Morphology and mechanical properties of polypropylene/maleated styrene–butadiene–styrene triblock copolymer blends

The morphology and mechanical properties of blends of isotactic polypropylene (i‐PP) and a maleated butadiene–styrene–butadiene triblock copolymer with maleic anhydride (SBS–MAH), i‐PP/SBS–MAH, were investigated and compared with those of corresponding blends of i‐PP and a styrene–butadiene–styrene triblock copolymer (SBS), i‐PP/SBS. The blends were prepared in a mixer at 190°C with 5–25 wt % elastomer compositions. The blends exhibited a two‐phase morphology with a disperse elastomer phase in the continuous i‐PP matrix. The size and shape of the elastomer particles and the mechanical properties of the blends depended on the nature and concentration of the elastomer. The i‐PP/SBS–MAH blends showed an impact strength superior to that of the corresponding i‐PP/SBS blends. These results were attributed to the formation of the graft copolymer during the melt blending, which was verified by Fourier transform infrared.