Real-time rheology of shear-induced organoclay dispersion in isotactic polypropylene

In this paper, rheological properties evolution of the simple mixed isotactic polypropylene/organoclay composites, impacted by intermediate- or large-amplitude oscillatory shear fields, was followed by dynamic melt rheometry. The physical meanings of such rheological evolution upon oscillatory shearing, which related closely to the dispersion and intercalation of organoclay in polymer, were discussed deeply. Especially, a structural recovery test was adopted to assess microstructure development induced by large-amplitude oscillatory shear and to better understand the intercalation mechanism. Based on the experimental results, a novel intercalation mechanism that was taken to account for the disentanglement of polymer chains was suggested to describe shear-induced dispersion behaviors of organoclay in polymer matrix.