The influence of thermal history on the small angle x-ray scattering of sulfonated polystyrene ionomers
The influence of thermal history on the small-angle X-ray scattering of the sodium and zinc salts of lightly sulphonated polystyrene (SPS) ionomers is described. Increasing temperature above Tg promotes phase mixing in ZnSPS and increased phase separation in NaSPS. The effect of annealing at elevated temperatures on the microstructure of ZnSPS is reversible, but dependent on the cooling rate. Changes in the microstructure of NaSPS on annealing are irreversible.