Preparation and functional study of epoxy composites reinforced with ultra-low content single-walled carbon nanotubes

In this paper, ultra-low content single-walled carbon nanotube(SWCNT)/epoxy composites were prepared by non-covalent modification of SWCNTs, which improved the dispersion of SWCNTs in epoxy resin, and their properties were investigated. It was shown that the electrical conductivity of SWCNT/epoxy composites increased by 7 orders of magnitude over that of epoxy resin when the content of SWCNTs was 0.005 wt%. The impact strength, tensile strength, and elastic modulus of the materials were increased by 47.9%, 58.9%, and 19.0%, respectively, and the strengthening mechanism of SWCNTs on the matrix was analyzed by SEM. Then SWCNTs were introduced into carbon fiber (CF)/epoxy composites and carbon fiber pressure vessels. In comparison to CF/epoxy composites, the shear and tensile strengths of SWCNT/CF/epoxy composites exhibited an increase of 49.2% and 9.8%, respectively, and the bursting pressure of nano-modified pressure vessels was increased by 15.5%. This study provides a new application method for nano-modified epoxy resins and broadens the application fields of epoxy resins.