A polyurethane, commonly abbreviated PU, is any polymer consisting of a chain of organic units joined by urethane (carbamate) links. Polyurethane polymers are formed through step-growth polymerization by reacting a monomer containing at least two isocyanate functional groups with another monomer containing at least two hydroxyl (alcohol) groups in the presence of a catalyst.
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 RTM cores
- · Soft solid elastomers used for gel pads and print rollers
- · Hard solid plastics used as electronic instrument bezels and structural parts
- Polyurethanes are widely used in high resiliency flexible 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 and sealants, Spandex fibers, seals, gaskets, carpet underlay, and hard plastic parts.