Remarkable properties
Within the past couple of years several companies have introduced polyaspartic polyurea products with remarkable features compared to other coating materials:
- They can be applied at temperatures as low as -30°F and as high as 140°F, depending on the product. In hot and cold climates contractors can install them all year long.
- When cured they can tolerate temperatures as high as 350°F.
- They are UV light stable, providing “water clear” finishes.
- Polyureas have much greater abrasion and impact resistance than either epoxy or urethane coatings.
- They do not blush or whiten.
- Curing is quick and work can be turned over to owners for use within a couple hours after application.
- High ambient humidity doesn’t restrict their application, although some products set more quickly in high humidity.
- They don’t stain, they resist fat and oil penetration, and concrete is protected from mild acids.
- Polyureas have excellent wetting and penetrating characteristics, which means they form excellent bonds to concrete.
Polyaspartic polyureas don’t require the deep profile preparations that other coatings do. Garage Floors 1 discovered that they could quickly diamond grind a garage floor surface with 80 grit pads to prepare the concrete surface. Photo: Garage Floors 1
History
Aspartic esters were invented and patented by Bayer Corp. in the 1990s. Aspartic resins followed and the manufacturer found that films could be formed which were very dense and shiny, leading to the creation of polyaspartic aliphatic polyureas. Now several companies have introduced formulations that contractors can use commercially. Their formulations share several common properties but there are also benefits and cautions unique to each product on the market.
Polyureas are 2-component materials. The system works when a resin is mixed with a catalyst, usually a polyisocyanate, which causes a reaction and develops a polymer compound. The first to be marketed were aromatic polyureas but installing them required expensive spraying equipment that mixed parts A and B together at the spray tip, with hardening of the material following a few seconds later. Aromatic polyureas are also susceptible to UV degradation at the membrane’s surface.