Polyurethane (PUR or PU) is a polymer formed by the chain reaction between the isocyanates and the polyols in the presence of a catalyst.
While most polyurethanes are thermosetting polymers that do not melt when heated, thermoplastic polyurethanes are also available.
The physical properties of the polyurethanes are influenced by the amount of cross-linking between the isocyanates and polyols. High amount of cross-linking between the two gives tough and rigid polymers. Similarly, low amount of cross-linking gives soft, elastic polymer. The amount of cross-linking can be controlled by the varying the amounts of isocyanates and polyols. Also, other additives are added to help processing the polymer or to change the properties of the polymer.
Polyurethane is also referred to as urethane. Polyurethane is an extremely versatile elastomer used in countless applications world wide. They are used in wide variety of applications both consumables and industrial products which make our lives convenient and comfortable.