Elongational Flow-induced Crystallization in Polypropylene/Talc Nanocomposites

During the processing of the polymers, macromolecules undergo a significant flow just before or during cooling. For semi-crystalline materials, the flow widely influences both the crystallization kinetics and the resulting crystalline orientation. Moreover, in the presence of nucleating filler, even more with a high aspect ratio, these phenomena of crystallization under elongational conditions can be disrupted. In this study, melt blended nanocomposites of PP /Talc were processed using an internal mixer. An elongational rheometer was used to generate well controlled different extensional flow conditions. Samples were then characterized by WAXS to reveal and quantify the fillers and PP crystalline phase orientation. Crystalline orientation of polypropylene was found to be strongly affected by the addition of Talc under extensional flow and the Talc orientation.