Dynamics of lightly sulfonated polystyrene ionomers

The tracer diffusion coefficients of both ion-containing polymer chains and their associated counterions were measured in lightly sulfonated ionomers as a function of temperature, ion content, and chain length. The data are shown to be in good agreement with relaxation times derived from viscoelastic measurements at high temperatures. The results are interpreted in terms of a reptation model, modified to account for the additional constraints on individual chain motion imposed by the associating ion pairs.