Solvay Solexis Hyflon

Solvay Solexis Hyflon MFA and PFA are semicrystalline fully fluorinated melt-processible fluoropolymers. Hyflon PFA belongs to the class of PFA having a lower melting point than standard PFA grades. 

Manufacturers and trade names DuPont Teflon Solvay Solexis Hyflon Dyneon (a 3M company) Daikin Industries Neoflon PFA. 

Figure 9.85 Stress vs. strain at two temperatures for Solvay Solexis Hyflon PFA resin [10],...

Figure 9.89 Young s modulus vs. temperature for Solvay Solexis Hyflon PFA resins [10].

Table 9.4 Solvay Solexis Hyflon MFA Typical Tensile Properties at Different Temperatures [12]...

Of all of the potential materials which can meet these requirements, only perfluorinated sulfonic acid (PFSA) membranes have so far found widespread acceptance in low-temperature (65-80 °C) hydrogen fuel-cell applications. The most widely used form of these PFSA-type membranes is produced by DuPont under the trade name Nation. Other PFSA types of PEMs are sold by Asahi Chemical (Flemion and Aciplex) and Solvay Solexis (Hyflon). Gore sells its reinforced PFSA membrane as an integral part of an MEA as its PRIMEA series. Likewise, 3M also sells its own PFSA-type membrane as part of its MEA. One of the best known and basic properties of the current PEMs is that their proton conductivity is a strong function of their level of hydration. 

Nafion ionomer is not the only perfluorosulfonic membrane material to be considered for PEMFCs. There are many other commercial perfluorinated ionomers, such as Asahi Glass (Flemion ), Asahi Kasei (Aciplex ), 3M (3M polymer), and Solvay Solexis (Hyflon ), all of which share some structural similarities with the polytetrafluoroethylene-based Nafion but use different perfluorinated vinyl ethers, as shown in Table 4.1. 

Manufacturers and trade names include the following Chemours Teflon , Solvay Solexis Hyflon , DyneonT (a 3M Company), and Daikin Industries NeoflonT PEA. 

Figure 11.35 MIT flex life versus melt flow index of two Solvay Solexis Hyflon PFA-type plastics [16],...

For instance, the Dow experimental membrane and the recently introduced Hyflon Ion E83 membrane by Solvay-Solexis are "short side chain" (SSC) fluoropolymers, which exhibit increased water uptake, significantly enhanced proton conductivity, and better stability at T > 100°C due to higher glass transition temperatures in comparison to Nafion. The membrane morphology and the basic mechanisms of proton transport are, however, similar for all PFSA ionomers mentioned. The base polymer of Nation, depicted schematically in Figure 6.3, consists of a copolymer of tetrafluoro-ethylene, forming the backbone, and randomly attached pendant side chains of perfluorinated vinyl ethers, terminated by sulfonic acid head groups. °... 

Hyflon D 5010X, Technical Information, MFA Dispersion for Impregnation, Solvay Solexis, 2006. 

Investigations on Dow membranes can be found in Refs. [70-82]. Solvay Solexis has started a research and development project to create new ionomer membranes for fuel cells and other applications similar to the Dow concept. The development is based on Solexis s capability for producing sulfonylfluoridevinylether by a much simpler route than the original Dow synthesis [83]. The Solexis route is schematically represented in Figure 27.29 and the monomer can be produced on an industrial scale. The SSC monomer and TFE are copolymerized by free-radical polymerization to obtain the polymers in Figure 27.30 (named Hyflon Ion). 

The other commercial dioxole monomer is 4-trifluoromethoxy-2,2,5-trifluoro-l, 3-dioxole, (TDD, XXI). Copolymers of TDD and tetrafluoroethylene are produced and sold by Solvay-Solexis as Hyflon AD amorphous fluoropolymer (XXII).Monomer XXII (TDD) has been synthesized by two related routes via perfluorohypofluorite intermediates (Eq 13.20). In the first route, trifluoromethylhypofluorite formed from either COF2 or CO and fluorine is added... 

Trade Name Synonyms Hyflon MFA 620 [Solvay Solexis http //www.solvaysolexis.com], Hyflon MFA 640 [Solvay Solexis http //WWW. solvaysolexis. com] Tetrafluoroethylene/perfluoro (propyl vinyl ether) copolymer CAS 26655-00-5 Synonyms PFA... 

Hyflon MFA design and processing guide. Solvay Solexis 2009. 

The structure of the PFSA developed by Solvay Solexis has the same chemical structure as the Dow ionomer, and is called Hyflon Ion for both the membrane and the ionomer solutions. PFSAs with shorter side chains... 

A modification of the polymer that has been adopted by various groups is to have shorter side chains as compared to Nafion. Short side chains increase the crystallinity of the PFSA, thus reducing the solubility. Solvay Solexis has developed Aquivion, a membrane based on Hyflon, which is a copolymer of Teflon and sulfonyl fluoride vinyl ether with low EW (790-870) and good crystallinity, with proton conductivity values in the order of 30 mS cm at 120°C, 30% RH [22]. A similar approach is followed by 3M, who have shown 580 EW membranes approaching 100 mS cm at 120°C and RH 50% [23]. Gore recently reported values >50 mS cm at 30% RH and > 100 mS cm 50% RH with a new, undisclosed ionomers [24]. DuPont recently presented results on MEAs with new ionomer that showed a much reduced dependence on the RH as compared to Nafion-based membranes [17]. 

Hyflon Dow polymer - -CF2CF2)n2-CFCF2- CF2 = CF-0-CF2-CF2-S02F Solvay Solexis Dow... 

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