Disclosed are polyimide blends and methods of making and using same. The disclosed polyimide blends are prepared by first blending an ionic polymer and a poly(amic acid) to form a poly(amic acid) precursor, followed by cyclization. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

To provide a method for producing modified polytetrafluoroethylene, in which formation of a fluorinated oligomer as a by-product is little. A method for producing modified polytetrafluoroethylene which contains substantially no C.sub.6-34 fluorinated oligomer containing hydrophilic functional groups and which contains substantially no fluorinated surfactant, the method comprising conducting copolymerization of tetrafluoroethylene and a monomer having a polar group, in a liquid dispersion 1 comprising a polymer containing units derived from a non-fluorinated monomer and an aqueous medium, or in a solution 2 obtainable by mixing at least one member selected from the group consisting of a polyalkylene oxide compound and a hydrocarbon-containing surfactant, with an oxidizing agent, in an aqueous medium, under such a condition that the amount of the monomer having a polar group to be used, is at most 0.150 mass % to the whole amount of tetrafluoroethylene, to obtain modified polytetrafluoroethylene.

Powder including low molecular weight polytetrafluoroethylene having a melt viscosity of 1×10.sup.2 to 7×10.sup.5 Pa.Math.s at 380° C., having a melt viscosity of 1×10.sup.2 to 7×10.sup.5 Pa.Math.s at 380° C., having an average particle size of 1.0 to 50 μm, and containing 30 or more carboxyl groups at ends of the molecule chain per 10.sup.6 carbon atoms in the main chain, wherein the powder is substantially free from C8-C14 perfluorocarboxylic acids and salts thereof.

A fluororubber composition containing a ternary fluororubber polymer including vinylidene fluoride, perfluorovinyl ether and tetrafluoroethylene; a reaction product of silica-aluminum silicate with vinyl ethoxysilane; and hydrotalcite. The fluororubber composition does not substantially contain magnesium oxide and calcium hydroxide. The fluororubber composition contains 2 to 55 parts by weight of the reaction product of silica-aluminum silicate with vinyl ethoxysilane and 0.5 to 10 parts by weight of the hydrotalcite relative to 100 parts by weight of the ternary fluororubber polymer.

A separator for an electrochemical device comprising a porous polymer substrate, and a porous coating layer on at least one surface of the porous polymer substrate. The porous coating layer comprises inorganic particles and an ion conducting polymer. The ion conducting polymer comprises a fluorine-based copolymer comprising fluoroolefin-based segments with anionic functional groups present in side chains or terminals, and an electrochemical device comprising the same. It is possible to provide a separator with high ionic conductivity and an increased peel strength between the porous polymer substrate and the porous coating layer, and an electrochemical device with improved properties.

A resin powder having a high bulk density and an average particle size of at most 50 μm from resin particles containing a fluorocopolymer as the main component and having a melting point of 260 to 320° C., where the fluorocopolymer contains a unit containing a carbonyl group-containing group, a unit based on tetrafluoroethylene, and a unit based on a perfluoro(alkyl vinyl ether) or a unit based on hexafluoropropylene. A method of producing the resin powder by subjecting resin particles (A) having an average particle size of at least 100 μm to mechanical pulverization treatment. The resin particles (A) is made of a material (X) having a fluorocopolymer (X1) as the main component, which has a unit (1) based on a monomer containing at least one functional group selected from a carbonyl group-containing group, a hydroxy group, an epoxy group and an isocyanate group, and a unit (2) based on tetrafluoroethylene.

The present invention provides, among other aspects, stabilized chromophoric nanoparticles. In certain embodiments, the chromophoric nanoparticles provided herein are rationally functionalized with a pre-determined number of functional groups. In certain embodiments, the stable chromophoric nanoparticles provided herein are modified with a low density of functional groups. In yet other embodiments, the chromophoric nanoparticles provided herein are conjugated to one or more molecules. Also provided herein are methods for making rationally functionalized chromophoric nanoparticles.

Powder including low molecular weight polytetrafluoroethylene having a melt viscosity of 110.sup.2 to 710.sup.5 Pa.Math.s at 380 C., having a melt viscosity of 110.sup.2 to 710.sup.5 Pa.Math.s at 380 C., having an average particle size of 1.0 to 50 m, and containing 30 or more carboxyl groups at ends of the molecule chain per 10.sup.6 carbon atoms in the main chain, wherein the powder is substantially free from C8-C14 perfluorocarboxylic acids and salts thereof.

A porous membrane having a porous matrix formed of a thermoplastic polymer material and inorganic filler particles embedded in the porous matrix, the inorganic filler particles having an accessible surface comprising nucleophilic groups bonded to the inorganic filler particles is functionalised by bringing the porous membrane in contact with an aqueous solution comprising a carboxylic acid and/or an anhydride thereof at a pH equal to or smaller than 3.5 to obtain a carboxylic acid functionalised membrane.

Process for the preparation of a vinylidene chloride polymer comprising polymerizing vinylidene chloride and optionally at least one ethylenically unsaturated monomer copolymerizable therewith under the control of a RAFT agent of formula (II).

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