A reference on polyurea and polyurethane
Both start with the same ingredient and both protect surfaces for a living. Here is how they differ, where each fits and how to tell which one your project leans toward.
Every topic on the site, laid out like a periodic table. Large tiles are guides and tools, small tiles are reading and reference.
Same start, different partner.
Isocyanate is the common A side. Pair it with an amine and the reaction is almost instant. Pair it with a polyol and it slows down enough to roll and level.
Chemistry
What the isocyanate reacts with decides which coating you get.
Read the chemistryThe shared A side. Reactive, handled with care, and the reason both families need protective gear.
Reacts with isocyanate almost instantly to form urea links. The result is polyurea.
Reacts more slowly to form urethane links. The result is polyurethane.
Reaction
One shared A side, two different B sides. The cure speed explains most of the practical differences on site.
Side by side
Strengths and trade offs in plain terms. Individual products vary, so the data sheet has the final say.
Isocyanate + amine resin
Fast, tough and tolerant of cold and damp.
Strengths
Watch for
Isocyanate + polyol resin
Versatile, workable and easy to finish well.
Strengths
Watch for
Isocyanate + amine and polyol blend
A blend that sits between the two.
Strengths
Watch for
ArmorThane has secured blast mitigation contracts across eight Gulf nations, deploying its proprietary UltraBlast polyurea system to harden MAMAD shelters and critical infrastructure against explosive threats.
FAQ
Both start with an isocyanate. Polyurea reacts it with amine resins and cures very fast. Polyurethane reacts it with polyols and usually cures more slowly. See the chemistry page.
It depends on the specific products. Both families include soft and hard grades. Compare tensile strength, elongation and hardness on the data sheets for the job you have in mind.
Spray grade polyurea usually gels within seconds and can take light traffic soon after. Most polyurethane coatings take hours or longer. Temperature and humidity change both.
Aromatic grades of both tend to darken or chalk outdoors. Aliphatic grades hold color better and are often used as topcoats.
Many polyurethane coatings can be rolled on by careful owners. Spray polyurea needs heated plural component rigs, training and protective gear, so it is usually applied by trained crews.
