Abstract: Ethylene-propylene-diene monomer (EPDM)/nano calcium carbonate(nano-CaCO3) masterbatch was prepared in an internal mixer, which was subsequently introduced into polypropylene(PP) leading to a ternary composite. The influences of the nano-CaCO3 dosage and the mixing time on the dynamic mechanical property of EPDM/nano-CaCO3 masterbatch were characterized by a dynamic mechanical analyzer. The morphology of nano-CaCO3 and EPDM dispersed in PP matrix were observed by scanning electron microscope. It showed that while blending for 15 min at room temperature, the storage modulus,loss modulus and loss tangent of EPDM/70 % nano-CaCO3 composite all reached their optimal values. In the ternary composites, a large amount of energy was dissipated by mechanizms of collaborative deformation of nano-CaCO3 agglomerate and EPDM, the fibrillation induced by interfacial debonding, and shear banding of PP matrix, which markedly improved the toughness.

Key words: polypropylene, nano calcium carbonate, ethylene-propylene-diene monomer, dynamic mechanical property