| 词条 | Isobutane |
| 释义 |
| Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 443882541 | ImageFileR1 = Isobutane4.png | ImageNameR1 = Skeletal formula of isobutane | Name = | ImageFile = | ImageFileL1 = Isobutane 1.svg | ImageNameL1 = Chemical structure of isobutane with all atoms explicitly shown | ImageFileL2 = Isobutane-3D-balls.png | ImageFileL2_Ref = {{chemboximage|correct|??}} | ImageNameL2 = Ball and stick model of isobutane | ImageFileR2 = isobutane3.png | ImageFileR2_Ref = {{chemboximage|correct|??}} | ImageNameR2 = Spacefill model of isobutane | PIN = 2-methylpropane[1] | SystematicName = | OtherNames = Isobutane (no longer recommended[1]) | IUPACName = | Section1 = {{Chembox Identifiers | CASNo = 75-28-5 | CASNo_Ref = {{cascite|correct|CAS}} | PubChem = 6360 | ChemSpiderID = 6120 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | UNII = BXR49TP611 | UNII_Ref = {{fdacite|correct|FDA}} | EINECS = 200-857-2 | UNNumber = 1969 | KEGG = D04623 | KEGG_Ref = {{keggcite|changed|kegg}} | ChEBI = 30363 | ChEBI_Ref = {{ebicite|correct|EBI}} | RTECS = TZ4300000 | Beilstein = 1730720 | Gmelin = 1301 | SMILES = CC(C)C | StdInChI = 1S/C4H10/c1-4(2)3/h4H,1-3H3 | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = NNPPMTNAJDCUHE-UHFFFAOYSA-N | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} }} | Section2 = {{Chembox Properties | C=4 | H=10 | Appearance = Colorless gas | Odor = Odorless | Density = 2.51 kg/m3 (at 15 °C, 100 kPa) 563 kg/m3 (at 15 °C, boiling liquid) | MeltingPtC = -159.42 | MeltingPt_ref = [2] | BoilingPtC = -11.7 | MagSus = -51.7·10−6 cm3/mol | BoilingPt_ref = [2] | Solubility = 48.9 mg L−1 (at {{convert|25|C}}) [3] | VaporPressure = {{convert|3.1|atm|abbr=on}} (at {{convert|21|C|K F}})[4] | HenryConstant = 8.6 nmol Pa−1 kg−1 | ConjugateAcid = Isobutanium }} | Section3 = {{Chembox Thermochemistry | DeltaHf = −134.8–−133.6 kJ mol−1 | DeltaHc = −2.86959–−2.86841 MJ mol−1 | HeatCapacity = 96.65 J K−1 mol−1 }} | Section4 = {{Chembox Hazards | ExternalSDS = praxair.com | GHSPictograms = {{GHS flame}} | GHSSignalWord = DANGER | HPhrases = {{H-phrases|220}} | PPhrases = {{P-phrases|210}} | NFPA-H = 1 | NFPA-F = 4 | NFPA-R = 0 | FlashPtC = -83 | AutoignitionPtC = 460 | ExploLimits = 1.4–8.3% | IDLH = N.D.[5] | PEL = none[5] | REL = TWA 800 ppm (1900 mg/m3)[5] }} | Section5 = {{Chembox Related | OtherFunction_label = alkane | OtherFunction = Isopentane }} | Section6 = }}Isobutane, also known as i-butane, 2-methylpropane or methylpropane, is a chemical compound with molecular formula HC(CH3)3. It is an isomer of butane. It is the simplest alkane with a tertiary carbon. Isobutane is used as a precursor molecule in the petrochemical industry, for example in the synthesis of isooctane.[6] ProductionIsobutane is obtained by isomerization of butane. UsesIsobutane is the principal feedstock in alkylation units of refineries. Using isobutane, gasoline-grade "blendstocks" are generated with high branching for good combustion characteristics. Typical products from isobutane are 2,4-dimethylpentane and especially 2,2,4-trimethylpentane.[7] SolventIn the Chevron Phillips slurry process for making high-density polyethylene, isobutane is used as a diluent. As the slurried polyethylene is removed, isobutane is "flashed" off, and condensed, and recycled back into the loop reactor for this purpose.[8] Precursor to tert-butyl hydroperoxideIsobutane is oxidized to tert-butyl hydroperoxide, which is subsequently reacted with propylene to yield propylene oxide. The tert-butanol that results as a by-product is typically used to make gasoline additives such as methyl tert-butyl ether (MTBE). Miscellaneous usesIsobutane is also used as a propellant for aerosol cans and foam products. Isobutane is used as part of blended fuels, especially common in fuel canisters used for camping.[9] RefrigerantIsobutane is used as a refrigerant.[10] The use in refrigerators started in 1993 when Greenpeace presented the Greenfreeze project with the German company Foron.[11] In this regard, blends of pure, dry "isobutane" (R-600a) (that is, isobutane mixtures) have negligible ozone depletion potential and very low global warming potential (having a value of 3.3 times the GWP of carbon dioxide) and can serve as a functional replacement for R-12, R-22, R-134a, and other chlorofluorocarbon or hydrofluorocarbon refrigerants in conventional stationary refrigeration and air conditioning systems. As a refrigerant, isobutane poses an explosion risk in addition to the hazards associated with non-flammable CFC refrigerants. Substitution of this refrigerant for motor vehicle air conditioning systems not originally designed for isobutane is widely prohibited or discouraged.[12][13][14][15][16][17][18] Vendors and advocates of hydrocarbon refrigerants argue against such bans on the grounds that there have been very few such incidents relative to the number of vehicle air conditioning systems filled with hydrocarbons.[19][20] NomenclatureThe traditional name isobutane was still retained in the 1993 IUPAC recommendations,[21] but is no longer recommended according to the 2013 recommendations.[1] Since the longest continuous chain in isobutane contains only three carbon atoms, the preferred IUPAC name is 2-methylpropane but the locant (2-) is typically omitted in general nomenclature as redundant; C2 is the only position on a propane chain where a methyl substituent can be located without altering the main chain and forming the constitutional isomer n-butane. References1. ^1 2 {{cite book | title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = The Royal Society of Chemistry | date = 2014 | location = Cambridge | page = 652 | doi = 10.1039/9781849733069-FP001 | isbn = 978-0-85404-182-4 | quote = The names ‘isobutane’, ‘isopentane’ and ‘neopentane’ are no longer recommended.}} 2. ^1 {{GESTIS|ZVG=25040}} 3. ^{{cite web|title=Solubility in Water|url=https://pubchem.ncbi.nlm.nih.gov/compound/isobutane#section=Solubility|website=PubChem|publisher=National Center for Biotechnology Information|accessdate=6 April 2017}} 4. ^{{cite web |title=CDC - NIOSH Pocket Guide to Chemical Hazards - Isobutane |url=https://www.cdc.gov/niosh/npg/npgd0350.html |website=CDC - NIOSH Pocket Guide to Chemical Hazards |publisher=CDC |accessdate=28 December 2018}} 5. ^1 2 {{PGCH|0350}} 6. ^Patent Watch, July 31, 2006. 7. ^{{cite encyclopedia|title=Alkylation|authors=Bipin V. Vora, Joseph A. Kocal, Paul T. Barger, Robert J. Schmidt, James A. Johnson|year=2003|encyclopedia=Kirk‐Othmer Encyclopedia of Chemical Technology|doi=10.1002/0471238961.0112112508011313.a01.pub2}} 8. ^{{Ullmann | title = Polyethylene | author = Kenneth S. Whiteley | doi = 10.1002/14356007.a21_487.pub2}} 9. ^{{cite web|url=http://www.backpackinglight.com/cgi-bin/backpackinglight/canister_stove_faq |title=Frequently Asked Questions About Lightweight Canister Stoves and Fuels |first=Will |last=Rietveld |publisher=Backpacking Light |date=2005-02-08 |accessdate=2014-07-26}} 10. ^{{cite web |url=http://ec.europa.eu/environment/ozone/pdf/hcfc_technical_meeting_summary.pdf |title=European Commission on retrofit refrigerants for stationary applications |format=PDF |date= |accessdate=2010-10-29 |deadurl=yes |archiveurl=https://web.archive.org/web/20090805150605/http://ec.europa.eu/environment/ozone/pdf/hcfc_technical_meeting_summary.pdf |archivedate=2009-08-05 |df= }} 11. ^{{cite web|author=Page - March 15, 2010 |url=http://www.greenpeace.org/usa/en/campaigns/global-warming-and-energy/green-solutions/greenfreeze/ |title=GreenFreeze |publisher=Greenpeace |date=2010-03-15 |accessdate=2013-01-02}} 12. ^{{cite web|url=http://www.epa.gov/ozone/snap/refrigerants/hc12alng.html |title=U.S. EPA hydrocarbon-refrigerants FAQ |publisher=Epa.gov |date= |accessdate=2010-10-29}} 13. ^Compendium of hydrocarbon-refrigerant policy statements, October 2006 14. ^{{cite web |url=http://www.autoacforum.com/MACS/HCwarning.pdf |title=MACS bulletin: hydrocarbon refrigerant usage in vehicles |format=PDF |date= |accessdate=2010-10-29 |deadurl=yes |archiveurl=https://web.archive.org/web/20110105174944/http://www.autoacforum.com/MACS/HCwarning.pdf |archivedate=2011-01-05 |df= }} 15. ^{{cite web|url=http://www.sae.org/news/releases/05hydrocarbon_warning.htm |title=Society of Automotive Engineers hydrocarbon refrigerant bulletin |publisher=Sae.org |date=2005-04-27 |accessdate=2010-10-29}} 16. ^{{cite web |url=http://www.labour.gov.sk.ca/Default.aspx?DN=2fb5ac24-d90e-4408-bf40-559793bd8e96 |title=Saskatchewan Labour bulletin on hydrocarbon refrigerants in vehicles |publisher=Labour.gov.sk.ca |date=2010-06-29 |accessdate=2010-10-29 |deadurl=yes |archiveurl=https://web.archive.org/web/20090701025850/http://www.labour.gov.sk.ca/Default.aspx?DN=2fb5ac24-d90e-4408-bf40-559793bd8e96 |archivedate=2009-07-01 |df= }} 17. ^VASA on refrigerant legality & advisability {{webarchive|url=https://web.archive.org/web/20090113163519/http://www.vasa.org.au/content/refriggas/index.php#Bookmark |date=January 13, 2009 }} 18. ^{{cite web|url=http://www.energy.qld.gov.au/zone_files/petroleum_pdf/safety_alert025.pdf |title=Queensland (Australia) government warning on hydrocarbon refrigerants |publisher=Energy.qld.gov.au |date= |accessdate=2010-10-29 |deadurl=yes |archiveurl=https://web.archive.org/web/20081217150006/http://www.energy.qld.gov.au/zone_files/petroleum_pdf/safety_alert025.pdf |archivedate=2008-12-17 |df= }} 19. ^{{cite web |url=http://www.parliament.nsw.gov.au/prod/parlment/HansArt.nsf/V3Key/LA19971016015 |title=New South Wales (Australia) Parliamentary record, 16 October 1997 |publisher=Parliament.nsw.gov.au |date=1997-10-16 |accessdate=2010-10-29 |deadurl=yes |archiveurl=https://web.archive.org/web/20090701025536/http://www.parliament.nsw.gov.au/prod/parlment/HansArt.nsf/V3Key/LA19971016015 |archivedate=1 July 2009 |df= }} 20. ^{{cite web |url=http://www.parliament.nsw.gov.au/prod/parlment/hansart.nsf/V3Key/LC20000629051 |title=New South Wales (Australia) Parliamentary record, 29 June 2000 |publisher=Parliament.nsw.gov.au |date= |accessdate=2010-10-29 |deadurl=yes |archiveurl=https://web.archive.org/web/20050522080708/http://www.parliament.nsw.gov.au/prod/parlment/hansart.nsf/V3Key/LC20000629051 |archivedate=22 May 2005 |df= }} 21. ^{{cite book | author=Panico, R.; & Powell, W. H. (Eds.) | title=A Guide to IUPAC Nomenclature of Organic Compounds 1993 | location=Oxford | publisher=Blackwell Science | year=1994 | isbn=0-632-03488-2}} http://www.acdlabs.com/iupac/nomenclature/93/r93_679.htm External links
4 : Alkanes|Refrigerants|Propellants|E-number additives |
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