{{chembox | Watchedfields = changed | verifiedrevid = 477182661 | ImageFile = Hydroxyethyl methacrylate.svg | ImageSize = 190px | ImageAlt = Skeletal formula of Hydroxyethyl methacrylate | ImageFile1 = Hydroxyethyl methacrylate molecule ball.png | ImageSize1 = 210px | ImageAlt1 = Ball-and-stick model of the hydroxyethyl methacrylate molecule | PIN = 2-Hydroxyethyl 2-methylprop-2-enoate | OtherNames = HEMA; hydroxyethylmethacrylate; glycol methacrylate; glycol monomethacrylate; hydroxyethyl methacrylate; ethylene glycol methacrylate; 2-(methacryloyloxy)ethanol | Section1 = {{Chembox Identifiers | Abbreviations = | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 12791 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 6E1I4IV47V | InChIKey = WOBHKFSMXKNTIM-UHFFFAOYAH | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C6H10O3/c1-5(2)6(8)9-4-3-7/h7H,1,3-4H2,2H3 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = WOBHKFSMXKNTIM-UHFFFAOYSA-N | CASNo_Ref = {{cascite|correct|CAS}} | CASNo = 868-77-9 | EINECS = 212-782-2 | PubChem = 13360 | ChEMBL = 1730239 | SMILES = O=C(OCCO)\C(=C)C | SMILES1 = CC(=C)C(=O)OCCO | InChI = 1/C6H10O3/c1-5(2)6(8)9-4-3-7/h7H,1,3-4H2,2H3 | RTECS = OZ4725000 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 34288 | KEGG_Ref = {{keggcite|correct|kegg}} | KEGG = C14530 | Beilstein = 1071583 | Gmelin = 936557 }} | Section2 = {{Chembox Properties | C=6 | H=10 | O=3 | Appearance = Colourless liquid | Density = 1.07{{nbsp}}g/cm{{sup|3}} | MeltingPtC = −99 | MeltingPt_ref = <ref name="gps">{{cite web|title=GPS Safety Summary 2-Hydroxyethyl methacrylate (HEMA)|url=http://corporate.evonik.com/_layouts/Websites/Internet/DownloadCenterFileHandler.ashx?fileid=1091|date=July 2013}}</ref> | BoilingPtC = 213 | BoilingPt_ref =<ref name=gps/> | Solubility = miscible | Solvent = Chloroform (poor) | LogP = 0.50<ref name="chemsrc">{{cite web|title=2-hydroxyethyl methacrylate_msds |publisher=ChemSrc: A Smart Chem-Search Engine |url=https://www.chemsrc.com/en/cas/868-77-9_1092316.html }}</ref> | VaporPressure = 0.08{{nbsp}}hPa }} | Section3 = | Section4 = {{Chembox Thermochemistry }} | Section7 = {{Chembox Hazards | MainHazards = Eye irritation | FlashPtC = 97 | GHSPictograms = {{GHS07}} | GHSSignalWord = Warning | HPhrases = {{H-phrases|315|317|319}} | PPhrases = {{P-phrases|261|264|272|280|302+352|305+351+338|321|332+313|333+313|337+313|362|363|501}} | PEL = }} }}
'''Hydroxyethylmethacrylate''' (also known as '''glycol methacrylate''')<ref name=Gerrits_1996/><ref name=Cole_1974/> is the organic compound with the chemical formula {{chem2|H2C\dC(CH3)CO2CH2CH2OH}}. It is a colorless viscous liquid that readily polymerizes, i.e. it is a monomer that is used to make various polymers.
==Synthesis== Hydroxyethylmethacrylate was first synthesized around 1925. Common methods of synthesis are:<ref name=Macret_1982/> * reaction of methacrylic acid with ethylene oxide: :{{chem2|H2C\dC(CH3)CO2H + CH2CH2O -> H2C\dC(CH3)CO2CH2CH2OH}} * esterification of methacrylic acid with a large excess of ethylene glycol. :{{chem2|H2C\dC(CH3)CO2H + HOCH2CH2OH -> H2C\dC(CH3)CO2CH2CH2OH + H2O}}
Both these methods give also some amount of ethylene glycol dimethacrylate. During polymerization of hydroxyethylmethacrylate, it works as crosslinking agent.<ref name=Macret_1982/>
==Properties== Hydroxyethylmethacrylate is completely miscible with water and ethanol, but its polymer is practically insoluble in common solvents. Its viscosity is 0.0701 Pa⋅s at 20°C<ref name=Rosenberg_1960/> and 0.005 Pa⋅s at 30°C.<ref name=Gerrits_1996/> During polymerization, it shrinks by approximately 6%.<ref name=Rosenberg_1960/>
==Applications== ===Contact lenses=== In 1960, O. Wichterle and D. Lím<ref name=Wichterle_1960/> described its use in synthesis of hydrophilic crosslinked networks, and these results had great importance for manufacture of soft contact lenses.<ref name=Macret_1982/> Polyhydroxyethylmethacrylate is hydrophilic: it is capable of absorbing from 10 to 600% water relative to the dry weight. Because of this property, it was one of the first materials to be used in the manufacture of soft contact lenses.<ref>Blasco, Joe; Kehoe, Vincent J-R; ''The professional make-up artist : motion pictures, television, print, theatre''; {{ISBN|0-9771580-0-4}}; LCC# PN2068.B53 2005</ref>
===Use in 3D printing=== Hydroxyethylmethacrylate lends itself well to applications in 3D printing as it cures quickly at room temperature when exposed to UV light in the presence of photoinitiators. It may be used as a monomeric matrix in which 40nm silica particles are suspended for 3D glass printing.<ref>{{cite journal |last1=Kotz |first1=Frederik |last2=Arnold |first2=Karl |last3=Bauer |first3=Werner |last4=Schild |first4=Dieter |last5=Keller |first5=Nico |last6=Sachsenheimer |first6=Kai |last7=Nargang |first7=Tobias M. |last8=Richter |first8=Christiane |last9=Helmer |first9=Dorothea |last10=Rapp |first10=Bastian E. |year=2017 |title=Three-dimensional printing of transparent fused silica glass |journal=Nature |language=en |volume=544 |issue=7650 |pages=337–339 |doi=10.1038/nature22061 |issn=0028-0836 |pmid=28425999 |doi-access=free|bibcode=2017Natur.544..337K }}</ref> When combined with a suitable blowing agent such as BOC anhydride it forms a foaming resin which expands when heated.<ref>{{cite journal|last1=Wirth |first1=D. |year= 2020|title=Highly Expandable Foam for Lithographic 3D Printing |journal=ACS Applied Materials and Interfaces |volume=12 |issue=16 |pages=19033–19043 |doi=10.1021/acsami.0c02683 |pmid=32267677 |s2cid=215603770 }}</ref>
=== Cosmetics === Hydroxyethylmethacrylate is the most common ingredient in cosmetic nail products, where it is used as a resin base and in polishes, primers, coats, and gels. Hydroxyethylmethacrylate is also a component of cosmetics glues for the application of eyelash and hair extensions.<ref>{{Cite journal |last=Symanzik |first=Cara |last2=Weinert |first2=Patricia |last3=Babić |first3=Željka |last4=Hallmann |first4=Sarah |last5=Havmose |first5=Martin S. |last6=Johansen |first6=Jeanne D. |last7=Kezic |first7=Sanja |last8=Macan |first8=Marija |last9=Macan |first9=Jelena |last10=Strahwald |first10=Julia |last11=Turk |first11=Rajka |last12=van der Molen |first12=Henk F. |last13=John |first13=Swen M. |last14=Uter |first14=Wolfgang |date=2022 |title=Allergic contact dermatitis caused by 2-hydroxyethyl methacrylate and ethyl cyanoacrylate contained in cosmetic glues among hairdressers and beauticians who perform nail treatments and eyelash extension as well as hair extension applications: A systematic review |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/cod.14056 |journal=Contact Dermatitis |language=en |volume=86 |issue=6 |pages=480–492 |doi=10.1111/cod.14056 |issn=1600-0536}}</ref><ref name=":0">{{Cite journal |last=Steunebrink |first=Iemke M. |last2=de Groot |first2=Anton |last3=Rustemeyer |first3=Thomas |date=2024 |title=Presence of 2-hydroxyethyl methacrylate (HEMA) and other (meth)acrylates in nail cosmetics, and compliance with EU legislation: An online market survey |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/cod.14441 |journal=Contact Dermatitis |language=en |volume=90 |issue=1 |pages=60–65 |doi=10.1111/cod.14441 |issn=1600-0536|doi-access=free }}</ref>
As a known skin irritant, European Union regulations mandate labeling of products that contain Hydroxyethylmethacrylate, with limited compliance.<ref name=":0" /> Products are also restricted to professionals.
===Other=== In electron microscopy, later in light microscopy, hydroxyethylmethacrylate serves as an embedding medium.<ref name=Cole_1974/><ref name=Gerrits_1996/>
When treated with polyisocyanates, polyhydroxyethylmethacrylate makes a crosslinked polymer, an acrylic resin, that is a useful component in some paints.<ref>{{Ullmann | last1 = Stoye | first1 = D. | last2 = Funke | first2 = W. | last3 = Hoppe | first3 = L. | last4 = Hasselkus | first4 = J. R. | last5 = Curtis | first5 = L. G. | last6 = Hoehne | first6 = K. | last7 = Zech | first7 = H. J. | last8 = Heiling | first8 = P. | last9 = Yamabe | first9 = M. | last10 = Dören | first10 = K. | last11 = Schupp | first11 = H. | last12 = Küchenmeister | first12 = R. | last13 = Schmitthenner | first13 = M. | last14 = Kremer | first14 = W. | last15 = Wieczorrek | first15 = W. | last16 = Gempeler | first16 = H. | last17 = Schneider | first17 = W. | last18 = White | first18 = J. W. | last19 = Short | first19 = A. G. | last20 = Blank | first20 = W. J. | last21 = Calbo | first21 = L. J. | last22 = Plath | first22 = D. | last23 = Wagner | first23 = F. | last24 = Haller | first24 = W. | last25 = Rödder | first25 = K. M. | last26 = Streitberger | first26 = H. J. | last27 = Urbano | first27 = E. | last28 = Laible | first28 = R. | last29 = Meyer | first29 = B. D. | last30 = Bagda | first30 = E. | display-authors = 3 | year = 2006 | title= Paints and Coatings | doi = 10.1002/14356007.a18_359.pub2 | isbn = 3-527-30673-0 }}</ref>
==Hazards== Hydroxyethylmethacrylate is a mild skin irritant and can cause allergic skin reactions.<ref name=Gerrits_1996/><ref name=":0" />
==References== <references>
<ref name="Cole_1974">{{cite journal |last1=Cole |first1=Madison B. |last2=Sykes |first2=Stephen M. |year=1974 |title=Glycol Methacrylate in Light Microscopy a Routine Method for Embedding and Sectioning Animal Tissues |url=http://www.tandfonline.com/doi/full/10.3109/10520297409117016 |journal=Stain Technology |language=en |volume=49 |issue=6 |pages=387–400 |doi=10.3109/10520297409117016 |issn=0038-9153 |pmid=4142140|url-access=subscription }}</ref> <ref name=Gerrits_1996>{{cite journal|last1=Gerrits |first1=P. O. |last2=Horobin |first2=R. W. |year=1996 |title =Glycol Methacrylate Embedding for Light Microscopy: Basic Principles and Trouble-Shooting |journal=Journal of Histotechnology |volume =19 |issue =4 |pages =297–311 |doi =10.1179/his.1996.19.4.297 }}</ref> <ref name=Macret_1982>{{cite journal|last1=Macret |first1=M. |last2=Hild |first2=G. |year=1982 |title = Hydroxyalkyl methacrylates: Kinetic investigations of radical polymerizations of pure 2-hydroxyethyl methacrylate and 2, 3-dihydroxypropyl methacrylate and the radical copolymerization of their mixtures |journal=Polymer |volume =23 |issue =1 |pages =81–90 |doi =10.1016/0032-3861(82)90020-9 |pmid = |url = }}</ref> <ref name=Rosenberg_1960>{{cite journal|last1=Rosenberg |first1=M. |last2=Bartl |first2=P. |last3=Lesko |first3=J. |year =1960 |title =Water-soluble methacrylate as an embedding medium for the preparation of ultrathin sections |journal=Journal of Ultrastructure Research |volume =4 |issue =3–4 |pages =298–303 |doi =10.1016/s0022-5320(60)80024-x |pmid =13743397 }}</ref> <ref name=Wichterle_1960>{{cite journal|last1=Wichterle |first1=O. |last2=Lím |first2=D. |year=1960 |title =Hydrophilic gels for biological use |journal=Nature |volume =185 |issue =4706 |pages =117–118 |doi =10.1038/185117a0 |bibcode=1960Natur.185..117W |pmid = |s2cid =4211987 |url = }}</ref>
</references> {{Clear}}
{{DEFAULTSORT:Hydroxyethylmethacrylate}} Category:Methacrylate esters Category:Monomers Category:Hydroxyethyl compounds