Effect of ionic liquid modified graphene oxide on mechanical and self-healing application of an ionic elastomer

Abstract

Thermo-reversible supramolecular crosslinking reactions such as Diels Alder reactions, disulfide metathesis reactions, imine bond formation, metal–ligand interactions, host–guest interactions, hydrogen bonds, and ionic interactions are broadly used for self-healing purposes. Herein, we have studied the ionic supramolecular interactions in miscellaneous nature, which benefit a strong and self-repairing carboxylate nitrile rubber by introducing a low cost and commercially available materials. The excellent mechanical and healing performance were combined by initiating the ionic liquid (IL) and ionic liquid modified graphene oxide (GO) with zinc oxide containing compounds into XNBR rubber. The healing performance and mechanical properties of various rubber composites essentially depend on the dispersion of ionic charges of ionic liquids via graphene oxide and the ionic network structures (zinc-carboxylate network). Graphene oxide and ionic liquid grafted graphene oxide were successfully synthesized. XRD, Raman spectroscopy, SEM, and TEM analysis were conducted for in-depth characterization of the ingredients and composite materials. Differential scanning calorimetry, rubber process analyzer, and thermogravimetric studies exhibit various thermal transitions present in the ionic crosslinked XNBR rubber. The ionic crosslinked XNBR rubber with 3 phr of ionic liquid grafted graphene oxide, and ionic liquid grafted graphene oxide with zinc oxide containing compounds exhibits very good tensile strength (3.1 ± 0.2 and 6.1 ± 0.6 MPa respectively) with excellent healing efficiency of 77.4 and 85.2% respectively, which is much greater than the utmost reported non-covalent supramolecular ionic crosslinked elastomers.