摘要:
Aqueous dispersions of fluoropolymers which are obtained by emulsion polymerization, are not processsable from the melt and form a film on sintering, which comprise a fluoropolymer A) having an average particle size (number average) of from 180 to 400 nm and a fluoropolymer B) having an average particle size which is lower by a factor of from about 0.3 to about 0.7, so that the total dispersion has a non-monomadal number distribution of the particle diameter, are suitable for soaking, impregnating or coating surfaces, for example of fibers or planiform articles of fibers or porous materials, in particular for coating fiberglass fabrics, and also for the formulation of metal coating systems.
摘要:
Polymerizing tetrafluoroethylene with modifying amounts of a perfluoro(alkyl vinyl ether) at temperatures below 60.degree. C. using permanganate or similar initiators by the suspension process and milling the raw polymer to an average particle size of from 10 to 50 .mu.m gives molding powders which are suitable for the preform free-sintering technique.
摘要:
A transparent thermoplastic molding compound consisting of 40 to 90% by weight of units derived from tetrafluoroethylene, and 60 to 10% by weight of units derived from compounds of formula I or II:CF.sub.2 .dbd.CF--O--(CF.sub.2 --CF(CF.sub.3)--O).sub.m --(CF.sub.2).sub.n --CF.sub.3 (I)CF.sub.2 .dbd.CF--O--(CF.sub.2 --CF(CF.sub.3)--O).sub.p --(CF.sub.2).sub.q --COO--R (II)is particularly suitable for manufacturing the sheath of beam waveguides whose core has a higher transparency than polymethyl methacrylate.
摘要:
Process for the preparation of fluorinated carboxylic acid fluoridesFluorinated carboxylic acid fluorides of the Formula I ##STR1## can be prepared from fluorinated vinyl ethers of the Formula II ##STR2## by heating the vinyl ethers to a temperature of 100.degree. to 350.degree. C.Perfluorinated carboxylic acids and derivatives thereof can be prepared from the carboxylic acid fluorides by secondary reactions, for example hydrolysis, esterification or aminolysis.
摘要:
Described herein is a polymerizable composition substantially free of an organic emulsifier, methods of making, and articles thereof. The polymerizable composition comprises: a continuous phase; a polymerizable monomer; an initiator; and inorganic nanoparticles, wherein the inorganic nanoparticles are substantially free of groups that will copolymerize with the polymerizable monomer.
摘要:
Provided are methods of bonding a fluoroelastomer to a metal substrate; fluoropolymer compounds comprising a fluoroelastomer, a curing agent and a bonding promoter; and composite materials obtained by curing the compound. Further provided is the use of bonding promoters for increasing the bond strength between a fluoroelastomer and a metal substrate.
摘要:
Described herein is a composition comprising an aqueous polymerization reaction product of fluorinated monomers and wherein the polymerization is initiated (i) in the absence of a fluorinated emulsifier and whereby no fluorinated emulsifier is added during polymerization or (ii) in the presence of an fluorinated emulsifier selected from: [Rf—O-L-COO-]i Xi+ (I) wherein L represents a linear or branched, non-fluorinated, partially fluorinated, or fully fluorinated alkylene group, Rf represents a linear or branched partially or fully fluorinated aliphatic group or a linear or branched partially or fully fluorinated aliphatic group interrupted with at least one oxygen atom, Xi+ represents a cation having the valence i and i is 1, 2 or 3; wherein the reaction product and/or the resulting aqueous phase are substantially free of di- and tri-alkylamines and substantially free of low molecular weight fluoroorganic compounds and methods thereof.
摘要翻译:本文描述的是包含氟化单体的水性聚合反应产物的组合物,其中聚合反应开始于(i)在不存在氟化乳化剂的情况下,并且由此在聚合过程中不加入氟化乳化剂,或(ii)在氟化乳化剂存在下 选自:[Rf-OL-COO-] i Xi +(I)其中L表示直链或支链,非氟化,部分氟化或完全氟化的亚烷基,Rf表示直链或支链部分或完全氟化的脂族基团或 间隔有至少一个氧原子的直链或支链部分或完全氟化的脂肪族基团,X i +表示i为i且i为1,2或3的阳离子; 其中所述反应产物和/或所得水相基本上不含二烷基胺和三烷基胺,并且基本上不含低分子量氟代有机化合物及其方法。
摘要:
A process is described of pyrolyzing at least one perfluorinated hydrocarbon, or a material containing at least one perfluorinated hydrocarbon, in the presence of hydrogen, to yield a reaction mixture containing difluorocarbene.
摘要:
Compounds represented by formula (Rf-Q-X)s—Z. Each Rf is independently a partially fluorinated or fully fluorinated group selected from Rfa-(O)r—CHF—(CF2)n—; [Rfb-(O)tC(L)H—CF2—O]m—W—; CF3CFH—O—(CF2)p—; CF3—(O—CF2)z—; and CF3—O—(CF2)3—O—CF2—. Methods of reducing surface tension of a liquid, making foams, and treating a surface using the compounds are also disclosed.
摘要:
There is provided a fluoroelastomer characterized by containing one type or more types of fluorinated emulsifiers represented by the formula: F—(CF2)t-[O(CF2)n]m-O—(CHF)o-(CF2)p-X where m=0 to 3; n=1 to 5; o=0 to 1; p=1 to 3; t=1 to 10; and where when t=2 than o≠0; and further where X is selected from a group consisting of a carboxyl acid group and a salt of a carboxylic acid group. A method for preparing fluoroelastomers by using such fluorinated emulsifiers in emulsion polymerization of fluoromonomers and articles containing such fluoroelastomers are also provided. A fluorinated elastomer dispersion including an aqueous mixture of a crosslinkable fluorinated elastomer and such fluorinated emulsifiers are also provided. The fluoroelastomers created with such fluorinated emulsifiers are essentially free of cations other than NH4+ and H+ and have a low glass transition temperature.
摘要翻译:提供一种含氟弹性体,其特征在于含有一种或多种由式F-(CF 2)t- [O(CF 2)n] m O - (CHF)o - (CF 2)p X表示的氟化乳化剂,其中m = 0 到3; n = 1〜5; o = 0至1; p = 1〜3; t = 1〜10; 并且当t = 2时,o <0; 并且进一步其中X选自羧酸基团和羧酸基团的盐。 还提供了通过使用这种氟化乳化剂在含氟单体和含有这些含氟弹性体的制品的乳液聚合中制备含氟弹性体的方法。 还提供了包含可交联氟化弹性体和这种氟化乳化剂的水性混合物的含氟弹性体分散体。 用这种氟化乳化剂生产的含氟弹性体基本上不含NH 4+和H +以外的阳离子,并具有低的玻璃化转变温度。