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.
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.
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.
摘要:
Fluoroelastomers comprising, by mole:(a) from 33 to 75% of tetrafluoroethylene (TFE);(b) from 15 to 45% of a perfluorovinylether (PVE);(c) from 10 to 22% of vinylidene fluoride (VDF).They are endowed with high resistance to polar solvents and to bases, excellent compression set also at high temperatures, low Tg and good processability.They result particularly suitable for the manufacture of sealing elements (O-rings) for plants intended to the production of methylterbutylether (MTBE).
摘要:
A composite ionomeric membrane comprising a layer or film of a porous inert material on which a (per) fluorinated sulphonic ionomer is deposited wherein the sulphonic groups are at the end of short side chains (SSC), said ionomer having: equivalent weight comprised between 280 and 1,700 g/eq; side chains of formula: —O—CF2—CF2—S03−M+, wherein M is hydrogen or an alkaline metal; said membrane having in each of the two orthogonal directions xy of the plane, after dipping in demineralized water at 100° C. for 30 minutes and preliminary drying at 105° C. under vacuum for one hour, the following size variations: in one direction, size variation lower than 25%; in the other direction, size variation lower than 20%.
摘要:
The present invention pertains to a solar cell module comprising at least one photovoltaic element encapsulated between a front layer on its light receiving surface side and a back layer, said front layer comprising at least one layer comprising a tetrafluoroethylene (TFE) polymer [polymer (F)], said polymer (F) comprising: recurring units derived from TFE; and from 15 to 25% wt of recurring units derived from at least one perfluoromonomer [monomer (CM)] chosen among: (i) perfluoroalkylvinylethers complying with formula CF2═CFORf1, in which Rf1 is a C1-C6 perfluoroalkyl, e.g. —CF3, —C2F5, —C3F7; and/or (ii) perfluoro-oxyalkylvinylethers complying with formula CF2═CFOX0, in which X0 is a C1-C12 perfluorooxyalkyl having one or more ether groups, like perfluoro-2-propoxy-propyl; and (iii) mixtures thereof. Still objects of the invention are a process for the manufacture of the solar cell module as above defined and its use for producing current to external sources, e.g. for powering a fixed-wing aircraft.
摘要:
The invention pertains to a semi-crystalline fluoropolymer having ion exchange groups comprising recurring units derived from at least one ethylenicalty unsaturated monomer comprising at least one fluorine atom (fluorinated monomer); and a substantial amount of recurring units derived from at least one ethylenically unsaturated monomer comprising at least one ion exchange group (functional monomer), wherein the amount of unstable end groups of —COF type is of less than 0.05 mmol/kg, and the use of the stabilized fluoropolymer in fuel cells devices, a membrane and a membrane-electrode assembly.
摘要:
The invention pertains to a process for operating a polymer electrolyte membrane fuel cell (PEMFC), said PEMFC comprising: (a) a membrane comprising at least one fluorinated ionomer [polymer (I)] comprising recurring units derived from tetrafluoroethylene (TFE) and from at least one monomer of formula (M): wherein m is an integer between 1 and 6 and X′ is chosen among halogens (Cl, F, Br, I), —O−M+, wherein M+ is a cation selected among H+, NH4+, K+, Li+, Na+, or mixtures thereof, said polymer (I) having an equivalent weight (EW) of from 700 to 850 g/eq.; (b) a cathode; (c) an anode; said process comprising: (i) feeding gaseous reactants at the electrodes at a relative humidity of at most 66%; (ii) maintaining an average current density between 0.05 and 1.5 A/cm2; and (iii) maintaining an average temperature of more than 65° C.
摘要:
The invention pertains to a process for manufacturing certain (per)fluoroionomer liquid compositions, comprising, inter alia, at least one of fluorination and treatment with a polar solvent, to the liquid compositions therefrom having an improved solids content/surface tension/liquid viscosity compromise, to the use of the same for manufacturing composite membranes and to composite membranes obtainable therefrom.
摘要:
A composite ionomeric membrane comprising a layer or film of a porous inert material on which a (per) fluorinated sulphonic ionomer is deposited wherein the sulphonic groups are at the end of short side chains (SSC), said ionomer having: equivalent weight comprised between 280 and 1,700 g/eq; side chains of formula: —O—CF2—CF2—SO3—M+, wherein M is hydrogen or an alkaline metal; said membrane having in each of the two orthogonal directions xy of the plane, after dipping in demineralized water at 100° C. for 30 minutes and preliminary drying at 105° C. under vacuum for one hour, the following size variations: in one direction, size variation lower than 25%; in the other direction, size variation lower than 20%.