Abstract:
The invention pertains to a process for manufacturing certain (per)fluoroionomer liquid compositions, comprising, inter alia, at least one of fluorination and treatment with a polar solvent, to the liquid compositions therefrom having an improved solids content/surface tension/liquid viscosity compromise, to the use of the same for manufacturing composite membranes and to composite membranes obtainable therefrom.
Abstract:
The present invention provides a fluorinated ionomer [polymer (I)] comprising recurring units derived from at least the following monomers: (i) 5 to 50% by weight of a fluorinated monomer [monomer (A)] containing at least one —SO2X functionality, preferably having the formula of CF2═CF—O—(CF2CF(CF3)O)m—(CF2)mSO2X (I) wherein m is 0 or 1, n is an integer between 0-10, and X is selected from F, OH, and O−Me+, wherein Me+ indicates an alkali metal ion or an ammonium cation of formula NR4− where each R independently represents a hydrogen atom or a monovalent organic radical selected from aliphatic radicals having from 1 to 8 carbon atoms and arylic or alicyclic radicals having from 3 to 8 carbon atoms; (ii) a non-functional fluorinated monomer [monomer (B)] having at least one ethylene unsaturation; and (iii) a fluorinated polyfunctional compound having the general formula: (CR1R2═CFCF2—O)a—Rf—((O)c—CF═CR3R4)b (II) wherein: a is an integer equal to or larger than 1, preferably a is 1, 2, or 3; b is 0 or 1 and the sum of a and b is an integer equal to or larger than 2; c is 0 or 1; R1, R2, R3 and R4 are independently selected from F, H, alkyl, alkoxy, polyoxy alkyl, perfluoroalkyl, perfluoroalkoxy or perfluoropolyoxy alkyl, preferably F; and Rf represents a hydrocarbon or fluorocarbon group having at least two carbon atoms. The low-EW perfluorinated ionomers made of polymer (I) are adapted to be processed into thin films, which are found to have superior physical stability than the existing products and are thus well suited for low humidity or high temperature electrochemical applications. Moreover, these low-EW ionomers are melt processable and have limited loss of volatile substances at their melt processing temperatures.
Abstract:
The present invention provides a fluorinated ionomer [polymer (I)] comprising recurring units derived from at least the following monomers: (i) 5 to 50% by weight of a fluorinated monomer [monomer (A)] containing at least one —SO2X functionality, preferably having the formula of CF2═CF—O—(CF2CF(CF3)O)m—(CF2)mSO2X (I) wherein m is 0 or 1, n is an integer between 0-10, and X is selected from F, OH, and O−Me+, wherein Me+ indicates an alkali metal ion or an ammonium cation of formula NR4− where each R independently represents a hydrogen atom or a monovalent organic radical selected from aliphatic radicals having from 1 to 8 carbon atoms and arylic or alicyclic radicals having from 3 to 8 carbon atoms; (ii) a non-functional fluorinated monomer [monomer (B)] having at least one ethylene unsaturation; and (iii) a fluorinated polyfunctional compound having the general formula: (CR1R2═CFCF2—O)a—Rf—((O)c—CF═CR3R4)b (II) wherein: a is an integer equal to or larger than 1, preferably a is 1, 2, or 3; b is 0 or 1 and the sum of a and b is an integer equal to or larger than 2; c is 0 or 1; R1, R2, R3 and R4 are independently selected from F, H, alkyl, alkoxy, polyoxy alkyl, perfluoroalkyl, perfluoroalkoxy or perfluoropolyoxy alkyl, preferably F; and Rf represents a hydrocarbon or fluorocarbon group having at least two carbon atoms. The low-EW perfluorinated ionomers made of polymer (I) are adapted to be processed into thin films, which are found to have superior physical stability than the existing products and are thus well suited for low humidity or high temperature electrochemical applications. Moreover, these low-EW ionomers are melt processable and have limited loss of volatile substances at their melt processing temperatures.
Abstract:
A mixed oxide of Si and at least one metal M comprising inorganic groups —SO3H. The addition of the mixed oxide to fluorinated polymers containing sulfonic acid functional groups increases their stability towards radical degradation when used in fuel cell applications.
Abstract:
The invention pertains to a method of making fluoropolymer dispersions using certain polymeric derivatives including a plurality of ionisable groups selected from the group consisting of —SO3Xa, —PO3Xa and —COOXa, whereas Xa is H, an ammonium group or a monovalent metal, and to fluoropolymer dispersions therefrom.
Abstract:
The present invention relates to a process for the one-pot hydrogenation and dehydration or isomerization of an organic compound, and to a catalyst composition for this process comprising transition metal particles having particle size below 50 nm supported on a material comprising at least one fluorinated polymer (P), wherein polymer (P) bears —SO2X functional groups, X being selected from X′ and OM, X′ being selected from the groups consisting of F, Cl, Br and I; and M being selected from the group consisting of H, and alkaline metal and NH4.
Abstract:
A process for reducing the amount of soluble polymeric fractions in a sulfonyl fluoride polymer. The process comprises contacting the sulfonyl fluoride polymer with a fluorinated fluid followed by separation of the polymer from the fluid. The fluorinated fluid is selected from hydrofluoroethers and hydrofluoropolyethers. The invention further relates to sulfonyl fluoride polymers obtainable by the process and having a heat of fusion not exceeding 4 J/g and containing less than 15% by weight of polymeric fractions having an average content of monomeric units comprising a sulfonyl functional group exceeding 24 mole %. The sulfonyl fluoride polymers so obtained are particularly suitable for the preparation of ionomeric membranes for use in electrochemical devices.
Abstract:
The present invention relates to a liquid composition comprising a polymer bearing —SO3H groups and a perfluoroelastomer, a method for manufacturing said liquid composition and an article manufactured by using said composition. Preferably, said article is a proton exchange membrane, which shows at the same time good mechanical resistance and electrochemical properties and is useful for example as separator in fuel cells.
Abstract:
The present invention pertains a fluoropolymer [polymer (F)] comprising: —recurring units derived from at least one ethylenically unsaturated fluorinated monomer [monomer (FM)]; —from 5% to 60% by moles [with respect to the total moles of recurring units of polymer (F)] of recurring units derived at least one ethylenically unsaturated fluorinated monomer containing at least one —SO2F functional group [monomer (IO)]; and —from 0.01% to 10% by moles [with respect to the total moles of recurring units of polymer (F)] of recurring units derived from at least one monomer comprising an azide group [monomer (Az)], to a process for its manufacture, to a cross-linkable composition comprising the same, to a process for cross-linking the same and to articles comprising the cross-linked polymer.
Abstract:
A mixed oxide of Si and at least one metal M comprising inorganic groups —SO3H. The addition of the mixed oxide to fluorinated polymers containing sulfonic acid functional groups increases their stability towards radical degradation when used in fuel cell applications.