Surface modification of vulcanized EPDM rubber by Ag(II): Kinetic study of Ag(II) generation and surface characterization

Ethylene Propylene Diene Monomer (EPDM) rubber is widely used in various outdoor and industrial applications. However, in order to improve its adhesion properties, some surface modications are required. Mediated electrochemical oxidation by Ag(II) was, thus, employed to evaluate the feasibility of EPDM surface modication. The electrochemical behavior of Ag(I)/Ag(II) redox couple was initially studied at dierent temperatures in an electro-membrane cell using IrO2/Ta2O5anode. The reversibility of the redox reaction improved at low temperatures. The apparent rate constant for Ag(I) oxidation (k1) at 3 kA m??2 was 2:20310??3 (s??1). The surface chemistry, morphology, and wettability of the activated EPDM rubber by Ag(II) were then analyzed, and the modied EPDM surface showed a signicant decrease in the water contact angle resulting in an increase in the surface free energy and improved wettability. ATR analysis revealed the presence of oxygen-containing polar groups on the modied rubber surface. SEM results showed that the short treatment time at room temperature only changed the morphology of the rubber surface, which is attributed to the etching of the outermost surface.