Large-scale simulations of adhesion in dense polymer melts

We study adhesion between a polymer melt and substrate due to tethered chains on the substrate surface. We have performed extensive molecular dynamics simulations to study the effect of tethered chain density (∑), tethered chain length (N t) and tensile pull velocity (μ) on the adhesive failure mechanisms. We incorporate a simple breaking model to study the scission of the tethered chains as they are pulled from the melt. We observe a crossover from pure chain pullout at short N t and small μv, to chain scission as N t and μ are increased. The value of N t for which this crossover occurs is comparable to the entanglement length.