ABSTRACT
An additive is any substance added to a polymer to alter certain properties. In the polyurethane Želd, additives are added to the polymers in small amounts to improve processing characteristics, enhance heat stability, provide antioxidant protection, stabilize against UV and gamma radiation, and so on. Figure 18.1 presents the universe of polyurethane additives, conveniently divided into process and functional additives. Process additives are incorporated into polyurethanes to improve the manufacture of the polymers, whereas the functional additives are incorporated to enhance certain properties of the Žnished polymer.
