. The CNTs were also introduced in the epoxy matrix separately to reinforce the rest of the matrix. Significant improvements have been observed in the tensile strength (193%) and elastic modulus (86%) compared with traditionally reinforced composites that can be ascribed by the extensive macro‐nano scale reinforcement of the epoxy matrix. It was found that the applied electric field plays a pivotal role in the achieved improvements probably due to the radial alignment of MWCNTs on the CF filaments. POLYM. COMPOS., 39:E1099–E1108, 2018. © 2017 Society of Plastics Engineers