Phosphorus-Containing Fluoropolymers: State of the Art and Applications

Abstract

Several strategies to synthesize fluorinated (co)polymers containing phosphorus groups and their applications are reviewed. First, original fluoromonomers bearing phosphorus atoms are supplied from relevant routes. They may possess fluorinated atoms linked to the ethylenic carbon atoms with different structures, such as F 2 CCF-or H 2 CC(CF 3 )-and a phosphonated ω-function adjacent to an aliphatic or aromatic linker, while other monomers display a difluoromethylene dialkylphosphonate end group such as -CF 2 −P(O)(OR) 2 . Then, fluorinated copolymers were obtained according to various pathways: (i) by radical homopolymerization of monomers containing both fluorine and phosphorus atoms, (ii) by direct radical copolymerization of fluoromonomers and phosphorus-based monomers, or (iii) by chemical modification of fluorinated copolymers with phosphorus-based reactants. Conventional radical and controlled (or reversible deactivation radical polymerization, RDRP) copolymerization have also been explored. As for the chemical change of halogenated polymers, either conventional organic reactions (e.g., Arbuzov reaction from a chlorine, iodine, or bromine atom) or radiation grafting with specific monomers led to graft copolymers composed of a fluorinated backbone and phosphonated grafts. This second part also details aliphatic and aromatic fluorophosphorous copolymers in which dialkylphosphonates or phosphonic acids are reported. Finally, since fluorine and phosphorus atoms bring complementary relevant properties (low refractive index and dielectric constants, chemical inertness, high electrochemical, soils, and heat resistances, electroattractivity from fluorine atoms and high acidity, complexation, anticorrosion, flame retardant, and biomedical properties from phosphorus ones), synergetic characteristics have been targeted. These properties allow such fluoro-phosphorus (co)polymers to be used as novel materials involved in various applications such as polymer exchange membranes for fuel cells, self-etching adhesives for dental materials, adhesion promoters, flame retardants, polymer blends, and anticorrosive coatings.

Solid–Liquid Europium Ion Extraction via Phosphonic Acid-Functionalized Polyvinylidene Fluoride Siloxanes

“…During the crosslinking terpolymers, the phosphonate groups were hydrolyzed into phosphonic acids using bromotrimethylsilane [ 54 ] at 24 °C ( Figure 8 ) (the detailed procedure is supplied in the Experimental Section), using an improved procedure reported by McKenna et al [ 81 ]. The solid state 31 P NMR spectrum ( Figure 9 ) indicates that the total hydrolysis of the phosphonate groups was not possible, as evidenced by the presence of two signals centered at 44 ppm (corresponding to the remaining dimethyl phosphonate group) and at 25 ppm (attributed to the totally hydrolyzed phosphonic acid groups).…”

“…It is worth noting that pristine PVDF does not show any Eu ion extraction which confirms that metal removal is related to the phosphonic acid function present in the terpolymer [ 54 ]. At low metal concentrations (2 mmol·L −1 ), terpolymer HCP 20 exhibits a very high ion uptake, evidenced by the absence of any free Eu in solution, which was expected according to the theoretical calculations.…”

“…Both teams indicated that the hydrophobicity of the copolymers (triggered from the fluorine atoms) led to an easier separation and material retrieval from the solution. Various investigations deal with the functionalization of PVDF-based membranes by multiple functional groups for wastewater treatment [ 49 , 50 , 51 , 52 ], but only one recent study has reported the prominence of phosphorus functional PVDF involved in Rare Earth metal extraction in strong acidic media [ 53 , 54 ].…”

The Promising Future of Fluoropolymers

“…[29] In addition, a growing research aims at synthesizing FPs containing phosphorous atoms which bring complementary properties, such as high acidity (case of phosphonic acids), complexation, anticorrosion, flame retardant, and biomedical applications (Scheme 3). [30]…”

Solid Polymer Electrolytes from Copolymers Based on Vinyl Dimethyl Phosphonate and Vinylidene Fluoride

“…[ 24 ] The rising interest in phosphorus compounds is due to their interesting properties such as high acidity, [ 25 ] anticorrosion, [ 26 ] adhesion, [ 27 ] flame retardancy, [ 28 ] proton exchange membranes, [ 29–33 ] biomedical applications [ 34 ] and complex formation. [ 35 ] To the best of our knowledge, there is no phosphorus functional fluoropolymer that has been employed as an electrolyte in Li‐ion batteries, [ 36 ] thus it is worth investigating the combination of the fluorine and phosphorus atoms, which bring synergistic complementary properties, for the preparation of new electrolytes for Li‐ion batteries.…”