摘要:
The present invention provides a process for reducing the amount of fluorinated emulsifier in fluoropolymer dispersions by contacting the fluoropolymer dispersion with an anion exchange resin in the presence of amphoteric surfactants or anionic surfactants of low molecular weight and provides fluoropolymer dispersions containing low amounts of fluorinated emulsifier and no or only low amounts of non-ionic surfactants.
摘要:
The present invention provides a fluorinated surfactant having the general formula: [Rf—(O)t—CQH—CF2—O]n—R—G (I) wherein Rf represents a partially or fully fluorinated aliphatic group optionally interrupted with one or more oxygen atoms, Q is CF3 or F, R is an aliphatic or aromatic hydrocarbon group, G represents a carboxylic or sulphonic acid or salt thereof, t is 0 or 1 and n is 1, 2 or 3. The surfactant is particularly useful in polymerizing fluorinated monomers in an aqueous emulsion polymerization.
摘要:
A process of reducing the amount of fluorinated emulsifiers in fluoropolymer dispersions by contacting the fluoropolymer dispersion with an anion exchange resin in the presence of a pH-dependent surfactant, and fluoropolymer dispersions containing the pH-dependent surfactant and uses thereof.
摘要:
Provided is a method comprising polymerizing at least one fluorinated monomer in an aqueous emulsion polymerization in the presence of a carbosilane surfactant having at least one hydrophobic part, wherein the hydrophobic part has at least one silicon atom, and having at least one hydrophilic part, with the proviso that the carbosilane contains no Si—O bonds.
摘要:
Anionic species are removed from aqueous dispersions of ionic fluoropolymers using anion exchange resins. In some embodiments, cationic species are also removed using cation exchange resins.
摘要:
A method is provided for making a crosslinked polymer electrolyte, typically in the form of a membrane for use as a polymer electrolyte membrane in an electrolytic cell such as a fuel cell, as well as the polymer so made, the method comprising application of electron beam radiation to a highly fluorinated fluoropolymer comprising: a backbone derived in part from tetrafluoro-ethylene monomer, first pendent groups which include a group according to the formula —SO2X, where X is F, Cl, Br, OH or —O−M+, where M+ is a monovalent cation, and second pendent groups which include Br, Cl or I. Typically, the membrane has a thickness of 90 microns or less, more typically 60 or less, and most typically 30 microns or less.
摘要:
A method of treating a fluorocarbon feedstock includes generating, in a high temperature zone, an electrical arc between at least one cathode and at least one anode, generating in the high temperature zone and by means of the electrical arc and a plasma gas, an upwardly burning thermal plasma having a tail flame, allowing a solid particulate fluorocarbon feedstock comprising at least on fluorocarbon compound to form a reactive thermal mixture with the thermal plasma tail flame, with the fluorocarbon compound dissociating into at least one fluorocarbon precursor or reactive species, and cooling the reactive thermal mixture to form, from the fluorocarbon precursor of reactive species, at least one more desirable fluorocarbon compound.
摘要:
The present invention is a fluoropolymer comprising a plurality of pendent groups terminating in —CF2SO3X, —CF2SO2F, or combinations thereof, where X is selected from a group consisting of H+ and a monovalent cation, and at least one —CF2Y end group, where Y is selected from a group consisting of a chlorine atom, a bromine atom, an iodine atom, a nitrile group, and an —SO3X group.
摘要翻译:本发明是含有多个终止于-CF 2 SO 3 X,-CF 2 SO 2的侧基的含氟聚合物 F或其组合,其中X选自H +和/或一价阳离子和至少一个-CF 2 Y Y端基 其中Y选自氯原子,溴原子,碘原子,腈基和-SO 3 X基。
摘要:
A fluoropolymer having a melting point of at least 160° C. is provided wherein the fluoropolymer is derived from tetrafluoroethylene as the major component, one or more perfluoro vinyl ethers as the minor component, the perfluoro vinyl ether having the formula CF2═CFO(CF2)nORf wherein n is from 2 to 6 and Rf is a perfluoroalkyl group having 1 to 6 carbon atoms, and optionally a perfluoro alkyl vinyl ether having from 1 to 5 carbon atoms in the alkyl radical.
摘要:
Fluorine-containing emulsifiers can be removed from fluoropolymer dispersions by adding to the dispersion a non ionic emulsifier, removing the fluorine-containing emulsifier by contact with an anion exchanger and separating the dispersion from the anion exchanger. The resulting dispersions can be concentrated and used for coating applications.