Enhanced mechanical properties and flame retardant of epoxy resin by using of GOPOS decorated MWCNTs

In this study, the multi-wall carbon nanotubes (MWCNTs) were grafted with Octa (propyl glycidyl ether) polyhedral oligomeric silsesquioxane (GOPOS) to form GOPOS-G-MWCNTs prior to use as an additive for improving the mechanical and the flame-retardant characteristics of the epoxy resin (EP). The surface of MWCNTs was also modified with a silane coupling agent before conducting the grafting reaction. The Fourier-transform infrared spectroscopy technique was applied to confirm the success of the grafting reaction. The epoxy-based composite materials were performed at room temperature using diethylenetriamine (DETA) as a hardener. Many characteristics of these materials were examined such as tensile strength, thermal stability, flammability, and fracture surface morphology. The presence of GOPOS-G-MWCNTs helped to reduce the total heat release, the peak of heat release rate (pHRR), and total smoke release by 68.68, 47.69, and 11.78%, respectively. While the tensile strength and fracture energy were also increased up to 30 and 102% when compared with virgin EP. The good dispersion of GOPOS-G-MWCNTs and char residue effect were considered as the main reasons for these improvements. A mechanism for enhancing flame-retardant behaviors of EP was also proposed. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.