Mechanisms of antioxidant action. Phosphite esters

Abstract

Catechol phosphite esters are powerful stabilizcrs for polymers and appear to behave differently from simple alkyl or aryl phosphites in that they destroy hydroperoxidcs in a Lewis acid catalysed reaction. The effcctive catalyst is formcd from the starting cster by rcaction with hydropcroxidcs in a series of chemical reactions which during thc initial stages involve the formation of frec radicals. Somc ofthc isolated reaction products do not show this behaviour and are themselves powerful thermal and u.v. stabilizer antioxidants.