摘要:
The invention relates to a process for the isolation of (per)fluorinated polymers containing sulfonyl fluoride functional groups from a polymerization latex. The process comprises adding the polymerization latex to an aqueous electrolyte solution under high shear stirring at a temperature equal to or lower than the glass transition temperature of the polymer. The invention further relates to the (per)fluorinated polymers containing sulfonyl fluoride functional groups isolated by the process and characterised by a loss of weight at 200° C. lower than 1% as determined by thermogravimetric analysis.
摘要:
A process for reducing the amount of soluble polymeric fractions in a sulfonyl fluoride polymer. The process comprises contacting the sulfonyl fluoride polymer with a fluorinated fluid followed by separation of the polymer from the fluid. The fluorinated fluid is selected from hydrofluoroethers and hydrofluoropolyethers. The invention further relates to sulfonyl fluoride polymers obtainable by the process and having a heat of fusion not exceeding 4 J/g and containing less than 15% by weight of polymeric fractions having an average content of monomeric units comprising a sulfonyl functional group exceeding 24 mole %.The sulfonyl fluoride polymers so obtained are particularly suitable for the preparation of ionomeric membranes for use in electrochemical devices.
摘要:
A process for reducing the amount of soluble polymeric fractions in a sulfonyl fluoride polymer. The process comprises contacting the sulfonyl fluoride polymer with a fluorinated fluid followed by separation of the polymer from the fluid. The fluorinated fluid is selected from hydrofluoroethers and hydrofluoropolyethers. The invention further relates to sulfonyl fluoride polymers obtainable by the process and having a heat of fusion not exceeding 4 J/g and containing less than 15% by weight of polymeric fractions having an average content of monomeric units comprising a sulfonyl functional group exceeding 24 mole %.The sulfonyl fluoride polymers so obtained are particularly suitable for the preparation of ionomeric membranes for use in electrochemical devices.
摘要:
A process for manufacturing a dispersion of a vinylidene fluoride (VDF) thermoplastic polymer [polymer (F)], said process comprising polymerizing VDF in an aqueous phase comprising from 0.5 to 1.5 g/l of at least one surfactant of formula F—(CF2CF2)3—CH2CH2—SO3Xa, wherein Xa is H, a alkali metal or a NRH4 group, with RH being H or a C1-C6 hydrocarbon group [surfactant (T)] and an organic oxidizing agent [agent (O)] as polymerization initiator.
摘要:
The invention pertains to certain hydro-fluorocompounds of the following formula (I): RfO—RH—O—(CH2)m-[CF(X)n]—COOXa wherein: —Xa is H, a monovalent metal (preferably an alkaline metal) or an ammonium group of formula —N(R′n)4, wherein each of R′n, equal to or different from each other, independently represents a hydrogen atom or a C1-6 hydrocarbon group (preferably an alkyl group); —Rf is a C1-C6 (per)fluoroalkyl optionally comprising one or more catenary oxygen atoms, preferably Rf is a group of formula Rf—CH2—, wherein R′f is a C1-C5 perfluorinated group, possibly comprising one or more ethereal oxygens, preferably a C1-C3 perfluorinated group, possibly comprising one or more ethereal oxygens; —RH is a fluorine-free hydrocarbon group optionally comprising one or more catenary oxygen atoms; —X is F or CF3, preferably X is F; -m is 0 or 1; -n is 1 to 3, to a process for the manufacture of said hydro-fluorocompounds, to a method of making fluoropolymers in the presence of said hydro-fluorocompounds, and to fluoropolymer dispersions comprising said hydro-fluorocompound.
摘要:
A process for manufacturing a dispersion of a vinylidene fluoride (VDF) thermoplastic polymer [polymer (F)], said process comprising polymerizing VDF in an aqueous phase comprising from 0.5 to 1.5 g/l of at least one surfactant of formula F—(CF2CF2)3—CH2CH2—SO3Xa, wherein Xa is H, a alkali metal or a NRH4 group, with RH being H or a C1-C6 hydrocarbon group [surfactant (T)] and an organic oxidizing agent [agent (O)] as polymerization initiator.