The antiozonant properties of two new classes of polymer bound antiozonants (PAS) based on N-substituted p-phenylenediamine (PPD's), (thioether and sulfoxides), in comparison to N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD) were studied using several test methods and elastomeric materials. The chemical bonding to the elastomer as cause for the favourable behaviour of the new antiozonants with respect to reducing the formation of cracks under ozone exposure, discolouring, staining and the formation of primary aromatic amines (PAA) was proofed.