The polyurea is a synthetic polymer obtained from the reaction of a diamine with a diisocyanate, polymerization reaction is very similar to polyurethane one, but in case of polyurea, resulting link is a "urea", so it is called polyurea.
By this link we get from generating molecular structure an insensitivity to moisture, thus making the polyurea (if pure) the best waterproof membrane.
We say "if pure" because in the market there are numerous polyurea-called "hybrid", which are a mixture between polyurea and polyurethane. These membranes do not have the same mechanical properties as the pure polyurea (elongation, abrasion resistance, etc ...). The following graph clearly shows the difference.
Isocyanate + Polyamine
Molecular structure completely insensitive to moisture. Pure polyurea does not react with water making it the best waterproofing material.
Isocyanate + Polyol + Polyamine
A polyol participates in the molecular structure of the hybrids, which gives it properties halfway between pure polyurea and polyurethane.
Isocyanate + Catalyst + Polyol
Polyurethane needs a catalyst in its structure which adds an extra molecular bond. Excellent waterproofing material but with lower mechanical properties than polyureas.
Polyurea types (pure)
Depending on polyurea chemical structure, it could be of two types: aliphatic or aromatic.
The aromatic polyurea is more tenacious and not resists UV exposure, causing some discoloration and loss of shine, which is not recommended for applications "face side". On the contrary, aliphatic polyurea is resistant to UV radiation and it is excellent as a finish coat, because of its raw materials high costs, it makes it a polyurea of higher price range.
The application of the polyurea is normally performed in hot state; for that is needed a hot spraying plural components (2-components) equipment under high pressure (type GRACO Reactor E-XP2). This equipment is capable of providing a pressure of 2700 psi at a temperature of 70 ° C. This kind of polyurea dry only in 3 or 4 seconds once applied.
There is also the called cold polyurea or polyurea cold applied, it not requires a spraying equipment because it is processed manually using a rubber float, spatula or trowel. This polyurea takes longer to dry than faster one hot sprayed.
Advantages and Properties of Polyurea
There are many advantages and properties of polyurea membrane, then the most important detail:
- membrane without joints or overlaps and of maximum flexibility - up to 600% elongation.
Polyurea properties make it a product for applications where waterproofing, protection and durability are fundamental. The endless possibilities for polyurea coloration are a clear advantage in those applications where the aesthetic aspect plays an important role. The adaptability and adhesion of the polyurea allow use in almost any application requirement waterproofing, coating and / or protection can include: waterproofing and corrosion protection on steel, concrete and many other supports.
In Tecnopol, we are constantly innovating in the creation and development of new products and the improvement of existing formulations. Currently, we have different membranes according to your needs: