Application of Ultrasonic Technique for Cure Monitoring of Epoxy/Graphene Oxide–Carbon Nanotubes Composites

A non-invasive ultrasonic transmission method was applied to on-line monitor the curing behavior of the nanocomposites based on epoxy matrix. Effects of dispersion and interfacial adhesion of the nanofiller on high frequency dynamic mechanical properties during curing process of the nanocomposites were discussed. The typical nanofillers, multi-wall carbon nanotubes (p-MWCNTs) were selected, which were doped with graphene oxides (GOs), and dispersed in epoxy resin. By measuring the velocity and attenuation coefficient of longitudinal ultrasonic waves throughout the entire curing cycle, the longitudinal storage modulus and loss tangent of the epoxy nanocomposites were obtained. And the curing kinetics of the epoxy matrix nanocomposites was analyzed based on the Hsich non-equilibrium fluctuation theory. The results proved that enhanced dispersion and interfacial bonding of the GO-MWCNTs with epoxy improved dynamic mechanical properties of the epoxy matrix nanocomposites, while made curing process accelerated. The proposed ultrasonic monitoring method could accurately evaluate the curing process of epoxy-matrix nanocomposites. In conclusion, this research offered a practical effective measurement method for monitoring of curing process of the thermosetting resin matrix nanocomposites.