Rheological and thermal properties of epoxy nanocomposites reinforced with alkylated multi-walled carbon nanotubes

The effects of functionalized multi-walled carbon nanotubes (MWCNTs) on thermal and chemorheological behaviors of an epoxy-based nanocomposite system were investigated. Chemical functionalization of MWCNTs by acid modification (A-MWCNTs) and chemical amidation (D-MWCNTs) was confirmed using Fourier transform infrared spectroscopy and thermogravimetric analysis. It was found that the D-MWCNTs had a significant effect on the chemorheological behaviors of the epoxy-based nanocomposite. Compared to the epoxy/A-MWCNT nanocomposite, the epoxy/D-MWCNTs nanocomposite showed a significant increase in gel time, as obtained from isothermal rheology measurements. Also, the storage modulus of the diglycidylether of bisphenol F (DGEBF)/D-MWCNTs nanocomposite was higher than that of the DGEBF/D-MWCNTs nanocomposite and gradually increased with an increase of frequency. This could be interpreted by the relatively strongly interconnected structure of the D-MWCNTs in the DGEBF epoxy resin, which arises from the functionalized alkyl groups of the D-MWCNTs in dispersion phases with the DGEBF epoxy resin.