FAR-INFRARED STUDIES OF ION CLUSTERING IN IONOMERS

In the reported experimental study, the far-infrared spectra of polystyrene methacrylic acid/(PSMA) ionomers have been investigated as a function of cation and ion-site concentration to obtain spectroscopic evidence of domain formation. A far-infrared band, due to the vibration of a higher-order cluster, is found at 170 cm** minus **1 in Na** plus -form PSMA. This band, which is observed in addition to the known cation-motion bands, is assigned to the vibrations of aggregates involving many cations and anionic sites close together, and the results are discussed in light of ion aggregation models.