Acrylate

Template:Short description Template:See also Acrylates (IUPAC: prop-2-enoates) are the salts, esters, and conjugate bases of acrylic acid. The acrylate ion is the anion Template:Chem2. Often, acrylate refers to esters of acrylic acid, the most common member being methyl acrylate. These acrylates contain vinyl groups. These compounds are of interest because they are bifunctional: the vinyl group is susceptible to polymerization and the carboxylate group carries myriad functionalities.<ref name=Ullmann>Template:Cite encyclopedia</ref>

MonomersEdit

Acrylates are defined by the formula Template:Chem2, where R can be many groups:

The versatility of the resulting polymers is owed to the range of R groups.

Structures of some acrylates
Acrylate-anion.svg

The acrylate anion
Trimethylolpropane triacrylate.svg

Trimethylolpropane triacrylate (TMPTA), a trifunctional acrylate ester
Methylacrylat.svg

Methyl acrylate, an acrylic ester
Hexandioldiacrylat.svg

Hexandiol diacrylate, a bifunctional acrylate
Pentaerythritol tetraacrylate.png

Pentaerythritol tetraacrylate (PETA), a tetrafunctional acrylate
Polyacrylate.svg

A generic polyacrylate

Acrylate derivativesEdit

Methacrylates ( Template:Chem2) and cyanoacrylates ( Template:Chem2,) are closely related to acrylates. The feature a methyl and a nitrile in place of the H alpha to the carboxy functional group. They share several properties, being polymerized by radicals and being colorless.<ref>Template:Cite encyclopedia</ref>

Structures of some important modified acrylates
Methyl-methacrylate-skeletal.svg

Methyl methacrylate, precursor to "perspex" (plexiglass)
Ethyl cyanoacrylate.svg

Ethyl cyanoacrylate, precursor to "super glue"

PolymersEdit

File:Polyacrylate.svg

Structure of a generic polyacrylate. Polyacrylates are derived from acrylates but do not contain acrylate groups.

{{#invoke:Labelled list hatnote|labelledList|Main article|Main articles|Main page|Main pages}} Some acrylate polymers (poly(methyl methacrylate) etc. not included):

Acrylate monomers are used to form acrylate polymers. Most commonly, these polymers are in fact copolymers, being derived from two monomers.<ref>Template:Cite encyclopedia Template:Subscription required</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Related polymersEdit

File:CyanoacrylatePolymer.svg

Structure of the backbone of a cyanoacrylate polymer.

In the same way that several variants of acrylic esters are known, so too are the corresponding polymers. Their properties strongly depends on the substituent.

A large family of acrylate-like polymers are derived from methyl methacrylate and many related esters, especially polymethyl methacrylate.

A second large family of acrylate-like polymers are derived from ethyl cyanoacrylate, which gives rise to cyanoacrylates.

Yet another family of acrylate-related polymers are the polyacrylamides, especially the parent derived from acrylamide.

Other usesEdit

In addition to forming polymers, acrylate esters participate in other reactions relevant to organic chemistry. They are Michael acceptors and dienophiles. They undergo transesterification.

ProductionEdit

Acrylates are industrially prepared by treating acrylic acid with the corresponding alcohol in presence of a catalyst. The reaction with lower alcohols (methanol, ethanol) takes place at 100–120 °C with acidic heterogeneous catalysts (cation exchanger). The reaction of higher alcohols (n-butanol, 2-ethylhexanol) is catalysed with sulfuric acid in homogeneous phase. Acrylates of even higher alcohols are obtainable by transesterification of lower esters catalysed by titanium alcoholates or organic tin compounds (e.g. dibutyltin dilaurate).<ref>Template:Cite book</ref>

ReferencesEdit

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