Water dispersible magnetite graphene oxide anchored sulfonic acid hybrid for mechanical enhancement of waterborne epoxy nanocomposites

The Fe3O4-functionalized graphene oxide (Fe3O4@GO-SO3H) and waterborne epoxy (WEP) nanocomposites (WEP/Fe3O4@GO-SO3H) were fabricated via co-precipitation followed by sulfonation, and the effects of modified GO on mechanical behaviors of the WEP nanocomposites were further examined. The synthesized Fe3O4@GO-SO3H hybrid was analyzed and confirmed by FTIR, Raman, XRD, and TGA. It was convinced from the FESEM and the related analyses that the covalent functionalization of graphene oxide with Fe3O4 nanoparticles followed by sulfonation with 3-mercaptopropyl trimethoxysilane was encouraging to equal distribution in the WEP system. Meanwhile, the tight mutual sharing interfaces amid WEP and Fe3O4@GO-SO3H promote the stress transfer. As the content of Fe3O4@GO-SO3H increases, the tensile strength of WEP increases, but the totaling more than 0.2 wt% Fe3O4@GO-SO3H yields unfavorable results. When the filler content of Fe3O4@GO-SO3H arises to 0.2 wt%, the tensile strength of the nanocomposites was found to be 257% higher than that of the blank group. Besides, the DMA shows that the storage modulus and tanδ of the WEP/Fe3O4@GO-SO3H was remarkably enhanced due to the strong interactions between Fe3O4@GO-SO3H and WEP. The improved thermal stability and conductivity of the WEP nanocomposites was also achieved. It could be concluded that the appropriate quantity of Fe3O4@GO-SO3H toting up can significantly improve the mechanical properties of WEP/Fe3O4@GO-SO3H nanocomposites.