Influence of morphology evolution on the mechanical properties of beta nucleated isotactic polypropylene in presence of polypropylene random copolymer

Abstract A promising method was developed by adding polypropylene random copolymer (co-PP) and β-nucleating agent (β-NA) simultaneously into isotactic polypropylene (iPP) matrix to improve its toughness. Results showed that the co-PP chains promoted crystal refinement, and the rubbery phases corresponding to the propylene–ethylene random segments offered superior toughness. This proves that crystal morphology, which correlates with β-NA content, is another important factor that determines toughness and tensile strength in addition to β crystal content. Furthermore, a mechanism for the morphology evolution is proposed. This study shows the feasibility of improving the mechanical properties of iPP and expanding its applications.