A method for producing a fluoropolymer which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a surfactant to provide a fluoropolymer, the surfactant being represented by the general formula (1): CR.sup.1R.sup.2R.sup.4—CR.sup.3R.sup.5—X-A, wherein R.sup.1 to R.sup.5 are each H or a monovalent substituent, with the proviso that at least one of R.sup.1 and R.sup.3 represents a group represented by the general formula: —Y—R.sup.6 and at least one of R.sup.2 and R.sup.5 represents a group represented by the general formula: —X-A or a group represented by the general formula: —Y—R.sup.6; and A is the same or different at each occurrence and is —COOM, —SO.sub.3M, or —OSO.sub.3M. Also disclosed is a surfactant for polymerization represented by the general formula (1), a method for producing a fluoropolymer using the surfactant and a composition including a fluoropolymer and the surfactant.

Composite materials that include fluoropolymers. Methods of reducing friction, which may include contacting a first article and a second article that include or are formed of one or more fluoropolymers. The composite materials may include a fluorinated polymer and a first filler. The first filler may be present at an amount of about 3% to about 50%, by weight, based on the total weight of the first fluorinated polymer and the first filler.

Composite materials that include fluoropolymers. Methods of reducing friction, which may include contacting a first article and a second article that include or are formed of one or more fluoropolymers. The composite materials may include a fluorinated polymer and a first filler. The first filler may be present at an amount of about 3% to about 50%, by weight, based on the total weight of the first fluorinated polymer and the first filler.

The present invention discloses a process for polymerizing fluoromonomers in an aqueous medium to form a fluoropolymer, said process comprising the steps of: (a) forming an aqueous solution comprising a first surfactant combination of at least one fluorinated surfactant and at least one non-10 fluorinated surfactant in a polymerization reactor; (b) pressurizing the polymerization reactor with said fluoromonomers; (c) initiating a polymerization reaction of said fluoromonomers to form said fluoropolymer; (d) propagation of said polymerization reaction, wherein a second surfactant combination of at least one fluorinated surfactant and at least one non-fluorinated surfactant is 15 metered or one shot dosed into the polymerization reactor; and (e) termination of said polymerization reaction after consumption of a desired quantity of said fluoromonomers.

The present invention discloses a process for polymerizing fluoromonomers in an aqueous medium to form a fluoropolymer, said process comprising the steps of: (a) forming an aqueous solution comprising a first surfactant combination of at least one fluorinated surfactant and at least one non-10 fluorinated surfactant in a polymerization reactor; (b) pressurizing the polymerization reactor with said fluoromonomers; (c) initiating a polymerization reaction of said fluoromonomers to form said fluoropolymer; (d) propagation of said polymerization reaction, wherein a second surfactant combination of at least one fluorinated surfactant and at least one non-fluorinated surfactant is 15 metered or one shot dosed into the polymerization reactor; and (e) termination of said polymerization reaction after consumption of a desired quantity of said fluoromonomers.

Powder including low molecular weight polytetrafluoroethylene having a melt viscosity of 1×10.sup.2 to 7×10.sup.5 Pa.Math.s at 380° C., having a melt viscosity of 1×10.sup.2 to 7×10.sup.5 Pa.Math.s at 380° C., having an average particle size of 1.0 to 50 μm, and containing 30 or more carboxyl groups at ends of the molecule chain per 10.sup.6 carbon atoms in the main chain, wherein the powder is substantially free from C8-C14 perfluorocarboxylic acids and salts thereof.

Powder including low molecular weight polytetrafluoroethylene having a melt viscosity of 1×10.sup.2 to 7×10.sup.5 Pa.Math.s at 380° C., having a melt viscosity of 1×10.sup.2 to 7×10.sup.5 Pa.Math.s at 380° C., having an average particle size of 1.0 to 50 μm, and containing 30 or more carboxyl groups at ends of the molecule chain per 10.sup.6 carbon atoms in the main chain, wherein the powder is substantially free from C8-C14 perfluorocarboxylic acids and salts thereof.

A polymer composition including a fluoropolymer composition including greater than 99 wt % polytetrafluoroethylene, where the fluoropolymer composition exhibits a melting temperature of greater than 327° C. at a pressure of 0.1 MPa.

A method of using a dental filler is disclosed. The method may include securing a prosthetic to a dental implant, the prosthetic having an access channel therethrough. The method may also include filling a portion of the access channel by inserting a polytetrafluoroethylene dental plug into the access channel and compressing the polytetrafluoroethylene dental plug within the access channel.

A method of using a dental filler is disclosed. The method may include securing a prosthetic to a dental implant, the prosthetic having an access channel therethrough. The method may also include filling a portion of the access channel by inserting a polytetrafluoroethylene dental plug into the access channel and compressing the polytetrafluoroethylene dental plug within the access channel.