Age Resisters for Rubber. A General Study

Abstract Many scientific and technical problems arise from the phenomenon of aging in elastomers. Aging is not a simple problem, since, in the first place, different elastomers give rise to different degradation effects, and secondly, one and the same elastomer may age in a variety of ways. These may include processes—such as autoxidation and fatigue—which entail complete disintegration of rubber articles under prolonged stress; other processes, however, may certainly impair properties, but under permanent environmental stress a stationary state is reached in which only slight destruction exists. “Frosting” and “crazing” are examples of these effects. Certain aging processes occur exclusively on the surface of an elastomer which is unaffected internally, e.g., ozone cracking. Others, however, arise preferentially within the article concerned, e.g., attrition effects. Finally, there are degradation effects, such as autoxidation which progress uniformly and are not localized. Following these preliminary remarks we shall now proceed to briefly examine the principal aging effects. This paper deals with measures to combat such effects by means of anti-agers or, in North America, simply “age resisters”.