Thermoplastic Elastomer Based on PP/EPDM/ENR25 and PP/EPDM/NR Blends

A series of ternary blends of polypropylene (PP)/ethylene-propylene-diene terpolymer (EPDM)/natural rubber (NR) and PP/EPDM/epoxidized natural rubber (ENR25) were prepared in a laboratory internal mixer at 180°C and a rotor speed of 50 rpm. The mechanical properties, oil resistance, and morphological studies of PP/EPDM/NR and PP/EPDM/ENR25 blends were investigated. Results indicated that PP/EPDM/ENR25 blends are slightly easier to process than PP/EPDM/NR blends and the torque values increased as the NR and ENR25 contents increased. The tensile strength and elongation at break decreased as NR and ENR25 content in the blends increased, whereas the tensile modulus shows an opposite trend. The PP/EPDM/NR blends show higher tensile strength, tensile modulus, and elongation at break than PP/EPDM/ENR25 blends in all blend compositions. However, PP/EPDM/ENR25 blends exhibited better oil resistance than PP/EPDM/NR blends. From morphological studies PP/EPDM/NR exhibit more homogeneous phases than PP/EPDM/ENR25 blends.