The influence of phase morphology of polycarbonate/polyethersulfone blends on the failure behavior between the blends and polyurethane in the peel test

In peel, tests between polycarbonate/polyethersulfone (PC/PES) blends with different compositions and thermoplastic polyurethane (TPU) films with differ-ent thicknesses a large decrease in energy release rate G(c) is observed when the PC/PES blends formed a co-continuous structure. With SEM analysis, XRD measurements, selective PC etching of failed samples, and finite element modeling of the stress distributions in the co-continuous region this fracture behavior can be explained. It is caused by the interplay between the formation of the main crack in the process zone and the size and density of microcracks in the energy dissipation zone. While the pure components PC and PES exhibit good adhesion to the TPU, the immiscibility of PC and PES causes the steady decrease of G(c) with increasing volume fraction of the minor phase.