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Polyurethane is a polymer composed of organic measurements joined by carbamate (urethane) links. They can be either closed-cell or open-cell Foam. Most polyurethanes appears to be thermoset polymers and will not melt when heated, but thermoplastic polyurethanes are also available.
Polyurethane products often are merely called “urethanes,” but should not be confused with ethyl carbamate, which is also called urethane. Polyurethanes do not contain nor are they produced from ethyl carbamate.

One of the most desirable attributes of polyurethanes is their ability to be turned into a foam material. Polyurethane foam (including foam rubber) can be made by using small amounts of blowing agents to achieve a less dense foam, better cushioning/energy absorption or thermal insulation.

Foams can be either “closed-cell,” in which the majority of the initial bubbles or cells stay undamaged, or “open-cell,” in which the bubbles have shattered but the edges of the bubbles are firm enough to maintain their form. Open-cell foams feel cushiony and enable air to move through, and are comfortable if utilized in seat cushions or bed mattresses. Closed-cell firm foams are used as thermal insulation, for instance in refrigerators.

Closed-Cell stiff, self-skinning and flexible polyurethane foams are generally utilized for high-performance applications by initial machinery manufacturers, especially in the aerospace, marine, defense, nuclear and other markets. Usually, they are utilized in tooling as well as mold making; as composite core and prototyping product; with regard to the protection of explosive products or radioactive; and also as a wood replacement for dimensional signs, sculptures, and displays.

Polyurethanes are used in the manufacture of products that need to recover its size and shape, along with high-performance adhesives, coatings, and sealants.