What is urethanes?

Urethanes, more formally known as polyurethanes (PUR and PU), are a class of polymers composed of organic units joined by carbamate (urethane) links. Polyurethanes are used in a wide variety of applications, including flexible and rigid foams, durable elastomers and coatings, adhesives, sealants, and fibers. They are formed by reacting a polyol (an alcohol with more than two reactive hydroxyl groups per molecule) with a diisocyanate or a polymeric isocyanate in the presence of suitable catalysts and additives.