Abstract: A process is provided for the polymerization of fluoromonomer to an dispersion of fluoropolymer particles in an aqueous medium in a polymerization reactor, by (a) providing the aqueous medium in the reactor, (b) adding the fluoromonomer to the reactor, (c) adding initiator to the aqueous medium, the combination of steps (b) and (c) being carried out essentially free of hydrocarbon-containing surfactant and resulting in the kickoff of the polymerization of the fluoromonomer, and (d) metering hydrocarbon-containing surfactant into the aqueous medium after the kickoff of polymerization, e.g. after the concentration of the fluoropolymer in the aqueous medium is at least 0.6 wt %, the metering being at a rate reducing the telogenic activity of said surfactant while maintaining surface activity.

Abstract: A process includes polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer. The polymerization agent includes fluoropolyether acid or salt having an Mn of at least about 800 g/mol and fluorosurfactant having the formula: [R1—On-L-A?] Y+. R1 is a linear or branched partially or fully fluorinated aliphatic group which may contain ether linkages; n is 1; L is a linear or branched alkylene group which may be nonfluorinated, partially fluorinated, or fully fluorinated and may contain ether linkages; A? is a carboxylate; and Y+ is hydrogen, ammonium, or alkali metal cation. The chain length of R1—On-L- is not greater than 6 atoms. The polymerization agent includes a minor amount of fluoropolyether acid or salt thereof and a major amount of fluorosurfactant. The polymerizing produces less than about 3 wt % undispersed fluoropolymer based on the total weight of fluoropolymer produced.

Abstract: A process comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer, the polymerization agent comprising: fluoropolyether acid or salt thereof having a number average molecular weight of at least about 800 g/mol; and fluorosurfactant having the formula: [R1—On-L-A?]Y+ wherein: R1 is a linear or branched partially or fully fluorinated aliphatic group which may contain ether linkages; n is 0 or 1; L is a linear or branched alkylene group which may be nonfluorinated, partially fluorinated or fully fluorinated and which may contain ether linkages; A? is an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion, and phosphonate; and Y+ is hydrogen, ammonium or alkali metal cation; with the proviso that the chain length of R1—On-L- is not greater than 6 atoms.

Abstract: A process is provided for the polymerization of fluoromonomer to an dispersion of fluoropolymer particles in an aqueous medium in a polymerization reactor, by (a) providing the aqueous medium in the reactor, (b) adding the fluoromonomer to the reactor, (c) adding initiator to the aqueous medium, the combination of steps (b) and (c) being carried out essentially free of hydrocarbon-containing surfactant and resulting in the kickoff of the polymerization of the fluoromonomer, and (d) metering hydrocarbon-containing surfactant into the aqueous medium after the kickoff of polymerization, e.g. after the concentration of the fluoropolymer in the aqueous medium is at least 0.6 wt %, the metering being at a rate reducing the telogenic activity of said surfactant while maintaining surface activity.

Abstract: A process is provided for the polymerization of fluoromonomer to an dispersion of fluoropolymer particles in an aqueous medium in a polymerization reactor, by (a) providing the aqueous medium in the reactor, (b) adding the fluoromonomer to the reactor, (c) adding initiator to the aqueous medium, the combination of steps (b) and (c) being carried out essentially free of hydrocarbon-containing surfactant and resulting in the kickoff of the polymerization of the fluoromonomer, and (d) metering hydrocarbon-containing surfactant into the aqueous medium after the kickoff of polymerization, e.g. after the concentration of the fluoropolymer in the aqueous medium is at least 0.6 wt %, the metering being at a rate reducing the telogenic activity of said surfactant while maintaining surface activity.

Abstract: A composition comprising a mixture of fluoropolyether acids or salts having a number average value of about 800 to about 2500 g/mol. The amount of fluoropolyether acids or salt in the mixture having a molecular weight of not more than 500 g/mol is not more than 50 ppm by weight of the total amount of fluoropolyether acids or salts in the mixture. The amount of fluoropolyether acids or salts in the mixture having a molecular weight of 2500 g/mol or greater is not more than 40% by weight of the total amount of fluoropolyether acids or salts in the mixture. Preferably the fluoropolyether acids or salts comprise an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion and phosphonate. Also disclosed is an aqueous dispersion polymerization process for fluoropolymer manufacture employing polymerization agent comprising the specified mixture of fluoropolyether acids or salts.

Abstract: A process comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer, the polymerization agent comprising: fluoropolyether acid or salt thereof having a number average molecular weight of at least about 800 g/mol; and fluorosurfactant having the formula: [R1—On-L-A?]Y+ wherein: R1 is a linear or branched partially or fully fluorinated aliphatic group which may contain ether linkages; n is 0 or 1; L is a linear or branched alkylene group which may be nonfluorinated, partially fluorinated or fully fluorinated and which may contain ether linkages; A? is an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion, and phosphonate; and Y+ is hydrogen, ammonium or alkali metal cation; with the proviso that the chain length of R1—On-L- is not greater than 6 atoms.

Abstract: Process for polymerizing fluoromonomer to form an aqueous dispersion of fluoropolymer particles including: (a) providing an aqueous medium in a polymerization reactor, (b) adding nucleating additive comprising polyalkylene oxide having a number average molecular weight of about 50 to about 2000 to the aqueous medium in an amount of about 0.1 ppm to about 50 ppm based on water in the aqueous medium, (c) exposing the nucleating additive to oxidizing agent to form a dispersion of oleophilic nucleation sites in the aqueous medium; (d) pressurizing the reactor by adding fluoromonomer, and (e) adding polymerization initiator to the aqueous medium to cause the polymerizing of the fluoromonomer to form fluoropolymer particles dispersed in the aqueous medium.

Abstract: A process is provided for the polymerization of fluoromonomer to an dispersion of fluoropolymer particles in an aqueous medium in a polymerization reactor, by (a) providing the aqueous medium in the reactor, (b) adding the fluoromonomer to the reactor, (c) adding initiator to the aqueous medium, the combination of steps (b) and (c) being carried out essentially free of hydrocarbon-containing surfactant and resulting in the kickoff of the polymerization of the fluoromonomer, and (d) metering hydrocarbon-containing surfactant into the aqueous medium after the kickoff of polymerization, e.g. after the concentration of the fluoropolymer in the aqueous medium is at least 0.6 wt %, the metering being at a rate reducing the telogenic activity of said surfactant while maintaining surface activity.

Abstract: A process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous dispersion medium to form aqueous fluoropolymer dispersion and isolating the fluoropolymer from the aqueous medium to obtain fluoropolymer resin. The process comprises contacting the aqueous fluoropolymer dispersion with sorbent.

Abstract: A process is provided for the polymerization of fluoromonomer to an dispersion of fluoropolymer particles in an aqueous medium in a polymerization reactor, by (a) providing the aqueous medium in the reactor, (b) adding the fluoromonomer to the reactor, (c) adding initiator to the aqueous medium, the combination of steps (b) and (c) being carried out essentially free of hydrocarbon-containing surfactant and resulting in the kickoff of the polymerization of the fluoromonomer, and (d) metering hydrocarbon-containing surfactant into the aqueous medium after the kickoff of polymerization, e.g. after the concentration of the fluoropolymer in the aqueous medium is at least 0.6 wt %, the metering being at a rate reducing the telogenic activity of said surfactant while maintaining surface activity.

Abstract: A process is provided for polymerizing fluoromonomer in an aqueous medium, wherein a dispersion of essentially surfactant-free hydrocarbon-containing oleophilic nucleation sites is first formed in the aqueous medium, and then polymerization is commenced to form a dispersion of fluoropolymer particles at the oleophilic nucleation sites, wherein the nucleation sites can be derived from hydrocarbon-containing compound. The surfactant used to stabilize the fluoropolymer dispersion can also be hydrocarbon-containing.

Abstract: A process is provided for the polymerization of fluoromonomer to an dispersion of fluoropolymer particles in an aqueous medium in a polymerization reactor, by (a) providing the aqueous medium in the reactor, (b) adding the fluoromonomer to the reactor, (c) adding initiator to the aqueous medium, the combination of steps (b) and (c) being carried out essentially free of hydrocarbon-containing surfactant and resulting in the kickoff of the polymerization of the fluoromonomer, and (d) metering hydrocarbon-containing surfactant into the aqueous medium after the kickoff of polymerization, e.g. after the concentration of the fluoropolymer in the aqueous medium is at least 0.6 wt %, the metering being at a rate reducing the telogenic activity of said surfactant while maintaining surface activity.

Abstract: A process is provided for the polymerization of fluoromonomer to an dispersion of fluoropolymer particles in an aqueous medium in a polymerization reactor, by (a) providing the aqueous medium in the reactor, (b) adding the fluoromonomer to the reactor, (c) adding initiator to the aqueous medium, the combination of steps (b) and (c) being carried out essentially free of hydrocarbon-containing surfactant and resulting in the kickoff of the polymerization of the fluoromonomer, and (d) metering hydrocarbon-containing surfactant into the aqueous medium after the kickoff of polymerization, e.g. after the concentration of the fluoropolymer in the aqueous medium is at least 0.6 wt %, the metering being at a rate reducing the telogenic activity of said surfactant while maintaining surface activity.

Abstract: A process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous dispersion medium to form aqueous fluoropolymer dispersion and isolating said fluoropolymer from the aqueous medium to obtain the fluoropolymer resin. The process comprises exposing the aqueous fluoropolymer dispersion to oxidizing agent.

Abstract: Process for reducing thermally induced discoloration of melt-processible fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous medium to form aqueous fluoropolymer dispersion and isolating said fluoropolymer from said aqueous medium to obtain said fluoropolymer resin. The process comprises melt extruding said fluoropolymer resin to produce molten fluoropolymer resin; and exposing said molten fluoropolymer resin to an oxygen source during said melt extruding.

Abstract: Process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous dispersion medium to form aqueous fluoropolymer dispersion and isolating fluoropolymer from said aqueous medium by separating wet fluoropolymer resin from the aqueous medium and drying to produce fluoropolymer resin. The process comprises exposing the wet fluoropolymer resin to an oxygen source during drying.

Abstract: Process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous medium to form aqueous fluoropolymer dispersion and isolating said fluoropolymer from said aqueous medium to obtain said fluoropolymer resin. The process comprises: heating the fluoropolymer resin to a temperature of about 160° C. to about 400° C.; and exposing the heated fluoropolymer resin to an oxygen source.

Abstract: A process for making fluoropolymer resin comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent comprising fluoroether carboxylic acid or salt thereof to form an aqueous dispersion of particles of fluoropolymer. The fluoroether carboxylic acid or salt thereof employed in the process has the formula: [R1—O-L-COO?]Y+ wherein R1 is a linear, branched or cyclic partially or fully fluorinated aliphatic group which may contain ether linkages; L is a branched partially or fully fluorinated alkylene group which may contain ether linkages; and Y+ is hydrogen, ammonium or alkali metal cation. Wet fluoropolymer resin is isolated from the aqueous medium. The wet fluoropolymer resin is to produce a dry fluoropolymer resin and to decarboxylate the residual fluoroether carboxylic acid or salt to produce a vapor of fluoroether byproduct. The vapor of fluoroether byproduct is captured.

Abstract: A polymerization process is provided, comprising polymerizing fluoromonomer in an aqueous medium to form a dispersion of fluoropolymer particles in the aqueous medium, said polymerizing being carried out in the presence of (i) polymerization initiator, and (ii) hydrocarbon-containing surfactant stabilizing the dispersion of fluoropolymer particles, the hydrocarbon-containing surfactant being passivated to reduce its the telogenic behavior.