Ethyl acrylate

Ethyl acrylate is produced by acid-catalysed esterification of acrylic acid, which in turn is produced by oxidation of propylene. It may also be prepared from acetylene, carbon monoxide and ethanol by a Reppe reaction. Commercial preparations contain a polymerization inhibitor such as hydroquinone, phenothiazine, or hydroquinone ethyl ether.

Ethyl acrylate is used in the production of polymers including resins, plastics, rubber, and denture material.[http://nj.gov/health/eoh/rtkweb/0843.pdf Ethyl acrylate] {{webarchive|url=https://web.archive.org/web/20061012101429/http://www.nj.gov/health/eoh/rtkweb/0843.pdf |date=2006-10-12 }} Hazardous Substance Fact Sheet, New Jersey Department of Health and Senior Services

Ethyl acrylate is a reactant for homologous alkyl acrylates (acrylic esters) by transesterification with higher alcohols through acidic or basic catalysis. In that way speciality acrylates are made accessible, e.g. 2-ethylhexyl acrylate (from 2-ethylhexanol) used for pressure-sensitive adhesives, cyclohexyl acrylate (from cyclohexanol) used for automotive clear lacquers, 2-hydroxyethyl acrylate (from ethylene glycol) which is crosslinkable with diisocyanates to form gels used with long-chain acrylates (from C18+ alcohols)

{{Cite patent | number= 1999031042 | invent1 = J.-M. Paul, J.-P. Gamet | title = Method for conditioning long chain alkyl acrylates | fdate= 1998-12-10 | pubdate = 1995-06-24 | country = WO | assign= Elf Atochem S.A.}} as comonomer for comb polymers for reduction of the solidification point of paraffin oils and 2-dimethylaminoethyl acrylate (from dimethylaminoethanol{{Cite patent | number= 1284954 | invent1 = Gerhard Nestler, Jürgen Schröder | title = Verfahren zur herstellung von estern ungesättigter carbonsäuren | pubdate = 2003-02-26 | country = EP | assign = BASF Aktiengesellschaft}}) for the preparation of flocculants for sewage clarification and paper production.

As a reactive monomer, ethyl acrylate is used in homopolymers and copolymers with e.g. ethene, acrylic acid and its salts, amides and esters, methacrylates, acrylonitrile, maleic esters, vinyl acetate, vinyl chloride, vinylidene chloride, styrene, butadiene and unsaturated polyesters.{{Cite web | title = Technical Data Sheet – Ethyl Acrylate | url = http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_0119/0901b803801196cb.pdf?filepath=acrylates/pdfs/noreg/745-00108.pdf&fromPage=GetDoc | publisher = dow.com | accessdate = 2013-02-20 | format = PDF | archive-url=https://web.archive.org/web/20120718235553/http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_0119/0901b803801196cb.pdf?filepath=acrylates%2Fpdfs%2Fnoreg%2F745-00108.pdf&fromPage=GetDoc | archive-date = 2012-07-18 | url-status = dead }} Copolymers of acrylic acid ethyl ester with ethene (EPA/ethylene-ethyl acrylate copolymers) are suitable as adhesives and polymer additives, just like ethene vinyl acetate copolymers.{{Cite web | title = DuPont Elvaloy AC Products and Properties | url = http://www2.dupont.com/Elvaloy/en_US/products/elvaloy_ac_resins.html | publisher = dupont.com | accessdate = 2013-02-20 | archive-date = 2013-03-13 | archive-url = https://web.archive.org/web/20130313180922/http://www2.dupont.com/Elvaloy/en_US/products/elvaloy_ac_resins.html | url-status = dead }} Copolymers with acrylic acid increase the cleaning effect of liquid detergents,{{Cite patent | number= 5409629 | invent1 = Jan E. Shulman, Charles E. Jones | title = Use of acrylic acid/ethyl acrylate copolymers for enhanced clay soil removal in liquid laundry detergents | pubdate = 1995-04-25 | country = US | assign = Rohm and Haas Company}} copolymers with methacrylic acid are used as gastric juices tablet covers (Eudragit).{{Cite web | title = EUDRAGIT L 100-55 - EUDRAGIT - Targeted Drug Release and Tailored Service | url = http://eudragit.evonik.com/product/eudragit/en/products-services/eudragit-products/enteric-formulations/l-100-55/pages/default.aspx | publisher = evonik.com | accessdate = 2013-02-20 | archive-date = 2013-08-12 | archive-url = https://web.archive.org/web/20130812171430/http://eudragit.evonik.com/product/eudragit/en/products-services/eudragit-products/enteric-formulations/l-100-55/Pages/default.aspx | url-status = dead }}

The large number of possible comonomer units and their combination in copolymers and terpolymers with ethyl acrylate allows the realization of different properties of the acrylate copolymers in a variety of applications in paints and adhesives, paper, textile and leather auxiliaries together with cosmetic and pharmaceutical products.

Ethyl acrylate reacts with amines catalyzed by Lewis acids in a Michael addition to β-alanine derivatives in high yields:{{citation|surname1=Jose Cabral, Pierre Laszlo, Loïc Mahé, Marie-Thérèse Montaufier, S. Lalatiana Randriamahefa|periodical=Tetrahedron Letters|title=Catalysis of the specific Michael addition: The example of acrylate acceptors|volume=30|issue=30|pages=3969–3972|date= 1989|language=German|doi=10.1016/S0040-4039(00)99297-9}}

:Michael addition of an amine to ethyl acrylate

The nucleophilic addition at ethyl acrylate as an α,β-unsaturated carbonyl compound is a frequent strategy in the synthesis of pharmaceutical intermediates. Examples are the hypnotic glutethimide or the vasodilator vincamin (obsolete by now)Pharmazeutische Wirkstoffe: Synthesen, Patente, Anwendungen; von A. Kleemann u. J. Engel; 2., neubearb. u. erw. Aufl.; Stuttgart, New York; Thieme; 1982, {{ISBN|3-13-558402-X}} or more recent therapeutics such as the COPD agent cilomilast or the nootropic leteprinim.D. Lednicer, The Organic Chemistry of Drug Synthesis, Volume 7, J. Wiley & Sons, 2008, {{ISBN|978-0-470-10750-8}}

Ethyl 3-bromopropionate is prepared by hydrobromination of ethyl acrylate.{{cite journal|first1=Ralph|last1=Mozingo|first2=L. A. |last2=Patterson|doi=10.15227/orgsyn.020.0064|title=Methyl β-Bromopropionate|journal=Organic Syntheses|year=1940|volume=20|pages=64}}

With dienes, ethyl acrylate reacts as a good dienophile in Diels–Alder reactions e.g. with buta-1,3-diene in a [4+2] cycloaddition reaction to give a cyclohexene carboxylic acid ester in a high yield.K.P.C. Vollhardt, N.E. Schore, Organische Chemie, 5. Aufl., Wiley-VCH, 2012, {{ISBN|978-3-527-33250-2}}

Ethyl acrylate is also used as a flavoring agent. It has been found as a volatile component in pineapples and Beaufort cheese{{Cite web | title = Ethyl Acrylate | url = http://monographs.iarc.fr/ENG/Monographs/vol71/mono71-99.pdf | publisher = iarc.fr | accessdate = 2013-02-20 | format = PDF; 43 kB}} and is a secondary component in vanilla flavor obtained from heat extraction of vanilla in amounts of up to 1 ppm. In such high concentrations it negatively affects the extracted aroma.Sensory-Directed Flavor Analysis, Ray Marsili edit., CRC Press, Taylor & Francis Group, Boca Raton, 2007, {{ISBN|1-57444-568-5}}

File:Placard 1993.jpg carrying ethyl acrylate, displaying hazardous materials information including a diamond-shaped U.S. DOT placard showing a UN number{{Cite web |last=Beaucham |first=Catherine C. |date=August 2023 |title=Evaluation of Potential Exposures to Railway Hazardous Material Inspectors |url=https://www.cdc.gov/niosh/hhe/reports/pdfs/2022-0049-3387.pdf |access-date=2024-05-04 |website=U.S. National Institute for Occupational Safety and Health |type=Health Hazard Evaluation Report}}]]

The International Agency for Research on Cancer stated, "Overall evaluation, ethyl acrylate is possibly carcinogenic to humans (Group 2B)."[http://monographs.iarc.fr/ENG/Monographs/vol71/mono71-99.pdf IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 71], International Agency for Research on Cancer (1999) The United States Environmental Protection Agency (EPA) states, "Human studies on occupational exposure to ethyl acrylate... have suggested a relationship between exposure to the chemical(s) and colorectal cancer, but the evidence is conflicting and inconclusive. In a study by the National Toxicology Program (NTP), increased incidence of squamous cell papillomas and carcinomas of the forestomach were observed in rats and mice exposed via gavage (experimentally placing the chemical in the stomach). However, the NTP recently determined that these data were not relevant to human carcinogenicity since humans do not have a forestomach, and removed ethyl acrylate from its list of carcinogens."[http://www.epa.gov/ttn/atw/hlthef/ethylacr.html EPA Technology Transfer Network, Air Toxics Web Site] {{webarchive|url=https://web.archive.org/web/20120511014749/http://www.epa.gov/ttn/atw/hlthef/ethylacr.html |date=2012-05-11 }}, United States Environmental Protection Agency (accessed 2008) However, ethyl acrylate also increased the incidence of thyroid follicular cell adenoma in male mice, and thyroid follicular cell adenoma or carcinoma (combined) in male rats exposed through inhalation.{{Cite journal |last1=Kromhout |first1=Hans |last2=Friesen |first2=Melissa |last3=Marques |first3=M Mathilde |last4=Sergi |first4=Consolato Maria |last5=Abdallah |first5=Mohamed |last6=Benke |first6=Geza |last7=Cesta |first7=Mark |last8=Germolec |first8=Dori |last9=Houck |first9=Keith |last10=Ichihara |first10=Gaku |last11=Jameson |first11=Charles William |last12=Kanno |first12=Jun |last13=Pogribny |first13=Igor |last14=Svendsen |first14=Camilla |last15=Benbrahim-Tallaa |first15=Lamia |date=2018-08-01 |title=Carcinogenicity of isobutyl nitrite, β-picoline, and some acrylates |url=https://www.sciencedirect.com/science/article/pii/S1470204518304911 |journal=The Lancet Oncology |language=en |volume=19 |issue=8 |pages=1020–1022 |doi=10.1016/S1470-2045(18)30491-1 |pmid=30700372 |issn=1470-2045|url-access=subscription }}

It is possibly carcinogenic and it is toxic in large doses, with an LD₅₀ (rats, oral) of 1020 mg/kg. As of October 2018, the FDA withdrew authorization for its use as a synthetic flavoring substance in food.{{Federal Register|83|50490}}

One favorable safety aspect is that ethyl acrylate has good warning properties; the odor threshold is much lower than the concentration required to create an atmosphere immediately dangerous to life and health. Reports of the exact levels vary somewhat, but, for example, the EPA reports an odor threshold of 0.0012 parts per million (ppm), but the EPA's lowest level of health concern, the Acute Exposure Guideline Level-1 (AEGL-1) is 8.3 ppm,{{cite web| url=https://www.epa.gov/aegl/ethyl-acrylate-results-aegl-program| work=Acute Exposure Guideline Levels| title=Ethyl acrylate| publisher=United States Environmental Protection Agency| access-date=2019-04-28}} which is almost 7000 times the odor threshold.

However, as a possible carconigen, NIOSH maintains "that there is no safe level of exposure to a carcinogen. Reduction of worker exposure to chemical carcinogens as much as possible through elimination or substitution and engineering controls is the primary way to prevent occupational cancer."{{Cite web |date=2023-05-08 |title=Occupational Cancer - NIOSH Chemical Carcinogen Policy {{!}} NIOSH {{!}} CDC |url=https://www.cdc.gov/niosh/topics/cancer/policy.html |access-date=2023-06-27 |website=www.cdc.gov |language=en-us}}

{{Reflist}}

• [https://www.cdc.gov/niosh/npg/npgd0261.html CDC - NIOSH Pocket Guide to Chemical Hazards - Ethyl Acrylate]

Category:Monomers

Category:Ethyl esters

Category:Lachrymatory agents

Category:IARC Group 2B carcinogens

Category:Acrylate esters