Polyurethane, usually abbreviated as PU, is any polymer composed of chains 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.
Polyurethane formulations cover a very wide range of hardness, hardness and density. These materials include:
1. Low density soft foam used for interior decoration and bedding,
2. Low-density rigid foam for heat insulation and e.g. automobile dashboards.
3. Soft solid elastomers are used for gel pads and printing rollers, and hard solid plastics are used for electronic instrument frames and structural parts.