Investigation of graphene/graphene oxide reinforced polyurethane nanocomposite: A molecular dynamics approach

The interaction interface between the 2D nanomaterials such as graphene and polymers play a crucial role in determining mechanical and thermal properties of nanocomposites. This study presents a molecular dynamics approach to investigate surface adsorption of polyurethane on graphene and graphene oxide models. Graphene (G) and graphene oxide (GO) samples were created of the same 2D sizes of 96 × 57 Å2, where the number of carbonyl, carboxyl, epoxy, and hydroxyl groups were altered to obtain GO samples with varied oxidation degrees. The highly functionalized samples exhibited better adsorption in comparison to pristine graphene. Furthermore, radial distribution function was analyzed and used for validation of simulation. Finally, the effects of G/GO addition into polymer on the mechanical properties of polyurethane were examined. It was found that addition of graphene resulted in enhanced Young's modulus with a significant increase from 0.42 GPa to 4.88 GPa, whereas highly oxidized G sheets resulted in proportionally lower figures such as 0.54 GPa, 1.39 GPa. © 2021