Abstract:
The present invention relates to a polymer composition comprising a sulphur-containing aromatic polymer and at least one fluoropolymer, which has high melt viscosity.The invention also relates to a process for the preparation of said polymer composition and to an article comprising the same.
Abstract:
The present invention relates to a method manufacturing an article having a high aspect ratio said method comprising : i) providing a uniform melted polymeric composition at a temperature comprised from 120 °C to 250 °C, said composition comprising 50% to 90% by weight of one or more thermoplastic vinylidene fluoride (VDF) polymers and 10 to 50% by weight of one or more thermoplastic acrylic or methacrylic ester polymers, ii) forming said composition into an article having a high aspect ratio at an apparent wall shear stress from 1·10 2 Pa to 3·10 5 Pa.
Abstract:
The present invention relates to a fluorosurfactant-free emulsion polymerization method for the synthesis of a fluoropolymer, more in particular of a VDF-based polymer.
Abstract:
The invention pertains to a method for making a fluoropolymer dispersion, said method comprising an aqueous emulsion polymerization of one or more fluorinated monomers wherein said aqueous emulsion polymerization is carried out in an aqueous medium comprising a surfactant mixture [mixture (S)] comprising: at least one perfluorohexanoic acid or salt thereof [surfactant (C6)], in an amount of 1 to 5 g/I, with respect to said aqueous medium; and at least one linear bifunctional perfluoropolyether surfactant [surfactant (PFPE)] complying with formula (I) here below: XpOOC-CF 2 -0-(CF 2 0) n' (CF 2 CF 2 0) m' -CF 2 -COOXp (I) wherein: Xp, equal to or different from each other, is a hydrogen atom, a monovalent metal, preferably an alkaline metal, or an ammonium group of formula -N(R' n ) 4 , wherein R' n , equal or different at each occurrence, is a hydrogen atom or a C 1 -C 6 hydrocarbon group, preferably an alkyl group; n' and m' are independently integers > 0 such that the number average molecular weight of the surfactant (PFPE) is of 500 to 2500, said surfactant (PFPE) being used in an amount of 0.005 to 0.5 g/I, with respect to said aqueous medium.
Abstract:
The invention mainly pertains to a method for heat treating a composition [composition (C)] which contains at least one melt-processible perfluoropolymer [polymer (F)] formed of tetrafluoroethylene (TFE) copolymer with one or more perfluorinated comonomers [comonomer (F)] containing at least one unsaturation of ethylene type in amounts from 0.5% to 13% by weight, preferably from 0.6% to 11 % by weight, and more preferably from 0.8% to 9% by weight; said polymer (F) possessing reactive end groups comprising at least one of the group consisting of hydrogen atoms, oxygen atoms and ethylenically unsaturated double bonds in an amount of at least 4.5 mmol/kg, the process comprising at least the step of heat-treating the composition (C) at a temperature of at least 260°C.
Abstract:
The invention pertains to certain composite materials featuring strong direct bonds between certain fluoropolymers and polyamides, which can be formed by using as additive certain chlorotrifluoroethylene-containing elastomers, in an ionic curable blend.
Abstract:
The present invention relates to a method for exchanging heat with an object said method comprising using a heat transfer fluid wherein said heat transfer fluid comprises one or more chemical compounds having the general formula: (I) wherein: - R 1 , R 2 , R 3 , R 4 can be the same or different, linear or branched, partially fluorinated alkyl groups having a C1-C6 carbon chain.
Abstract:
The invention pertains to a method of making fluoropolymer dispersions using certain reactive oligomeric dispersing agents, of given molecular weight, comprising I and/or Br, and a plurality of ionisable groups selected from the group consisting of -SO 3 X a , -PO 3 X a and -COOX a , whereas X a is H, an ammonium group or a monovalent metal, and to fluoropolymer dispersions therefrom.
Abstract:
The invention pertains to a tetrafluoroethylene (TFE) copolymer comprising recurring units derived from at least one per(halo)fluoroolefin different from TFE [monomer (F)] [monomer (F)], in an amount of 0.005 to 0.250 % moles, with respect to the total moles of the copolymer, wherein a particular relation between monomer content and amorphous index is satisfied, and to a process for its manufacture by emulsion polymerization in the presence of certain cyclic surfactants.
Abstract:
The invention pertains to a process for manufacturing a fluoroelastomer [fluoroelastomer (A)] having a heat of fusion of less than 5 J/g as measured by ASTM D-3418-08, said method comprising emulsion polymerizing vinylidene fluoride (VDF) in the presence of at least one additional fluorinated monomer, in an aqueous polymerization medium, said method comprising polymerizing VDF and said additional fluorinated monomer(s) in the presence of a redox radical initiator system comprising: - at least one organic oxidizing agent [agent (O)]; - at least one organic reducing agent [agent (R)]; wherein agent (O) is fed to said polymerization medium separately from agent (R), so that agent (O) comes in contact with agent (R) exclusively in said polymerization medium comprising VDF and optional additional monomer(s), to fluoroelastomers having low amount of chain defects and low amount of polar end groups, notably obtainable from said process, and to curable compositions therefrom.