Iodine transfer polymerization (ITP) of vinylidene fluoride (VDF) in the presence of two chain transfer agents (CTA, such as C6F13I and HC2F4CH2I) is presented. Various experimental conditions in terms of the nature of the radical initiators, time, temperature and initial [initiator]0/[VDF]0 and [CTA]0/[VDF]0 molar ratios influenced the yield of the reaction, the obtained average degree of polymerization in number, n, of PVDF−I, the defect of VDF-chaining, and the CX2I functionality (where X = H or F). The microstructures of these produced PVDF−I oligomers were characterized by 1H and 19F NMR spectroscopy which enabled one to assess the n values and to quantify the head-to-head or tail-to-tail defects of VDF-chainings. A low amount of defect of chaining in PVDF−I when C6F13I was used in contrast to a higher content from HC2F4CH2I. These PVDF−Is exhibited a favored −CH2CF2I functionality from the former CTA which was not observed in the latter one. A good agreement between the targeted and the obtained n values was noted for ITP of VDF in the presence of C6F13I (representative of normal addition) whereas that carried out from HC2F4CH2I (representative of inverse addition) led to experimental n values higher than the targeted ones in all cases. A low conversion of HC2F4CH2I was observed in contrast to that of C6F13I, which shows a better efficiency as the transfer agent.

The kinetics of the iodine transfer polymerization (ITP) of vinylidene fluoride (VDF) was achieved in the presence of three different chain‐transfer agents (CTAs): 1‐iodoperfluorohexane (C6F13I), 1‐iodo‐2H,2H‐perfluorooctane (C6F13CH2CF2I), and 1,1,2,2‐tetrafluoro‐3‐iodopropane (HCF2CF2CH2I). ITPs of VDF carried out in the presence of C6F13I and C6F13CH2CF2I showed the following: (1) a linear increase in DPn versus αVDF, which evidenced the controlled character of ITP, although the polydispersity indices were slightly high (ca 1.5), and (2) theoretical DPn values close to the targeted ones. In contrast, neither of these statements was observed for the ITP of VDF in the presence of HCF2CF2CH2I achieved under the same conditions, even if the synthesized oligomers could be reactivated. Although the CTr values of C6F13I and C6F13CH2CF2I were close (i.e., 7.7 at 75 °C), that of HCF2CF2CH2I was lower (0.3 at 75 °C). The percentages of CF2I and CH2I functionalities were also assessed, and in the course of the reaction, a reduction of CF2I end groups was noted. Then, the mechanism of the ITP of VDF was proposed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5763–5777, 2006