A study on the compatibility of NR-EPDM blends using electrical and mechanical techniques

Systematic electrical and physicomechanical studies have been carried out on natural rubber (NR) blended with synthetic rubber ethylene-propylene diene monomer (EPDM) as non-polar rubber. The permittivity (epsilon') and dielectric loss (epsilon '') of this blend have been measured over a wide range of frequencies (42Hz-5MHz) at room temperature (approximate to 25 degrees C). Compatibility of NR-EPDM can be enhanced by the addition of compatibilizers, such as polybutadiene (BR), chlorinated rubber, chloro-sulfonated polyethylene (SPE), polyvinyl chloride (PVC), and graft copolymerization of EPDM with metallic anhydride [EPDM-g-MAH]. The compatibility results obtained from the dielectric measurements are comparable with those obtained from the calculation of the strain energy, fatigue, mechanical failure tests, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The results obtained reveal that the addition of a small percentage of compatibilizers can improve the compatibility of such a blend to some extent.