The curing (optimum cure (t₉₀) and scorch time (t_s2), cure rate index (CRI), torque difference (∆M), maximum torque (M_h) and minimum torque (M_l)), physical (hardness, rebound resilience, compression set and abrasion resistance), and mechanical properties (tensile strength, tensile modulus, tear strength and elongation at break) of ethylene-propylene-diene monomer terpolymer (EPDM)/styrene-butadiene copolymer rubber (SBR) nano-composites with additions of modified nano-graphene oxide (mGO) for possible usage as flexible and durable materials were examined in this study. Nano-graphene oxide (GO) was treated with two types of surfactants, 3-aminopropyltriethoxysilane (KH550) coupling agent and 4,4'-diphenylmethane diisocyanate (MDI), and then incorporated into an EPDM/SBR rubber matrix at a varying loading (2-10 phr), mixed by an open mill mixer, and vulcanized by hydraulic press. The particle size altered after modification, and the modified GO diffused efficiently in the EPDM/SBR rubber matrix, according to the FESEM. The MDI modified GO nano-composites have better mechanical properties than the KH550 modified GO nano-composites. The findings suggest that the produced nano-composites could be employed in a diversity of outdoor uses, including window seals, door seals and cooling system hoses.

Keywords: ethylene-propylene-diene monomer terpolymer/styrene-butadiene copolymer rubber, graphene oxide, modifier, mechanical properties.