1,1,1,2-Tetrafluoroethane
| 1,1,1,2-Tetrafluoroethane | |
|---|---|
 |
 |
|
1,1,1,2-Tetrafluoroethane |
|
|
Other names
Dymel 134a |
|
| Identifiers | |
| CAS number | 811-97-2  |
| ChemSpider | 12577 |
| UNII | DH9E53K1Y8 |
| EC number | 212-377-0 |
| KEGG | D05208 |
| RTECS number | KI8842500 |
| Jmol-3D images | Image 1 |
|
|
|
|
| Properties | |
| Molecular formula | CH2FCF3 [1] |
| Molar mass | 102.03 g/mol |
| Appearance | Colorless gas |
| Density | 0.00425 g/cm³, gas |
| Melting point |
-103.3°C (169.85 K) |
| Boiling point |
-26.3°C (246.85 K) |
| Solubility in water | 0.15 wt% |
| Hazards | |
| MSDS | External MSDS |
| S-phrases | (S2), S23, S24/25, S51 |
| Main hazards | Asphyxiant |
| NFPA 704 |
 0
1
1
|
| Flash point | 250 °C (482 °F) |
| Related compounds | |
| Related refrigerants | Difluoromethane Pentafluoroethane |
| Related compounds | 1,1,2,2,2-pentafluoroethane 2-Chloro- 1,1,1,2-tetrafluoroethane 1,1,1-Trichloroethane |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
|
| Infobox references | |
1,1,1,2-Tetrafluoroethane, R-134a, Genetron 134a, Suva 134a or HFC-134a, is a haloalkane refrigerant with thermodynamic properties similar to R-12 (dichlorodifluoromethane), but with less ozone depletion potential. It has the formula CH2FCF3, and a boiling point of −26.3 °C (−15.34 °F) at atmospheric pressure.
Contents |
[edit] Uses
1,1,1,2-Tetrafluoroethane is an inert gas used primarily as a “high-temperature” refrigerant for domestic refrigeration and automobile air conditioners. These devices began using 1,1,1,2-tetrafluoroethane in the early 1990s as a replacement for the more environmentally harmful R-12, and retrofit kits are available to convert units that were originally R-12-equipped. Other uses include plastic foam blowing, as a cleaning solvent, a propellant for the delivery of pharmaceuticals (e.g. bronchodilators), wine cork removers, gas dusters, and in air driers for removing the moisture from compressed air. 1,1,1,2-Tetrafluoroethane has also been used to cool computers in some overclocking attempts. It is also commonly used as a propellant for airsoft airguns.
Recently, 1,1,1,2-tetrafluoroethane has been subject to use restrictions due to its contribution to climate change. In the EU, it will be banned as of 2011 in all new cars.[2] The Society of Automotive Engineers (SAE) has proposed 1,1,1,2-tetrafluoroethane (HFC-134a) to be best replaced by a new fluorochemical refrigerant HFO-1234yf (CF3CF=CH2) in automobile air-conditioning systems.[3] California may also prohibit the sale of canned 1,1,1,2-tetrafluoroethane to individuals to avoid non-professional recharge of air conditioners.[4] A ban has been in place in Wisconsin since October 1994 under ATCP 136 prohibiting sales of container sizes holding less than 15 lbs of 1,1,1,2-tetrafluoroethane, but this restriction applies only when the chemical is intended to be a refrigerant.[5] It appears, for example, that it is legal for a person to purchase gas duster containers with any amount of the chemical because in that instance the chemical is neither intended to be a refrigerant [5] nor is HFC-134a included in the § 7671a listing of class I and class II substances.[6]
1,1,1,2-tetrafluoroethane is also being considered as an organic solvent suitable for extraction of flavor and fragrance compounds, as a possible alternative to other organic solvents and supercritical carbon dioxide.[7][8] It can also be used as a solvent in organic chemistry, both in liquid and supercritical fluid.[9] It is used in the resistive plate chamber particle detectors in the Large Hadron Collider.[10][11] It is also used for other types of particle detectors, e.g. some cryogenic particle detectors.[12] It can be used as an alternative to sulfur hexafluoride in magnesium smelting as a shielding gas.[13]
1,1,1,2-tetrafluoroethane is also being considered as an alternative to sulfur hexafluoride as a dielectric gas.[14] Its arc-quenching properties are poor, but its dielectric properties are fairly good.
[edit] History
1,1,1,2-Tetrafluoroethane first appeared in the early 1990s as a replacement for dichlorodifluoromethane (R-12), which has ozone depleting properties.[15] 1,1,1,2-Tetrafluoroethane has been atmospherically modeled for its impact on depleting ozone and as a contributor to global warming. Research suggests that over the past 10 years the concentration of 1,1,1,2-tetrafluoroethane has increased significantly in the Earth's atmosphere, with a recent study revealing a doubling in atmospheric concentration between 2001 and 2004.[16] It has insignificant ozone depletion potential (ozone layer), significant global warming potential (100-yr GWP = 1430)[17] and negligible acidification potential (acid rain).
[edit] Safety
Contact of 1,1,1,2-tetrafluoroethane with flames or hot surfaces in excess of 250 °C (482 °F) may cause vapor decomposition and the emission of toxic gases including hydrogen fluoride and carbonyl halides.[18] 1,1,1,2-Tetrafluoroethane itself has an LD50 (lethal concentration for 50% of subjects) in rats of 1,500 g/m³, making it relatively non-toxic, apart from the dangers inherent to inhalant abuse.
Aerosol cans containing 1,1,1,2-tetrafluoroethane, when inverted, become effective freeze sprays. Under pressure, 1,1,1,2-tetrafluoroethane is compressed into a liquid, which upon vaporization absorbs a significant amount of thermal energy. As a result, it will greatly lower the temperature of any object it contacts as it evaporates. This can result in frostbite when it contacts skin, as well as blindness upon eye contact.
[edit] See also
- List of refrigerants
- Dichlorodifluoromethane
- 1,1,1,2-Tetrafluoroethane (data page)
- Tetrabromoethane
- Tetrachloroethane
[edit] References
- ^ Global Warming Potentials of ODS Substitutes | Ozone Layer Protection | US EPA. Epa.gov (2006-06-28). Retrieved on 2011-08-21.
- ^ European Directive 2006/40/EC relating to emissions from air-conditioning systems in motor vehicles. (PDF) . Retrieved on 2011-08-21.
- ^ HFO-1234yf A Low GWP Refrigerant For MAC. Refrigerants.dupont.com (2011-08-17). Retrieved on 2011-08-21.
- ^ California restricts use of HFC-134a in cars. 27 June 2007. R744.com. Retrieved on 2011-08-21.
- ^ a b Chapter ATCP 136. MOBILE AIR CONDITIONERS; RECLAIMING OR RECYCLING REFRIGERANT. State.wi.us. (PDF) . Retrieved on 2011-08-21.
- ^ Class I Ozone-depleting Substances. EPA.gov. Retrieved on 2011-08-21.
- ^ Corr, Stuart (2005). "1,1,1,2-Tetrafluoroethane (R-134a): A Selective Solvent for the Generation of Flavor and Fragrance Ingredients". Natural Flavors and Fragrances. ACS Symposium Series. 908. pp. 41. doi:10.1021/bk-2005-0908.ch003. ISBN 0-8412-3904-5.
- ^ Abbott, Andrew P.; Eltringham, Wayne; Hope, Eric G.; Nicola, Mazin (2005). "Solubility of unsaturated carboxylic acids in supercritical 1,1,1,2-tetrafluoroethane (HFC 134a) and a methodology for the separation of ternary mixtures". Green Chemistry 7 (4): 210. doi:10.1039/B412697A.
- ^ Abbott, Andrew P.; Eltringham, Wayne; Hope, Eric G.; Nicola, Mazin (2005). "Hydrogenation in supercritical 1,1,1,2 tetrafluoroethane (HFC 134a)". Green Chemistry 7 (10): 721. doi:10.1039/B507554H.
- ^ Anushree Ghosh STUDY OF GLASS RESISTIVE PLATE CHAMBERS (RPC) AND CALCULATION OF EFFICIENCY. INO Graduate Training Programme DHEP, TIFR, Mumbai.
- ^ M. Capeans, I. Glushkov, R. Guida, F. Hahn, S. Haider (CERN, Switzerland) RPC operation at the LHC experiments in an optimized closed loop gas system. Medical Imaging Conference. 25–31 October 2009.
- ^ Norbeck, E.; Olson, J. E.; Moeller, A.; Onel, Y. (2006). "Rad Hard Active Media For Calorimeters". AIP Conference Proceedings. 867. pp. 84. Bibcode 2006AIPC..867...84N. doi:10.1063/1.2396941. http://highenergy.physics.uiowa.edu/HEP/Files/Talks/RadHardPaper.pdf.
- ^ Magnesium recycling in the United States in 1998. (PDF) . USGS. Retrieved on 2011-08-21.
- ^ Gaseous dielectrics with low global warming potentials – US Patent Application 20080135817 Description. Patentstorm.us (2006-12-12). Retrieved on 2011-08-21.
- ^ Franklin J (1993). "The Atmospheric Degradation and Impact of 1,1,1,2-Tetrafluorethane (Hydrofluorocarbon 134a)". Chemosphere 27 (8): 1565–1601. doi:10.1016/0045-6535(93)90251-Y.
- ^ "Greenhouse gas monitoring at the Zeppelin station – Annual report 2004 (TA-2110/2005)". Norwegian Institute for Air Research. http://www.r744.com/news/files/NILU-%20exec%20summary%20of%20annual%20report%202004.pdf. Retrieved 2006-01-19.
- ^ Forster, P. et al. (2007). "Changes in Atmospheric Constituents and in Radiative Forcing.". Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf.
- ^ Honeywell International (December 2005). MSDS # GTRN-0047 For Genetron 134aUV.
[edit] External links
 |
Wikimedia Commons has media related to: Tetrafluoroethane |
- International Chemical Safety Card 1281
- Information about HFCs, European Fluorocarbons Technical Committee (EFCTC)
- MSDS at Oxford University
- Concise International Chemical Assessment Document 11, at inchem.org
- Pressure temperature calculator
- The Coexisting Curve of the Refrigerant HFC 134a: Some Scaling Models
- R134a 2 phase computer cooling
