What are Polyurethane Coatings?

We come in contact with polyurethanes, and their cousin’s polyureas, every day without realizing it. For the purpose of our introduction we will refer to these materials as “urethanes”.

Urethanes are a family of plastic materials that can be formulated to produce a wide variety of physical properties from soft seat cushions to rigid automotive body panels. Urethanes are a combination of two components, a “resin” and an “isocyanate.” These two materials come together in liquid form and react to form a urethane. The reaction time can be regulated by the addition of catalysts and other ingredients and can vary from a couple of seconds to several hours.

Urethanes can be manufactured using two different types of components – aromatic and aliphatic. Aromatic urethanes are more economical and will discolor with exposure to light. Aliphatic urethanes are twice as expensive but will not discolor. Automotive paint is a common example of aliphatic urethane. Virtually all sprayed bedliners use aromatic urethane.

Some companies in our industry claim that their colors will not fade because they have “UV stabilizers” in their aromatic urethane. This is chemically impossible. Even the best stabilizers will only slow down the rate of discoloration, not prevent it. Therefore, if it is not aliphatic urethane it will change color over time.

All Armaguard color bedliners (excluding Black) are applied using an aliphatic elastomer top coat; incorporating automotive paint pigments to produce a color match that will keep its color as long as any automotive finish.