Fluorochemical acid

Several excellent review articles (28—31) cover the chemistry of the acid and its derivatives in great detail. Trifluoromethanesulfonic acid is available from the 3M Co. as Fluorochemical Acid FC-24 the lithium salt is available as Fluorochemical Specialties FC-122, FC-123, and FC-124 (32). 

Trifluoromethaiiesulfonic acid, CFjSO. tH. Mol. wt. 150.09. Suppliers Fluka, WBL. Trifluoromethanesulfonic acid is available from the 3M Company under the name Fluorochemical acid FC-24. It is the strongest known acid and fumes upon exposure to air. Great care must be exercised in handling this acid. 

FLUORAD Fluorochemical Acid Salt FC-124 is the lithium salt of trlfluoromethane sulfonic salt. It is a white powder developed for use as a battery electrolyte. 

Fluorine and its compounds are used in producing uranium (from the hexafluoride) and more than 100 commercial fluorochemicals, including many well known high-temperature plastics. Hydrofluoric acid etches the glass of light bulbs, etc. Fluorochlorohydrocarbons are extensively used in air conditioning and refrigeration. 

Health and Safety Factors. Completely fluorinated alkanes are essentially nontoxic (16). Rats exposed for four hours to 80% perfluorocyclobutane and 20% oxygen showed only slight effects on respiration, but no pathological changes in organs. However, some fluorochemicals, especially functionalized derivatives and fluoroolefins, can be lethal. Monofluoroacetic acid and perfluoroisobutylene [382-21-8] are notoriously toxic (16). 

Quarpel is an important combination of fluorochemical finish and resin-based extender developed by the U.S. Army Natick Laboratories for military use. This finish typicaUy contains 4—6 wt % commercial fluorochemical emulsion, 4—6 wt % resin-based repeUent emulsion, 0.1 wt % acetic acid, and 5 wt % isopropyl alcohol. If necessary, the formulation includes a catalyst to cross-link the resin-based component. Quarpel specifications demand exceUent initial water and oU repeUency and exceUent durabUity to washing and dry cleaning. 

Resin-based repeUents may be used alone or in combination with durable-press resins. They are widely used as extenders for fluorochemical repeUents. When used alone, several of the resin-based finishes require an acid catalyst and curing at temperatures above 150°C for maximum repeUency and durabUity. When coappUed with durable-press finishes, which themselves require a magnesium chloride catalyst, the catalyst and curing conditions for the durable-press finish provide the necessary conditions for the repeUent. 

As a leader in fluorine technology, Honeywell Chemicals is committed to safety, customer satisfaction, the development of new technology, and the manufacture and supply of fluorochemicals worldwide. We are proud to be the world s largest producer of hydrofluoric acid and sulfur hexafluoride supplying customers globally. 

Additions of halogen fluorides to the more electrophilic peifluonnated olefins generally require different conditions Reactions of iodine fluoride, generated in situ from iodine and iodine pentafluonde [62 102 103, 705] or iodine, hydrogen fluoride, and parapenodic acid [104], with fluorinated olefins (equations 8-10) are especially well studied because the perfluoroalkyl iodide products are useful precursors of surfactants and other fluorochemicals Somewhat higher temperatures are required compared with reactions with hydrocarbon olefins Additions of bromine fluoride, from bromine and bromine trifluonde, to perfluormated olefins are also known [106]... 

Commonly used repeUents for leather are sUicones, chrome complexes of long chain fatty acids, and fluorochemicals. Fluorochemical repeUents also provide repeUency to oUs and greases so that the treated leather resists staining. A water repeUent may also be a hydrophobic chemical insolubUized in the leather. A simple water-repeUent treatment consists of forming an aluminum soap in leather by the two-step process of applying a soap, and then an aluminum salt. 

The worldwide consumption of fluorine can be adduced from the consumption of fluorspar, since the contribution from the possible second fluorine source, hexafluorosilicic acid, which is a byproduct in the production of pho.sphate-containing fertilizers, has been minor up to now. Starting materials for the manufacture of industrial fluorochemicals are ... 

The hexafluorosilicic acid solutions produced as a byproduct in the production of phosphoric acid by the digestion of apatite [Ca (P04)2 Cap2 with 2-4% fluorine content, byproduct silicon dioxide] with sulfuric acid are important raw materials for the manufacture of fluorochemicals (e.g. manufacture of sodium fluoride NaF). The reserves of available fluorine from fluorapatite are estimated to be 327 10 t Cap2 (of which 32 10 t is in the USA), the fluorine quantities available in fluorapatite being therefore considerably greater than the fluorspar reserves. However, the industrial exploitation is still negligible. The reasons therefor are that ... 

Hydrofluoric acid is the most basic common precursor of most fluorochemicals. Aqueous hydrofluoric acid is prepared by reaction of sulfuric acid with fluorspar (CaF2). Because HF etches glass with formation of silicon tetrafluoride, it must be handled in platinum, lead, copper. Monel (a Cu-Ni alloy developed during the Manhattan Project), or plastic (e.g. polyethylene or PTFE) apparatus. The azeotrope contains 38 % w/w HF and it is a relatively weak acid (pfC 3.18, 8 % dissociation), comparable with formic acid. Other physicochemical properties of hydrofluoric acid are listed in Table 1.2. 

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