MOLECULAR ASPECTS OF THE FATIGUE AND FRACTURE OF RUBBER

The molecular aspects controlling the fracture of rubber and rubber enforcement are described, with a focus on the importance of mechano-chemistry. The events occurring at the tip of a crack are deemed important in controlling its growth. Particularly, if a crack tip becomes blunted during deformation, or if other processes reduce the load borne by the molecular chains at the crack tip, the stress concentration will be reduced and fracture inhibited. If an elastomeric network can dissipate input energy into heat through irreversible molecular motions, less elastic energy will be available to break network bonds apart, and fracture energy is increased. A further description of the role of energy dissipation in fracture is presented.