Polyurethane elastomer is the first class coating material
Polyurathane is a polymer, which contains the urethane group -NH-CO-O-. Polyurethane is formed in reaction with isocyanate and polyol. After the reaction isocyanate is safe to handle. The characteristics of polyurethane vary depending on the chosen types of isocyanate and polyol. Polyurethane is used most commonly as rigid foam insulation panes in cars or buildings, as cellular foam in furnitures and mattresses, or as microcellular foam in shoe soles.
Polyurethane elastomers (PU) are part of the polyurethane group, and castable polyurethane elastomers are thus only a small part of the global polyurethane production and use. PU elastomers are formed by combining hard (isocyanate) and elastic (polyol) parts, and changing these selections creates the superiour qualities of the polyurethane elastomers.
Raw materials used in PU-elastomer production can be split in four groups
- isocyanates, most common are TDI and MDI
- polyols, most common are polyethers and polyesters
- chain extenters or cross linkers
- additives like pigments, flame retardants, fillers.
Polyurethane elastomers are superiour in following features
- resistance to abrasion
- tear strenght
- resistance to chemicals (oil, gas)
- load resistance
- oxidation resistance
More information about comparing PU to metals and plastics can be found here.