Ageing of rubber

The reduction in stress which takes place in a test strip of rubber held at constant elongation. Stress relaxation measurements are used in the study of the ageing of rubber vulcanisates, the degradation of the network structure resulting in a reduction of the tension. 

Oxidative ageing of rubbers is limited by the rate of diffusion of oxygen into the rubber product and is usually confined to the outer 3 mm. Antioxidants are used to protect rubbers from the effects of thermal oxidation and the vast majority of compounds will contain one or more. Peroxide vulcanisates are usually protected with dihydroquinolines. Other antioxidants react adversely with the peroxide inhibiting the crosslinking reaction. 

R.P. Brown and T. Butler, Natural Ageing of Rubber - Changes in Physical Properties Over 40 Years, Rapra Technology Limited, Shawbury, UK, 2000. 

Brown R P, Butler T, Hawley S W. Aging of Rubber. Accelerated Heat Ageing Results, Rapra Technology Ltd., 2001. 

Ageing of Rubber - Accelerated Heat Ageing Test Results... 

R.P. Brown, T. Butler and S.W. Hawley, Ageing of Rubber—Accelerated Weathering and Ozone Test Results, Rapra Technology Limited, 2001. 

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