View source for Chemistry:Polyaspartic

 '''Polyaspartic''' [[Chemistry:Chemistry|chemistry]] was first introduced in the early 1990s making it a relatively new technology.<ref>European Patent EP-A-0,403,921</ref><ref>US Patent US 5,243,012</ref><ref>{{Cite web|url=https://laticrete.com/en/solution-center/featured-solutions/resinous-flooring-and-decorative-coatings/about-polyaspartic-technology/polyaspartic-concrete-coating-facts|title=Polyaspartic Concrete Coating Facts - LATICRETE|website=laticrete.com|access-date=2019-11-11}}</ref> The patents were issued to [[Company:Bayer|Bayer]] in {{wipe|Germany}} and Miles Corporation in the {{wipe|United States}}. Pure [[Chemistry:Polyurea|polyurea]] reacts extremely quickly making them almost unusable without plural component spray equipment. Polyaspartic technology utilizes a partially blocked amine to react more slowly with the [[Chemistry:Isocyanate|isocyanate]]s and thus produce a modified [[Chemistry:Polyurea|polyurea]]. The [[Chemistry:Amine|amine]]/[[Chemistry:Diamine|diamine]] or even triamine functional coreactant for aliphatic polyisocyanate is typically reacted with a maleate.<ref>{{Cite journal|last=Howarth|first=G.A|date=2003|title=Polyurethanes, polyurethane dispersions and polyureas: Past, present and future|journal=Surface Coatings International Part B: Coatings Transactions|volume=86|issue=2|pages=1110–118|doi=10.1007/BF02699621}}</ref> Polyaspartic esters (PAE) as they are often called,<ref>US Patent US 6,790,925 B2</ref> initially found use in conventional [[Physics:Solvent|solvent]]-borne two-component polyurethane coatings.
== Chemistry ==

To manufacture a polyaspartic, an amine is reacted with dialkyl maleate by the [[Chemistry:Michael reaction|Michael reaction]].<ref>US Patent US 5,821,326</ref> This converts the primary amines to secondary amines and also introduces bulky groups to the molecule which causes steric hindrance, slowing the reaction down. As the resulting aspartic molecule is now much bigger, less of the [[Chemistry:Isocyanate|isocyanate]] is needed on a weight for weight basis. The isocyanate is often the most expensive part of the system especially if an aliphatic [[Chemistry:Isocyanate|isocyanate]] [[Chemistry:Oligomer|oligomer]] is used and so may result in an overall lower system cost per applied film thickness. Isocyanates are known pulmonary sensitizers and hence oligomeric forms are often used with polyaspartic technology as these are much less volatile.

== Uses ==

Eventually, the advantages of using polyaspartic esters as the main component of the co-reactant for reaction with an aliphatic polyisocyanate in low to zero [[Earth:Volatile organic compound|volatile organic compound]] (VOC) coatings was  realized.<ref>US Patent US 2016/0024339 A1</ref> The rate of reaction of polyaspartic esters can be manipulated, thus extending the pot-life and controlling the cure rate of aliphatic coatings.  This allows formulators to create high solids coatings systems which are user-friendly with longer working times and still maintain a fast-cure.<ref>{{Cite web|url=https://www.coatingsworld.com/contents/view_suppliers-news/2012-01-17/pflaumer-introduces-new-amine-functional-resin-for-polyaspartic-polyurea-and-polyurethane-coatings/|title=Pflaumer introduces new amine-functional resin for polyaspartic, polyurea and polyurethane coatings|website=Coatings World|access-date=2019-11-11}}</ref>  Traditional aliphatic polyurea formulations required high-pressure, high-temperature plural component spray systems to be applied due to fast initial reaction rates.  Aliphatic polyaspartics can be formulated with slower reaction rates to accommodate batch-mixing and application by roller-applied methods or spray-applied through conventional single components paint sprayers without the use of solvent. As with aliphatic polyurethane or acrylic coatings, polyaspartic coatings made with aliphatic isocyanates and derivatives are UV and light stable and have a low yellowing tendency. When coating concrete, polyaspartics can be installed in both clear and pigmented form. Additionally, broadcast media such as quartz and/or vinyl  paint chips can be incorporating, as well as metallic pigments.<ref name="Bayer">{{cite web|url=http://www.bayermaterialsciencenafta.com/processing/cas/polyaspartic/definition.html|publisher=Bayer|title=Polyaspartic Coating Technology definition|access-date=2012-08-23|archive-url=https://web.archive.org/web/20130605145807/http://www.bayermaterialsciencenafta.com/processing/cas/polyaspartic/definition.html|archive-date=2013-06-05|url-status=dead}}</ref>

== References ==
<references />

== External websites==
* [https://www.covestro.com/en/company/profile/overview?gclid=EAIaIQobChMImd-o5M7i5QIVqvfjBx1uWgqcEAAYASAAEgKB3PD_BwE Covestro (formerly Bayer Material Science)]
* [http://www.arnettepolymers.com Arnette Polymers LLC]
* [https://www.cargill.com/bioindustrial/polyaspartic-esters Cargill Polyaspartate product line]
* [https://www.tse-industries.com TSE Industries]

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