Experimental Studies of Thermal Aging Effects on the Tensile and Tearing Fracture Behavior of Carbon Black Filled Rubbers

Abstract The effects of thermal aging on the tensile and tearing fracture behavior of carbon black filled rubbers with different filler loadings have been investigated in this paper. Thermal aging experiments were performed in a convection oven at 70oC and 120oC for various periods of aging time. Measurements of tensile strength, stretch to fracture and tearing strength were conducted with a 5943 Instron single column materials testing system as a function of aging time and aging temperature. It is found that the initial elastic modulus increases with increasing aging time, while the tensile strength decreases with the increase in aging time up to 100 hours and then increases when the material aged over 144 hours. The changes in tensile strength and stretch to fracture are found to be dependent on aging temperature, the higher the aging temperature, the more pronounced decrease in tensile strength and stretch to fracture. From the tearing fracture tests, the tearing strength generally is found to decrease with the increase in aging time