Synergistic effects of toughening of nano-CaCO3 and toughness of β-polypropylene

High performance beta-polypropylene (beta-PP) nanocomposites were prepared by nano-CaCO3 with beta-nucleation (beta-CC) filled PP, and the crystallization and mechanical properties of beta-PP nanocomposites were investigated. The results show that beta-CC prepared by nano-CaCO3 supported beta-nucleating agent calcium pimelate (CaPA) does not only increase the crystallization temperature of PP, but also induce the forming of a number of beta-PP. It indicates that the nucleation mechanism of nano-CaCO3 has been changed from alpha- to beta-nucleation. The notched impact strength of beta-CC filled PP nanocomposites was higher than that of CC filled PP and CaPA nucleated PP. It is suggested that there is a synergistic effect of toughening of CC and toughness of beta-PP. Meanwhile, the reinforcing of CC nanoparticles increased the stiffness of beta-PP. The synergistic toughening effect of CC and beta-PP was discussed. This method can be extended to prepare other high performance filled beta-PP composites. (C) 2011 Elsevier Ltd. All rights reserved.