Propylene carbonate

Propylene carbonate[1][2]
Names
IUPAC name
4-Methyl-1,3-dioxolan-2-one
Other names
(R,S)-4-Methyl-1,3-dioxolan-2-one
Cyclic propylene carbonate
Carbonic acid propylene ester
Cyclic 1,2-propylene carbonate
Propylene glycol cyclic carbonate
1,2-Propanediol carbonate
4-Methyl-2-oxo-1,3-dioxolane
Arconate 5000
Texacar PC
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.003.248
UNII
Properties
C4H6O3
Molar mass 102.09 g·mol−1
Appearance Colorless liquid
Density 1.205 g/cm3
Melting point −48.8 °C (−55.8 °F; 224.3 K)
Boiling point 242 °C (468 °F; 515 K)
Very soluble (240 g/L at 20°C)
1.4189
Hazards
Main hazards Xi
Safety data sheet MSDS by Mallinckrodt Baker
R-phrases (outdated) R36
S-phrases (outdated) S26 S36
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
1
1
1
Flash point 132 °C (270 °F; 405 K)
455 °C (851 °F; 728 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

Propylene carbonate (often abbreviated PC) is an organic compound with the formula CH3C2H3O2CO. It is a carbonate ester derived from propylene glycol.[3] This colorless and odorless liquid is useful as a polar, aprotic solvent.[4] Propylene carbonate is chiral but is used exclusively as the racemic mixture.

Preparation

Although many organic carbonates are produced using phosgene, propylene and ethylene carbonates are exceptions. They are mainly prepared by the carbonation of the epoxides[4] (epoxypropane, or propylene oxide here):

CH3CHCH2O + CO2 → CH3C2H3O2CO

The process is particularly attractive since the production of these epoxides consumes carbon dioxide. Thus this reaction is a good example of a green process. The corresponding reaction of 1,2-propanediol with phosgene is complex, yielding not only propylene carbonate but also oligomeric products.

Applications

As a solvent

Propylene carbonate is used as a polar, aprotic solvent.[5] It has a high molecular dipole moment (4.9 D), considerably higher than those of acetone (2.91 D) and ethyl acetate (1.78 D).[1] It is possible, for example, to obtain potassium, sodium, and other alkali metals by electrolysis of their chlorides and other salts dissolved in propylene carbonate.[6]

Due to its high dielectric constant of 64, it is frequently used as a high-permittivity component of electrolytes in lithium batteries, usually together with a low-viscosity solvent (e.g. dimethoxyethane). Its high polarity allows it to create an effective solvation shell around lithium ions, thereby creating a conductive electrolyte. However, it is not used in lithium-ion batteries due to its destructive effect on graphite.[7]

Propylene carbonate can also be found in some adhesives, paint strippers, and in cosmetics.[8] It is also used as plasticizer. Propylene carbonate is also used as a solvent for removal of CO2 from natural gas and synthesis gas where H2S is not also present. This use was developed by El Paso Natural Gas Company and Fluor Corporation in the 1950s.[9]

Other

Propylene carbonate product may be converted to other carbonate esters by transesterification as well (see Carbonate ester#Carbonate transesterification).[4]

In electrospray ionization mass spectrometry, propylene carbonate is doped into low surface tension solutions to increase analyte charging.[10]

Safety

Clinical studies indicate that propylene carbonate does not cause skin irritation or sensitization when used in cosmetic preparations, whereas moderate skin irritation is observed when used undiluted. No significant toxic effects were observed in rats fed propylene carbonate, exposed to the vapor, or exposed to the undiluted liquid.[11] In the US, propylene carbonate is not regulated as a volatile organic compound (VOC) because it does not contribute significantly to the formation of smog and because its vapor is not known or suspected to cause cancer or other toxic effects.[12]

See also

References

  1. 1 2 Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. ISBN 1439855110.
  2. ↑ Propylene carbonate at Sigma-Aldrich
  3. ↑ WebBook page for propylene carbonate
  4. 1 2 3 Hans-Josef Buysch (2005), "Carbonic Esters", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a05_197
  5. ↑ Dieter Stoye (2005), "Solvents", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a24_437
  6. ↑ J. Jorné; C. W. Tobias (1975). "Electrodeposition of the alkali metals from propylene carbonate". J. Appl. Electrochem. 5 (4): 279–290. doi:10.1007/BF00608791.
  7. ↑ Doron Aurbach (1999). Nonaqueous Electrochemistry. CRC Press. ISBN 978-0824773342.
  8. ↑ Record in the Household Products Database of NLM
  9. ↑ Schendel, R. "Comparison of Fluor Solvent and Selexol Processes" (PDF). Retrieved 4 April 2016.
  10. ↑ Teo CA, Donald WA (May 2014). "Solution additives for supercharging proteins beyond the theoretical maximum proton-transfer limit in electrospray ionization mass spectrometry". Anal. Chem. 86 (9): 4455–62. PMID 24712886. doi:10.1021/ac500304r.
  11. ↑ "Environmental Profile for Propylene Carbonate". U.S. Environmental Protection Agency. 1998.
  12. ↑ Johnson, William L. "REVISION TO DEFINITION OF VOLATILE ORGANIC COMPOUNDS - EXCLUSION OF PROPYLENE CARBONATE AND DIMETHYL CARBONATE". US Environmental Protection Agency. US EPA. Retrieved 11 July 2015.
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