Polyurethanes

{
  "id": "MLC-T-ENV-021575",
  "term": "Polyurethanes",
  "field": "Environment",
  "definition": "1. They are extremely versatile plastics in terms of the forms in which they are available: flexible or rigid foams, solid elastomers (or rubbers), coatings, adhesives and sealants. Their versatility also extends to chemical structure in that, although the urethanes are generally considered to be thermosets, there are grades of urethane elastomers that are thermoplastic in nature and are supplied in pellet form for molding, calendering and extrusion. Polyurethane’s major and best known form, however, is a foamed or “cellular” material. Like all urethanes, the foams are prepared by first reacting two liquid components--polyols and isocyanates--together.\n\n2. A group of thermoplastic or thermosetting polymers containing polyisocyanate. They are used as ELASTOMERS, as coatings, as fibers and as foams.",
  "references": [
    "EPA EV-Chemical Substances",
    "NLM Medical Subject Headings (MeSH)"
  ],
  "url": "https://mlchart.com/terminology/environment/polyurethanes/"
}