Fracture behavior of elastomers: case of EPDM

Brittle fracture of elastomers has been treated with the paradigm of fracture mechanics.  For example, Rivlin and Thomas proposed a formula to evaluate the critical energy release rate G_c for pure shear to understand fracture of crosslinked rubber polymers.  Unlike the case of brittle plastics, the fracture mechanics paradigm appears more successful because Lake-Thomas model provides an estimate of G_c comparable to experimental observation.  Nevertheless, inspired by our parallel investigation of plastics, we have pursued an alternative approach to fracture of elastomers. In this presentation, we show, based on ethylene-propylene diene monomer (EPDM) rubbers (acquired from Lion Elastomers), how the new approach compares with the Rivlin-Thomas method and indicate that a different framework may offer more effective instructions on how to improve mechanical characteristics of polymers.