Morphology and mechanical properties of styrene homoblends of methacrylateand sulfonate ionomers

Dynamic mechanical properties and morphology of homoblends of sulfonated po lystyrene and poly(styrene-co-methacrylate) ionomers were investigated. Whi le two tan delta peaks were found in the unblended ionomer samples, three t an delta peaks were observed for the homoblend. The peak at 152 degrees C i s thought to be due to the matrix T-g, and those at 194 and 261 degrees C p robably represent the glass transitions of cluster regions, containing meth acrylate-rich multiplets and sulfonate-rich multiplets, respectively. In SA XS profile, only a very broad plateau-type feature was seen for the homoble nd. This result implies either that the number density of the scattering ce nters at prevalent distances is low or that each scattering center has a di fferent electron density. Thus we suggest that in the present study the mul tiplets of the homoblend consist of random mixtures of sulfonate and carbox ylate groups.