Trifluorovinyl aromatic ether

By attaching trifluorovinyl groups to the traditional HTMs, a series PFCB-based cross-linkable HTMs were developed (Figure 8.6). It is well-documented that trifluorovinyl aromatic ether can undergo thermal... 

SEMIFLUORINATED POLYMERS FROM TRIFLUOROVINYL AROMATIC ETHER MONOMERS... 

Trifluorovinyl aromatic ethers can be prepared by several methods. In 1966, phenyl trifluorovinyl ether was first obtained by the reaction of an alkali metal phenoxide (PhONa or PhOK) with tetrafluoroethylene in Parr bombs [25]. The yield of the reaction was mediocre because of side reactions, where reactive fluorocarbanions are trapped by the available proton donors in the reaction system to give saturated 1,1,2,2-tetrafluoroethyl phenyl ethers (Scheme 14.1). 

To date, this method has become the most popular protocol to synthesize trifluorovinyl aromatic ether monomers. A variety of mono-, di-, and trifunctional trifluorovinyl ether monomers have been prepared simply by choosing the appropriate phenolic starting materials (Scheme 14.4), such as 3-trifluorovinyloxy-a,a,a-trifluorotoluene (2) [27], l,3-bis(trifluorovinyloxy)benzene (11) [27], 4,4 -bis (trifluorovinyloxy)biphenyl (6), [4] and l,l,l-tris(4-trifluorovinyloxyphenyl)ethane (14) [4]. Other monofunctional monomers include p-bromo(trifluorovinyloxy)... 

SCHEME 14.4 Mono-, di-, and trifunctional trifluorovinyl aromatic ether monomers prepared from phenolic precursors. 

In this chapter, various synthesis routes for trifluorovinyl aromatic ethers are discussed. PFCB polymers are prepared via thermally activated [2+2] cycloaddition of aryl trifluorovinyl ether monomers. The cyclodimerizaton proceeds in a stereorandom fashion giving a roughly equal distribution of cis- and trans- stereoisomers. The PFCB technology can serve as a versatile materials platform for many industrial... 

Figure 3.3. Synthesis of trifluorovinyl ether monomers and perfluorocyclobutane aromatic ether polymers.

S. Wong, H. Ma, A.K.Y. Jen, R. Barto, C.W. Frank, Highly fluorinated trifluorovinyl aryl ether monomers and perfluorocyclobu-tane aromatic ether polymers for optical waveguide applications. Macromolecules 36 (21) (2003)8001-8007. 

Our ongoing strategy to develop new fluorosilicone materials has been to combine the well known preparative chemistry of silicon containing compounds with the relatively new development of perfluorocyclobutane (PFCB) aromatic ether polymers. PFCB materials are prepared by the thermal cyclodimerization of trifluorovinyl ether (TFVE) monomers." " Recently we developed a synthetic... 

D.K. Brown, J.-M. Cracowski, S.T. lacono, K. Christensen, D.W. Smith Jr., Preparation of segmented semifluorinated poly(atyl ether)s from aromatic trifluorovinyl ethers and oligo(ethylene glycol)s, J. Appl. Polym. Sci. 132 (2015) 41798. 

The current intensified interests in the preparation of PEMs have prompted us to synthesize aromatic monomers such as trifluorovinyl ethers functionalized by acid groups. In particular, we reported the first preparation of 4-[(a,, -trifluorovinyl)oxy] benzene phosphonic acid (Fig. 2.21) [99]. [(a,, -Trifluorovinyl)oxy]benzene dialkyl phosphonate was prepared by several phosphonation methods, such as Michaehs-Arbuzov, Michaelis-Becker, or palladium-catalyzed arylation in the presence of various reactants. The reaction involving palladium triphenylphosphine as the catalyst led to the best yield [99]. 

Using the optimal conditions for the radical terpolymerization of 4-[(a,/ ,/ -trifluorovinyl)oxy]bromobenzene with the fluoroalkenes, these authors reported the synthesis of new polymer electrolyte membranes based on fluoropolymers incorporating aromatic perfluorovinyl ether sulfonic acids [85,107]. In fact, a novel synthetic route for the preparation of perfluorovinyl ether monomer containing sulfonic functionalities, 4-[(a,, -trifluorovinyl)oxy]benzenesulfonic acid (TFVOBSA), was proposed. This monomer was synthesized in 72% overall yield. Further, the radical (co)- and terpolymerization of 4-[(a,, -trifluorovinyl)oxy] benzenesulfonyl chloride (TFVOBSC) with VDF, HFP, and PMVE (Fig. 2.25)... 

---