Effect of Vibrating Extrusion on the Structure and Mechanical Properties of Isotactic Polypropylene

An electromagnetic dynamic plasticating extruder, invented by the authors, was used to prepare isotactic polypropylene (PP) sheets. Tensile and impact tests show that the extruded samples can simultaneously be reinforced and toughened along the flow and transverse directions in a moderate frequency and amplitude range. The microstructures of the obtained samples were characterized by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), and scanning electron microcopy (SEM). The results indicate that the vibration plasticating extrusion affected the morphology of the PP extrudate, it especially resulted in finer spherulites, and move tie molecules, which account for the enhancement of the tensile strength and impact toughness of PP sheets in both extrusion and transversal directions.