Abstract: A modified fine powder polytetrafluoroethylene, and the process for preparing the polymer, in which the modifying copolymerizable monomer is a selected dioxole monomer. The composition is dispersion-process-produced and includes a core portion having a copolymer comprising repeat units provided by tetrafluoroethylene monomer and dioxole monomer, and a shell portion that is substantially free of dioxole units. The core and shell portions may contain perfluoro (n-propylvinyl) ether. The composition is useful for paste extrusion, such as in wire coating and tubing applications.

Abstract: Advantageous modification of non-melt processible, fibrillatible TFE copolymers for past extrusion is possible by including small amounts of perfluoro(n-alkyl vinyl ether) in the shell of the copolymer particle.

Abstract: A tetrafluoroethylene copolymer composition in which the modifying comonomer is a fluorinated alkyl ethylene of the formula CF.sub.3 --CF.sub.2 --(CF.sub.2).sub.2 --CH.dbd.CH.sub.2.

Abstract: A bromate/bisulfite redox initiator system has been found useful for polymerizing tetrafluoroethylene to make resins of good stretch capability.

Abstract: Tetrafluoroethylene fine powder resins are described which have surprisingly high extrusion pressures and molecular weights which make them useful in post-paste extruded stretching operations. The resins are made by using a permanganate polymerization initiator and controlling its rate of addition.

Abstract: Ce(IV) salts and oxalic acid form a redox initiator system for polymerizing tetrafluoroethylene.

Abstract: Tetrafluoroethylene fine powder resins are described which have surprisingly high extrusion pressures and molecular weights which make them useful in post-paste extruded stretching operations. The resins are made by using a permanganate polymerization initiator and controlling its rate of addition.

Abstract: Tetrafluoroethylene fine powder resins are described which have surprisingly high extrusion pressures and molecular weights which make them useful in post-paste extruded stretching operations. The resins are made by using a manganese triacetate/selected reducing agent polymerization initiator and controlling its rate of addition.

Abstract: A tetrafluoroethylene copolymer composition in which the modifying comonomer is a fluorinated alkyl ethylene of the formulaCF.sub.3 (CF.sub.2).sub.3 CH.dbd.CH.sub.2,wherein the units of acid comonomers are located in the interior of the copolymer.

Abstract: Tetrafluoroethylene fine powder resins are described which have surprisingly high extrusion pressures and molecular weights which make them useful in post-paste extruded stretching operations. The resins are made by using a permanganate polymerization initiator and controlling its rate of addition so that the reaction slows down at the end of the polymerization.

Abstract: Tetrafluoroethylene fine powder resins are made by adjusting temperature during polymerization wherein:(a) at the beginning of the polymerization the temperature is between 70.degree.-90.degree. C.,(b) when between 5-30% of the total amount of tetrafluoroethylene has been polymerized, the temperature is raised to between 100.degree.-125.degree. C.,(c) after 20-80% of the total tetrafluoroethylene has been polymerized and after step (b) has been carried out, the temperature is lowered by at least 30.degree. C. from the temperature used in step (b).

Abstract: Oversize agglomerates produced during the agglomeration of small granular tetrafluoroethylene polymer particles, are conveyed to an agitation vessel where they are subjected to agitation to convert them to smaller size agglomerates.