FRACTURE-MECHANICS INVESTIGATION ON THE PP EPDM/IONOMER TERNARY BLENDS USING J-INTEGRAL BY LOCUS METHOD/

The fracture mechanics investigation of the polypropylene (PP)/ethylen e-propylene-diene terpolymer (EPDM)/ionomer ternary blends was perform ed in terms of the J-integral by measuring fracture energy via the loc us method. Blends were prepared in a laboratory internal mixer. The co mposition of PP and EPDM was fixed at a 50/50 ratio by weight. Two kin ds 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 con tents (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 t he fracture topology by a scanning electron microscope (SEM). (C) 1994 John Wiley & Sons, Inc.