REINFORCEMENT OF EPDM-BASED IONIC THERMOPLASTIC ELASTOMER BY CARBON-BLACK

High abrasion furnace carbon black improves the physical properties of zinc sulfonated ethylene-propylene-diene terpolymer of high (75 wt%) ethylene content. Properties studied include hardness, stress-strain c haracteristics, tear strength, hysteresis and abrasion resistance. Sca nning electron photomicrographs of the tear fractured and abraded surf aces show changes in failure mode of the polymer on incorporation of c arbon black. Results of dynamic mechanical analyses and dielectric the rmal analyses show that carbon black reinforces the ionomers, presumab ly through weak rubber-filler interaction involving the backbone chain s and strong interaction between the active sites of the filler surfac e and the ionic aggregates present in the 'multiplets' and 'clusters'. Reprocessability studies in the Monsanto Processability Tester (MPT) show that the carbon black filled polymer can be reprocessed like a th ermoplastic elastomer and there was no fall in properties even after t hree cycles of extrusion through the MPT.