A phenolic antioxidant trapping both alkyl and peroxy radicals

Phenolic antioxidants are well known for trapping peroxy radicals to prevent organic materials from oxidative degradation. It is also important, however, to trap alkyl radicals for prevention of such degradation, because autoxidation includes both peroxy and alkyl radicals as chain carriers. In this study, on the basis of new ortho-substituent effect, o-allylphenols were molecularly designed to enhance the number of peroxy radicals trapped. It has been found by chance that some o-allylphenols can trap both peroxy and alkyl radicals, depending on the oxygen concentration of the surrounding atmosphere. The alkyl radical trapping mechanism is discussed.