摘要:
A method for polymerizing, in an aqueous medium, at least one fluorinated monomer in the presence of a non-copolymerizable, non-fluorinated surfactant. The surfactant is generally selected from a non-ionic surfactant, a primary anionic surfactant, or a combination thereof. Fluorinated surfactants are not utilized. The resulting partially fluorinated polymer in the aqueous medium is either a semi-crystalline polymer or a crystalline polymer.
摘要:
The invention provides a fluorinated surfactant having the general formula: [Rf—(O)t—CHF—(CF2)n—COO—]iXi+ (I) wherein Rf represents a partially or fully fluorinated aliphatic group optionally interrupted with one or more oxygen atoms, t is 0 or 1 and n is 0 or 1, Xi+ represents a cation having a valence i and i is 1, 2 or 3. The surfactant can be used in emulsion polymerization of fluoromonomers to prepare fluoropolymers.
摘要:
A method for removing a fluorinated carboxylic acid or salt thereof from an aqueous liquid by contacting the aqueous liquid with adsorbent particles. The fluorinated carboxylic acid or salt thereof is selected from the group consisting of (i) partially fluorinated carboxylic acids or salts thereof corresponding to the general formula: [PF1—O-L1-COO−]iXi+ (I) wherein PF1 represents a linear partially or fully fluorinated aliphatic group or a linear partially or fully fluorinated aliphatic group interrupted with one or more oxygen atoms, L1 represents a linear partially or fully fluorinated alkylene group or an aliphatic hydrocarbon group with the proviso that when PF1 is fully fluorinated, L1 is a linear partially fluorinated alkylene group or an aliphatic hydrocarbon group, Xi+ represents a cation having the valence i and i is 1, 2 or 3; and (ii) fully fluorinated carboxylic acids or salts thereof corresponding to one of the following general formulas: [PF2—O—(CF2)p—COO−]iXi+ (II) wherein PF2 represents a linear fully fluorinated aliphatic group or a linear fully fluorinated aliphatic group interrupted with one or more oxygen atoms, p is an integer of 2 to 6 and Xi+ and i have the same meaning as in formula (I); or [PF3-(L2)f-O—CF2—COO−]iXi+ (III) wherein PF3 represents a linear fully fluorinated aliphatic group or a linear fully fluorinated aliphatic group interrupted with one or more oxygen atoms, L2 represents —O(CF2)x— wherein x is an integer of 1 or 3 to 6, —(O—CF2CF2)s— wherein s is 1, 2 or 3 or —(OCF2)u— wherein u is an integer of 1 to 6, f is 0 or 1 with the proviso that when f is 0, PF3 represents F(CF2)1— wherein 1 is 1, 2, 4, 5 or 6 and with the proviso that when f is 1 and L2 represents —(O—CF2CF2)s—, PF3 represents CF3 or CF3CF2 and Xi+ and i have the same meaning as in formula (I).
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, a thermal plasma having a tail flame, allowing a fluorocarbon feedstock comprising at least one 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 having fewer carbon atoms than the fluorocarbon compound, and cooling the reactive thermal mixture to form, from the fluorocarbon precursor or reactive species, a fluorocarbon product.
摘要:
Emulsifier free fluoropolymer manufacturing method in which (a) a chain transfer agent, or a mixture of chain transfer agents are used wherein the chain transfer agents do not yield more than 0.4 weight % relative to the monomer feed of water soluble fluorinated compounds, or (b) a chain transfer agent or a mixture of chain transfer agents selected from alkanes, dialkyl ethers, hydrofluoroethers and/or hydrofluorocarbons.
摘要:
The present invention relates to a fluoropolymer comprising repeating units derived from one or more gaseous fluorinated olefins and having one or more cure sites comprising (a) a halogen capable of participating in a peroxide cure reaction or (b) a nitrile group, said fluoropolymer further comprising repeating units derived from one or more fluorinated allyl ethers of the formula: CF2═CF—CF(Z)—O—Rf (I) wherein Z represents F or CF3 and Rf represents a fluorinated alkyl group that may contain one or more catenary oxygen atoms. The fluoropolymer can be cured to a fluoroelastomer. The invention also relates to a curable fluoroelastomer composition comprising the fluoropolymer and a curing agent.
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:
The present invention provides a method of recovering a fluorinated acid surfactant or salt thereof from adsorbent particles to which said fluorinated acid surfactant has been adsorbed. The method comprises mixing adsorbent particles having adsorbed fluorinated acid surfactant or salt thereof with an alcohol and optionally an acid. The mixture is generally heated to cause esterification of the fluorinated acid surfactant or salt thereof with the alcohol so as to form an ester derivative of the fluorinated acid surfactant, distilling the mixture to form a distillate comprising the ester derivative, separating the ester derivative from the distillate and optionally feeding the remainder of the distillate back into the mixture.
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:
Non-free flowable, non-dusting molding powders with a bulk density of more than 450 g/l are obtained when a suspension polymer of tetrafluoroethylene with a content of 0.01 to 1% by weight of units of at least one perfluoro(alkyl-vinyl) ether is ground to a particle diameter of 10 to 50 .mu.m and agglomerated in water.