摘要:
A catalyst composition includes a compound having the general formula: {RA}(−){QR′k}(+)or the precursors thereof, wherein R is a nonfluorinated, partially fluorinated, or perfluorinated alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl or aralkyl, A is an acid- or acid-derivative anion, Q is phosphorous, sulfur, nitrogen, arsenic, or antimony, and each R′ is hydrogen or an alkyl, aryl, aralkyl, or alkenyl group, k is the valence of Q; and optionally (c) an alcohol of the formula: R2—OH, wherein R2 is an alkyl group which can be fluorinated. Also provided are curable and cured fluoropolymer compositions involving such a catalyst.
摘要:
The present invention provides a process of reducing the amount of fluorinated emulsifier in an aqueous fluoropolymer dispersion by contacting the aqueous fluoropolymer dispersion with an anion exchange resin in a non-fixed resin bed, the process comprising: (a) mixing the aqueous fluoropolymer dispersion with an effective amount of a surfactant so as to stabilize the fluoropolymer dispersion while being contacted with the anion exchange resin; (b) contacting the aqueous fluoropolymer dispersion with an anion exchange resin by agitating the aqueous fluoropolymer dispersion with an effective amount of anion exchange resin for a time of less than 4 hours to reduce the amount of fluorinated emulsifier in the aqueous fluoropolymer dispersion to a desired level; and (c) separating the anion exchange resin from the aqueous fluoropolymer dispersion.
摘要:
The present invention provides a process of reducing the amount of fluorinated emulsifier in an aqueous fluoropolymer dispersion by contacting the aqueous fluoropolymer dispersion with an anion exchange resin in a non-fixed resin bed, the process comprising: (a) mixing the aqueous fluoropolymer dispersion with an effective amount of a surfactant so as to stabilize the fluoropolymer dispersion while being contacted with the anion exchange resin; (b) contacting the aqueous fluoropolyrner dispersion with an anion exchange resin by agitating the aqueous fluoropolymer dispersion with an effective amount of anion exchange resin for a time of less than 4 hours to reduce the amount of fluorinated emulsifier in the aqueous fluoropolymer dispersion to a desired level; and (c) separating the anion exchange resin from the aqueous fluoropolymer dispersion.
摘要:
The present invention provides a method of making a fluoropolymer comprising repeating units derived from one or more gaseous fluorinated monomers. The method comprises an aqueous emulsion polymerization of gaseous fluorinated monomers in the presence of an ether selected from the group consisting of dimethyl ether (DME), methyl tertiary butyl ether (MTBE) and mixtures thereof.
摘要:
The present invention provides a process for preparing a desired halogenated ester, which process comprises the steps of: (a) contacting (A) a substantially organic solvent free liquid mixture of (i) an alkanolate of the formula M—O—Z, wherein M is an alkali or alkaline earth metal, and Z is a linear, branched or cyclic alkyl group of 1 to 10 carbon atoms and (ii) a diester with (B) a halogenated ethylenically unsaturated olefin at a temperature of not more than 40° C. and with a mol ratio of halogenated ethylenically unsaturated olefin to alkanolate of not more than 1.1; (b) contacting an acid with a thus obtained reaction mixture thereby obtaining a mixture comprising the desired halogenated ester; and (c) recovering the halogenated ester from said reaction mixture. In step (a) of the process, the mixture of the alkanolate and diester is contacted with the halogenated ethylenically unsaturated olefin under conditions of agitation sufficient such that the weight ratio of halogenated ester to halogenated ketone as a byproduct obtained after step (b) is at least 10:1.
摘要:
Emulsion polymerization of liquid fluorinated monomers which have a boiling point above 50° C. and low water-solubility is markedly more efficient if the monomer is pre-emulsified with a nontelogenic fluorinated emulsifier in water.
摘要:
Process for working up aqueous dispersions of fluoropolymers. Fluoropolymer dispersions, in particular of fluoroelasomers, can be coagulated without adding chemicals, by compression with the aid of a gas and release through one or more small apertures.
摘要:
Non-free flowable, non-dusting molding powders with a bulk density of more than 450 g/l are obtained when a suspension polymer of tetrafluoroethylene with a content of 0.01 to 1% by weight of units of at least one perfluoro(alkyl-vinyl) ether is ground to a particle diameter of 10 to 50 &mgr;m and agglomerated in water.
摘要:
The present invention describes a novel process for the preparation of perfluoro allyl ethers. The process involves providing a hydrogen-containing precursor comprising at least one 1,2-dichloro alkyl ether moiety, fluorinating the precursor to provide a perfluorinated intermediate, and dechlorinating the perfluorinated intermediate to the corresponding perfluorinated ether. A reaction product of a perfluorinated olefin and an allyl ether may also be used as a precursor. Such a reaction product is chlorinated before the fluorination step. Perfluoro vinyl or allyl ethers may be used in place of the perfluorinated olefin. Novel perfluoro alkoxy compounds are also described.
摘要:
A multimodal fluoroplastic terpolymer composition is provided. The terpolymer can be extruded at high extrusion speeds without having to reduce its molecular weight. The terpolymer is useful by itself; in combination with conductive fillers to provide an electrostatically dissipative composition; and as a polymer processing aid. The polymer has a low molecular weight component, a high molecular weight component and, optionally an ultra-high molecular weight component.