Phase structure and property relationships in ternary polypropylene/elastomer/filler composites: Effect of elastomer polarity

Ternary composites of polypropylene (PP), elastomer, and calcium carbonate (CaCO3) filler were prepared to study their structure/property relationships. Two kinds of phase structure were formed, depending on the elastomer present in the composites. Separation of elastomer and filler particles was found when a nonpolar ethylene–octene copolymer was used. Encapsulation of filler by the elastomer was achieved by using a polar ethylene–vinyl acetate elastomer. The mechanical properties of ternary composites were strongly dependent on material composition and their phase structures. In the present study, composites with separate dispersion structure showed higher modulus and impact strength than those of encapsulation type. The deformation mechanisms of both composites were studied using scanning electron microscopy.