Deeper Insight into the MADIX Polymerization of Vinylidene Fluoride

Controlled radical polymerization protocols for vinylidene fluoride (VDF) are still very elusive. MADIX polymerization of VDF has very rarely been reported. The synthesis of PVDF using MADIX solution polymerization was thus investigated in detail. More efficient protocols for solution polymerization were developed and afforded relatively well-defined PVDF. Careful polymer chain-end monitoring using MALDI-TOF as well as H-1, F-19, and HETCOR H-1-F-19 NMR revealed that VDF reverse additions and transfer to solvent reactions severely affect the control of the polymerization. Indeed, these unwanted reactions are responsible for a non-negligible loss of CTA and for the accumulation of nonreactive polymer chains in the reaction medium. MADIX polymerization lead to the synthesis of PVDF with high chain-end functionality. However, these PVDF chains cannot reinitiate the polymerization of VDF. This work is the first comprehensive study of the MADIX solution polymerization of VDF.