Fourier-transform infrared studies of ionomeric blend and ionic aggregation

Abstract

The ionomeric blend and the ionic aggregation studies by using Fourier-transform infrared spectroscopy(FT-IR) are presented. The two ionomers were prepared. One is barium polyacrylate and the other is barium polystyrenesulfonate. The blend of the two ionomers with barium salt shows intermolecular ionic interaction between the carboxylated ionomer and the sulfonated ionomer. This interaction leads to considerable differences between the spectrum of the blend and the spectra of the two pure ionomers. From our results, it is shown that ionic interactions must play an important role in the compatibility of the two iconomers. In the ionic aggregation study, the bands due to asymmetric stretching mode of carboxylate anion ($COO^-$) in the carboxylated ionomer and the ionomer blend increase in intensity with increasing the divalent barium cations. These results indicate the formation of ion pairs. The doublet due to the asymmetric stretching modes of the carboxylate anion($COO^-$) is concerned with sort of local structure found in ion aggregation. By considering the possible structure for multiplet about the blend, it is well explained the spectra splitting and the frequency shift.