Study of Mechanical and Morphological Properties of Polypropylene Blended with EPDM Rubber Powder from Automotive Door Seals

This research studied the mechanical properties and morphology of polypropylene (PP) mixed with ethylene propylene diene rubber (EPDM) powder from automotive door seals. The EPDM rubber powder is prepared untreated and devulcanized using heat and mechanical force. The devulcanizing process of EPDM was studied by mixing method with the two-roll mill at temperatures of 220 and 230 ^oC, with a roller speed of 40 rpm for 25 minutes, and then mixing in an internal mixer at a temperature of 200 ^oC, rotor speed 140 rpm for 10 minutes, then tested for the ability to devulcanize rubber by soxhlet extraction method to select the appropriate temperature. The untreated and devulcanized wasted ethylene propylene diene rubber powder was added to polypropylene at a ratio of 0/100, 10/90, 20/80, 30/70, and 40/60 percent by weight with an internal mixer and molded into a specimen by a hydraulic press. Then, the tensile and impact properties and the morphology. It was found that the devulcanizing process was done in the mixing method with the two-roll mill at temperatures of 230 ^oC there was a higher percentage of melted rubber than at 220 ^oC, indicating better devulcanization ability. With increasing EPDM content in PP, Young's modulus decreased, but the elongation at break and impact strength increased. The tensile strength tended to decrease when increasing with untreated and devulcanized EPDM.