摘要:
Microporous membrane composites that are non-dewetting are disclosed. These microporous membrane composites are wet with solutions of methanol and water and are non-dewetting following autoclave treatment in water. The microporous membrane composites comprise a microporous membrane support that is coated with a crosslinked ionomer comprising hydrophilic groups. Compared to the microporous membrane support, the microporous membrane composite has a flow loss on average in isopropyl alcohol of less than 82%.
摘要:
The invention pertains to a method for making a fluoropolymer comprising an aqueous emulsion polymerization of one or more fluorinated monomers wherein said aqueous emulsion polymerization is carried out in the presence of at least one cyclic fluorocompound of the following formula (I): wherein X1, X2, X3, equal or different from each other are independently selected among H, F, and C1-6 (per)fluoroalkyl groups, optionally comprising one or more catenary or non-catenary oxygen atoms; L represents a bond or a divalent group; RF is a divalent fluorinated C1-3 bridging group; Y is a hydrophilic function selected among anionic functionalities, cationic functionalities and non-ionic functionalities.
摘要:
The invention pertains to a method for replicating a pattern, said method comprising: (a) providing patterned template, wherein said patterned template comprises a patterned template surface having a plurality of recessed or protruded areas formed therein; (b) contacting a volume of a curable perfluoropolyether composition [composition (C)] with said patterned template surface, said composition comprising: - at least one functional perfluoropolyether compound [compound (E)], said compound (E) comprising a (per)fluoropolyoxyalkylene chain [chain (R f )], wherein the molecular weight of said chain R f is more than 1000 and less than 3500; and at least two unsaturated moieties; and - at least one photoinitiator; (c) submitting to UV radiations said composition (C) to yield a mould comprising a patterned mould surface, and separating said mould from said patterned template; (d) contacting said patterned mould surface with a (pre)polymer composition [composition (P)]; (e) processing said composition (P) to yield an article having a patterned surface, and separating said article from said mould.
摘要:
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 (I) 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.
摘要:
The invention pertains to a process for the purification from ionic impurities of a fluoroionomer liquid composition, said process comprising: - providing a liquid composition comprising at least one fluoroionomer (1-1) in a liquid medium, said liquid composition comprising ionic impurities; and - contacting said liquid composition with a solid particulate comprising at least one fluoroionomer (I-2) having ion exchange groups, wherein H + Or OH - ions are bound to at least a fraction of said ion exchange groups, and - separating said liquid composition from said solid particulate.
摘要:
The invention pertains to a process for stabilizing a semi-crystalline fluoropolymer comprising ion exchange groups, said process comprising: suspending at least one semi-crystalline fluoropolymer having ion exchange groups [polymer (I)] in at least one fluorinated organic dispersing medium [medium (M)] so as to obtain a dispersion (D) of polymer (I) in a dispersing medium (M); contacting said dispersion (D) with fluorine under irradiation with U. V. radiation so as to obtain a stabilized polymer. Still objects of the invention are a stable semi-crystalline fluoropolymer as above defined having a low amount of unstable ends groups of -COF type, the use of the stabilized fluoropolymer obtained by the process or of the stable fluoropolymer in fuel cells devices, a membrane and a membrane-electrode assembly comprising said fluoropolymers.
摘要:
The invention pertains to a method for making a fluoropolymer comprising an aqueous emulsion polymerization of one or more fluorinated monomers wherein said aqueous emulsion polymerization is carried out in the presence of at least one cyclic fluorocompound of the following formula (I): wherein X 1 , X 2 , X 3 , equal or different from each other are independently selected among H, F, and C 1-6 (per)fluoroalkyl groups, optionally comprising one or more catenary or non-catenary oxygen atoms; L represents a bond or a divalent group; R F is a divalent fluorinated C 1-3 bridging group; Y is a hydrophilic function selected among anionic functionalities, cationic functionalities and non-ionic functionalities.