A molecular dynamics simulation study on enhancement of mechanical and tribological properties of polymer composites by introduction of graphene

Molecular models for graphene reinforced polymer composites are developed to study the enhanced mechanical and tribological properties of the composites by introduction of graphene as reinforcements. Strain constant method is applied to evaluate the Young's modulus and shear modulus of the polymer composites. A layer model containing iron atoms as the top nanorod and the graphene reinforced polymer composites as the core are constructed to study the tribological properties of polymer composites, i.e. friction coefficient and abrasion rate, by sliding the top iron nanorod on the surface of the polymer matrix. The molecular dynamics simulation results show that increases of about 150% in Young's modulus, 27.6% in shear modulus and 35% in hardness of the polymer composites are obtained respectively by incorporation of graphene reinforcements. In addition, decreases of around 35% and 48% in the average friction coefficient and abrasion rate of the polymer composites are achieved. The research findings are discussed and interpreted by monitoring the interaction energy between graphene and the polymer matrix, the angle, bond and kinetic energy of the polymer chains of the polymer composites. (a) RDF values of the top iron nanorod and C atoms of the pure polymer matrix and graphene/polymer composites during the MD simulations. (b) and (c) The snapshot of the final states of the pure polymer matrix and graphene/polymer composites subjected to the friction by the top iron nanorod. [Display omitted]