Abstract:
Presently described are methods of making coating comprising aqueous fluoropolymer latex dispersions, aqueous fluoropolymer coating compositions, coated substrates, and (e.g. backside) films of photovoltaic cells. In one embodiment, the film comprises at least one fluoropolymer comprising repeat units derived from VF, VDF, or a combination thereof; inorganic oxide nanoparticles; and a compound that reacts with the repeat units derived from VF and VDF to crosslink the fluoropolymer and/or couple the fluoropolymer to the inorganic oxide nanoparticles. In another embodiment, the backside film comprises at least one fluoropolymer comprising repeat units derived from VF, VDF, or a combination thereof; and an amino-substituted organosilane ester or ester equivalent crosslinking compound.
Abstract:
Functionalized fluoropolymer films, methods of making functionalized fluoropolymer films, laminates comprising functionalized fluoropolymer films, and methods of using functionalized fluoropolymer films are described.
Abstract:
Methods of acidifying and purifying aqueous ionomer dispersions are described. The methods include hydrolyzing a polymer comprising pendent sulfonyl fluoride groups with a base having the formula XOH to form a fluorinated ionomer salt comprising SO3- X+, acidifying an aqueous dispersion of the ionomer salts with a protic acid having a pKa of less than 1 to form an acidified dispersion having a pH of no greater than 1 prior to or simultaneously with purifying the dispersion by ultrafiltration.
Abstract:
A composite includes a fluorinated polymer and nanoparticles of a metal salt. The metal salt has a solubility product of not more than 1 x 10-4. The fluorinated polymer includes a fluorinated polymer backbone chain and a plurality of groups represented by formula -SO2X, in which each X is independently -NZH, -NZSO2(CF2)1-6SO2X', -NZ[SO2(CF2)dSO2NZ]1-10SO2(CF2)dSO2X' or -OZ, and Z is independently a hydrogen, an alkali-metal cation, or a quaternary ammonium cation, X' is independently -NZH or -OZ, and each d is independently 1 to 6. A polymer electrolyte membrane, an electrode, and a membrane electrode assembly including the composite are also provided.
Abstract:
The process produces a fluorinated olefin from a fluorinated copolymer having at least one of sulfonic acid groups, carboxylic acid groups, or salts thereof. The process includes heating the fluorinated copolymer at a first temperature not more than 450 ̊ C to decompose at least one of the sulfonic acid groups, carboxylic acid groups, or salts thereof to form a partially pyrolyzed intermediate and subsequently heating the partially pyrolyzed intermediate at a second temperature of at least 550 ˚C to produce the fluorinated olefin.
Abstract:
PFSA ionomer particles having a BET surface area of at least 0.1 g/m2 are described. The PFSA ionomer comprises (i) divalent units derived from tetrafluoroethene (TFE) and represented by formula –[CF2-CF2]- and (ii) divalent units represented by formula (I), (I) wherein a represents 0 or 1, b is an integer from 2 to 8, c is an integer from 0 to 2, and e is an integer from 1 to 8 and X represents an OH group or a group OZ wherein O is an oxygen anion and Z represents a counter cation other than a hydrogen cation. Methods of making such particles as well as dispersions and compositions containing such particles are also described.
Abstract:
A capacitor comprises an electrically conductive cylinder, an electrically conductive or semi-conductive cylindrical shell or shell segment arranged concentrically around the electrically conductive cylinder, and a dielectric arranged between the electrically conductive cylinder and the electrically conductive or semi-conductive cylindrical shell or shell segment. The dielectric comprises a particulate composite including a matrix material having a non-zero (e.g. negative) thermal coefficient of relative permittivity and a particulate filler material blended with the matrix material, the particulate filler material having an opposite (e.g. positive thermal) coefficient of relative permittivity. The positive thermal coefficient of relative permittivity is thereby selected such that the capacitance value of the capacitor is constant within a stability margin over a predefined temperature interval.
Abstract:
Described herein is a composition comprising (i) a hydrofluorothermoplastic polymer, wherein the hydrofluorothermoplastic polymer is derived from: (a) 50-85 mol% tetrafluoroethene; (b) 2-15 mol% hexafluoropropene; (c) 10-35 mol% vinylidene fluoride; and (d) 0.1 to 5 mol% of a bromine-containing monomer; and (ii) a perhalogenated thermoplastic polymer. Such compositions can be used in multilayer constructions in, for example, fuel hose applications.