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Some properties of styrene-based ionomers containing alkali metal salts of acrylic acid or methacrylic acid have been investigated. A study has been conducted to examine the influence of the acidic content and nature (acrylic or methacrylic) and the nature of the alkali metal salt on the glass transition temperature, density, melt index and activation energy of a flow of the styrene-based ionomers. The present studies have indicated that the temperature of glass transition (T g ) of sodium ionomers increases as the sodium content rises and the region of the glass transition broadens. The T g 's of the styrene-acrylic acid (S-AA) ionomers do not depend on the nature of the alkali metal intro-duced into the copolymer. The density of films rises with the content of acid or salt introduced to the polystyrene chain. The melt index of the investigated ionomers depends on the amount and type of the introduced acid and salt as well as on the molecular weight of the initial copolymer. The energy of activation of the flow is independent of the polymer molecular weight; however, the energy of activation of flow of the ionomers increases with larger ionic radii of the introduced alkali metal.

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Small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) were used to determine the miscibility and the morphology of blends of poly(ethylene-oxide) (PEO) and styreneacrylic acid (S-AA) copolymers neutralized with alkali metals (Na + , Li + ). In this study, we investigated the effects of blend composition and the content of ionic groups in amorphous ionomers on the segregation of amorphous component. It was found that PEO is partially miscible with styrene based ionomers due to the ion-dipole interactions. These interactions reduce mobility of PEO chains and hence, they are responsible for the decrease of crystallinity and the thickness of PEO lamellar crystals. SAXS revealed that ionomers segregated interfibrillarly during the crystallization process of PEO.