Relaxation transitions in crosslinked ethylene-propylene elastomers

Eight relaxation transitions have been detected above the glass transition temperature by relaxational spectrometric analysis in ethylene-propylene elastomers SKEP-50 and SKEPT-50 crosslinked through CC bonds. The first six transitions are the so-called λ-processes associated with the high-elastic plateau region. Longer relaxation times for λ-processes of the ternary SKEPT elastomer are the result of stronger intermolecular interaction owing to the third component, viz. dicyclopentadiene. The nature of the seventh transition is not clear. The longest relaxation process (the eighth) corresponds to chemical relaxation (mobility of CC bonds as a result of thermooxidative degradation).