PU Foam

A polyurethane, commonly abbreviated PU, is any polymer consisting of a chain of organic units joined by urethane links. Polyurethane polymers are formed by reacting a monomer containing at least two isocyanate
functional groups with another monomer containing at least two alcohol groups in the presence of a catalyst.

PU polymer formed by reacting a diisocyanate with a polyol

Polyurethane formulations cover an extremely wide range of stiffness, hardness, and densities. These materials include:

• low density flexible foam used in upholstery and bedding,
  
• low density rigid foam used for thermal insulation and e.g. automobile dashboards,
  
• soft solid elastomers used for gel pads and print rollers, and
  
• hard solid plastics used as electronic instrument bezels and structural parts.
  

 
 

Pasted from <http://en.wikipedia.org/wiki/Polyurethane>