Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Fluorinated oligomeric ethers

Alkali metal fluorides are, in general, not much used for the ring-opening fluorination of epoxides. However, the oligomerization of trifluoro(trifluoromethyl)oxirane induced by cesium fluoride is of some importance for the preparation of fluorinated polymeric ethers 1. ... [Pg.153]

Grown Ethers. Ethylene oxide forms cycHc oligomers (crown ethers) in the presence of fluorinated Lewis acids such as boron tritiuoride, phosphoms pentafluoride, or antimony pentafluoride. Hydrogen fluoride is the preferred catalyst (47). The presence of BF , PF , or SbF salts of alkah, alkaline earth, or transition metals directs the oligomerization to the cycHc tetramer, 1,4,7,10-tetraoxacyclododecane [294-93-9] (12-crown-4), pentamer, 1,4,7,10,13-pentaoxacyclopentadecane [33100-27-6] (15-crown-6), andhexamer, 1,4,7,10,13,16-hexaoxacyclooctadecane [17455-13-9]... [Pg.453]

Perfluormated oligoethers with the acetylacetonate group at the end of the polymer formed complexes 56 with nickel(I), which catalyzed ethylene oligomerization. The turnover number in the reaction reached 2460 in a perfluorinated ether-toluene two-phase system, and the catalyst, which was in the fluorine-containing phase, was readily separable [169]. [Pg.480]

Polymerization of 7V-vinylcarbazole catalyzed by dimethylglyoxime complexes of different metals immobilized on PVC follows the cationic mechanism. Lewis acids immobilized in a volume of swollen polymer gel catalyze cationic polymerization and oligomerization of vinyl ethers, etc. Cationic complexes of Pd(II) bound to modified PS initiate alternative copolymerization of fluorinated olefins (C F2 +i)(CH2)mCH=CH2 with carbon monoxide [112,113]. The product thus obtained was polyspiroketal rather than polyketone. [Pg.541]

The acid-base Nafion composite membranes include blends of Nafion with polypyrrole (PPy) [98-104], polybenzimidazole (PBI) [105-107], poly (propyleneoxide) (PPO) [108, 109], polyfurfuryl alcohol (PFA) [110], poly(vinyl alcohol) (PVA) [111-115], sulfonated phenol-formaldehyde (sPF) [116], polyvinylidene fluoride (PVdF) [117-122], poly(p-phenylene vinylene) (PPV) [123], poly(vinyl pyrrolidone) (PVP) [124] polyanifine (PANI) [125-128], polyethylene (PE) [129], poly(ethylene-terephtalate) [130], sulfated p-cyclodextrin (sCD) [131], sulfonated poly(ether ether ketone) (sPEEK) [132-135], sulfonated poly(aryl ether ketone) (sPAEK) [136], poly(arylene ether sulfone) (PAES) [137], poly(vinylimidazole) (PVl) [138], poly(vinyl pyridine) (PVPy) [139], poly (tetrafluoroethylene) (PTFE) [140-142], poly(fluorinated ethylene-propylene) [143], sulfonated polyhedral oligomeric silsesquioxane (sPOSS) [144], poly (3,4-ethylenedioxythiophene) (PEDT) [145, 146], polyrotaxanes (PR) [147], purple membrane [148], sulfonated polystyrene (PSSA) [149, 150], polystyrene-b-poly(ethylene-ran-butylene)-bpolystyrene (SEES) [151], poly(2-acrylamido-2-methyl-l-propanesulphonic acid-co-l,6-hexanediol propoxylate diacrylate-co-ethyl methacrylate) (AMPS) [152], and chitosan [31]. A binary PVA/chitosan [153] and a ternary Nafion composite with PVA, polyimide (PI) and 8-trimethoxy silylpropyl glycerin ether-1,3,6-pyrenetrisulfonic acid (TSPS) has also been reported [154]. [Pg.129]

Oligomerization of tetrafluoroethylene provides intermediates for amphoteric fluorinated surfactants. The tetrafluoroethylene pentamer reacts with phenol to form a phenyl ether [96]. Chlorosulfonation of the phenyl ether with chlorosul-fonic acid yields a sulfonyl chloride, which is allowed to react with A dimethyl-propanediamine ... [Pg.60]


See other pages where Fluorinated oligomeric ethers is mentioned: [Pg.311]    [Pg.7]    [Pg.1061]   
See also in sourсe #XX -- [ Pg.640 ]




SEARCH



Ethers fluorinated

© 2024 chempedia.info