Relaxation processes in polymer-salt complexes

Pure poly(ethylene glycol)ethyl ether methacrylate (pPEGMA) and its complexes with NH4CF3SO3 and NaCF3SO3 have been investigated by an Incoherent Quasi Elastic Neutron Scattering experiment, with the aim of investigating the effect of the salt addition on the local relaxation of the polymeric matrix. A reorientational relaxation has been detected while the Q-dependence of the elastic scattering suggests for the existence of a slow translational diffusion. The comparison with previous conductivity results suggests that the variation of the glass transition temperature, induced by the presence of cations, is enough to justify the charge diffusion process in the case of alkali ions, while a more complicated scenario has to be depicted when complex cations, like ammonium, are taken into consideration.