The miscibility and crystallization behavior of poly(ethylene oxide) (PEO) and poly(styrene-co-maleic anhydride) ionomer (SMAI) blends were studied by the dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). This study has demonstrated that the presence of ion-dipole interactions enhances the miscibility of otherwise immiscible polymers in the PEO and high molecular weight poly(styrene-co-maleic anhydride) (SMA). The effect of ion-dipole interactions on enhancing miscibility is confirmed by the presence of a single glass transition temperature (T-g) and a depression of the equilibrium melting temperature of the PEO component. The equilibrium melting temperature of PEO in the blends are obtained using Hoffman-Weeks plots. The interaction energy density, beta, is calculated from these data using the Nishi-Wang equation. The results suggest that PEO and SMAI blends are thermodynamically miscible in the melt.