Synthesis and characterization of PS-block-PEO associative water-soluble polymers F. Boschet, C. Branger * , A Margaillan Equipe d’accueil Mat eriaux  a Finalit es Sp ecifiques, Laboratoire de Chimie Appliqu ee––MFS EA 1356, ISITV––Universit e de Toulon et du Var, Avenue George Pompidou, BP 56, 83162 La Valette Cedex, France Received 24 January 2002; received in revised form 14 June 2002; accepted 1 August 2002 Abstract We report the synthesis and structure determination of PS-block-PEO functionalized by fluorocarbon end-group (C 8 F 17 )viaanesterbridge.ThesynthesiswasdonebyananionicpolymerizationofPSandPOEterminatedbygrafting 3-perfluorooctylpropanoyle chloride (C 8 F 17 –C 2 H 4 –COCl) onto PS-POE alcoholate. The structure has been charac- terized by a number of techniques: size exclusion chromatography, elementary analysis, UV spectroscopy, 1 H nuclear magnetic resonance. Those analyses have allowed the determination of the real molar mass of the copolymers and the percentage functionalization. Because of their well-defined structure, these copolymers can be used as model com- pounds for the determination of structure–property relationships. Ó 2002 Elsevier Science Ltd. All rights reserved. Keywords: Fluorine; Associative; PEO 1. Introduction From a theoretical and practical point of view, the study of associative polymers has recently drawn a considerable interest due to their original and specific rheological properties [1–3]. These properties distin- guishthemfromotherpolymersconcerningtheviscosity enhancement and the reversibility of the associative phenomenon. These particular rheological properties are explained by the incompatibility between various groups,forexamplehydrophilicandhydrophobicgroups, within the same macromolecule. According to the im- portance of the repulsion and attraction forces (steric, electrostatic, ...), these compounds have a more or less marked antagonistic character [4–7]. There is a growing interest in the interpretation and the understanding of the structure–property relation- ships of these associative polymers [8–12]. The estab- lishment of these relationships requires the precise knowledge of the polymer structure. Classical radical and micellar polymerization mainly produce associative polymers for which it is difficult to determine the exact structure due to its polymolecularity or composition variation (preferential consumption of a monomer compared to another monomer during polymerization). Therefore, the given structure is only apparent and corresponds to an average structure, which cannot be used for structure–property relationship interpretation becausesomepropertiesarerelatedonlytoafractionof the sample. Recent improvements of controlled radical polymerization makes it possible to achieve the re- quested structure (very low polydispersity) [13–15]. We previously reported the synthesis and the hydrophobically associative behaviour of fluorocarbon derivatives of water-soluble poly(ethylene glycol)s [16] consisting of two-ended perfluorocarbon PEG deriva- tives. These compounds were obtained by a grafting reaction onto the PEG end chains: an esterification be- tweenhydroxylend-groupsofPEGandanacylchloride European Polymer Journal 39 (2003) 333–339 www.elsevier.com/locate/europolj * Corresponding author. Tel: +33-4-9414-2580; fax: +33-4- 9414-2598. E-mail address: branger@univ-tln.fr (C. Branger). 0014-3057/02/$ - see front matter Ó 2002 Elsevier Science Ltd. All rights reserved. PII:S0014-3057(02)00223-9