Essential work of interfacial fracture: a method to characterise adhesion at polymer–polymer interfaces

The essential work of fracture method (EWF) to determine the fracture toughness of bulk polymers, blends and filled polymers is extended to determine the essential work of interfacial fracture (EWIF) of polymer–polymer composites. It was found that the EWIF-concept is appropriate to determine the interface toughness between two different polymers, where at least one of them shows large-scale plasticity. The interfacial toughness, or EWIF (w12), for the material system: polypropylene (blockcopolymer, PP-PR1042, Hoechst) and a blend consisting of polyamide and modified polypropylene was determined.