Urethane is a type of molecule that is used most commonly as part of polyurethane. Polyurethane, a polymer, is created by joining various monomers by urethane. Polyurethane foams is one of the most important and consequential derivatives of urethane. Polyurethane foams can be used for cushioning, structural support and many other functions in industry.
Urethane on its own is primarily used as part of polymers, called polyurethane. Polyurethane, a generic term, is given to any compound that has several organic compounds connected by the urethane chemical group. This basic polyurethane model is the standard structure. However, it can be tweaked in many ways, by adding other compounds that can include molecules such as flame retardants, pigments and surfactants.
Urethanes and polyurethanes are a type of reaction polymers. Other examples of reaction polymers are epoxies, phenols and polyester. Polyurethane is a polymer that that is made by combining monomer with at least two alcohol groups with monomers with two or more isocyanate groups. The two monomers, fused with a urea group, extend this reaction. This reaction commonly includes a catalyst, which speeds the polymerization process.
Urethane is a critical component of polyurethane polymers. Polyurethane is primarily used to generate a foam. Water and other reactants, such as halocarbons and hydrocarbons (an example of which is n-pentane) can be blown into the polyurethane. Water and other reactants will interact with the polymer, which will cause the formation of carbon dioxide, causing small cells to form and expand. Once the polyurethane thickens and hardens, a foam is created. Other compounds, such as surfactants can be used to modify the size of these cells of foam and to prevent their collapse.
The properties of urethane foam can be altered via certain modifications. Softer foam, such as that used for soft rubber and spandex can be generated by using polyether compounds, which can serve as the source of the alcohols (the alcohols which are required for reaction with the isocyanate groups). Rigid polyurethane can be made by using special catalysts and other compounds which give the matrix of the foam a stronger, cyclic structure. Additionally, control of the monomers and the catalysts can be used to create memory foam.
Polyurethane foam has differing properties based on the reaction conditions, which makes it useful for commercial purposes. It can be used a a form of support behind other structures such as cushioning. In addition, it can be used as insulation. Its ability to change its pliability allows for careful and easy molding, which allows it to retain the shape of body parts that are carefully pressed to it, which allows for the generation of form-fitting structures.