Polyethylene, polypropylene and polyvinyl chloride comprise over 75% of the polymers used in today's markets. The processing and end-use properties of these polymers depend on the resin's resistance to degradation. The environments experienced by these resins often promote degradation by exposing the polymer to high temperatures, high shear conditions, ultraviolet light, and chemical prodegradants such as oxygen. To counteract these degradative conditions, processors and manufacturers incorporate stabilizers to the polymer. Numerous methods have been employed to elucidate the mechanisms by which the polymers degrade as well as to understand the means by which stabilization systems work.
Degradation and Stabilization of Commodity Polymers