Effect of Repeated Extrusion Cycles on the Structure and Properties of Polypropylene/Polyolefin Elastomer/Organic Montmorillonite Nanocomposites Using a β-Nucleating Agent

Abstract

In this study the compatibilizer, maleic anhydride/hydroxyethyl acrylate-grafted-polyolefin elastomer (POE-g-MAH/HEA), was utilized in the preparation of polypropylene/polyolefin elastomer/organic nano-montmorillonite (PP/POE/OMMT) nanocomposites with a β-nucleating agent (β-NA) via twin-screw extrusion. The impact of repeated extrusion cycles (up to three) on the properties and structure of the nanocomposites was investigated. The results indicated that the dispersion of the OMMT within the polymer matrix improved with increased extrusion cycles, thereby enhancing the interfacial interactions between the constituents. In addition, the OMMT platelets led to increased crystallinity of the nanocomposites, accompanied by polymer chain degradation. The second extrusion cycle resulted in the nanocomposite with the best melt strength and mechanical properties. Additionally, the three cycles of additional repeated extrusion significantly enhanced the thermal stabilities of the nanocomposites.