RAMAN-SCATTERING INVESTIGATIONS OF PEO AND PPO SULFONIC-ACIDS

Sulphonic acid derivatives of polyethers, of interest as proton conduc ting materials, were investigated using Raman spectroscopy, focusing o n influence of hydration on ion configuration and polymer conformation . Upon increasing hydration we observe a polarised mode building up at approximately 1040 cm(-1), assigned to the symmetric stretching vibra tion of a completely hydrated SO3- group. The data suggest that the pr oton-sulphonic groups do not dissociate until the materials are consid erably hydrated thus explaining the low proton conductivities found fo r these materials below a relative humidity of 75%.