Abstract
The radical telomerisation of vinylidene fluoride (VDF) with 2-mercaptoethanol as chain transfer agent (CTA) was studied to synthesise fluorinated telomers which bear a hydroxy end-group, as H(VDF)nS(CH2)2OH, under thermal (di-tert-butyl peroxide as the initiator) or photochemical initiations. A careful structural study of typical H-VDF-S(CH2)2OH telomer was performed by 1 H and 19 F NMR spectroscopies. These analytical methods allowed us to evidence the selective addition of the thiyl radical onto the hydrogenated side of VDF, and the telomer containing one VDF unit was obtained selectively. Surprisingly, for higher [VDF]o initial concentrations, monoadduct telomer was produced as well as PVDF homopolymer. This feature was related to the fast consumption of the CTA. The kinetics of radical telomerisation led to a quite high transfer constant of the CTA (40 at 140 °C) that evidences the formation of monoadduct as the only telomer formed.