Establishing structure-properties relationships for an associative polymer requires a precise knowledge of its structure. In previous works, we studied water-soluble telechelic perfluorocarbon (C8F17) derivatives of poly(ethylene glycol)s. They exhibit stronger hydrophobic intermolecular associations than the corresponding hydrocarbon derivatives (C8H17). We now report the synthesis and study of one-ended perfluorocarbon derivative of poly(ethylene glycol). The composition and structure of this polymer were elucidated before analysing its behaviour in aqueous solution by viscosimetry and F-19 NMR. The synthesis procedure allows us to reach total grafting. This polymer presents a micellar behaviour above 2 X 10(-4) g/ml and an associative behaviour above 10(-3) g/ml.