The effect of carbon black morphological characteristics on tear propagation in rubbers

A systematic study of surface area, structure and loading effects of carbon black in relation to fatigue crack growth and tear propagation has been completed. The main contributing effects of these parameters to fracture in an SBR formulation at constant temperature, frequency or strain rate were identified. They were found to affect: the nature of the fracture surface, as well as the rate of crack growth (FCG) and level of tearing energy obtained in single cycle tests. In a classical FCG model the exponential factor was found to be dependent on the structure level of the carbon black. It was independent of tearing energy used. The FCG rate depends on carbon black loading with the other contributions depending upon method of tear energy assessment.