Overview

Polyurethanes (pol-ee-YUR-eth-anes) are a group of thermoplastic polymers formed in the reaction between a diisocyanate and a polyol, an alcohol with two or more hydoxyl (-OH) groups. Diisocyanates are compounds that contain two isocyanate (-N=C=O) groups.

Key Facts

Other Names:

None

Formula:

-[-CONH-C₆H₄-NCOO-CH₂CH₂-O-]-_n; other structures are possible

Elements:

Carbon, hydrogen, oxygen, nitrogen

Compound Type:

Organic polymer

State:

Solid

Molecular Weight:

Varies; very large

Melting Point:

Variable

Boiling Point:

Not applicable

Solubility:

Insoluble in water; soluble in aromatic hydrocarbons, such as benzene and toluene

Polyurethanes are available in a variety of forms, including fibers, foams, coatings, and elastomers, rubber-like materials. Each form of polyurethane has its own set of physical and chemical properties. For example, fibers are moisture proof, stretchable, and resistant to the flow of electric current. Foams can be either rigid or flexible, with densities as low...