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.

To provide a fluorinated copolymer composition whereby a crosslinked rubber article having a low compression set at high temperature can be formed, and a crosslinked rubber article.

The fluorinated copolymer composition of the present invention comprises a fluorinated copolymer, an organic peroxide, a compound having at least two polymerizable unsaturated bonds and a phosphorus compound having a melting point of 60° C. or lower.

To provide a fluorinated copolymer composition whereby a crosslinked rubber article having a low compression set at high temperature can be formed, and a crosslinked rubber article.

The fluorinated copolymer composition of the present invention comprises a fluorinated copolymer, an organic peroxide, a compound having at least two polymerizable unsaturated bonds and a phosphorus compound having a melting point of 60° C. or lower.

To provide a fluorinated copolymer composition whereby a crosslinked rubber article having a low compression set at high temperature can be formed, and a crosslinked rubber article.

The fluorinated copolymer composition of the present invention comprises a fluorinated copolymer, an organic peroxide, a compound having at least two polymerizable unsaturated bonds and a phosphorus compound having a melting point of 60° C. or lower.

Disclosed is a graft copolymer containing a polyfluorene-based polymer as a main chain and a polyvinylidene fluoride (PVDF) as a side chain, and an element including the same. The graft copolymer contains both the polyfluorene-based polymer and the PVDF, so that the graft copolymer may increase miscibility between polymers to prepare a composite having excellent performance, prepare an uniform thin film through a solution process, and be used as a single material that exhibits both piezoelectric properties and luminescence properties.

Disclosed is a graft copolymer containing a polyfluorene-based polymer as a main chain and a polyvinylidene fluoride (PVDF) as a side chain, and an element including the same. The graft copolymer contains both the polyfluorene-based polymer and the PVDF, so that the graft copolymer may increase miscibility between polymers to prepare a composite having excellent performance, prepare an uniform thin film through a solution process, and be used as a single material that exhibits both piezoelectric properties and luminescence properties.

The present invention relates to a fluorine-containing alternating copolymer macromonomer and a synthesis method thereof. The synthesis method comprises steps of: subjecting a fluorine-containing alternating copolymer to a reduction reaction at 60-100° C. in an organic solvent in the presence of a reducing agent and a first catalyst to obtain a reduction product; in the presence of a second catalyst, reacting the reduction product with a mercapto-monohydric alcohol in an organic solvent at 60-100° C., to obtain a hydroxyl-terminated fluorine-containing alternating copolymer; and in the presence of a third catalyst, reacting the hydroxyl-terminated fluorine-containing alternating copolymer with an acrylic monomer or acryloyl chloride monomer at 0-30° C., to obtain the fluorine-containing alternating copolymer macromonomer. In the present invention, a fluorine-containing alternating copolymer macromonomer is initially synthesized from a fluorine-containing alternating copolymer through polymer modification.

The present invention relates to a fluorine-containing alternating copolymer macromonomer and a synthesis method thereof. The synthesis method comprises steps of: subjecting a fluorine-containing alternating copolymer to a reduction reaction at 60-100° C. in an organic solvent in the presence of a reducing agent and a first catalyst to obtain a reduction product; in the presence of a second catalyst, reacting the reduction product with a mercapto-monohydric alcohol in an organic solvent at 60-100° C., to obtain a hydroxyl-terminated fluorine-containing alternating copolymer; and in the presence of a third catalyst, reacting the hydroxyl-terminated fluorine-containing alternating copolymer with an acrylic monomer or acryloyl chloride monomer at 0-30° C., to obtain the fluorine-containing alternating copolymer macromonomer. In the present invention, a fluorine-containing alternating copolymer macromonomer is initially synthesized from a fluorine-containing alternating copolymer through polymer modification.