Abstract:
A dispersible solid perfluorosulfonic acid ionomer (PFSA ionomer) composition comprising at least 50% by weight of PFSA ionomer wherein the PFSA ionomer comprises divalent units derived from tetrafluoroethene (TFE) and represented by formula –[CF 2 -CF 2 ]- and divalent units represented by formula (I), (I) and divalent units derived from formula (II), (II), 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 and wherein m' is 0 or 1 and Rf 1 is selected from a linear or branched perfluoroalkyl group having from 1 to 12 carbon atoms that can be interrupted once or more than once by an (ether) oxygen atom, and wherein the PFSA ionomer contains up to 150 carboxylic acid end groups per 10 6 carbon atoms. Also provided are methods of using the composition and method of making the composition.
Abstract:
The fluoropolymer dispersion includes a copolymer having divalent units represented by formula -[CF 2 -CF 2 ]-, divalent units represented by formula: [Formula should be inserted here], and one or more divalent units independently represented by formula: [Formula should be inserted here] dispersed in at least one of water or organic solvent. Methods of making the fluoropolymer dispersion and methods of using the fluoropolymer to make a at least one of a catalyst ink or polymer electrolyte membrane are also provided.
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:
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:
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.
Abstract:
Method of producing purified fluoropolymers comprising repeat units of tetrafluoroethylene and a fluoro-olefin comprising SO3- groups are described. In a first step, an unpurified aqueous dispersion of the fluoropolymer, including the counter-cations of the SO3- groups, is subjected to cation exchange. This cation-exchanged dispersion is then subjected to ultrafiltration. The resulting purified dispersions and fluoropolymers contain low levels of both cations and anions. Articles prepared from such purified fluoropolymers are also described.
Abstract:
The copolymer includes divalent units represented by formula -[CF2-CF2]-, at least one divalent unit represented by formula (I): and at least one divalent unit independently represented by formula (II): A is -N(RFa)2 or a is non-aromatic, 5- to 8-membered, perfluorinated ring comprising one or two nitrogen atoms in the ring and optionally comprising at least one oxygen atom in the ring, each RFa is independently linear or branched perfluoroalkyl having 1 to 8 carbon atoms and optionally interrupted by at least one catenated O or N atom, each Y is independently - H or -F, with the proviso that one Y may be -CF3, h is 0, 1, or 2, each i is independently 2 to 8, and j is 0, 1, or 2. A catalyst ink and polymer electrolyte membrane including the copolymer are also provided.
Abstract:
The copolymer includes divalent units represented by formula -[CF 2 -CF 2 ]-, divalent units represented by formula:, and one or more divalent units independently represented by formula: The copolymer has an -SO 2 X equivalent weight in a range from 300 to 2000. A polymer electrolyte membrane that includes the copolymer and a membrane electrode assembly that includes such a polymer electrolyte membrane are also provided.
Abstract:
Described herein is a composition comprising a fluorothermoplastic polymer, wherein the fluorothermoplastic polymer is derived from: (a) 60-85 mol% tetrafluoroethene; (b) 2-12 mol% hexafluoropropene; (c) 10-30 mol% vinylidene fluoride; (d) 0.2 to 5 mol% of a bromine-containing monomer. Such compositions can be used in multilayer constructions in, for example, fuel hose applications.
Abstract:
A fluoropolymer suitable for the preparation of a fluoroelastomer. The fluoropolymer generally includes repeating units derived from the monomers tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, chlorotrifluoroethylene and optionally one or more repeating units from fluorinated monomers other than tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride and chlorotrifluoroethylene.