The effect of extrusion reprocessing on the properties of montmorillonite filled polypropylene

Composites of polypropylene (PP) reinforced with organic modified montmorillonite (MMT) (4 wt%) and compatibilizer were subjected to 15 extrusion cycles and compared with extruded virgin PP and extruded PP-compatibilizer. The materials were characterized by melt flow index (MFI), tensile testing and X-ray diffraction (XRD). The results showed an improved intercalation of the MMT clay in the first few extrusions, thus improving the mechanical properties. Further extrusion lead to a decrease in elastic modulus, which was attributed to a reduction in matrix-filler interaction, most probably caused by organoclay degradation as shown by thermogravimetric analysis (TGA).Composites of polypropylene (PP) reinforced with organic modified montmorillonite (MMT) (4 wt%) and compatibilizer were subjected to 15 extrusion cycles and compared with extruded virgin PP and extruded PP-compatibilizer. The materials were characterized by melt flow index (MFI), tensile testing and X-ray diffraction (XRD). The results showed an improved intercalation of the MMT clay in the first few extrusions, thus improving the mechanical properties. Further extrusion lead to a decrease in elastic modulus, which was attributed to a reduction in matrix-filler interaction, most probably caused by organoclay degradation as shown by thermogravimetric analysis (TGA).P