Fracture mechanics investigation on the PP/EPDM/ionomer ternary blends using j‐integral by locus method

The fracture mechanics investigation of the polypropylene (PP)/ethylene–propylene–diene terpolymer (EPDM)/ionomer ternary blends was performed in terms of the J‐integral by measuring fracture energy via the locus method. Blends were prepared in a laboratory internal mixer. The composition of PP and EPDM was fixed at a 50/50 ratio by weight. Two kinds of Poly(ethylene‐co‐methacrylic acid) (EMA) ionomers were used. The J‐integral value at crack initiation, Jc, of the PP/EPDM/EMA ionomer ternary blends were affected by the cation types (Na+ or Zn2+) and contents (5–20 wt %) of the added EMA ionomers. The ternary blend having 5 wt % of Na‐neutralized ionomer showed a higher Jc value than that of any other ternary blends. The results were discussed with regard to the fracture topology by a scanning electron microscope (SEM).