Acrylic acid

The word "acrylic" was coined in 1843, for a chemical derivative of acrolein, an acrid-smelling oil derived from glycerol.

Acrylic acid is produced by oxidation of propylene, which is a byproduct of the production of ethylene and gasoline:

:File:Acrylic acid from propylene.svg

Because acrylic acid and its esters have long been valued commercially, many other methods have been developed. Most have been abandoned for economic or environmental reasons. An early method was the hydrocarboxylation of acetylene ("Reppe chemistry"):

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This method requires nickel carbonyl, high pressures of carbon monoxide, and acetylene, which is relatively expensive compared to propylene.

Acrylic acid was once manufactured by the hydrolysis of acrylonitrile, a material derived from propene by ammoxidation, but this route was abandoned because it cogenerates ammonium side products, which must be disposed of. Other now abandoned precursors to acrylic acid include ethenone and ethylene cyanohydrin.

Carboxylating ethylene to acrylic acid under supercritical carbon dioxide is thermodynamically possible, but efficient catalysts have not been developed.{{cite journal | last1 = Sakakura | first1 = Toshiyasu | last2 = Choi | first2 = Jun-Chul | last3 = Yasuda | first3 = Hiroyuki | title = Transformation of Carbon dioxide | journal = Chemical Reviews | volume = 107 | issue = 6 | pages = 2365–2387 | date = 13 June 2007 | doi = 10.1021/cr068357u | pmid=17564481}} 3-Hydroxypropionic acid (3HP), an acrylic-acid precursor by dehydration, can be produced from sugars, but the process is not competitive.[http://www.durabilityanddesign.com/news/?fuseaction=view&id=5417 Sweet Deal: Dow and Partner Cook up Sugar-to-Acrylic Plan]. Durabilityanddesign.com. Retrieved on 2012-05-24.[http://www.technologyreview.com/energy/26313/ Better Bugs to Make Plastics, Technology Review, September 20, 2010, retrieved January 9, 2012]. Technologyreview.com (2010-09-20). Retrieved on 2012-05-24.

Acrylic acid undergoes the typical reactions of a carboxylic acid. When reacted with an alcohol, it forms the corresponding ester. The esters and salts of acrylic acid are collectively known as acrylates (or propenoates). The most common alkyl esters of acrylic acid are methyl, butyl, ethyl, and 2-ethylhexyl acrylate.

Acrylic acid and its esters readily combine with themselves (to form polyacrylic acid) or other monomers (e.g. acrylamides, acrylonitrile, vinyl compounds, styrene, and butadiene) by reacting at their double bond, forming homopolymers or copolymers, which are used in the manufacture of various plastics, coatings, adhesives, elastomers, as well as floor polishes and paints.

Acrylic acid is used in many industries, including the diaper industry, the water treatment industry, and the textile industry. The annual worldwide consumption of acrylic acid is projected to reach more than an estimated 8,000 kilotons by 2020. This increase is expected due to its use in new applications, including personal care products, detergents, and products for adult incontinence.{{Cite web|url=https://www.openpr.com/wiki/acrylic-acid-market|title=Acrylic acid market|access-date=2018-05-30}}

As a substituent acrylic acid can be found as an acyl group or a carboxyalkyl group, depending on the removal of the group from the molecule.

More specifically, these are:

1. The acryloyl group, with the removal of the −OH from carbon-1.
2. The 2-carboxyethenyl group, with the removal of a −H from carbon-3. This substituent group is found in chlorophyll.

Acrylic acid is severely irritating and corrosive to the skin and the respiratory tract. Eye contact can result in severe and irreversible injury. Low exposure will cause minimal or no health effects, while high exposure could result in pulmonary edema. The {{LD50}} is 340 mg/kg (rat, oral) with the lowest recorded {{LD50}} being 293 mg/kg (oral, rat), comparable to ethylene glycol, which is indicative of being a potent poison.{{Cite web |title=Webwiser Acrylic Acid |url=https://webwiser.nlm.nih.gov/substance?substanceId=406&identifier=Acrylic%20acid&identifierType=name&menuItemId=78&catId=92}} Ethyl acrylate was once used as a synthetic food flavoring and was withdrawn by the FDA possibly due to cancerogenic effects observed in lab animals.{{Cite web |title=Synthetic food flavorings law update |date=9 October 2018 |url=https://www.federalregister.gov/documents/2018/10/09/2018-21807/food-additive-regulations-synthetic-flavoring-agents-and-adjuvants}}

Animal studies showed that high doses of acrylic acid decreased weight gain. Acrylic acid can be converted to non-toxic lactic acid.{{Cite web |title= Provisional Peer-Reviewed Toxicity Values for Acrylic Acid|url=https://cfpub.epa.gov/ncea/pprtv/documents/AcrylicAcid.pdf |access-date=2022-04-29 |website=www.google.com}}

Acrylic acid is a constituent of tobacco smoke.{{cite journal|last1=Talhout|first1=Reinskje|last2=Schulz|first2=Thomas|last3=Florek|first3=Ewa|last4=Van Benthem|first4=Jan|last5=Wester|first5=Piet|last6=Opperhuizen|first6=Antoon|title=Hazardous Compounds in Tobacco Smoke|journal=International Journal of Environmental Research and Public Health|volume=8|issue=12|year=2011|pages=613–628|issn=1660-4601|doi=10.3390/ijerph8020613|pmid=21556207|pmc=3084482|doi-access=free}}

• Methacrylic acid
• Acryloyl chloride
• Acrylamide
• Acrylate polymer
• Sodium polyacrylate

{{reflist}}

• [http://www.npi.gov.au/substances/acrylic-acid/index.html National Pollutant Inventory: Acrylic acid]
• [https://www.cdc.gov/niosh/npg/npgd0013.html CDC – NIOSH Pocket Guide to Chemical Hazards – Acrylic acid]

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Category:Alkenoic acids

Category:Carboxylic acid-based monomers

Category:Commodity chemicals

Category:Suspected fetotoxicants

Category:Vinyl compounds