5. Protection system

5.1 Mechanisms

The main causes of rubber ageing, alone or in combination, are :

• thermal aging ;

• thermo-oxidative ageing (temperature and oxygen) ;

• mechanical ageing (stress and temperature) ;

• ozone action;

• the action of light;

• the action of water or organic derivatives

By way of illustration, when a rubber is subjected simultaneously to thermomechanical stress in the presence of oxygen, the reaction mechanisms are :

• thermomechanical effect (figure