Polypropylene Injection Molded Part with Novel Macroscopic Bamboo-like Bionic Structure

A macroscopic bamboo-like bionic structure was fabricated in the injection-molded bar of isotactic polypropylene via the combined effect of "melt manipulation" and beta-nucleator. Such structure consists of strengthened shell zone with high orientation and low beta-phase amount, and toughened core part with isotropic texture and dominant beta-modification. The influences of shear intensity on structural hierarchies, polymorphism, and crystalline morphology were estimated. Both toughness and strength can be significantly improved with increasing shear intensity on the bamboo-like structure. Our study suggested an alternative approach to achieve excellent comprehensive mechanics in polypropylene via macroscopic structural design during the practical molding process.