The J-integral fracture toughness of PP/CaCO₃ composites

Abstract

The J-integral method was introduced to investigate the fracture process of PP/CaCO₃ composites. The results showed that the resistance of PP/CaCO₃ composites to crack initiation and propagation was greatly improved with the addition of CaCO₃ filler. Large scale plasticity was caused in PP/CaCO₃ composites, from which a large amount of energy was absorbed by the PP matrix. The reason for the increase in the fracture toughness of PP/CaCO₃ composites was attributed to the partial micro-drawing ahead of the crack tip in the PP matrix, which was formed by the stress concentration caused by the filler particles in the PP matrix and/or by the interfacial debonding between filler particles and the PP matrix. It was indicated that the presence of CaCO₃ filler could augment the ductility of composites locally, resulting in higher fracture energy in the crack initiation and propagation of the PP/CaCO₃ composites in a certain CaCO₃ content range.