Hydroxyethylmethacrylate (also known as glycol methyacrylate)
[ is the ]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. The ...
with the chemical formula . It is a colorless viscous liquid that readily polymerizes. Hydroxyethylmethacrylate is a monomer
In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization.
Classification
Mo ...
that is used to make various polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...
s.
Synthesis
Hydroxyethylmethacrylate was first synthesized around 1925. Common methods of synthesis are:[
* reaction of ]methacrylic acid
Methacrylic acid, abbreviated MAA, is an organic compound. This colorless, viscous liquid is a carboxylic acid with an acrid unpleasant odor. It is soluble in warm water and miscible with most organic solvents. Methacrylic acid is produced indu ...
with ethylene oxide
Ethylene oxide is an organic compound with the chemical formula, formula . It is a cyclic ether and the simplest epoxide: a three-membered Ring (chemistry), ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless a ...
;
* esterification
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 ar ...
of methacrylic acid with a large excess of 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 ...
.
Both these methods give also some amount of ethylene dimethacrylate. During polymerization of hydroxyethylmethacrylate, it works as crosslinking agent
In chemistry and biology a cross-link is a bond or a short sequence of bonds that links one polymer chain to another. These links may take the form of covalent bonds or ionic bonds and the polymers can be either synthetic polymers or natural ...
.[
]
Properties
Hydroxyethylmethacrylate is completely miscible with water and ethanol, but its polymer is practically insoluble in common solvents. Its viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
is 0.0701 Pa⋅s at 20°C[ and 0.005 Pa⋅s at 30°C.][ During polymerization, it shrinks by approximately 6%.][
]
Applications
Contact lenses
In 1960, O. Wichterle and D. Lím[ described its use in synthesis of hydrophilic crosslinked networks, and these results had great importance for manufacture of soft ]contact lenses
Contact lenses, or simply contacts, are thin lenses placed directly on the surface of the eyes. Contact lenses are ocular prosthetic devices used by over 150 million people worldwide, and they can be worn to correct vision or for cosmetic ...
.[ Polyhydroxyethylmethacrylate is hydrophilic: it is capable of absorbing from 10 to 600% ]water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...
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.
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. When combined with a suitable blowing agent
A blowing agent is a substance which is capable of producing a cellular structure via a foaming process in a variety of materials that undergo hardening or phase transition, such as polymers, plastics, and metals. They are typically applied wh ...
such as BOC anhydride
Di-''tert''-butyl dicarbonate is a reagent widely used in organic synthesis. Since this compound can be regarded formally as the acid anhydride derived from a ''tert''-butoxycarbonyl (Boc) group, it is commonly referred to as Boc anhydride. This ...
it forms a foaming resin which expands when heated.
Other
In electron microscopy
An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a hi ...
, later in light microscopy
Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of micr ...
, hydroxyethylmethacrylate serves as an embedding medium.[
When treated with ]polyisocyanate
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, polyhydroxyethylmethacrylate makes a crosslinked polymer, an acrylic resin
186 px, Polyhydroxyethylmethacrylate is a typical acrylate resin.
An acrylic resin is a thermoplastic or thermosetting plastic substance typically derived from acrylic acid, methacrylic acid and acrylate monomers such as butyl acrylate and or me ...
, that is a useful component in some paints.
Hazards
Hydroxyethylmethacrylate is a mild skin irritant
Irritation, in biology and physiology, is a state of inflammation or painful reaction to allergy or cell-lining damage. A stimulus or agent which induces the state of irritation is an irritant. Irritants are typically thought of as chemical age ...
and can cause allergic skin reactions.[
]
References
{{DEFAULTSORT:Hydroxyethylmethacrylate
Methacrylate esters
Monomers