Polyols
Oligomeric and polymeric polyols are an important group of functional resins which are used in the manufacture of a large number of products. They are typically viscous liquids or waxy solids depending on molecular weight, type of backbone and hydroxyl content. The five most important types of polyols are polyether, polyester, polybutadiene, polycarbonate and polyacrylate polyols. The latter two are used on a much smaller scale because they are more expensive and are typically chosen where superior weathering and/or heat resistance is important.
Polyols are very important components of polyesters and polyurethanes. As chain extenders, they control to a large extent the mechanical, thermal and physical properties and can reduce the overall cost. For example, oligomeric polyether polyols are known to greatly improve the flexibilty and toughness of polyesters and polyurethanes whereas monomeric polyols, due to their low equivalent weights, produce more rigid polymers.
Properties
Since the generic term polyol is only derived from chemical nomenclature and just indicates the presence of several hydroxyl groups, no common properties can be assigned to all polyols. The performance characteristics of polyurethanes are sometimes modified with a variety of additives, to increase, for example, strength, rigidity, or flexibility. However, thy are usually highly viscous (when polymeric) to solid at room temperature.
Applications
Polyols are alcohols with more than one hydroxyl group and they constitute one of the main raw materials for manufacturing polyurethane.
- Polyether Polyols are useful in the production of high-resiliency, flexible molded foams and can be used to formulate coatings, adhesives, sealants and elastomers.
- Polyether Polyols make it easier to comply with regulatory standards and deliver excellent fire-retardant properties, ultra-low emissions and increased comfort levels in flexible foams for furniture, bedding and seating applications.
- Active Additive Polyols help reduce or eliminate the addition of catalysts while creating consistent, high-quality bonds, and enabling resistance to severe elements, including humidity, heat, fog, oil and water exposure.
