Specific functionalized graphene oxide-based vitrimer epoxy nanocomposites for self-healing applications

Abstract

For the development of vitrimer epoxy nanocomposites, this study employed covalent functionalization to specifically modify graphene oxide (GO) with 4-aminophenyl disulfide (4-AFD). To verify the functionalization of graphene oxide, Fourier transform infrared (FT-IR), Raman, and X-ray diffraction (XRD) analyses were conducted, while transmission electron microscopy (TEM) coupled with elemental analysis was employed to examine the surface morphology. Additionally, the dispersion of GO and 4-AFD functionalized graphene oxide (FGO) inside the vitrimer epoxy polymer matrix was examined through the use of field emission scanning electron spectroscopy (FE-SEM). By functionalizing GO, its tendency to agglomerate was reduced, thereby enhancing the dispersion of FGO within the polymeric matrix. The vitrimer epoxy/FGO nanocomposites developed in this study demonstrate outstanding self-healing and shape memory properties, attributed to the covalent adaptive network based on disulfide exchange. The findings of this study indicate that incorporating FGO-based nanofillers in vitrimer epoxy nanocomposites improves their self-healing properties, including shape memory, flexural strength, storage modulus, and loss modulus, compared to GO-filled counterparts. In addition, this significantly improved the thermal properties of vitrimer epoxy/FGO nanocomposites, such as glass transition temperature (Tg) and thermal degradation temperature. In particular, the Tg of vitrimer epoxy/FGO nanocomposites experienced a significant increase of 10 °C. Additionally, the thermal decomposition temperature saw substantial improvements, with a 5% increase of 15 °C and a 50% increase of 7 °C.