Calculation of the work of adhesion of polyisoprene on graphite by molecular dynamics simulations

Elastomeric compounds are reinforced with fillers such as carbon-black and silica to improve mechanical, dynamical, and tribological properties. The stability and physical properties of these materials are dominated by the intermolecular interactions occurring at the polymer/particles interface that determine the magnitude of the polymer/particles adhesion. Using molecular dynamics simulations, in this work, we evaluate the solid-liquid interfacial tension and the corresponding work of adhesion for a system composed of graphite/Polyisoprene 100% cis-1,4 within a range of molar masses and temperatures. We employ a simulation strategy for estimating the surface tension of fluid/vacuum and fluid/solid interfaces that use directly the local stress fields in the Irving-Kirkwood formalism. Using such procedure, we decompose the stress field into the individual components of the stress tensor and correlate them with the values of the work of adhesion in the different systems analyzed.