Described herein is a method of purifying a product and recycling water comprising the following steps: (i) providing a crude product comprising at least one low molecular weight fluoroorganic compounds wherein the low molecular weight fluoroorganic compounds is partially fluorinated and comprises a polar group and/or a reactive group; (ii) extracting the impurity from the product using water to form an extract, (iii) contacting the extract with a radical-forming process to degrade the low molecular weight fluoroorganic compounds into carbon dioxide, water, fluorine ions, and optionally cations; and (iv) using the water from step (iii) in step (ii)

Described herein is a method of purifying a product and recycling water comprising the following steps: (i) providing a crude product comprising at least one low molecular weight fluoroorganic compounds wherein the low molecular weight fluoroorganic compounds is partially fluorinated and comprises a polar group and/or a reactive group; (ii) extracting the impurity from the product using water to form an extract, (iii) contacting the extract with a radical-forming process to degrade the low molecular weight fluoroorganic compounds into carbon dioxide, water, fluorine ions, and optionally cations; and (iv) using the water from step (iii) in step (ii)

Described herein is a method of purifying a product and recycling water comprising the following steps: (i) providing a crude product comprising at least one low molecular weight fluoroorganic compounds wherein the low molecular weight fluoroorganic compounds is partially fluorinated and comprises a polar group and/or a reactive group; (ii) extracting the impurity from the product using water to form an extract, (iii) contacting the extract with a radical-forming process to degrade the low molecular weight fluoroorganic compounds into carbon dioxide, water, fluorine ions, and optionally cations; and (iv) using the water from step (iii) in step (ii)

An apparatus suitable for extruding curable polymers for forming elastomer articles using additive manufacturing, and curable fluorine-containing polymer compositions suitable for use in such an apparatus are disclosed along with an additive manufacturing method for forming a fluorine-containing elastomer article including providing a filament formed of a curable fluoropolymer composition; providing an additive manufacturing printer having a drive mechanism and a printer nozzle; feeding the filament into an additive manufacturing printer through the drive mechanism and through a longitudinal passage defined by an interior wall of a support tube, wherein the support tube extends from a first end to a second end, and wherein the second end of the support tube is positioned near an inlet to a printer nozzle; applying heat to the filament; and printing successive layers of the heated filament exiting an outlet of the nozzle onto a substrate using the additive manufacturing printer to form the fluorine-containing elastomer article.

An apparatus suitable for extruding curable polymers for forming elastomer articles using additive manufacturing, and curable fluorine-containing polymer compositions suitable for use in such an apparatus are disclosed along with an additive manufacturing method for forming a fluorine-containing elastomer article including providing a filament formed of a curable fluoropolymer composition; providing an additive manufacturing printer having a drive mechanism and a printer nozzle; feeding the filament into an additive manufacturing printer through the drive mechanism and through a longitudinal passage defined by an interior wall of a support tube, wherein the support tube extends from a first end to a second end, and wherein the second end of the support tube is positioned near an inlet to a printer nozzle; applying heat to the filament; and printing successive layers of the heated filament exiting an outlet of the nozzle onto a substrate using the additive manufacturing printer to form the fluorine-containing elastomer article.

An aqueous dispersion comprising a tetrafluoroethylene core-shell polymer and at least one surfactant corresponding to the general formula R.sub.10-[CH.sub.2CH.sub.20].sub.n[R.sub.20].sub.m-R.sub.3 wherein R.sub.1 represents a linear or branched aliphatic hydrocarbon group having at least 8 carbon atoms, preferably 8 to 18 carbon atoms, R2 represents an alkylene having 3 carbon atoms, R3 represents hydrogen, a C1-C3 alkyl group, or a C1-C3 hydroxyalkyl group, n has a value of 0 to 40, m has a value of 0 to 40 and the sum of n+m is at least 2, wherein the dispersion is free of fluorinated emulsifiers or contains them in an amount of less than 50 ppm based on the weight of the dispersion and wherein the core-shell polymer contains an outer shell of tetrafluoroethylene homopolymer. Further provided are methods of making the dispersions, coating compositions comprising the dispersions and article coated by the coating composition.

A method for producing a perfluoroelastomer, which includes carrying out polymerization of a perfluoromonomer in an aqueous medium in the presence of a polymer (1) having a number average molecular weight of 0.3×10.sup.4 or more to provide a perfluoroelastomer, the polymer (1) containing a polymerized unit (1) derived from a monomer represented by the following general formula (1):

CX.sub.2═CY(—CZ.sub.2—O—Rf-A)   (1)

wherein X, Y, Z, Rf and A are as defined herein, with the proviso that at least one of X, Y, and Z contains a fluorine atom.

A method for producing a perfluoroelastomer, which includes carrying out polymerization of a perfluoromonomer in an aqueous medium in the presence of a polymer (1) having a number average molecular weight of 0.3×10.sup.4 or more to provide a perfluoroelastomer, the polymer (1) containing a polymerized unit (1) derived from a monomer represented by the following general formula (1):

CX.sub.2═CY(—CZ.sub.2—O—Rf-A)   (1)

wherein X, Y, Z, Rf and A are as defined herein, with the proviso that at least one of X, Y, and Z contains a fluorine atom.

A method for producing a perfluoroelastomer, which includes carrying out polymerization of a perfluoromonomer in an aqueous medium in the presence of a polymer (1) having a number average molecular weight of 0.3×10.sup.4 or more to provide a perfluoroelastomer, the polymer (1) containing a polymerized unit (1) derived from a monomer represented by the following general formula (1):

CX.sub.2═CY(—CZ.sub.2—O—Rf-A)   (1)

wherein X, Y, Z, Rf and A are as defined herein, with the proviso that at least one of X, Y, and Z contains a fluorine atom.

A method of producing a fluorine-containing compound is a method of producing a compound (30) having partial structure (3) by an insertion reaction of compound (20) into compound (10) that has partial structure (1), in the presence of an ionic catalyst formed from a specific monovalent anion and a counter cation. In the formulas, * represents a bonding site, and X.sup.1 and R.sup.1 to R.sup.4 each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, or an organic group having a carbon number of 1 to 20 which may have a substituent.

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