Ethyl acrylate is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

with the formula CH₂CHCO₂CH₂CH₃. It is the ethyl

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides a ...

acrylic acid Acrylic acid (IUPAC: propenoic acid) is an organic compound with the formula CH2=CHCOOH. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group connected directly to a carboxylic acid terminus. This colorless liquid has a ...

. It is a colourless liquid with a characteristic acrid odor. It is mainly produced for paints, textiles, and non-woven fibers. It is also a reagent in the synthesis of various pharmaceutical intermediates.

Production

Ethyl acrylate is produced by acid-catalysed esterification of acrylic acid, which in turn is produced by oxidation of

propylene Propylene, also known as propene, is an unsaturated organic compound with the chemical formula CH3CH=CH2. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petro ...

. It may also be prepared from acetylene,

carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...

and ethanol by a Reppe reaction. Commercial preparations contain a

polymerization inhibitor Polymerisation inhibitors (US: polymerization inhibitors) are chemical compounds added to monomers to prevent their auto-polymerisation. Unsaturated monomers such as acrylates, vinyl chloride, butadiene and styrene require inhibitors for both proces ...

such as

hydroquinone Hydroquinone, also known as benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, a derivative of benzene, having the chemical formula C6H4(OH)2. It has two hydroxyl groups bonded to a benzene ring in a ''para' ...

phenothiazine Phenothiazine, abbreviated PTZ, is an organic compound that has the formula S(C6H4)2NH and is related to the thiazine-class of heterocyclic compounds. Derivatives of phenothiazine are highly bioactive and have widespread use and rich history. T ...

, or hydroquinone ethyl ether.

Reactions and uses

Precursor to polymers and other monomers

Ethyl acrylate is used in the production of polymers including resins, plastics, rubber, and denture material.Ethyl acrylate
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 2-Ethylhexyl acrylate is a colorless liquid acrylate with a pleasant odor. Preparation Racemic 2-ethylhexyl acrylate can be prepared with a high yield by esterification of acrylic acid with racemic 2-ethylhexanol in the presence of hydroquinone ...

(from

2-ethylhexanol 2-Ethylhexanol (abbreviated 2-EH) is an organic compound with formula CHO. It is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is poorly soluble in water but soluble in most organic solvents. It is produced on a large scal ...

) used for pressure-sensitive adhesives, cyclohexyl acrylate (from

cyclohexanol Cyclohexanol is the organic compound with the formula HOCH(CH2)5. The molecule is related to cyclohexane by replacement of one hydrogen atom by a hydroxyl group. This compound exists as a deliquescent colorless solid with a camphor-like odor, w ...

) used for automotive clear lacquers, 2-hydroxyethyl acrylate (from

ethylene glycol Ethylene glycol (IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula . It is mainly used for two purposes, as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odo ...

) which is crosslinkable with

diisocyanate In organic chemistry, isocyanate is the functional group with the formula . Organic compounds that contain an isocyanate group are referred to as isocyanates. An organic compound with two isocyanate groups is known as a diisocyanate. Diisocyan ...

s to form gels used with long-chain acrylates (from C18+ alcohols) as comonomer for

comb polymers In polymer chemistry, graft polymers are segmented copolymers with a linear backbone of one composite and randomly distributed branches of another composite. The picture labeled "graft polymer" shows how grafted chains of species B are covalent ...

for reduction of the solidification point of paraffin oils and

2-dimethylaminoethyl acrylate Dimethylaminoethyl acrylate (2-dimethylaminoethyl acrylate) or DMAEA is an unsaturated carboxylic acid ester having a tertiary amino group. It is a colorless to yellowish, water-miscible liquid with a pungent, amine-like odor. DMAEA is an import ...

(from

dimethylaminoethanol Dimethylethanolamine (DMAE or DMEA) is an organic compound with the formula (CH3)2NCH2CH2OH. It is bifunctional, containing both a tertiary amine and primary alcohol functional groups. It is a colorless viscous liquid. It is used in skin care produ ...

) 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 Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds). Ethylene i ...

and its salts,

amide In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent organic groups or hydrogen atoms. The amide group is called a peptide bond when it i ...

s and esters,

methacrylate Methacrylates are derivatives of methacrylic acid. * Methyl methacrylate * Ethyl methacrylate * Butyl methacrylate * Hydroxyethyl methacrylate * Glycidyl methacrylate Glycidyl methacrylate (GMA) is an ester of methacrylic acid and glycidol. Co ...

acrylonitrile Acrylonitrile is an organic compound with the formula and the structure . It is a colorless, volatile liquid although commercial samples can be yellow due to impurities. It has a pungent odor of garlic or onions. In terms of its molecula ...

, maleic esters,

vinyl acetate Vinyl acetate is an organic compound with the formula CH3CO2CH=CH2. This colorless liquid is the precursor to polyvinyl acetate and ethene-vinyl acetate copolymers, important industrial polymers. Production The worldwide production capacity of v ...

vinyl chloride Vinyl chloride is an organochloride with the formula H2C=CHCl. It is also called vinyl chloride monomer (VCM) or chloroethene. This colorless compound is an important industrial chemical chiefly used to produce the polymer polyvinyl chloride (PVC ...

vinylidene chloride 1,1-Dichloroethene, commonly called 1,1-dichloroethylene or vinylidene chloride or 1,1-DCE, is an organochloride with the molecular formula CHCl. It is a colorless liquid with a sharp odor. Like most chlorocarbons, it is poorly soluble in water, ...

styrene Styrene () is an organic compound with the chemical formula C6H5CH=CH2. This derivative of benzene is a colorless oily liquid, although aged samples can appear yellowish. The compound evaporates easily and has a sweet smell, although high concen ...

, butadiene and unsaturated polyesters. 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. Copolymers with acrylic acid increase the cleaning effect of liquid detergents, copolymers with methacrylic acid are used as gastric juices tablet covers (Eudragit). 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 Auxiliaries are support personnel that assist the military or police but are organised differently from regular forces. Auxiliary may be military volunteers undertaking support functions or performing certain duties such as garrison troops, ...

together with cosmetic and pharmaceutical products.

As Michael acceptor and HX acceptor

Ethyl acrylate reacts with amines catalyzed by Lewis acids in a

Michael addition In organic chemistry, the Michael reaction or Michael addition is a reaction between a Michael donor (an enolate or other nucleophile) and a Michael acceptor (usually an α,β-unsaturated carbonyl) to produce a Michael adduct by creating a carbon ...

to β-alanine derivatives in high yields: Michael-Addition von Amin an EA

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) or more recent therapeutics such as the COPD agent cilomilast or the

nootropic Nootropics ( , or ) (colloquial: smart drugs and cognitive enhancers, similar to adaptogens) are a wide range of natural or synthetic dietary supplement, supplements or drugs and other substances that are claimed to improve cognitive function ...

leteprinim. Ethyl 3-bromopropionate is prepared by hydrobromination of ethyl acrylate.

Dienophile

With

diene In organic chemistry a diene ( ) (diolefin ( ) or alkadiene) is a covalent compound that contains two double bonds, usually among carbon atoms. They thus contain two alk''ene'' units, with the standard prefix ''di'' of systematic nomenclature. ...

s, ethyl acrylate reacts as a good dienophile in Diels–Alder reactions e.g. with

buta-1,3-diene 1,3-Butadiene () is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two viny ...

in a +2

cycloaddition In organic chemistry, a cycloaddition is a chemical reaction in which "two or more unsaturated molecules (or parts of the same molecule) combine with the formation of a cyclic adduct in which there is a net reduction of the bond multiplicity". T ...

reaction to give a cyclohexene carboxylic acid ester in a high yield.

Natural occurrence

Ethyl acrylate is also used as a flavoring agent. It has been found as a volatile component in

pineapple The pineapple (''Ananas comosus'') is a tropical plant with an edible fruit; it is the most economically significant plant in the family Bromeliaceae. The pineapple is indigenous to South America, where it has been cultivated for many centuri ...

s and Beaufort cheese 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.

Safety

The

International Agency for Research on Cancer The International Agency for Research on Cancer (IARC; french: Centre International de Recherche sur le Cancer, CIRC) is an intergovernmental agency forming part of the World Health Organization of the United Nations. Its role is to conduct and ...

stated, "Overall evaluation, ethyl acrylate is possibly carcinogenic to humans (Group 2B)."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 The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it ...

(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 papilloma A squamous cell papilloma is a generally benign papilloma that arises from the stratified squamous epithelium of the skin, lip, oral cavity, tongue, pharynx, larynx, esophagus, cervix, vagina or anal canal. Squamous cell papillomas are typically ...

s 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."EPA Technology Transfer Network, Air Toxics Web Site
, United States Environmental Protection Agency (accessed 2008) (Occupational exposure generally involves exposure that occurs regularly, over an extended period of time.) It is toxic in large doses, with an

LD50 In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is the ...

(rats, oral) of 1020 mg/kg, and day to day continuous exposure to 5 ppm is considered safe. As of October 2018, the

FDA The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

withdrew authorization for its use as a synthetic flavoring substance in food, without regard to its continuing stance that this substance does not pose a risk to public health under the conditions of its intended use. One favorable safety aspect is that ethyl acrylate has good warning properties; the

odor threshold The odor detection threshold is the lowest concentration of a certain odor compound that is perceivable by the human sense of smell. The threshold of a chemical compound is determined in part by its shape, polarity, partial charges, and molecu ...

is much lower than any level of health concern. In other words, the bad odor warns people of ethyl acrylate's presence long before the concentration reaches a level capable of creating a serious health risk. Reports of the exact levels vary somewhat, but, for example, the U.S. E.P.A. reports an odor threshold of 0.0012 parts per million (ppm), but the E.P.A.'s lowest level of health concern, the Acute Exposure Guideline Level-1 (AEGL-1) is 8.3 ppm, which is almost 7000 times the odor threshold.

References

{{Reflist

External links

CDC - NIOSH Pocket Guide to Chemical Hazards - Ethyl Acrylate
Monomers Ethyl esters Lachrymatory agents IARC Group 2B carcinogens Acrylate esters