Poly(vinylidene fluoride) with low content of head‐to‐head chain imperfections

Synthesis and copolymerization of vinylidene fluoride (VDF) with Trifluorovinyl Monomers, 11

“…As expected, the head‐to‐tail VDF units (i.e., produced from normal VDF propagation) of the VDF block are represented by a group of signals in the −91 to −95 ppm range, while the signals centered at −113 and −116 ppm are assigned to the reversed VDF units (i.e., head‐to‐head VDF chaining). These attributions are in good agreement with those already described by various authors for low40 or high molecular weight PVDF,41–48 or for telomers of VDF with perfluoroalkyl iodides,9,13,35,36 α , ω ‐diiodoperfluoroalkanes,37 methanol,2,3 polyhalogenomethanes9–14 or diethyl hydrogen phosphonate 7,8…”

Random and sequential radical cotelomerizations of 3,3,3‐trifluoropropene (H2CCHCF3) with vinylidene fluoride (F2CCH2)

“…[22][23][24] On the other hand, vinylidene fluoride (VDF) is a non-toxic, non-explosive, and environmentally friendly gas (it does not contain any Cl or Br atoms). It can easily polymerize under radical 25 or ionic 26 conditions. Poly(VDF) is an attractive polymer endowed with remarkable properties (it is a piezo-and pyroelectric, resistant to acids, solvents, and to nuclear radiation, and is a gas barrier polymer).…”

“…It has found numerous applications just like its copolymers which have been marketed by most major companies. 3,[25][26][27][28][29][30] The telomerization of VDF has been investigated by many authors and 4 reviewed. 3 Almost all kinds of chain transfer agents have been used with a suitable initiation (thermal, photochemical, by redox systems or by radical initiators).…”

Organometallic‐Mediated Radical Polymerization of Vinylidene Fluoride

“…[1c] Reversible deactivation radical polymerization (RDRP) of VDF has only been achieved using two techniques: 1) iodine transfer polymerization (ITP), [1c,5] and 2) reversible addition fragmentation chain transfer (RAFT) polymeri-zation. [6b,c, 8] Ideally, aRDRP technique should reactivate both PVDF chain ends at the same rate.A sandei et al [9] were able to reactivate the -CF 2 CH 2 -I terminated PVDF chains and to synthesize block copolymers using Mn 2 (CO) 10 and ap hotoirradiation process in ITP.H owever,f urther reactivation to access block copolymer structures was only possible using conventional radical polymerization. However,the chain defects resulting from head-to-head (HH, -CH 2 CF 2 -CF 2 CH 2 -) monomer additions impose limits on the molar masses (M n )and dispersities ()attainable with these techniques,a sdemonstrated in both ITP [5c] and RAFT [6b] polymerization.…”

“…[6,7] Both techniques require the use of ar adical initiator and as uitable chain transfer agent (CTA), which ensures the reversible degenerative transfer (DT) at the heart of ITP and RAFT.B oth were shown to produce relatively well-defined diblock [1c, 5b,c,6c, 7] and triblock [1c,5b,c] copolymers. Liepins et al [10] reported the synthesis of PVDF with al ow content of HH chain defects using am odified Ziegler-Natta catalyst, while Chungsg roup [11] used atrialkylborane/oxygenmixture as the initiating system resulting in significant chain defects.However, the controlled nature of these polymerizations was not addressed. Upon transfer to the CTA, the HH additions generate less-reactive species that lead to as lowdown of the degenerative chain transfer, ab roadening of the molar mass distribution and ad egradation of the control.…”