摘要:
Sulphonic fluorinated ionomers crosslinked by radical crosslinking of: A) crosslinkable sulphonic fluorinated ionomers, having equivalent weight 380-1300 g/eq and comprising: from 48% to 85% by moles of monomeric units deriving from tetrafluoroethylene (TFE); from 15% to 47% by moles of fluorinated monomeric units containing sulphonyl groups —SO2F; from 0.01% to 5% by moles of monomeric units deriving from a bis-olefin of formula: wherein: m=2-10, preferably 4-8; R1, R2, R5, R6, equal to or different from each other, are H or C1-C5 alkyl groups; B) a fluorinated compound as crosslinking radical initiator; C) a fluorinated bis-olefin of structure (I) as crosslinking agent; the radical crosslinking being carried out at a temperature in the range 250° C.-310° C., preferaably 260° C.-300° C.
摘要:
Amorphous perfluorinated copolymers, comprising cyclic perfluorinated units deriving from at least two different perfluorinated comonomers, optionally with units deriving from a perfluorinated monomer containing at least one olefinic unsaturation (perfluoroolefin), or comprising cyclic perfluorinated units and units deriving from a perfluorinated monomer containing at least one olefinic unsaturation, said perfluorinated copolymers having the following combination of properties: substantial absence of unstable polar end groups, polymer Tg higher than 120° C., narrow monomeric composition distribution.
摘要:
A process for obtaining (per) fluoropolyethers substituted at one or at both end groups with a halogen atom selected from bromine or iodine, having the formula: A—CF2—O—(CF2CF2O)p—(CF2O)q—CF2—B (III) wherein A=B=halogen; or A=halogen and B=COOH or F, and the halogen is I or Br; p and q are integers such as to give a number average molecular weight (MW) in the range 350-5000 and the ratio p/q=0.5-2.0. The process includes treating di- or poly-acylperoxides having an average equivalent weight in the range 350-5000, of formula: T—CF2—O—[(CF2CF2O)p—(CF2O)q—CF2—CO—O—O——CO—CF2—(OCF2)q—(OCF2CF2)p]y—OCF2—COOH (II) with a halogen selected from iodine or bromine, in a polyhalogenated organic solvent, at temperatures between 20° and 80° C.
摘要:
Perfluoroether acylperoxides having an average equivalent weight in the range of 350-5000, and of the following formulae: Y′—(CF2—CF(CF3)O)m—(CX′FO)n—CF2CO—O—O—CO—CF2—(OCX′F)n—(OCF(CF3)—CF2)—Y′ (I) wherein Y′=Cl, ORf wherein Rf is a C1-C3 perfluoroalkyl; m, n are integers such that the average equivalent weight of (I) is in the range of 350-5000 and m/n≧40; X′=F, CF3; T—CF2—O—[(CF2CF2O)p—(CF2O)q—CF2—CO—O—O—CO—CF2(OCF2)q—(OCF2CF2)p]y—OCF2—COOH (II) wherein y is an integer comprised between 1 and 5; p and q are integers such as to give the above mentioned EW and p/q=0.5 to 2.0; T=COOH, F with the proviso that when T=COOH y=1-5, when T=F then y=1, and processes for manufacturing them.
摘要:
New fluoroelastomers are described, having iodine atoms in terminal position and monomeric units in the chain deriving from an iodinated olefin of formula:CHR.dbd.CH--Z--CH.sub.2 CHR--I (I)wherein: R is --H or --CH.sub.3 ; Z is a (per)fluoroalkylene radical C.sub.1 -C.sub.18, linear or branched, optionally containing one or more ether oxygen atoms, or a (per)fluoropolyoxyalkylene radical.These products, upon peroxide curing, require extremely short post-curing treatments (around 30-60 minutes at 180.degree.-230.degree. C.) and are characterized by compression set values lower than 25% (measured on O-rings at 200.degree. C. for 70 hours according to ASTM Standard D395 Method B).
摘要:
Fluorinated thermoplastic elastomers comprising monomeric units deriving from a bis-olefin having general formula: ##STR1## wherein: R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, equal or different from each other, are H or alkyls C.sub.1 -C.sub.5 ; Z is an alkylene or cycloalkylene radical C.sub.1 -C.sub.18, linear or branched, optionally containing oxygen atoms, preferably at least partially fluorinated, or a (per)fluoropolyoxyalkylene radical.
摘要:
Fluorinated thermoplastic elastomers comprising monomeric units deriving from at least an iodinated olefin of formula:CX.sub.2 .dbd.CX--R.sub.f --CHR--I (I)wherein:X is --H, --F, or --CH.sub.3 ; R is --H or --CH.sub.3 ; R.sub.f is a (per) fluoroalkylene radical, linear or branched, optionally containing one or more ether oxygen atoms, or a (per) fluoropolyoxyalkylene radical.
摘要:
The present invention relates to the synthesis of new terminal olefins, perfluoro 2,4-dimethyl 3-ethylpentene and perfluoro 2-isopropyl 3,3-dimethylbutene, and to the subsequent fluorination thereof in order to obtain highly branched perfluoroalkanes, capable of providing perfluoroalkyl radicals, which are utilizable as initiators for the polymerization of ethylenically unsaturated monomers.
摘要:
The present invention relates to new perfluoroalkyl halides and to their preparation by a process based on the thermodecomposition of perfluorocarbides in the presence of Cl.sub.2, Br.sub.2 and I.sub.2.
摘要:
This invention relates to perfluoro-2,3,4-trimethylpentane of formula (I): ##STR1## and to its use as an indicator fluid in the method NID for carrying out the Gross leak test.