Covalent incorporation of aminated carbon nanotubes into epoxy resin network

In order to expand applied field of epoxy resin, its mechanical properties have to be improved. Carbon nanotube (CNT) is regarded as an exceptional toughening agent for polymers. However, poor dispersion quality of CNT in polymer matrix and weak interfacial force between them commonly lead to low reinforcing efficiency. This article presented a study on the mechanical properties of epoxy composite reinforced with aminated CNT (CNT-NH2). The amination of CNT was achieved via a wet chemical procedure using 1,6-diaminohexane (DAH) as amine source. Fourier transform infrared spectroscopy, zeta potential test, and thermogravimetric analysis were employed to investigate the as-prepared CNT-NH2. The results show that DAH has been successfully grafted onto the surface of CNT. Scanning electron microscopic images show that CNT-NH2 is homogenously dispersed in epoxy matrix. Mechanical properties tests suggest that the tensile strength and fracture toughness of the obtained CNT-NH2/epoxy composite are all enhanced compared with cured pure epoxy resin. The tensile strength and fracture toughness of the as-prepared CNT-NH2/epoxy composite with 0.8 wt% CNT-NH2 show 42% and 95% improvement, respectively. These results indicate that CNT-NH2 is a promising toughening agent for enhancing the mechanical properties of epoxy resin.