A polyurethane (PUR and PU) is polymer composed of a chain of organic units joined by carbamate (urethane) links.

Polyurethane polymers are formed by combining two or several bi- or higher functional monomers. One contains two or more isocyanate functional groups (with formula –N=C=O) and the other contains two or more hydroxyl groups (with formula –OH). The alcohol and the isocyanate groups combine to form a urethane linkage:

ROH + R'NCO → ROC(O)N(H)R' (R and R' are alkyl or aryl groups)

This combining process, sometimes called condensation, typically requires the presence of a catalyst. More complicated monomers are also used.

Polyurethanes are used in the manufacture of flexible, high-resilience foam seating; rigid foam insulation panels; microcellular foam seals and gaskets; durable elastomeric wheels and tires; automotive suspension bushings; electrical potting compounds; high performance adhesives; surface coatings and surface sealants; synthetic fibers (e.g., Spandex); carpet underlay; and hard-plastic parts (e.g., for electronic instruments).

Polyurethane is also used for the manufacture of hoses and skateboard wheels as it combines the best properties of both rubber and plastic.

Read more about PolyurethaneHistory, Chemistry, Raw Materials, Production, Health and Safety, Fungus, Manufacturing, Applications

Other articles related to "polyurethane, polyurethanes":

Thermoplastic Polyurethane
... Thermoplastic polyurethane (TPU) is any of a class of polyurethane plastics with many useful properties, including elasticity, transparency, and ...
Polytetrahydrofuran - Applications
... (elastan) for stretchable fabrics and for polyurethane resins ... The latter are polyurethane prepolymers dissolved in solvent ... These elastomers are either polyurethanes made by reacting PTMEG with diisocyanates, or polyesters made by reacting PTMEG with diacids or their ...
... folds into a 73x36X22cm package and has polyurethane wheels of diameter 125mm or 110mm ... Made of high-rebound polyurethane, they achieve low rolling friction despite the small diameter ... ski wheels, the only 100mm quality polyurethane wheels then available ...
Polyurethane - Testing - Effects of Visible Light
... Polyurethanes, especially those made using aromatic isocyanates, contain chromophores which interact with light ... This is of particular interest in the area of polyurethane coatings, where light stability is a critical factor and is the main reason that aliphatic isocyanates are used in making polyurethane ...
Uses - Castor Oil in Polyurethane
... Castor oil can be used as bio-based polyol in the polyurethane industry ... The average functionality of castor oil is 2.7, so it is widely used as rigid polyol of polyurethane industry ...