Aging Behaviors of Natural Rubber in Isolation Bearings

This paper attempts to reveal the aging behaviors of natural rubber (NR) used in isolation bearings. Using various degradation factors like thermal oxidation, ultraviolet, ozone, low temperature ozone, salt water and acid rain, a series of environmental accelerated aging tests were conducted to investigate the aging characteristics. From the test results, it was clarified that the thermal oxidation is the dominant degradation factor, which hardens the rubbers and results in a significant drop of performance. This study is fundamental to predicting the lifecycle of NR isolation bearings.