Model functionalized telechelics based on poly(ethylene oxide) (PEO) capped with OH- groups. with protons (H+) in the terminals have been prepared and the effects of structure on molecular mobility and protonic conductivity have been investigated. Molecular mobility and protonic conductivity were measured by means of broadband dielectric relaxation spectroscopy (DRS, 10(-2)-10(9) Hz) and of thermally stimulated depolarisation currents techniques (TSDC, 77-300 K). The features of alpha relaxation, associated to the glass transition, and of dc conductivity sigma (dc), determined from ac conductivity (alpha (ac)(f)) plots. were analysed in detail. Protonic conductivity was found to be governed by the motion of the polymeric chains.