Polyurethane is an incredibly resilient, flexible, and durable manufactured material that can take the place of paint, cotton, rubber, metal, and wood in thousands of applications across all fields. Polyurethane might be hard, like fiberglass, squishy like upholstery foam, protective like varnish, bouncy like rubber wheels, or sticky like glue. Since its invention in the 40s, polyurethane has been used in everything from baby toys to airplane wings, and continues to be adapted for contemporary technology.

Polyurethane is a substance categorized as a polymer based on its chemical structure. One manufacturers polyurethane by combining a diisocyanate and a diol, two monomers, through a chemical reaction. This makes a basic material whose variations can be stretched, smashed, or scratched, and remain fairly indestructible. Depending on the different diisocyanates and diol or polyol constituents, the resulting polyurethane might take a liquid, foam, or solid form, each with advantages and limitations.

Some polyurethane is categorized as an elastomer. It has elastic properties while maintaining some rigidity, such as in the wheels of a dolly that absorb shock but don't compress too much. It can be extremely flexible when used as a foam insulator in construction or a foam cushion in upholstery. It can be deformed over and over and still maintain its original shape; in other words, it has a structural memory. Elastomers have made our home and work environments warm and comfortable.

Other polyurethane is a thermoplastic that resembles other kinds of plastic, metal, or fiberglass. Thermoplastics are rigid and smooth with a sealed surface impermeable to water. These are used when strength and durability are important, such as in seats at an airport terminal or packaging crates on a truck. Some polymer thermoplastics are difficult to recycle, but they can be reused.

We can find polyurethane in every room of our house and practically everywhere we go. Since this material's popularity grew during World War II, the polymer has protected, reinvented, joined, or transported countless items. It seals surfaces like wood, metal, and paint to protect them from rot, corrosion, or fading. As an adhesive, polyurethane resists moisture and heat, so it's ideal for use in the sun or ocean. It insulates walls, temperature-controlled vehicles, and consumer coolers.