Estimating the polymer-metal work of adhesion from molecular dynamics simulations

The thermodynamic concept used to quantify adhesion on a fundamental molecular level is the work of adhesion. However, most of the experimental techniques give no, or very limited information about its magnitude. In this paper, a way to estimate the work of adhesion for copper-(acrylonitrile-butadiene-styrene) (ABS) interface using molecular dynamics simulations is presented. The work of adhesion is calculated from the interactions between single molecules constituting the ABS polymer (poly(styrene-co-acrylonitrile) and polybutadiene molecules) and copper (oxide) surface, using their van der Waals contact area. The calculated work of adhesion seems to be independent of the number of polymer molecules present on the copper surface, monomer residue unit sequence within the polymer molecule, and the type of copper surface. Introduction of oxygen atoms to the metallic surface and the polymer molecules significantly increases the work of adhesion. The highest work of adhesion was found between the oxidized copper surface and high oxygen content copolymer poly(styrene-alt-maleic anhydride). Results are shown to qualitatively correspond to previously reported experimental observations.