Impact‐toughening mechanisms of calcium carbonate‐reinforced polypropylene nanocomposite Academic Article uri icon


  • The impact fracture mechanisms of polypropylene (PP), containing 9.2 vol % of calcium carbonate (CaCO 3) nanoparticles, were investigated using optical microscopy and transmission electron microscopy. The incorporation of CaCO 3 nanoparticles reduces the size of spherulites and induces the formation of β-phase crystallites, which leads to a more ductile PP matrix. Double-notch four-point bending (DN-4PB) Charpy impact specimens and notched Izod impact specimens were utilized to study the fracture mechanism(s) responsible for the observed toughening effect. A detailed investigation reveals that the CaCO 3 nanoparticles act as stress concentrators to initiate massive crazes, followed by shear banding in PP matrix. These toughening mechanisms are responsible for the observed, improved impact strength. A comparison of the fracture mechanisms observed between DN-4PB Charpy and Izod impact tests is also made to show the effectiveness of DN-4PB for investigation of impact fracture mechanisms of polymeric systems. © 2006 Wiley Periodicals, Inc.

author list (cited authors)

  • Weon, J., Gam, K., Boo, W., Sue, H., & Chan, C.

citation count

  • 38

publication date

  • March 2006