Mechanical properties of carbon nanotube fibers reinforced epoxy resin composite films prepared by wet winding

Abstract

Carbon nanotubes (CNTs) have a unique bond structure, high tensile strength, and high elongation at break, and thus are considered as excellent reinforcements for the preparation of high performance composites. However, the composites prepared by conventional methods suffer from poor CNT dispersion, low CNT alignment and low homogeneity of CNT-resin mixing. In this study, a new method is demonstrated to overcome these deficiencies. This method involves the preparation of CNT/epoxy (EP) resin composite films by wet winding using CNT macroscopic fibers as the reinforcements. Composite films with different EP contents are prepared by adjusting the EP concentration in the resin solution used for impregnation, the length of the resin container and the further impregnation time after winding. Thermogravimetric analysis, Raman spectroscopy and tensile testing are used to characterize the composite materials. Results show that the EP content and CNT alignment in the composite material can be controlled, and the composite film has a high tensile strength of 2 GPa and elongation at break of 4.5% when the EP content is optimized to be 44.62 wt% under the premise of a good degree of CNT alignment. The present study may provide a new technical route for the preparation of high-performance CNT composite materials.