Zinc neutralized maleated natural rubbers (Zn-MNR) were prepared by solution grafting and neutralization with zinc acetate in one-step. It was later used for blending with carboxylated nitrile rubber (XNBR) in the composition of 50/50 parts by weight. The effect of grafted anhydride content (1.2, 1.6, 2.0, and 2.5% wt of NR) on the tensile properties of ionic rubber blends (Zn-MNR/XNBR) was investigated. The tensile strength of the ionic blends was found to be greater than those of pure rubbers. The modulus, tensile, and tear strength of the blends dramatically increased with increasing levels of grafted anhydride. The ionic rubber blends also possessed superior physical properties compared to those of the corresponding nonionic rubber blends (MNR/XNBR). Dynamic mechanical thermal analysis and scanning electron microscopic studies were performed to verify the process of mixing. Fourier transform infrared spectroscopic studies were carried out to characterize the nature of specific intermolecular interactions between Zn-MNR and XNBR chain segments. The results indicated that the ion-ion (Zn+-COO-) interactions between Zn-MNR and XNBR are formed at the interface, which provides the mean of compatibilization in the ionic rubber blends. (c) 2007 Wiley Periodicals, Inc.