Abstract: A fluoropolymer [polymer (F)], a polymerisation process for its manufacture, and a moulding process using such fluoropolymer [polymer (F)]. The polymerisation process comprises polymerising at least one fluorinated monomer in a polymerization medium, in which the polymerization medium is mixed by means of a stirring system comprising at least two counter-rotating impellers. Surprisingly and advantageously, the polymerization occurs without fouling or deposit formation on the reactor walls, and moreover, occurs with improved homogeneity, without composition, pressure or temperature gradients, thus enabling obtaining homogeneous polymer composition with no risk of local overheating. A polymer (F) obtained from such process has improved morphology (percentage of organized structures, i.e.

Abstract: Ionomeric membranes comprising (per)fluorinated, se-micrystalline or amorphous, ionomeric polymers, having equivalent weight (EW) from 380 g/eq to 1,800 g/eq, which used in fuel cells, under the following conditions: membrane thickness 50 ?m assembled between two electrodes catalyzed with 0.6 mg/cm2 Pt/C and treated with 0.7 mg/cm2 of Nafion®, having a 10 cm2 area; hydrogen and air feeding, both at the pressure of 0.25 MPa, both saturated with water at 80° C.; cell temperature 75° C.; for membranes formed of copolymers TFE/F2C?CF—O—(CF2)2—SO2F, give the following maximum specific power (PMAX) values, at the indicated EW values: at EW=670 PMAX higher than 0.55 Watt/cm2; at EW=830 PMAX higher than 0.66 Watt/cm2; at EW=1,160 PMAX higher than 0.50 Watt/cm2; at EW=1,600 PMAX higher than 0.32 Watt/cm2.

Abstract: Amorphous perfluorinated homopolymers and copolymers of perfluorodioxoles of formula (IA): wherein R?F is equal to RF or ORF wherein RF is a linear or branched perfluoroalkyl radical having 1-5 carbon atoms; X1 and X2, equal to or different from each other, are F, CF3; said polymers having a dioxole content?95% by moles, having the following property combination: Tg, measured according to the ASTM 3418 (DSC) method, from 180° C. to 195° C.; intrinsic viscosity, measured at the temperature of 30° C. in perfluoroheptane (Galden® D80) according to the ASTM D 2857-87 method, from 13 cc/g to 100 cc/g.

Abstract: A continuous process for applying subgaskets to both the flat surfaces of CCM assemblies, comprising the following steps: a) preparation of a roll (A) formed of a composite (20) consisting in one central layer (1), formed of an ionomeric membrane sheet, wherein on each of the two surfaces, electrocatalytic layers (2) longitudinally distributed at regular intervals are applied, said layers being on each of the two surfaces in symmetric position among each other with respect to the membrane plane; b) preparation of two subgasket rolls (B) wherein, on a subgasket sheet (21), in correspondence to the position of the electrocatalytic layers (2) in the roll (A), openings (3) are made; the percent ratio (subgasket opening area (3))/(electrocatalytic layer area (2)) being between 90% and 99%; c) hot lamination of two rolls (B) with the roll (A), carried out by feeding the roll (A) between the two rolls (B), with the two drums (8) for the lamination; the step being carried out so that the perimeter of the openings

Abstract: Assemblies or MEA devices (Membrane Electrode Assembly) comprising a membrane and two electrocatalytic layers on each side thereof, wherein: the area of each of the two electrocatalytic layers is lower than that of the membrane; on each of the two sides of the ionomeric membrane there is at least one subgasket, applied on the MEA non catalyzed area; the edges of the ionomeric membranes being enclosed among said subgaskets.

Abstract: Amorphous perfluorinated homopolymers and copolymers of perfluorodioxoles of formula (IA): wherein R?F is equal to RF or ORF wherein RF is a linear or branched perfluoroalkyl radical having 1-5 carbon atoms; X1 and X2, equal to or different from each other, are F, CF3; said polymers having a dioxole content ?95% by moles, having the following property combination: Tg, measured according to the ASTM 3418 (DSC) method, from 180° C. to 195° C.; intrinsic viscosity, measured at the temperature of 30° C. in perfluoroheptane (Galden® D80) according to the ASTM D 2857-87 method, from 13 cc/g to 100 cc/g.

Abstract: Amorphous perfluorinated homopolymers and copolymers of perfluorodioxoles of formula (IA): wherein R?F is equal to RF or ORF wherein RF is a linear or branched perfluoroalkyl radical having 1-5 carbon atoms; X1 and X2, equal to or different from each other, are F, CF3; said polymers having a dioxole content ?95% by moles, having the following property combination: Tg, measured according to the ASTM 3418 (DSC) method, from 180° C. to 195° C.; intrinsic viscosity, measured at the temperature of 30° C. in perfluoroheptane (Galden® D80) according to the ASTM D 2857-87 method, from 13 cc/g to 100 cc/g.

Abstract: Amorphous perfluorinated homopolymers and copolymers of perfluorodioxoles of formula (IA): wherein R?F is equal to RF or ORF wherein RF is a linear or branched perfluoroalkyl radical having 1–5 carbon atoms; X1 and X2, equal to or different from each other, are F, CF3; said polymers having a dioxole content ?95% by moles, having the following property combination: Tg, measured according to the ASTM 3418 (DSC) method, from 180° C. to 195° C.; intrinsic viscosity, measured at the temperature of 30° C. in perfluoroheptane (Galden® D80) according to the ASTM D2857-87 method, from 13 cc/g to 100 cc/g.

Abstract: 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%.

Abstract: A purification process of thermoprocessable tetrafluoroethylene (TFE) copolymers comprising the following steps: A) the polymer latex is transformed into gel form, under mechanical stirring, by addition of an acid electrolyte having pH values?2; B) washing of the polymer gel with aqueous solutions having pH from 1 to 7.

Abstract: VDF polymerization process, optionally modified with small amounts of one or more fluoro-containing comonomers, carried out in the presence of a microemulsion comprising a (per) fluoropolyether having neutral end groups, having number average molecular weight between 400 and 3000, and a surfactant based on perfluoropolyethers with salified acid end groups, said surfactant having a number molecular weight Mn comprised between 400–600 and having a distribution of molecular weights such that fractions having a number average molecular weight higher than 700 are not present, or are in amount less than 5% by weight.

Abstract: An ionomeric membrane formed of a sulphonic (per)fluorinated ionomer wherein the sulphonic groups are at the end of short side chains (SSC), said ionomer having: equivalent weight between 700 and 1600 g/eq; side chains of formula: —O—CF2—CF2—SO331 M+, wherein M is hydrogen or an alkaline metal; said membrane having the following combination of properties: size variations, for both the orthogonal directions xy of the plane, lower than 15%, measured after dipping of the ionomeric membrane, dried at 105° C. under vacuum for one hour, in demineralized water at 100° C. for 30 minutes; the membrane, dipped at the temperature of 50° C. for 22 hours in a water/ethanol mixture containing 40% by weight of alcohol, remains integral.

Abstract: CCM formed of a membrane having on one of the two surfaces a first electrocatalytic layer containing a catalyst and on the other one a second electrocatalytic layer containing a catalyst, said electrocatalytic layers and said membrane containing (per)fluorinated ionomers, said CCM having the following characteristics: size variations, for both the orthogonal directions of the plane xy, lower than 15%, by dipping the CCM, after drying at 105° C. under vacuum for one hour in demineralized water at 100° C. for 30 minutes; the CCM remains substantially unchanged after having been subjected to treatments of 60 cycles by dipping in water at 80° C. for 8 hours and then in water at the temperature of 25° C. for 16 hours.

Abstract: 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.

Abstract: Use of amorphous perfluorinated polymers for preparing transparent films at 157 nm, said perfluorinated polymers being free from unstable ionic end groups COF, COOH or their amidic derivatives, esters or salts, said polymers formed by cyclic units deriving from perfluorodioxoles of formula: wherein R?F is equal to RF or ORF wherein RF is a perfluoroalkyl radical having 1–5 carbon atoms; X1 and X2, equal to or different from each other, are F, CF3; said polymers optionally containing units deriving from perfluorinated comonomers optionally containing oxygen atoms; in said polymers the cyclic units deriving from the perfluorodioxoles of formula (IA) being ?95% by moles.

Abstract: Copolymers formed by TFE and FMVE containing FMVE in percent by moles from 2.5% to 8%; the % TFE moles being the complement to 100% of the FMVE moles.

Abstract: 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.

Abstract: A purification process of thermoprocessable tetrafluoroethylene (TFE) copolymers comprising the following steps: A) the polymer latex is transformed into gel form, under mechanical stirring, by addition of an acid electrolyte having pH values ?2; B) washing of the polymer gel with aqueous solutions having pH from 1 to 7.

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: Ionomeric membranes comprising (per)fluorinated, se-micrystalline or amorphous, ionomeric polymers, having equivalent weight (EW) from 380 g/eq to 1,800 g/eq, which used in fuel cells, under the following conditions: membrane thickness 50 ?m assembled between two electrodes catalyzed with 0.6 mg/cm2 Pt/C and treated with 0.7 mg/cm2 of Nafion®, having a 10 cm2 area; hydrogen and air feeding, both at the pressure of 0.25 MPa, both saturated with water at 80° C.; cell temperature 75° C.; for membranes formed of copolymers TFE/F2C?CF—O—(CF2)2—SO2F, give the following maximum specific power (PMAX) values, at the indicated EW values: at EW=670 PMAX higher than 0.55 Watt/cm2; at EW=830 PMAX higher than 0.66 Watt/cm2; at EW=1,160 PMAX higher than 0.50 Watt/cm2; at EW=1,600 PMAX higher than 0.32 Watt/cm2.