Mechanical and morphological properties of elastomer‐modified polypropylene/polyamide‐6 blends

Polypropylene/polyamide‐6 (70:30) blends, containing dispersed discrete polyamide‐6 microphases as matrix reinforcement, represent attractive materials for engineering applications. In order to enhance impact resistance, ethene/propene (EPM) was incorporated as a second separately dispersed microphase using reactive blending technology. Blend morphologies were controlled by adding maleic‐anhydride‐grafted‐polypropylene (PP‐g‐MA) as compatibilizer during melt processing, thus enhancing dispersion and interfacial adhesion of the polyamide‐6 phase. With PP‐g‐MA volume fractions increasing from 2.5 to 10 vol %, much finer dispersions of discrete polyamide‐6 with average domain sizes decreasing from 8 to 0.8 μm were obtained. When polyamide‐6 and ethene/propene (EPM)‐rubber are dispersed simultaneously in the polypropylene matrix, impact resistance was improved. The influence of PP‐g‐MA volume fraction and blend morphologies on mechanical properties such as Young's modulus, yield stress, notched Charpy impact resistance was investigated. The ternary polypropylene/polyamide‐6/EPM blend properties were compared with those of binary polypropylene blends containing the equivalent volume fraction of EPM.