Photo-oxidation of elastomers. A fundamental approach based on the study of a series of photo-sensitive elastomeric systems: A review

Abstract

The photo-oxidation and crosslinking of increasingly complex photo-sensitized elastomers were quantitatively investigated. An ethylene-propenebutadiene terpolymer (EPDM), selected as an elastomeric medium exhibiting reactive unsaturated side chains, was photo-sensitized with various chromophoric groups: grafted phenyl groups (systems I and II), different carbonyl functions (systems III and IV), blended photo-initiators dimethoxyphenylacetophenone (DMPA) (system V) and benzophenone (BP) (system VI). Knowledge of the behaviour of these model systems proves necessary to the understanding of the predominant processes involved in the photo-oxidation of ethylene-propene rubber (EPR or EPM) blended with DMPA (system VII) or BP (system VIII) and of a random styrene-butadiene (SBR) copolymer (system IX).