Effects of nanoparticle treatment and compatibilizers on the properties of (PP/EPR)/nano-CaCO3 blends

Effects of nanoparticle surface treatment and compatibilizers (PEP and EPR-g-MAH) on the mechanical behavior, rheological and morphological properties of (PP/EPR)/CaCO3 blends were investigated by using differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA). Blends of various compositions (with and without compatibilizer and nanoparticles) were prepared using a corotating twin-screw extruder. The results demonstrated that the dispersion of nano-CaCO3 depends on surface-treating agent (Stearic acid or Fatty acids). The presence of the nanoparticles and the compatibilizers does not modify significantly thermal and rheological properties. But, EPR-g-MAH copolymer seems to modify the interface between PP and EPR phases and increase the size of EPR particles. The study of mechanical properties (tensile and impact tests) shows the presence of compatibilizers in (PP/EPR) blends; especially PEP significantly increases the deformation and the energy at break. But the reduction of the elongation at break and the impact strength respectively of 7 and 30% seems to be due to lower adhesion between the nanoparticles and the (PP/EPR) matrix.