Improving rheological properties of covalently MWCNT/epoxy nanocomposites via surface re-modification

This article describes the application of the chemical surface re-modification of carboxylated multi-walled carbon nanotubes (MWCNTs) through in-situ esterification of oligomeric unsaturated aliphatic hydroxyl terminated polyesters. The Fourier transform infrared spectroscopy and the thermogravimetric analysis proved covalent treatment of MWCNTs. Consequently, the acid–base titration method was employed to determine the population of the re-modified sites within the polyester chains. The dispersion state of the re-modified MWCNTs was investigated by the transmission electron microscopy relevant to the cured nanocomposite sample along with the Ultraviolet–Visible spectroscopy while using various solvents. The degree of dispersion was correlated to the Hansen solubility parameters. In summary, our study shows an appropriate dispersion of the re-modified MWCNTs into the solvents with a high dispersive fashion. In addition, the rheological properties of the re-modified MWCNTs/epoxy resin having various nanoinclusions were considerably studied and discussed. Also, an improved rheological response was observed in the case of the re-modified MWCNT nanocomposite samples.