Abstract: A thermoplastic, non-thermosettable copolymer of tetrafluoroethylene, an iodoperfluoroalkyl ethylene and an optional selected third comonomer. The copolymer can be extruded at higher rates than heretofore possible.

Abstract: An aqueous PTFE dispersion containing colloidal PTFE particles having a comparatively large average particle size is prepared by polymerizing TFE in an aqueous medium at a temperature of from 10.degree. to 100.degree. C. in the presence of a fluorine-containing dispersant and a water soluble polymerization initiator, in which, after the initiation of the polymerization and before consumption of 30% of TFE to be polymerized, TFE is polymerized at a pressure not higher than 4 Kg/cm.sup.2 for a period in which at least 1 g of TFE per liter of the aqueous medium is consumed, and then the rest of TFE is polymerized at a pressure of from 6 to 30 Kg/cm.sup.2, which dispersion does not contain any metal ion that reduces interfacial potential of the colloidal particle.

Abstract: A method is shown for making porous thermoresin structures. By the method, the thermoresin is at least partially solvated, formed into a desired shape, and cooled until droplets of the solvent form by syneresis within the shape. Further cooling crystalizes the droplets. These crystalized droplets are subsequently removed to leave a porous structure.

Abstract: Vinylidene fluoride polymers of high quality are prepared consistently by an emulsion polymerization process in which the monomer, chain transfer agent (isopropyl alcohol), and an aqueous emulsion of the initiator (diisopropylperoxydicarbonate) containing a fluoro surfactant of a limited class are fed incremently to an aqueous reaction medium containing a fluoro surfactant.

Abstract: Polytetrafluoroethylene dispersions obtained from dispersion polymerization which have high solids content and small polytetrafluoroethylene particles are obtained by employing a combination of disuccinic acid peroxide and an inorganic persulfate, and a combination of an anionic and a hydrocarbon dispersing agent, precharged to the polymerization mixture, and by adding a combination of disuccinic acid peroxide and an anionic dispersing agent during the course of the polymerization.

Abstract: Latexes suited for homogeneously incorporating compounds with a photographically useful group into photographic silver halide emulsion materials. The latex incorporates a copolymer comprising recurring units of a monomer with photographically useful group, and recurring units of surface active monomer, according to the general formula: ##STR1## wherein: R.sup.1 is hydrogen or methyl,n is 0 or 1 to 20,L is ##STR2## R.sup.2 is hydrogen or a hydrocarbon group, R.sup.3 is a monovalent chemical bond or a bivalent aliphatic hydrocarbon group or such group interrupted by the group --COO-- or --CONR--, andY is a sulpho, sulphato or phosphono group in acid or salt form, and at least one of the groups --(CH.sub.2).sub.n --, R.sup.2 and R.sup.3 is or comprises a hydrocarbon chain of at least 8 C-atoms.

Abstract: Terpolymer consisting of 12 to 48% by weight TFE units, 7 to 24% by weight HFP units and 30 to 81% by weight VF.sub.2 units, provided that when the content of TFE units is less than 42% by weight, the content of HFP units is less than 15% by weight. Heat-stable films such as polyimide film can be coated with a coating comprising the terpolymer to provide heat-sealable film useful as wire insulation.