Tensile fracture morphologies of nylon‐6/montmorillonite nanocomposites

Nylon‐6/montmorillonite nanocomposites with different dispersion states of clay and different clay loadings were prepared by melt processing. The nanostructure and mechanical properties were also investigated. The influence of the montmorillonite dispersion state and clay content on the tensile fracture morphology of the injection‐molded nanocomposites was studied by scanning electron microscopy. A rounded ‘cabbage‐like‐sheet’ structure was observed in the fracture surface of the well‐exfoliated nanocomposites, which was absent in the intercalated and poorly dispersed nanocomposite and neat nylon‐6. The formation of this ‘cabbage‐like‐sheet’ pattern has been attributed to the extensive plastic fibrillations of the nylon‐6 matrix, facilitated by the stress concentration and the strengthened effect caused by the well‐exfoliated clay platelets. The change in stiffness caused by the skin–core structure was also considered. The difference in the patterns observed in this present work and those reported by Uribe‐Arocha et al. (Polymer, 44, 2441 (2003)) were discussed, based on the diversity in preparation of the tensile specimens.