Effect of crystalline structure on the cell morphology and mechanical properties of polypropylene foams fabricated by core-back foam injection molding

摘要

Foam injection molding (FIM) is an advanced technology for preparing lightweight plastic foams, but its inferior mechanical performance remains a challenge. In this study, microcellular injection-molded beta-polypropylene (beta-PP) foams with high ductility were successfully prepared by combing the beta-nucleating agent with controllable temperature field. Foaming results showed that the microcellular beta-PP foams exhibiting a cell size of about 8 mu m and cell density over 10(8) cells/cm(3) were prepared with a crystalline diameter approximately 5 mu m, while PP foams had a rather large cell size approximately 150 mu m and low cell density of 10(5) cells/cm(3) with 30 mu m crystalline size. As a result, this significant improvement in cell structure as well as the crystalline size lead to a significant increment of 86 for the ductility of beta-PP foams. This work offers a facile strategy to prepare injection-molded foams with desirable mechanical properties for their wide range of applications, such as automotive construction and consumer electronics.