Performance of bio-ethylene propylene diene monomer (bio-EPDM) foam with mixed chemical and encapsulated blowing agents

Abstract

Bio-EPDM, produced from sugarcane-derived ethylene, is an eco-friendly alternative material that can solve environmental pollution problems while showing performances similar to neoprene, a petroleum-based synthetic rubber. In this study, the optimum foaming conditions were determined for maximizing the properties of bio-EPDM foam for application in highly functional environment-friendly diving wetsuits. The bio-EPDM foam was prepared by mixing chemical and encapsulated blowing agents in different mixing ratios, and the mechanical properties, thermal stability, and salt-water resistance of the bio-EPDM foam were evaluated. The mechanical and elastic properties of the bio-EPDM foam decreased with increasing amount of encapsulated blowing agents, whereas the thermal stability and salt-water resistance remarkably improved with increasing mixing ratio of the encapsulated blowing agent. The mechanical properties and salt-water resistance of the bio-EPDM foam prepared using the mixed blowing agents were better than those of the foam prepared using a single blowing agent. At a mixing ratio of 2.5:2.5, a foam with excellent dimensional stability was achieved without a significant reduction in mechanical properties. In addition, the physical and mechanical properties of the bio-EPDM foams were not significantly affected by the curing system; however, the dimensional stability of the foam cured with the peroxide system was superior to that of the foam cured with sulfur system. Therefore, a proper control of the mixing ratio of chemical and encapsulated blowing agents can produce foams with optimal mechanical properties and salt-water resistance for application in watersport apparels.