E.i. Dupont De Nemours and Company

Other

David William Johnson

Clay Woodward Jones

Charles Joseph Noelke

Stephen Thomas Breske

James R Combes

Robert John Cavanaugh

Kenneth Scott Teter

Michael Gene McClusky

Steven Henry Swearingen

Daniel N Levy

David Wood

Fabric with a stylized-v armor pattern

A process for reducing fluorosurfactant content of a stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion comprising contacting the stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion with an anion exchange resin comprising a polymer and quaternary ammonium functional groups to reduce fluorosurfactant content, the functional groups being resistant to degradation which releases trialkylamines. The anion exchange resin is separated from the dispersion after the fluorosurfactant content has been reduced.

Removing fluorosurfactant from aqueous fluoropolymer dispersions using anion exchange polymer with functional groups resistant to degradation to trialkylamines

A process for reducing the fluoroether carboxylic acid or salt content of aqueous fluoropolymer dispersion. The fluoroether carboxylic acid or salt employed comprises fluoroether carboxylic acid or salt having the formula below:[R&#x2014;O-L-COO]Ywherein 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. The process comprises adding stabilizer to the aqueous fluoropolymer dispersion to form a stabilized aqueous fluoropolymer dispersion and heating the stabilized aqueous fluoropolymer dispersion to decarboxylate the fluoroether carboxylic acid or salt to produce a fluoroether byproduct. At least a portion of the fluoroether byproduct is removed.

Thermal reduction of fluoroether carboxylic acids or salts from fluoropolymer dispersions

Removing fluorosurfactant from aqueous fluoropolymer dispersions using anion exchange polymer with functional groups resistant to degradation to trialkyl amines

A process for reducing the fluorosurfactant content of an aqueous fluoropolymer dispersion by filling a container with fluoropolymer dispersion, inserting into the container a fabric pouch containing a fluorosurfactant sorbent so that the sorbent contacts the fluorosurfactant-containing aqueous fluoropolymer dispersion in the container and retains the fluorosurfactant to reduce fluorosurfactant content of said fluorosurfactant-containing aqueous fluoropolymer dispersion, and removing the fabric pouch from the container.

Process for removing fluorosurfactant from an aqueous fluoropolymer dispersion using sorbent pouches

A process for reducing the fluorosurfactant content of an aqueous fluoropolymer dispersion by filling a shipping container with fluoropolymer dispersion and contacting the dispersion with a fluorosurfactant sorbent in the shipping container.

Removing fluorosurfactant from aqueous fluoropolymer dispersions

A process for reducing the fluorosurfactant content of a stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion by passing dispersion through a first fixed bed of anion exchange resin to reduce fluorosurfactant content. The first fixed bed has a working zone which moves though the column as the ion exchange resin is saturated. The process includes monitoring a property of the dispersion as the dispersion exits the fixed bed to determine break though of the working zone indicating saturation of the fixed bed. The property being monitored is selected from the group consisting of pH and conductivity.

Monitoring column breakthrough in a process for removing fluorosurfactant from aqueous fluoropolymer dispersions

A process for reducing fluorosurfactant content of a stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion. The process includes providing a fixed bed of anion exchange resin having anion exchange groups with counter ions. The anion exchange resin is treated to replace at least some the counter ions with counter ions of non-fluorinated anionic surfactant. The stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion is passed through the treated fixed bed of anion exchange resin.

Process for reducing fluorosurfactant content of fluropolymer dispersions using anionic surfactant-treated anion exchange resin

A process for reducing fluorosurfactant content of a fluorosurfactant-containing aqueous fluoropolymer dispersion stabilized with nonionic surfactant. The process includes reducing the fluorosurfactant content of the stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion to a predetermined level to provide a reduced surfactant dispersion, adding non-fluorinated anionic surfactant to the reduced fluorosurfactant dispersion, and concentrating the reduced fluorosurfactant dispersion. The non-fluorinated anionic surfactant is added in stages wherein a first portion is added to the dispersion prior to concentrating and a second portion of the non-fluorinated anionic surfactant is added to the dispersion after concentrating.

Staged addition of non-fluorinated anionic surfactant to reduced fluorosurfactant fluoropolymer dispersion

A process for reducing fluorosurfactant content of a stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion containing ferric ions by contacting the fluoropolymer dispersion with strong base anion exchange resin to reduce fluorosurfactant content to a predetermined level, the anion exchange resin being in the hydroxide form, separating the dispersion from the anion exchange resin, and adding an effective amount of chelating agent having an equilibrium constant when complexed with iron of at least 10prior to the contacting with the ion exchange resin for complexing ferric ions to prevent scum formation.

Process for removing fluorosurfactant from aqueous fluoropolymer dispersions and reducing scum formation

A stabilized aqueous fluoropolymer dispersion comprising:

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Washington, WV, United States of America

David William Johnson