Issue 10: Polyurea Hybrid Coatings: Understand the Differences
Sometimes a customer is told that a supplier has a polyurea hybrid and that a hybrid will outperform polyurethane because of the polyurea component of the formula. However, all polyurea hybrid coatings are not created equal.
Most customers take what they are told at face value, without a more in-depth understanding of the issues involved. Customers should ask questions. If the polyurea component is the determining factor that boosts the physical properties, exactly how much of the hybrid product is polyurea coating and how much is polyurethane? One supplier could offer an 80% polyurea coating/20% polyurethane mix to get one level of performance; a second could have a 50%/50% ratio to have a perfectly balanced blend, according to its claims; and a third could use a 99% polyurethane/1% polyurea coating system. While each supplier would be correct in calling their product a Polyurea Hybrid, the customers of each would be purchasing a coating with drastically different performance characteristics.
It’s extremely important to know what you’re buying. Too many coating specifiers are unaware of the subtle differences in these coatings and their properties. Every contractor should either seek out specifiers that understand the key differences between polyurea hybrid coatings or be willing to train the specifiers with whom they work.
The Importance of Aliphatic Coatings and UV-Stability
In theory, UV-stable products should have very little loss of gloss or color fade over time, even when exposed to sunlight. On the other hand, non-UV-stable products will first lose gloss when exposed to sunlight, then fade and/or yellow, and, eventually, experience polymer breakdown and coating failure. By definition, aliphatic polyurea coating systems are UV-stable, while aromatic polyurea coating systems are not. What seems pure and simple, is neither pure or simple.
Labels of aliphatic coating products can be deceptive. Although a number of aliphatic systems are truly 100% aliphatic, there are too many aliphatic products out there that are, in fact, blends of aliphatic and aromatic. Some producers will make a blend that is only 51% aliphatic and 49% aromatic and still claim it is an aliphatic product. While there is some argument for this being true, is the customer educated during the purchasing process?
Educate yourself. When purchasing an aliphatic system, ask the producer about the percent of aliphatic materials in their product. Read the product’s Material Safety Data Sheet (MSDS). An aliphatic polyurea coating will contain only IPDI and/or HDI isocyanate (Side A) component. An aromatic polyurea coating uses MDI or TDI isocyanate. Since MDI and TDI are not UV-stable, you should not find either of these components in a truly aliphatic product.