Where do polymer adhesives fail?

We use molecular-dynamics simulations of a. polymer film confined between t wo walls to isolate the factors that control where an adhesive bond breaks. Failure occurs either at the wall/film interface (adhesive failure) or wit hin the film (cohesive failure). Most theories relate the location of failu re to equilibrium interfacial free energies. However, we find that the loca tion of failure coincides with the region of;lowest initial yield stress an d cannot be predicted from equilibrium interfacial free energies.