Degradation Mechanism of Peroxide-crosslinked EPDMs by Residual Peroxide

Abstract

The chemical structures of aged dicumyl peroxide(DCP)-crosslinked EPDMs were investigated with FT-IR and 13C high-resolution solid state NMR. The mechanism of degradation induced by residual DCP was studied in DCP-crosslinked EPDMs.The thermal degradation of DCP-crosslinked EPDMs occurred with the disappearance of C=C bond of ethylidene norbornene and generation of carbonyl, carboxy and hydroxy groups and the scission of polymer chains. It can be considered that the residual DCP in DCP-crosslinked EPDMs accelerated the production of peroxide and hydroperoxide. The peroxide and hydroperoxide are extremely unstable, thereby causing various degradation reactions such as production of radicals, chain scission, and oxidation reactions of EPDM polymer.