MECHANISMS OF FATIGUE RESISTANCE AND OF ANTIFATIGUE AGENTS IN ELASTOMERS.

This paper is concerned with the mechanochemical transformations in rubber subjected to static or dynamic loading. The processes occurring additionally involve oxygen, ozone, heat and light. The results of recent investigations are summarized and it is shown that mechanical stress actively interferes at all stages of the fatiguing process. From the first elementary act of hydrogen abstraction from the molecular chain up to the point of failure of the rubber, the sequence, rate and character of the reactions are changed by the application of stress. The role of different inhibitors in the rubber fatigue process has been shown to be in accord with current views on fatigue and on the mechanisms of antioxidant action. The modifying action of mechanical stresses applies to all elastomer and rubber compounding ingredients and hence directly affects the fatigue resistance of rubbers.