The effects of mixing two metal cation ionomers on the structure and properties were investigated. Samples used in this study were binary mixtures selected from Li, Na, Mg, Cu(II), and Zn(II) salts of poly-(ethylene-co-methacrylic acid) (EMAA). Stiffness, tensile, and melt index results in accordance with differential scanning calorimetry (DSC) and dynamic mechanical property measurements showed that binary cation mixtures gave rise to unexpectedly higher small-strain moduli if cations were selected from different metal groups such as alkali, alkaline earth, and transition metals. However, their large-strain moduli and properties measured in a molten state were essentially unchanged or as expected. For the binary mixtures exhibiting enhanced small-strain moduli, infrared results uncovered the appearance of a new peak in the carboxylate asymmetric stretching band at blend ratios where the binary mixtures exhibited the highest small-strain moduli. The results indicate that ionic aggregates of these mixtures form a conjugated binary metal salt.