Abstract: Use of amorphous perfluoropolymers based on homopolymers of the TTD dioxole or its amorphous copolymers to prepare solutions in fluoro-containing solvents, to obtain solutions for coatings, wherein TTD has the formula: ##STR1## wherein R.sub.F is a perfluoroalkylic radical with 1-5 carbon atoms, linear or branched when possible; X.sub.1 and X.sub.2 equal to or different from each other being F or CF.sub.3 ; the TTD amount ranges from 40 to 100% by moles.

Abstract: New fluoroelastomers are described, having iodine atoms in terminal position and monomeric units in the chain deriving from an iodinated olefin of formula:CHR.dbd.CH--Z--CH.sub.2 CHR--I (I)wherein: R is --H or --CH.sub.3 ; Z is a (per)fluoroalkylene radical C.sub.1 -C.sub.18, linear or branched, optionally containing one or more ether oxygen atoms, or a (per) fluoropolyoxyalkylene radical.These products, upon peroxide curing, require extremely short post-curing treatments (around 30-60 minutes at 180.degree.-230.degree. C.) and are characterized by compression set values lower than 25% (measured on O-rings at 200.degree. C. for 70 hours according to ASTM Standard D395 Method B).

Abstract: New fluoroelastomers are described, having iodine atoms in terminal position and monomeric units in the chain deriving from an iodinated olefin of formula:CHR.dbd.CH--Z--CH.sub.2 CHR--I (I)wherein: R is --H or --CH.sub.3 ; Z is a (per)fluoroalkylene radical C.sub.1 -C.sub.18, linear or branched, optionally containing one or more ether oxygen atoms, or a (per)fluoropolyoxyalkylene radical.These products, upon peroxide curing, require extremely short post-curing treatments (around 30-60 minutes at 180.degree.-230.degree. C.) and are characterized by compression set values lower than 25% (measured on O-rings at 200.degree. C. for 70 hours according to ASTM Standard D395 Method B).

Abstract: Fluorinated thermoplastic elastomers comprising monomeric units deriving from a bis-olefin having general formula: ##STR1## wherein: R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, equal or different from each other, are H or alkyls C.sub.1 -C.sub.5 ; Z is an alkylene or cycloalkylene radical C.sub.1 -C.sub.18, linear or branched, optionally containing oxygen atoms, preferably at least partially fluorinated, or a (per)fluoropolyoxyalkylene radical.

Abstract: Fluorinated thermoplastic elastomers comprising monomeric units deriving from at least an iodinated olefin of formula:CX.sub.2 .dbd.CX--R.sub.f --CHR--I (I)wherein:X is --H, --F, or --CH.sub.3 ; R is --H or --CH.sub.3 ; R.sub.f is a (per) fluoroalkylene radical, linear or branched, optionally containing one or more ether oxygen atoms, or a (per) fluoropolyoxyalkylene radical.

Abstract: New fluoroelastomers are described, comprising monomeric units deriving from a bis-olefin having general formula: ##STR1## wherein: R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, equal or different from each other, are H or alkyls C.sub.1 -C.sub.5 ; Z is an alkylene or cycloalkylene radical C.sub.1 -C.sub.18, linear or branched, optionally containing oxygen atoms, preferably at least partially fluorinated, or a (per)fluoropolyoxyalkylene radical.Such products are endowed with improved processability, especially during calendering of the vulcanization mixture, along with superior mechanical and workability properties during extrusion and injection molding, with a very good mold release.

Abstract: A polyvinylidenefluoride (PVDF) having high mechanical properties both at room temperature and at high temperatures, having very good processability and high thermochemical resistance to dehydrofluorination, is prepared by means of a polymerization process of vinylidenefluoride in aqueous emulsion at a temperature comprised between 95.degree. and 120.degree. C., in the presence of a chain transfer agent. In this way it is possible to obtain, using non-hazardous peroxidic initiators (for instance diterbutylperoxide), a PVDF particularly suitable for applications where high mechanical and thermochemical resistance properties are required, such as for instance the manufacture of articles for chemical industry (pipes, valves, fittings, tanks, heat exchangers, membranes, flanges, etc.).

Abstract: Object of the present invention is a process for preparing vinylidenefluoride (VDF) polymers which comprises polymerizing VDF, optionally in association with other fluorinated oiefins in an aqueous medium in the presence of a radical initiator and of 1,1,1-trifluoro-2,2-dichloroethane (HCFC-123) as chain transfer agent.A final product with very good colour characteristics (appearance), substantially devoid of discoloration effects at high temperatures, is so obtained.

Abstract: The invention relates to new fluoroelastomeric copolymers endowed with resistance to bases and suitable in particular for preparing O-rings, comprising:______________________________________ (I) VDF 47-80 mols % HFP and/or PAVE 16-30 mols % hydrogenated olefin containing 2-25 mols % 2-4 C or (II) VDF 42-80 mols % PAVE 16-30 mols % hydrogenated olefin containing 2-30 mols % 2-4 C ______________________________________The invention relates to new fluoroplastomeric copolymers endowed with resistance to bases, comprising: ______________________________________ (III) VDF 70-99 mols % HFP and/or PAVE 0-16 mols % hydrogenated olefin containing 1-30 mols % 2-4 C ______________________________________A further object of the invention is a process for preparing the abovesaid fluoroelastomeric and fluoroplastomeric copolymers.

Abstract: Fluoroelastomeric copolymers exhibiting high resistance to bases and alcohols, as well as high mechanical properties and low-temperature resistance, comprising, in moles:4-75% of units of vinylidene fluoride;12-40% of units of hexafluoropropene and/or perfluorovinylether and/or hydropentafluoropropene and/or chlorotrifluoroethylene;2-35% of units of an olefin containing up to 4 carbon atoms;2-60% of units of tetrafluoroethylene, provided that, when the sum of the olefin units and the perfluorovinylether units is equal to or greater than 70%, such copolymers possess a molecular weight sufficiently high to exhibit good mechanical characteristics.

Abstract: Fluoroelastic copolymers, suitable for the manufacture of O-rings, comprising by weight:48-65% of VDF units21-36% of HFP units3-9% of PAVE units0-17% of TFE units

Abstract: Fluoroelastomeric copolymers, vulcanizable by ionic methods, suitable for the manufacture of "shaft seals" and "fuel hoses", comprising by weight:______________________________________ VDF 30-47% HFP 20-40% PAVE 3-20% TFE 10-30% ______________________________________

Abstract: Fluoroelastomers characterized by the presence of iodine or bromine atoms at the end of the polymeric chain in an amount equal to or lower than 1 iodine or bromine atom per polymeric chain, and by a bromine content in the chain ranging from 0.05 to 2% by weight referred to the total weight of the monomeric units.Said fluoroelastomers exhibit improved characteristics of processability, particularly as regards the utilization in injection molding processes and the detaching from the molds, as well as of stability to heat.A process for preparing fluoroelastomers containing iodine or bromine atoms at the ends of the polymeric chain, in an amount equal to or lower than 1 iodine or bromine atom per polymeric chain, which process comprises polymerizing mixes of fluorinated monomers (VDF, TFE, HFP, FVE) in bulk, in suspension, in aqueous emulsion, or in solution of organic solvents by means of radical starters, in the presence of compounds capable of providing I.sup.- or Br.sup.

Abstract: Covulcanizable compositions comprising (A) 55-100% by weight of an elastomeric copolymer of vinylidene fluoride with perfluoropropene optionally tetrafluoroethylene and containing from 0.001 to 2% by weight of bromine; (B) 0-45% by weight of a tetrafluoroethylene and propylene copolymer; (C) 0.7-2.5 parts for 100 parts of mix (A)+(B) of a bisphenol compound; (D) 0.3-1.5 parts for 100 parts of mix (A)+(B) of an organic guaternary compound of ammonium, phosphonium or aminophosphonium; (E) 0.4-5 parts for 100 parts of mix (A)+(B) of an organic peroxide; (F) 1-5% by weight of (A)+(B) of a peroxide cross-linking coagent.

Abstract: The invention relates to new fluoroelastomers endowed with a low Tg and a low compression set at low temperature, characterized by the following monomeric composition:______________________________________ vinylidene fluoride: 60.5-64% by weight hexafluoropropene: 30-33% by weight tetrafluoroethylene: 5-8% by weight.

Abstract: Fluoroelastomers characterized by the presence of iodine or bromine atoms at the end of the polymeric chain in an amount equal to or lower than 1 iodine or bromine atom per polymeric chain, and by a bromine content in the chain ranging from 0.05 to 2% by weight referred to the total weight of the monomeric units.Said fluoroelastomers exhibit improved characteristics of processability, particularly as regards the utilization in injection molding processes and the detaching from the molds, as well as of stability to heat.A process for preparing fluoroelastomers containing iodine or bromine atoms at the ends of the polymeric chain, in an amount equal to or lower than 1 iodine or bromine atom per polymeric chain, which process comprises polymerizing mixes of fluorinated monomers (VDF, TFE, HFP, FVE) in bulk, in suspension, in aqueous emulsion, or in solution of organic solvents by means of radical starters, in the presence of compounds capable of providing I.sup.- or Br.sup.

Abstract: Use of perfluoropolyethers having perfluoroalkyl end groups with a molecular weight ranging from 500 to 1500, in amounts from 0.5 to 3 parts by weight per 100 parts by weight of elastomer and, optimally, in combination wit polytetrafluoroethylene having a molecular weight lower than about 200,000, as additives to the polymerization latex of rubbers vulcanizable by means of peroxides in order to improve the detachability of the vulcanizate from forming molds.

Abstract: Process for the preparation of curable fluoroelastomers comprising reacting form 35 to 80 mol % of vinylidene fluoride, from 15 to 35 mol % of hexafluoropropene, from 0 to 30 mol % of another comonomer selected from fluoroolefins and/or perfluorovinyl ethers and from 0.01 to 1 mol % of a brominated fluorovinyl ether having general formula:CF.sub.2 BR--(R.sub.f).sub.n --O--CF.dbd.CF.sub.2wherein R.sub.f is a fluorinated alkylene radical containing from 1 to 9 carbon atoms and n can be either 0 or 1, in the presence of a known polymerization initiator for fluoroelastomers, and of small amounts of a chain-transfer agent having general formula:R--(CF.sub.2 Br).sub.mwherein m is either 1 or 2; when m is 1, R can be either bromine or a perfluoroalkyl radical of 2 to 4 carbon atoms containing a bromine atom bonded to a secondary carbon atom; and when m is 2, R is an alkylene radical of up to 4 carbon atoms containing a bromineatom bonded to a secondary carbon atom.