Block copolymers based on poly(vinylidene fluoride), PVDF, and a series of poly(aromatic sulfonate) sequences were synthesized from controlled radical polymerizations (CRPs). According to the aromatic monomers, appropriate techniques of CRP were chosen: either iodine transfer polymerization (ITP) or atom transfer radical polymerization (ATRP) from PVDF-I macromolecular chain transfer agents (CTAs) or PVDF-CCl(3) macroinitiator, respectively. These precursors were produced either by ITP of VDF with C(6)F(13)I or by radical telomerization of VDF with chloroform, respectively. Poly(vinylidene fluoride)-b-poly(sodium styrene sulfonate), PVDF-b-PSSS, block copolymers were produced from both techniques via a direct polymerization of sodium styrene sulfonate (SSS) monomer or an indirect way with the use of styrene sulfonate ethyl ester (SSE) as a protected monomer. Although the reaction led to block copolymers, the kinetics of ITP of SSS showed that PVDF-I macromolecular CTAs were not totally efficient because a limitation of the CTA consumption (56%) was observed. This was probably explained by both the low activity of the CTA (that contained inefficient PVDF-CF(2)CH(2)-I) and a fast propagation rate of the monomer. That behavior was also noted in the ITP of SSE. On the other hand, ATRP of SSS initiated by PVDF-CCl(3) was more controlled up to 50% of conversion leading to PVDF-b-PSSS block copolymer with an average number molar mass of 6000 g.mol(-1). (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 3960-3969, 2011