Molecular Dynamics Study of Vacancy Effect on Mechanical Properties of Polyurethane-Graphene Nanocomposite

Abstract

Abstract A molecular dynamics (MD) approach is used to describe the mechanical properties of polyurethane matrix using defective graphene nanosheets. In MD simulations of polyurethane matrix and graphene nanosheets, we applied DREIDING and Tersoff force fields, respectively. The temperature and total energy variations in the equilibrium phase show their physical stability. Numerically, the total energy of the pure and reinforced polymeric matrix converged to -491.10 kcal/mol and − 524.83 kcal/mol, respectively. These calculations show the atomic stability of the structure improves in presence of defective nanoparticles. Also, the mechanical properties of modelled samples were investigated by measuring stress-strain curves, Young's modulus, ultimate tensile strength, and atomic energy between polymeric matrix and modeled nanosheets. Numerically, by inserting defective nanosheets into polyurethane chains, Young’s modulus and their ultimate tensile strength increase to 22.00 MPa and 71.39 MPa, respectively. By combining graphene nanosheets with vacancy defects to the additive nanoparticles, we conclude that designed nanocomposites can exhibit promising (improved) mechanical properties.