This paper studied mechanical properties of several grades of composite materials consisting of polypropylene （PP） and nano-CaCO3, and examined the influences of twin-screw extrusion and internal mixing process and compatibilizer content on the mechanical properties of the composite. The distribution of nano-CaCO3 particles in the PP matrix was observed by means of transmission electron microscope （TEM）. The results indicate that nano-CaCO3 can act as a toughening agent to all grades of PP involved in the experiment, however, the toughening effectiveness is specially dependent on the character of the matrix resin. A remarkable toughening effectiveness can be acquired for the matrix resin with a better toughness, as demonstrated by an 81% increase in the impact strength. Both twin-screw extrusion and internal mixing are able to make nano-CaCO3 particles disperse homogeneously in PP.
China Synthetic Resin and Plastics