Polyurethane is a long chain of organic compounds which react on contact with oxygen, while urethane has a central group of reactive compounds. The two are variously effective at preventing damage from weather and accidents.
Urethane and polyurethane are both sealants commonly used in painting and in flooring. They form distinct finishes, with polyurethane darkening wood noticeably, while urethane dries quickly and forms a thin veneer. They are most often used indoors, but outdoor sealants are also manufactured and used in contracting and building.
The finish formed with polyurethane displays the following qualities:
- Resistant to blunt force and solvents.
- Dark, thick gloss.
- Slow setting period.
The finish formed with urethane displays the following qualities:
- Easily buffed or polished to a high sheen.
- Short drying time.
- Adheres less readily to surfaces.
Urethane forms a lighter finish that does not darken underlying wood like polyurethane can. It is more easily damaged than polyurethane, but it is also easier to maintain and to keep at a high gloss.