COMPLEXES OF POLYSTYRENE IONOMERS WITH BUTYL ACRYLATE OLIGOMERS (HETEROGRAFTS)

Monodisperse tert-butyl acrylate (tBA) oligomers of several lengths, f unctionalized at one end by a tertiary amine, were ionically grafted t o lightly sulfonated polystyrene. Despite the oligomers being immiscib le with the polystyrene matrix, dynamic mechanical analysis of the ble nds indicates only a weak phase separation effect, and the polymer is plasticized moderately. However, the blends (studied up to 30 wt %) ar e translucent, suggesting phase separation on a larger scale. A possib le explanation is given in terms of nonspherical tBA domains subject t o a hard-wall effect coupled with interfacial ionic interactions as we ll as ester-acid interactions. Evidence for the latter was noted in th e infrared spectra.