Great toughness reinforcement of isotactic polypropylene/elastomer blends with quasi-cocontinuous phase morphology by traces of β-nucleating agents and carbon nanotubes

Aiming at obtaining the polyolefin blends potentially applied in the field of the super-tough polymer products, in this work, isotactic polypropylene (iPP)/styrene-ethylene-butadiene-styrene block copolymer (SEBS) blends with great impact toughness were successfully fabricated by adding traces of β-nucleating agents (β-NAs) and carbon nanotubes (CNTs). The impact toughness of iPP blends with 30 wt% SEBS was as high as 62.4 kJ/m², when simultaneously containing 0.1 wt% β-NAs and 0.05 wt% CNTs. Their toughness was about 13.1 kJ/m² more than iPP blends with 30 wt% SEBS and 0.1 wt% β-NAs, 49.6 kJ/m² more than iPP blends with 30 wt% SEBS and 0.05 wt% CNTs, and almost 22.3 times of pure iPP. The iPP matrix with abundant self-toughed β-crystals generated by β-NAs, the quasi-cocontiunous morphology of the SEBS dispersed phase as well as some small SEBS droplets induced by CNTs in the iPP matrix, and the good interfacial compatibility between SEBS and the iPP matrix all harmoniously took effect to synergistically enhance the toughness of iPP blends.