摘要:
1. Crosslinked sulphonic fluorinated ionomers having an equivalent weight 380-1300 g/eq, comprising:
(A) monomeric units deriving from one or more fluorinated monomers containing at least one ethylene unsaturation; (B) fluorinated monomeric units containing sulphonyl groups -SO 2 F in an amount such as to give the above indicated equivalent weight.
A) a fluoroelastomeric matrix based on vinylidene fluoride (VDF); B) a semi-crystalline fluoropolymer, in an amount from 1 to 40% by weight based on the total of A) + B), comprising a semi-crystalline fluoropolymer core coated by a semi-crystalline fluoropolymer shell containing bromine and/or iodine in the polymer chain; the fluoroelastomer A) incorporates the fluoropolymer B), the fluoropolymer B) being formed by tetrafluoroethylene (TFE) homopolymers, or by TFE copolymers with one or more monomers containing at least one unsaturation of ethylene type, the average sizes of the semi-crystalline fluoropolymer particles being from 10 to 100 nm, preferably from 10 to 60 nm.
摘要:
Curable fluoroelastomers comprising in the chain monomeric units formed by a triazine iodinated derivative having general formula: wherein Y' is independently H, Cl, F, CH 3 , CF 3 ; m' and t' are integers selected between 0 and 1, and m' + t' = 0 or 1 , preferably m' + t' = 0 ; p' is an integer and it is equal to 1 when t' = 1, or p' = 0; X' is independently H, Cl, F, alkyl or perfluoroalkyl C 1 -C 3 , preferably F; n' is an integer comprised between 2 and 20, preferably between 4 and 12, more preferably between 4 and 8.
摘要:
Fluoroelastomeric compositions comprising: A) a fluoroelastomeric matrix based on tetrafluoroethylene (TFE); B) a semi-crystalline fluoropolymer, in an amount from 2 to 90% by weight based on the total of A) + B), comprising a semi-crystalline fluoropolymer core coated by a semi-crystalline fluoropolymer shell containing bromine and/or iodine in the polymer chain; the fluoroelastomer A) incorporates the fluoropolymer B), the fluoropolymer B) being formed by tetrafluoroethylene (TFE) homopolymers, or by TFE copolymers with one or more monomers containing at least one unsaturation of ethylene type, the average sizes of the semi-crystalline fluoropolymer particles being from 10 to 100 nm, preferably from 10 to 60 nm.
A) a fluoroelastomeric matrix; B) a semi-crystalline fluoropolymer, in an amount from higher than 40% to 90% by weight based on the total of A) + B); the fluoroelastomer A) incorporates the fluoropolymer B), the fluoropolymer B) being formed by tetrafluoroethylene (TFE) homopolymers, or by TFE by copolymers with one or more monomers containing at least one unsaturation of ethylene type, the average sizes of the semi-crystalline fluoropolymer particles being from 10 to 100 nm, preferably from 10 to 60 nm.
摘要:
Fluoropolymers comprising a fluoroelastomer matrix incorporating therein particles of a semicrystalline fluoropolymer formed of tetrafluoroethylene (TFE) homopolymers or copolymers, wherein the average particle sizes of the semicrystalline fluoropolymer latex range from 10 to 100 nm.
A) a fluoroelastomeric matrix based on vinylidene fluoride (VDF) ; B) a semi-crystalline fluoropolymer, in an amount from > 40% to 90% by weight based on the total of A) + B), comprising a semi-crystalline fluoropolymer core coated by a semi-crystalline fluoropolymer shell containing bromine and/or iodine in the polymer chain; the fluoroelastomer A) incorporates the fluoropolymer B), the fluoropolymer B) being formed by tetrafluoroethylene (TFE) homopolymers, or by TFE copolymers with one or more monomers containing at least one unsaturation of ethylene type, the average sizes of the semi-crystalline fluoropolymer particles being from 10 to 100 nm, preferably from 10 to 60 nm.
摘要:
Amorphous perfluorinated copolymers, comprising cyclic perfluorinated units deriving from at least two different perfluorinated comonomers, optionally with units deriving from a perfluorinated monomer containing at least one olefinic unsaturation (perfluoroolefin), or comprising cyclic perfluorinated units and units deriving from a perfluorinated monomer containing at least one olefinic unsaturation, said perfluorinated copolymers having the following combination of properties:
substantial absence of unstable polar end groups, polymer Tg higher than 120°C, narrow monomeric composition distribution.
(I) one or more fluorinated monomers containing at least one ethylene unsaturation; (II) one or more fluorinated monomers containing sulphonyl groups -SO 2 F; said process comprising:
a) preparation of an aqueous microemulsion, having a pH in the range 4-7, of perfluoropolyethers (PFPEs); b) feeding of the microemulsion to the polymerization reactor, in an amount higher than 18 ml per litre of reaction medium; c) introduction of the monomer (II) in liquid form into the reactor, reactor pressurization with the gaseous monomers (I); d) addition of the initiator, and feeding of the monomers (I) during the polymerization so as to maintain constant the reactor pressure.
摘要:
Curable fluoroelastomers essentially formed by the following fluoroelastomer mixtures:
a) from 20 to 70% by weight of a fluoroelastomer having the Mooney viscosity value, ML (1+10) at 121 °C higher than 60 points and containing from 0.01 to 3% by weight of iodine; b) from 0 to 70% by weight of a fluoroelastomer having the Mooney viscosity value, ML (1+10) at 121 °C, in the range 20-60 points and containing from 0.2 to 5% by weight of iodine; c) from 5 to 60% by weight of a fluoroelastomer having the Mooney viscosity value, ML (1+10) at 121 °C, in the range 1-20 points and containing an iodine percentage by weight higher than 0.3; said Mooney viscosity ML (1+10) at 121°C being determined according to the ASTM D 1646 method; where said fluoroelastomers comprise monomeric units deriving from a bis-olefin.