Polyurethane  is a polymer composed of two units. One of them is isocyanate. The other is a mixture of polyol (composed of polyester or polyether together with additives – catalysts, stabilizers, emulsifiers, blowing agents, flame retardants, solvents, pigments). If we mix all ingredients properly, we will cause a reaction which produces foam that quickly expands and solidifies when applied on a surface. This unique feature makes it an universal material for insulating all kinds of surfaces, , including areas which are hard to reach.

Polyurethane foams have good thermal properties in wide range of temperatures from -200 C to 135°C - PUR and from -200°C to 200°C – PIR.

Average thermal conductivity is λ₄₀ is 0,026 W/(m·K) and 0,024 W/(m·K). Average bulk density is 35-50 kg/m³.

PUR and PIR foams are light as well as chemically and biologically resistant. They also bear relatively high mechanical load. That is why these hi-tech materials are used in insulating techniques.