摘要:
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.
摘要:
A fluoropolymer composition is provided. The polymer comprises interpolymerized units derived from (i) tetrafluoroethylene, (ii) vinylidene fluoride, (iii) at least one ethylenically unsaturated monomer of the formula CF2═CFRf where Rf is a perfluoroalkyl or a perfluoroalkoxy of 1 to 8 carbon atoms, and (iv) a perfluorovinyl ether of the formula CF2═CF—(OCF2CF(Rf))aOR′f where Rf is as described in (iii), R′f is a perfluoroaliphatic, preferably a perfluoroalkyl or a perfluoroalkoxy, of 1 to 8, preferably 1 to 3, carbon atoms, and a has a value of 0 to 3.
摘要:
A fluoropolymer composition is provided. The polymer comprises interpolymerized units derived from (i) tetrafluoroethylene, (ii) vinylidene fluoride, (iii) at least one ethylenically unsaturated monomer of the formula CF2═CFRf where Rf is a perfluoroalkyl or a perfluoroalkoxy of 1 to 8 carbon atoms, and (iv) a perfluorovinyl ether of the formula CF2═CF—(OCF2CF(Rf))aORf where Rf is as described in (iii), Rf is a perfluoroaliphatic, preferably a perfluoroalkyl or a perfluoroalkoxy, of 1 to 8, preferably 1 to 3, carbon atoms, and a has a value of 0 to 3.
摘要:
A fluoropolymer having a reduced amount of polar end groups. The fluoropolymer is produced by free radical polymerization of fluorinated monomers and the initiation of the polymerization is carried out in the presence of a chloride salt. Polar end groups include hydroxy groups and ionized or ionizable end groups. Examples of ionized or ionizable end groups include acid groups and salts thereof such as sulfonic acid and salts thereof, —CH2—OSO3H groups, sulfates and carbonyl containing end groups such as carboxylic and carboxylate groups. Due to the presence of chloride salt at the initiation of the free radical polymerization, CF2Cl end groups are formed instead of the polar end groups. As a result, a fluoropolymer is obtained that has improved processibility and heat resistance.
摘要:
Provided is a process for making a copolymer of fluorinated olefin and hydrocarbon olefin selected from ethylene, propylene and mixtures thereof, the process comprising a substantially emulsifier free aqueous emulsion polymerization of said fluorinated olefin and said hydrocarbon olefin, optionally in the presence of fluoropolymer particles and/or fluorinated liquid in a form suitable to improve the copolymerization of fluorinated olefin and hydrocarbon olefin.
摘要:
A curable fluoroelastomer composition for preparing a perfluoroelastomer. The composition includes; (1) a perfluoropolymer having one or more cure-sites selected from a halogen capable of participating in peroxide cure reaction and/or nitrile groups; (2) an organic peroxide and/or a compound capable of effecting curing of the perfluoropolymer through said nitrile groups; and (3) optionally a polyunsaturated coagent. The perfluoropolymer in the composition is essentially free of ionic end groups and the total amount of metal cations in the composition is not more than 10 μg/g perfluoropolymer. The perfluoroelastomers may be obtained from curing the composition in a sufficiently low amount of metal cations so as to make the fluoroelastomer suitable for use in the semi-conductor industry.
摘要:
Aqueous microemulsions obtained from a perfluorinated alkane sulphonic or carboxylic acid or salt thereof, a liquid fluorinated monomer comprising a cure-site and optionally an inert liquid and highly fluorinated hydrocarbon compound. The aqueous microemulsion may be formed by mixing together water, a perfluorinated alkane sulphonic or carboxylic acid or salt thereof, optionally an inert liquid and highly fluorinated hydrocarbon compound and a liquid fluorinated monomer having a cure-site.
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.
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:
Fluorine-containing emulsifiers can be removed from fluoropolymer dispersions by adding to the dispersion a nonionic 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.