(Hydroxyethyl)methacrylate
Chemical compound
From Wikipedia, the free encyclopedia
Hydroxyethylmethacrylate (also known as glycol methacrylate)[3][4] is the organic compound with the chemical formula H2C=C(CH3)CO2CH2CH2OH. It is a colorless viscous liquid that readily polymerizes, i.e. it is a monomer that is used to make various polymers.
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| Names | |
|---|---|
| Preferred IUPAC name
2-Hydroxyethyl 2-methylprop-2-enoate | |
| Other names
HEMA; hydroxyethylmethacrylate; glycol methacrylate; glycol monomethacrylate; hydroxyethyl methacrylate; ethylene glycol methacrylate; 2-(methacryloyloxy)ethanol | |
| Identifiers | |
3D model (JSmol) |
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| 1071583 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.011.621 |
| EC Number |
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| 936557 | |
| KEGG | |
PubChem CID |
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| RTECS number |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C6H10O3 | |
| Molar mass | 130.143 g·mol−1 |
| Appearance | Colourless liquid |
| Density | 1.07 g/cm3 |
| Melting point | −99 °C (−146 °F; 174 K)[1] |
| Boiling point | 213 °C (415 °F; 486 K)[1] |
| miscible | |
| log P | 0.50[2] |
| Vapor pressure | 0.08 hPa |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards |
Eye irritation |
| GHS labelling: | |
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| Warning | |
| H315, H317, H319 | |
| P261, P264, P272, P280, P302+P352, P305+P351+P338, P321, P332+P313, P333+P313, P337+P313, P362, P363, P501 | |
| Flash point | 97 °C (207 °F; 370 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis
Hydroxyethylmethacrylate was first synthesized around 1925. Common methods of synthesis are:[5]
- reaction of methacrylic acid with ethylene oxide:
- H2C=C(CH3)CO2H + CH2CH2O → H2C=C(CH3)CO2CH2CH2OH
- esterification of methacrylic acid with a large excess of ethylene glycol.
- H2C=C(CH3)CO2H + HOCH2CH2OH → H2C=C(CH3)CO2CH2CH2OH + H2O
Both these methods give also some amount of ethylene glycol dimethacrylate. During polymerization of hydroxyethylmethacrylate, it works as crosslinking agent.[5]
Properties
Applications
Contact lenses
In 1960, O. Wichterle and D. Lím[7] described its use in synthesis of hydrophilic crosslinked networks, and these results had great importance for manufacture of soft contact lenses.[5] 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.[8]
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.[9] When combined with a suitable blowing agent such as BOC anhydride it forms a foaming resin which expands when heated.[10]
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.[11][12]
As a known skin irritant, European Union regulations mandate labeling of products that contain Hydroxyethylmethacrylate, with limited compliance.[12] Products are also restricted to professionals.
Other
In electron microscopy, later in light microscopy, hydroxyethylmethacrylate serves as an embedding medium.[4][3]
When treated with polyisocyanates, polyhydroxyethylmethacrylate makes a crosslinked polymer, an acrylic resin, that is a useful component in some paints.[13]
Hazards
Hydroxyethylmethacrylate is a mild skin irritant and can cause allergic skin reactions.[3][12]