Polyurethane is made by reacting polyols and diisocyanates,
Polyols and diisocyanates are derived from crude oil and removed during the refining process just like gasoline.
Polyurethane foam can be flexible or rigid. Each form of polyurethane has many uses.
Most polyurethanes do not melt when heated but there are some (thermoplastic polyurethanes) that do.
Polyurethane formulations cover an extremely wide range of stiffness, hardness, and densities. These materials include:
Low-density flexible foam used in upholstery, bedding, and automotive and truck seating
Low-density rigid foam used for thermal insulation and RTM cores
Soft solid elastomers used for gel pads and print rollers
Low density elastomers used in footwear
Hard solid plastics used as electronic instrument bezels and structural parts
Flexible plastics used as straps and bands
lining the cups of brassieres.