Abstract: This invention pertains to sealing articles of vulcanized (per)fluoroelastomer compositions incorporating particles of a vinylidene fluoride (VDF) polymers having a Shore A hardness of at least 85 when determined according to ASTM D 2240 Type A Durometer method, and a compression set of less than 30%, when determined according to ASTM D395 at 200° C. for 70 h on O-ring according to ASTM D1414, and to a process for their manufacture by vulcanizing-molding and thermal post-treating at a temperature above the melting point of the VDF polymer.

Abstract: Vulcanizable fluoroelastomer compositions comprising: A) a fluoroelastomer matrix based on vinylidene fluoride (VDF) with a Mooney viscosity (1+10) at 121° C. of less than 35 MU (Mooney Units) measured according to ASTM standard D 1646; and B) a semi-crystalline fluoropolymer, in an amount of from 20% to 70% by weight relative to the total weight of A)+B), the semi-crystalline fluoropolymer being constituted of tetrafluoroethylene (TFE) homopolymers and copolymers of TFE with one or more monomers containing at least one unsaturation of ethylenic type, in an amount of from 0.01 to 10 mol %, said semi-crystalline fluoropolymer having a mean particle size between 10 and 400 nm.

Abstract: VDF-based curable fluorelastomers, having a glass transition temperature from ?10° C. to ?35° C., comprising: B) monomer of formula: CF2?CFOCF2OCF3 (a), C) one or more comonomers selected from: tetrafluoroethylene (TFE), per-fluoromethylvinylether (PMVE), perfluoropropene (HFP), and an amount of —COF end groups in the polymer lower than the sensitivity limit of the method which uses the FT-IR spectroscopy described in the present application.

Abstract: VDF curable fluoroelastomers, ionically cured, having a compression set after a time of 24 h (ASTM D 39/B) at ?10° C. lower than 60%, preferably lower than 50% and at ?25° C. lower than 90%, preferably lower than 75%, comprising hexafluoropropene (HFP) in amounts higher than 10% by moles and one vinylether of formula: CF2?CFOCF2OCF3 (a), an amount of —COF and groups in the polymer lower than the sensitivity limit of the method using the FT-IR spectroscopy described in the present application.

Abstract: VDF-based curable fluoroelastomers, having a glass transition temperature lower than ?49° C., preferably lower than ?50° C., and having the following composition, as percent moles: A) from 25% to 50%, preferably from 30% to 45%, of the monomer of formula: CF2?CFOCF2OCF3 (a); B) one or more (per)fluorinated comonomers having at least one unsaturation of ethylene type in amounts from 75% to 50%; preferably from 70% to 55%; said one or more comonomers comprising vinylidene fluoride (VDF) in amounts from 50% to 75% on the total of the monomer moles; the sum of the molar percentages of the monomers being 100%; said fluoroelastomers containing an amount of —COF end groups in the polymer lower than the sensitivity limit of the method reported in the description.

Abstract: Ionically curable fluoroelastomers based on vinylidenfluoride (VDF) comprising: a) 100 parts by weight of fluoroelastomer based on vinylidenfluoride (VDF) substantially polar end groups free; b) from 0.1 to 0.35 phr of accelerating agent; c) from 1 to 15 phr of curing agent; d) from 2 to 20 phr of one or more inorganic acid acceptors, preferably bivalent metal oxides; e) from 0 to 3 phr, preferably from 0 to 1.5 phr of one or more basic compounds preferably hydroxides of bivalent metals or of weak acid metal salts; f) from 0 to 80 phr of reinforcing fillers; g) from 0 to 3 phr of coadjuvants of processability.

Abstract: A (per)fluoroelastomeric composition curable by peroxidic way comprising for 100 phr of (per)fluoroelastomer: as filler, from 2 to 70 phr of carbon black having a surface area between 25 and 35 m2/g; as crosslinking agent, from 0.5 to 10 phr of a bis-olefin having general formula: wherein: R1, R2, R3, R4, R5, R6, equal to or different from each other, are H or C1-C5 alkyls; Z is selected between a linear or branched C1-C18 alkylene or cycloalkylene radical, optionally containing oxygen atoms, preferably at least partially fluorinated, or a (per)fluoropolyoxyalkylene radical.

Abstract: A (per)fluoroelastomeric composition curable by peroxidic way comprising: 100 phr as (per)fluoroelastomer as filler, 0.5-50 phr of silica having a pH value, determined according to the DIN ISO 787-9 standard, higher than 7, preferably higher than 8, as crosslinking agent, from 0.5 to 10 phr of a bis-olefin having general formula: wherein: R1, R2, R3, R4, R5, R6, equal to or different from each other, are H or C1-C5 alkyls; Z is selected between a C1-C18 linear or branched alkylene or cycloalkylene radical, optionally containing oxygen atoms, preferably at least partially fluorinated, or a (per)fluoropolyoxyalkylene radical.

Abstract: VDF-based curable fluoroelastomers, having a glass transition temperature lower than ?49° C., preferably lower than ?50° C., and having the following composition, as percent by moles: A) from 25% to 50%, preferably from 30% to 45%, of the monomer of formula: CF2=CFOCF2OCF3 (a); B) one or more (per)fluorinated comonomers having at least one unsaturation of ethylene type in amounts from 75% to 50%, preferably from 70% to 55%; said one or more comonomers comprising vinylidene fluoride (VDF) in amounts from 50% to 75% on the total of the monomer moles; the sum of the molar percentages of the monomers being 100%; said fluoroelastomers containing an amount of —COF end groups in the polymer lower than the sensitivity limit of the method reported in the description.

Abstract: VDF curable fluoroelastomers, ionically cured, having a compression set after a time of 24 h (ASTM D 39/B) at ?10° C. lower than 60%, preferably lower than 50% and at ?25° C. lower than 90%, preferably lower than 75%, comprising hexafluoropropene (HFP) in amounts higher than 10% by moles and one vinylether of formula: CF2?CFOCF2OCF3 (a), an amount of —COF and groups in the polymer lower than the sensitivity limit of the method using the FT-IR spectroscopy described in the present application.

Abstract: VDF-based curable fluorelastomers, having a glass transition temperature from ?10° C. to ?35° C., comprising: B) monomer of formula: CF2?CFOCF2OCF3 (a), C) one or more comonomers selected from: tetrafluoroethylene (TFE), per-fluoromethylvinylether (PMVE), perfluoropropene (HFP), and an amount of —COF end groups in the polymer lower than the sensitivity limit of the method which uses the FT-IR spectroscopy described in the present application.

Abstract: Ionically curable fluoroelastomers based on vinylidenfluoride (VDF) comprising: a) 100 parts by weight of fluoroelastomer based on vinylidenfluoride (VDF) substantially polar end groups free; b) from 0.1 to 0.35 phr of accelerating agent; c) from 1 to 15 phr of curing agent; d) from 2 to 20 phr of one or more inorganic acid acceptors, preferably bivalent metal oxides; e) from 0 to 3 phr, preferably from 0 to 1.5 phr of one or more basic compounds preferably hydroxides of bivalent metals or of weak acid metal salts; f) from 0 to 80 phr of reinforcing fillers;. g) from 0 to 3 phr of coadjuvants of processability.