Tensile mechanical properties of carbon nanotube/epoxy composite fabricated by pultrusion of carbon nanotube spun yarn preform

In order to achieve a sufficiently high volume fraction and the preferred alignment of long carbon nanotubes (CNTs), CNT spun yarns were used as preforms for fabricating epoxy-based composite materials with excellent mechanical properties using the pultrusion technique. Epoxy resin was well impregnated into the preforms, resulting in better load transfer from the resin to the CNTs. By using CNT spun yarn as the preform, the Young’s modulus and tensile strength were improved by up to 15 times and 7 times over those of the epoxy resin, respectively. SEM observation suggested that the dominant fracture mode of the composite was fiber breakage of the CNTs.