Glycolic acid
2351041
217799152
2008-06-07T19:00:37Z
74.73.39.250
[[WP:UNDO|Undid]] revision 217798786 by [[Special:Contributions/67.175.54.65|67.175.54.65]] ([[User talk:67.175.54.65|talk]])
{{Chembox new
| Name = Glycolic acid
| ImageFileL1 = glycolic acid.svg
| ImageSizeL1 = 120px
| ImageNameL1 = Chemical structure of glycolic acid
| ImageFileR1 = Glycolic acid3d.png
| ImageSizeR1 = 140px
| ImageNameR1 = Ball-and-stick model of glycolic acid
| IUPACName = 2-Hydroxyethanoic acid
| OtherNames = glycolic acid,<br />hydroxyacetic acid
| Section1 = {{Chembox Identifiers
| SMILES = O=C(O)CO
| CASNo = 79-14-1
| RTECS = MC5250000
}}
| Section2 = {{Chembox Properties
| Formula = C<sub>2</sub>H<sub>4</sub>O<sub>3</sub>
| MolarMass = 76.05 g/mol
| Appearance = colorless solid
| Density = 1.27 g/cm<sup>3</sup>
| Solubility = 0.1 g/mL
| Solvent = other solvents
| SolubleOther = [[alcohol]]s, [[acetone]],<br /> [[acetic acid]] and<br />[[ethyl acetate]]<ref name="dupont">{{cite web | title=DuPont Glycolic Acid Technical Information | url=http://www.dupont.com/glycolicacid/applications/index.html | accessdate=2006-07-06}}</ref>
| MeltingPt = 75 °C
| BoilingPt = decomposes
| pKa = 3.83
| Viscosity =
}}
| Section3 = {{Chembox Structure
| CrystalStruct =
| Dipole =
}}
| Section7 = {{Chembox Hazards
| ExternalMSDS =
| MainHazards = Corrosive ('''C''')
| NFPA-H = 3
| NFPA-F = 1
| NFPA-R =
| FlashPt = 129 °C<ref name="Akron">{{cite web | title=Glycolic Acid MSDS | url=http://ull.chemistry.uakron.edu/erd/chemicals/7/6540.html | publisher = University of Akron | accessdate=2006-09-18}}</ref>
| RPhrases = {{R22}}-{{R34}}
| SPhrases = {{S26}}-{{S36/37/39}}-{{S45}}
}}
| Section8 = {{Chembox Related
| Function = [[alpha hydroxy acid|α-hydroxy acid]]s
| OtherFunctn = [[lactic acid]]
| OtherCpds = [[acetic acid]],<br />[[glycerol]]
}}
}}
'''Glycolic acid''' (or '''hydroxyacetic acid''') is the smallest [[alpha hydroxy acid|α-hydroxy acid]] (AHA). It appears in the form of a colorless, odorless and [[hygroscopic]] crystalline solid that is highly [[soluble]] in [[water]] and related [[solvent]]s. Glycolic acid is associated with sugar-crops and is isolated from [[sugarcane]], [[sugar beets]], [[pineapple]], [[canteloupe]], and unripe [[grape]]s.
==Uses==
Due to its excellent capability to penetrate [[skin]], glycolic acid finds applications in skin care products, most often as a chemical peel performed by a [[dermatologist]] in concentrations of 20%-80% or at-home kits in lower concentrations of 10%. It is used to improve the skin's appearance and texture. It may reduce wrinkles, [[Acne vulgaris|acne]] scarring, hyperpigmentation and improve many other skin conditions. Once applied, glycolic acid reacts with the upper layer of the epidermis, weakening the binding properties of the lipids that hold the dead skin cells together. This allows the outer skin to "dissolve" revealing the underlying skin.
Glycolic acid is also a useful intermediate for organic synthesis, in a range of reactions including: [[oxidation]]-[[Redox|reduction]], [[esterification]] and long chain polymerization. It is used as a [[monomer]] in the preparation of [[polyglycolide|polyglycolic acid]] and other [[biocompatible]] [[heteropolymer|copolymer]]s (e.g. [[PLGA]]). Among other uses this compound finds employment in the textile industry as a [[dye]]ing and [[tanning]] agent, in food processing as a [[flavor]]ing agent and as a preservative. Glycolic acid is often included into emulsion polymers, solvents and additives for ink and paint in order to improve flow properties and impart gloss.
==Preparation==
Glycolic acid is isolated from natural sources and is inexpensively available. It can be prepared by the reaction of [[chloroacetic acid]] with [[sodium hydroxide]] followed by re-acidification.
Glycolic acid can also be prepared using an enzymatic biochemical process which produces fewer impurities compared to traditional chemical synthesis, requires less energy in production and produces less co-product.<ref>[http://www.crosschem.net/crystalline.php GlyAcid EBP Crystalline] at CrossChem.net</ref> This process is used by the specialty chemical company CrossChem.
==Safety==
Glycolic acid is a strong irritant.<ref name="NIOSH">{{cite web | title=Glycolic Acid MSDS | work=ICSC:NENG1537 International Chemical Safety Cards (WHO/IPCS/ILO) | CDC/NIOSH | url=http://www.cdc.gov/niosh/ipcsneng/neng1537.html | accessdate=2006-06-08}}</ref> Like [[ethylene glycol]], it is metabolized to [[oxalic acid]], which makes it dangerous if ingested.
==References==
<references/>
==External links==
* [http://www.dupont.com/glycolicacid/ DuPont Glycolic Acid]
* [http://www.crosschem.net/glycolic_acid.php CrossChem GlyAcid EBP (glycolic acid)]
* [http://www.glycolic.org/ Glycolic.org Glycolic Acid]
* [http://www.compchemwiki.org/index.php?title=Glycolic_acid Computational Chemistry Wiki]
{{Acne Agents}}
[[Category:Dermatological preparations]]
[[Category:Hydroxy acids]]
[[Category:Preservatives]]
[[de:Glycolsäure]]
[[es:Ácido glicólico]]
[[fr:Acide glycolique]]
[[it:Acido glicolico]]
[[lv:Glikolskābe]]
[[nl:Glycolzuur]]