Radiochemical oxidation of ethylene-propylene elastomers in the presence of some phenolic antioxidants

The oxidative degradation of gamma-irradiated ethylene-propylene elastomers (EPR and EPDM) in the presence of some phenolic antioxidants (Topanol OC, Cyanox 2246, Santonox R, Irganox 1010 and Irganox 1076) was studied. The st abilization activity of these antioxidants was related to the gel content o f polymer matrix and the G values for radiochemically formed ketones, aldeh ydes, acids, esters and alcohols. The oxidation rates, obtained by IR measu rements of C=O concentrations, provide an order of antirad efficiency. Some considerations concerning the influence of the chemical structure of antio xidants on the stabilization of elastomers and a radiochemical oxidation me chanism are presented. (C) 1999 Elsevier Science Ltd. All rights reserved.