Polyurethane is based on the polyaddition reaction between a polyol (an alcohol with more than one hydroxyl group per molecule) and adiisocyanate. The reaction is exothermic.
The polymerization can be influenced by the type of polyol and isocyanate components as well as additives.
The cell formation is obtained by the addition of a blowing agent or inclusion of air.
The blowing agent can be an Halogented Hydro Carbons with a low boiling point but also the presence of water in the reacting mixture produces a foaming effect because the isocyanate groups react with water forming carbon dioxide.
Basic Polyurethane Properties:
|Solid Polyurethane Elastomers||1,200 kg/m3||Print Rollers, Cast Elastomers, RIM solid plastics|
|Microcellular Foams and Elastomers||800 kg/m3||Coatings, Adhesives, Sealants, and Elastomers|
|Low Density Foams||6 kg/m||
Footwear Outsoles, Footwear Midsoles, Integral Skin Foam,
Simulated Wood For Vehicle Interiors High Resiliency Foam
For Insulation Foam Bedding And Upholstery Packaging Foam
|Density Stiffness||Flexible, Semi- Rigid, Rigid|
Thermal Conductivity Comparison List:
|Insulation Material||Thermal Conductivity (K_Value) W/mC||Thickness (MM)|
|Rigid Polyurethane Foam||0.019||34|
|Glass Mineral Wool||0.055||55|
The following Table Shows How Polyurethanes Are Used:
|Application||Amount of Polyurethane used (Millions of Pounds)||Percentage of total|
|Building & Constructions||1,298||23.8%|
|Furniture & Bedding||1,127||20.7%|
|Textiles, Fibers & Apparel||181||3.3%|
|Machinery & Foundry||178||3.3%|