New segmented polyurethane (PU) anionomers based on hydroxytelechelic polybutadiene (HTPB) were synthesized via an environment-friendly chemical route. Incorporation of carboxylated functions on the PU soft segment was carried Out using a thiol-ene reaction on HTPB vinyl double bonds with thioglycolic acid. PU water dispersions were obtained by addition of a water dispersible polyisocyanate, i.e., Bayhydur (R) 3100, to the modified ionic HTPB water dispersions. The key factor of this formulation is the control of ionic concentration apart from the hard segment content, oppositely to all other PU anionomer formulations. The influence of ionic content was studied through all steps of the PU material synthesis, from aqueous dispersions upto crosslinked materials' physical properties. For fully neutralized precursors, the stability of the ionic aqueous dispersions was higher than that was in six months. In all cases, particles were smaller than 200 nm. PU glass transition temperature, surface hydrophily and swelling increased with ionic content. But, however, PUs exhibit hydrophobic surface properties with a maximum surface tension of 45 mN m(-1) and a limited water uptake. (c) 2006 Wiley Periodicals, Inc.