Polypropylene/polyolefin elastomer composites with enhanced impact strength: the effect of rubber domain size on toughness

Herein, the morphological properties of polypropylene/polyolefin elastomer (PP/POE) composites with various rubber compositions are investigated by scanning electron microscopy (SEM). Further, to understand the relationship between the rubber domain size and the impact toughness of the PP composites, the phase structure and rubber particle size in the PP matrix are analyzed. The results indicate that an increased flowability of the rubber reduces the domain size, thereby enhancing the impact strength of the PP composite. In particular, the maximum impact strength of 76 kJ/m(2) is obtained for the PP/POE composite in which an increased concentration of ethylene octene random copolymer (EOR) is used as the POE. The experimental results are in good agreement with the interparticle distance model for plastic/rubber blends. The results demonstrate that the rubber particle size in the polymer matrix is an important parameter for designing optimized thermoplastic elastomers.