All polyolefin based materials undergo oxidation reactions which may occur at every stageof the polymer's life cycle,during manufacture and storage as well as processing and end use.Polyolefins undergo a wide varity of oxidative reactions that eigher cause chain scission(decreased molecular weight) or molecular enlargements(increased molecular weight).Oxidation may change the appearance of the polymer as well as mechanical properties.The addition of antioxidants is the commonly used method to protect polymersagainst oxidation,and thus retarding the resulting aging of the polymers.