Characteristics of Functionalized Carbon Nanotube Composites to Reinforce Hydrogen Storage Applications

Abstract

Recent studies have extensively studied the use of composites of carbon nanotubes (CNTs) dispersed in epoxy resin to mechanically reinforce hydrogen storage and lightweight vehicle applications. The mechanical properties of the composite are strengthened due to load transfer from the epoxy matrix to the CNTs when an external force is generated. However, there is a limit to the level of reinforcement that can be achieved by simply dispersing CNTs in the epoxy polymer. In this study, a composite was prepared by dispersing functionalized CNTs with carboxyl groups, which formed covalent bonds with the epoxy resin (EPON 862). The covalent bonding improved the load transfer from the epoxy resin to the CNTs, which increased the Young’s modulus and ultimate tensile strength of the composite. In addition, the interfacial interaction and adhesion between the matrix and the filler were improved by the covalent bonding, thereby improving the degree of dispersion. The changes in elastic modulus and ultimate tensile strength according to the nanofiller content and the presence of the functional groups in the MWCNT were observed, and exhibited consistent values.