Study of the modification of the properties of (PP/EPR) blends with a view to preserving natural resources when elaborating new formulation and recycling polymers

Abstract The aim of the present work is to study how CaCO₃, very abundant on earth, can be blended with polypropylene/ethylene propylene rubber (PP/EPR) either to preserve natural resources when elaborating virgin formulations or to simulate mixtures of waste made of CaCO₃ filled PP with PP/EPR which could result from end‐of‐life‐vehicles (ELV). The article focuses on the studies of PP/EPR blends, used in the manufacture of automobile fenders, in the presence of nano‐CaCO₃ and compatibilizers. Blends of various compositions (with and without compatibilizer and nanoparticles) were prepared using a corotating twin‐screw extruder. The results were compared with the ones presented by a commercial (PP/EPR) blend. The experiments included mechanical tests, differential scanning calorimetry, scanning electron microscopy, and dynamic mechanical analysis experiments. The presence of the compatibilizers in the (PP/EPR) blends decreases the size of elastomer particles, improves the adherence to the interface and improves the mechanical properties. The nano‐CaCO₃ would also seem to act as a nucleating agent in the PP/EPR matrix; it increases the cristallinity and the Young modulus of the blends. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers