Preparation And Performance Of Multiwalled CNTs/Epoxy Composites

Caron nanotubes (CNTs) exhibit an excellent mechanical properties: the super high tensile strength, toughness and Young's modulus, and a unique microstructure: high specific surface area and high aspect ratio, which can be considered as an ideal reinforcement additive for advanced composites.In this paper, multiwalled carbon nanotubes (MWCNTs)/epoxy resin composites with different MWCNTs contents have been prepared by cast molding method. The MWCNTs were firstly surface functionalized in mixed acids (1:3 concentration HNO₃/ H₂SO₄) and then dispersed by high power sonication. The mechanical properties and the relationship between microstructure and properties of the composites were investigated by TEM SEM HRSEM and tensile testing machine. The results indicated that:(1) MWCNTs were purified by dilute nitric acid first, and then chemically modified by a 3:1 mixture of concentrated mixture of sulfur acid/nitric acid. A large amount of polarity functional groups were generated on the surface of MWCNTs, which could lead to an improvement of the MWCNTs/epoxy resin interfacial interaction and an increase of the solubility and compatibility of MWCNTs with the matrix.(2) The tensile strength and toughness of the composites were...