Preparation of polymer/clay nanocomposites via melt intercalation under continuous elongation flow

Polymer/clay nanocomposites exhibit desirable performance and multifunctional properties. The ideal dispersion and exfoliation of clay layers in polymeric matrixes is a significant drawback that affects its application. In this study, a novel extruder generating a continuous elongation flow was used to fabricate the representative polypropylene (PP)/organic montmorillonite (OMMT) nanocomposites and then compare with the twin-screw extruder (TSE). Phase morphology, dynamic rheological properties, and mechanical properties were characterized by thermal gravimetric analysis, wide-angle X-ray diffraction, transmission electron microscopy, rotational rheometer and impact tests. The morphology and rheological behavior of the nanocomposites evidenced that ideal intercalation or/and exfoliation dispersion of OMMT in PP matrixes can be achieved under continuous elongation flow. Thus, the double-side exfoliation of the OMMT platelets combined with the pulling/diffusion process under an elongation flow is leading to an effective strengthening and toughening of PP better than that in the TSE.