Polyols

A polyol, or Component B, is is the second primary component of a polyurethane formulation. The name polyol refers to chemical compounds containing multiple hydroxyl groups. Polyols are used in both food science and polymer chemistry, including the formulation of polyurethanes. In polymer chemistry polyols are polymers or monomers with hydroxyl functional groups available for organic reactions . Polymeric polyols may be polyethers, such as polyethylene glycol , polypropylene glycol , or polytetrahydrofuran . Another class of polymeric polyols is the polyesters. A specialist class of polyol is the hydroxyl-terminated polybutadienes . These polyols are extensively used in formulations for polyurethanes.

When polyols are combined with many different additives or materials according to a formulation, the resulting polyol is called a polyol blend and is used to produce a variety of polyurethane products. A polyol blend remains unchanged until it is reacted with an isocyanate to form a polyurethane. The most important materials contained in Component B, more commonly known as a resin, are:

• Base polyol – makes up the bulk of the polyol blend and forms the backbone of the polyurethane polymer.

• Chain extender – a special type of polyol consisting of many short chains which connect the longer chains of the base polyol together.

• Catalyst – like a spark plug, the catalyst makes the reaction between the isocyanate and resin go.

• Surfactant – if you are producing a polyurethane foam, the surfactant controls the foaming when Components A and B react. It gives the final polyurethane product the right foam structure.

• Blowing agent – This ingredient creates the foam. Without the blowing agent, the polyurethane is heavy and solid. The blowing agent may be simple water, carbon dioxide, a chemical that imparts insulating properties to the polyurethane foam (such as HFC-15 or pentane) or another material. You can learn more about blowing agents by reading Bayer's library of polyurethane technical papers. If no blowing agent is used, a solid polyurethane is produced, such as polyurethane elastomer inline skate wheels.

Bayer manufactures and markets a wide range of polyols, including polyether, polyether polymer and polyester grades. These polyol products by tradename include Acclaim® polyethers, Arcol® polyethers, Desmophen® polyesters, Hyperlite® polyether polymers, Multranol® polyethers, Softcel® polyethers and Ultracel™ polyethers.