A CLOSER LOOK AT THE CLAIMS

There are numerous claims that many new polyurea system manufacturers or suppliers are making which need a closer look:

Moisture Insensitivity/Moisture Resistance

It's true that typical polyurethane systems can be sensitive to humidity and moisture. A urethane can react with atmospheric moisture or high humidity. The result is carbon dioxide gas which causes the foaming and/or pinholing. The reaction of Component A and Component B (polyamines) or a polyurea system is so fast that the moisture reaction can't occur. Therefore, the polyurea systems are not sensitive to moisture and humidity and do not normally produce carbon dioxide bubbles. (The A & B components react together faster than the A component can react with moisture or water). This feature is an advantage in high humidity climates or regions. Furthermore, this feature is also helpful if a substrate is moist or has condensation on it. However, it's a poor practice to apply any system over moisture or an unprimed substrate. (We will address the surface preparation details later in this paper). To be fair, don't stereotype. Some polyurethane systems can be formulated to also have high tolerance to moisture. Futura has developed a second generation of polyurethanes coatings elastomers and structurals that are extremely resistant to foaming or pinholing in high humidity or most environments. Since Futura produces its own prepolymers (The "A" component) and has a high investment in innovative research, most of the moisture sensitivity of typical urethanes has been overcome on the products that we produce and market. Therefore, if moisture insensitivity is the key reason that a polyurea is being chosen over a polyurethane, then, in most cases, Futura's polyurethane technology will do the job as well.

Spraying Over Wet Surfaces

Another claim in the industry is that the polyureas can be sprayed on moist or wet substrates without any foaming, moisture reaction or detrimental effect. Part of this claim is true. However, there could be detrimental results in regards to adhesion. It should be fairly obvious that if there is a substantial amount of water or moisture the adhesion will be compromised. It's an industrial standard (NACE, SSPC, etc.) that all surfaces be properly prepared and primed, especially in critical applications such as containment linings, abrasion resistant elastomers and flooring. (Furthermore, once a porous surface is primed, the moist substrate issue is basically eliminated). There are a few non-critical applications where spraying a polyurea system directly to moist concrete, wood or fabric will have satisfactory results. Consult Futura for these specific applications or approvals to do so.

Fast Cure Properties

Polyurea systems are being promoted as fast cure, which is true, and they can gel as fast as 3-10 seconds. The polyurethane can be catalyzed as fast as five seconds but when necessary can be slowed down to a few minutes or more. Both systems can be considered fast gel/cure systems and can be used to increase fabrication or production efficiency in all applications. However, it is important to note that sometimes a polyurea can be too fast and may not produce the results required for a specific application.

Fast Cure Surface Finish

The polyurethane reaction profile can be adjusted to achieve an aesthetically smooth gloss finish. Most polyurea are so fast that the surface has a rough orange peel texture to it. As mentioned previously, both systems use a common or similar component A which is a low to medium viscosity resin. And while the component B sides have different terminated reactive groups on the polymer (hydrols vs amine groups), the resins are otherwise very similar in viscosity and both are solventless. As a result, either a polyurea or polyurethane can both provide some advantages in regards to having zero VOC and meeting all environmental regulations. Solventless