Hydrogen bond networks and wrinkles in graphene oxide/nitrile butadiene rubber composites for enhancement of damping capability: Molecular simulation and experimental study

Abstract

By combining molecular dynamics (MD) simulation and experiments, this work describes a systematic, quantitative study on the nanoscale damping of nitrile butadiene rubber (NBR) by adding graphene oxide (GO) with different oxidation degrees. Using MD simulation, the proposed two-component solubility parameters predict that GO2 (O wt %, 17.05%) and NBR have excellent thermodynamic compatibility. GO2/NBR system shows the largest molar concentration of intermolecular hydrogen bonds and the lowest free volume fraction and mean square displacement. GO2 presents a strong adsorption effect on NBR polymer chains. Meanwhile, the green preparation method of reduced graphene oxide has been developed for improving damping properties of reduced graphene oxide/nitrile butadiene rubber (RGO/NBR) composites. The prepared RGO/NBR composites with tailor-made oxidation degrees are adopted to validate the theoretical prediction by MD simulation. Fourier transform infrared spectroscopy verifies that hydrogen bond networks exist between GO and NBR polymer chains. Two main factors, the number of intermolecular hydrogen bonds and the degree of wrinkles of GO sheets dominate the damping performance of the composites. The results indicate that when the GO oxidation degree is about 17.05%, the damping capability of GO/NBR composites is maximum improved. These results pave the way for the environmentally modifying interface to design high performance GO/rubber composites.