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Answers to your Questions |
What is Polyurea?
Polyurea is an elastomer that is obtained by mixing two reactive components: an isocyanate component and an amine component.
What can you do with Polyurea?
Polyurea systems are used as spray-applied protective or wear coatings in various industrial applications, for example in the construction of tanks and industrial buildings, roads and bridges, in hard landscaping and in interior fitting. When used to spray out moulds, for example for rigid plastic parts for automotive applications, Polyurea helps to produce a wide variety of shaped parts with excellent surface finish quality. They ensure smooth and flawless coating results.
What are the advantages of Polyurea?
Polyurea coatings stand out for their excellent resistance to ageing, chemicals and mechanical wear and tear and outstanding abrasion resistance. By their elasticity these coatings readily bridge cracks in concrete and seal them durably; they also adhere superbly to a wide variety of substrates. A major advantage of Polyurea coatings is the fact that they set within a matter of seconds and take just a few hours to cure through. This allows surfaces coated with Polyurea to be reopened for use without any limitations after just 24 hours. Unlike other spray coatings, Polyurea systems can also be applied in humid and low-temperature outdoor conditions.
How do you apply Polyurea?
When the components are mixed, the isocyanate component (based on diphenylmethane diisocyanate, hexamethylene diisocyanate or isophorone diisocyanate) reacts with an amine or an amine mixture. The two Polyurea components are processed in practice at a mixing ratio of 1:1 by volume. The components are blended in the mixing chamber of the spray nozzle. You need special spraying equipment because the components must have a specified temperature for mixing, and because they are atomized by means of high pressure.
How do you need to pretreat the substrate before applying a Polyurea system?
The durability and functional properties of the Polyurea coating depend largely on the care taken to pretreat the substrate before the coating is applied. In order to prevent water creeping under the Polyurea coating, you will need to clean and seal the substrate surface prior to applying the Polyurea system. The coating will be sprayed onto the homogeneously prepared surface.
Which amines do you need to use for a Polyurea coating?
The main amine component for Polyurea coatings is the polyetheramine D2000. Shorter-chain polyetheramines (D230, D400) determine the degree of curing, while branched polyetheramines (T403, T5000) influence the elasticity of the spray coating. Polytetrahydrofuranamine 1700 (PolyTHF) guarantees low water absorption, and adding cycloaliphatic amines (such as dimethyldiaminodicyclohexylmethane) improves thermal stability. As the world’s leading amine manufacturer, BASF offers a broad range of polyetheramines and cycloaliphatic amines that may be used as crosslinking agents.
What type of amine has BASF developed specifically for Polyurea coatings?
The newly developed cycloaliphatic amine Baxxodur™ PC 136 from BASF allows the reactivity of the appropriate Polyurea system to be modified to suit the particular application. Apart from the primary amines already mentioned, secondary amines are used as so-called chain extenders. They modify the application properties as well as the functional properties of the coating, which makes them indispensable components of a high-quality protective Polyurea coating.
What other properties distinguish Baxxodur PC 136?
Baxxodur PC 136 stands out for its excellent UV resistance and color stability in purely aliphatic systems. In contrast to Baxxodur PC 136, systems based on aromatic isocyanates and amines show significant yellowing.
How do users of Polyurea benefit from cooperating with BASF?
BASF offers a globally unrivalled portfolio of amine-based curing agents and accelerators that are essential to the favorable properties of the finished product. As a reliable long-term partner who offers high-grade products and intelligent solutions, BASF helps its customers to be more successful. The products of BASF’s Intermediates division help to improve the properties of final products and the efficiency of production processes.
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stephan.goettke@basf.com
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