Copper(0) Mediated Single Electron Transfer Controlled Radical Polymerization toward CF Bonds on Poly(vinylidene fluoride)

Abstract

The first copper(0) mediated controlled radical polymerization (CRP) of methyl methacrylate (MMA) toward CF bonds onto poly(vinylidene fluoride) (PVDF) is reported with rather high activity. By avoiding the halogen exchange, Cu instead of Cu complexes utilized as catalyst is responsible for the significantly improved polymerization activity. Using FH decoupled nuclear magnetic resonance technique, the grafting sites onto PVDF are finely located. From this, detailed topologic information including the grafting density, average length of each side chain, along with the overall grafted content of PMMA, is detected by tracking the polymerization as a function of time. This work offers not only a facile CRP strategy based on inactive CF bonds but also a deep insight into the cleavage of F-bearing compounds in organic chemistry.

Tailoring the Dielectric Performance of Poly(vinylidene fluoride-co-tetrafluoroethylene) through Chemical Grafting via Visible-Light Induced C–F Bond Activation

“…Recent finding indicates that the utilization of F−H decoupled 1 H NMR can detect slight alterations in chemical shifts and confirm the activation sites in PVDF-based graft copolymers, as detailed in our previous report. 22 To further elucidate the initiating sites associated with C−F bond activation, F−H decoupled 1 H NMR of the graft copolymer was performed and compared with that prepared with Cu(0)/ Bpy complexes, as depicted in Figure 2b. In addition to the typical signals of VDF units and residual solvent peaks, a distinctive signal at 2.82 ppm is observed in the graft copolymer prepared with the Cu(0)/Bpy complex.…”

“…To avoid the halogen exchange reaction that arises from mixed halogen species in the reaction system, our group first reported Cu(0)-mediated single electron transfer controlled radical polymerization (SET-CRP) for grafting modification of PVDF. 22 The activating sites in the graft copolymer were confirmed through careful characterization of its chemical structure. Furthermore, the reactivity of the C−F bond in PVDF-based fluoropolymers is closely linked to their chemical structure, which subsequently impacts the grafting efficiency.…”

Grafting Modification of Poly(vinylidene fluoride‐trifluoroethylene) via Visible‐Light Mediated C–F Bond Activation

“…At present, the only effective catalytic system for activating C-F bonds to prepare PVDF-based graft copolymers is copper complexes. [18][19][20][21] However, the side reaction of dehydrofluorination (𝛽-H elimination) inevitably occurs when the copper complex is used as the catalyst, which has been reported in Cu(0)-mediated single electron transfer controlled radical polymerization (SET-CRP). [22][23][24] In fact, Cu-induced catalytic radical termination is a non-negligible reason for the loss of chain-end functionality in traditional Cu-mediated ATRP, involving a 𝛽-H elimination to form an unsaturated polymer chain.…”

Macromolecular engineering approach for the preparation of new architectures from fluorinated olefins and their applications

“…Besides ATRP strategy, Zhang et al [214] reported the grafting of PMMA onto PVDF by single electron transfer-controlled radical polymerization (SET-CRP) toward C-F bonds catalyzed with Cu 0 and bipyridine (bpy). In the absence of halogen exchange, Cu 0 showed significantly improved catalytic activity than Cu I complexes based typical ATRP system.…”