Effect of Temperature on the Stress Strain Characteristics of Styrene Butadiene Rubber loaded with HAF and GPF carbon black

Abstract

#The true stress-true strain curves of HAF/SBR (styrene butadiene rubber SBR loaded with high abraision furnace (HAF)) carbon black and GPF/SBR (Styrene butadiene rubber loaded with general purpose furnace) carbon black composites of different concentrations of carbon black have been determined. The yield stress σ_y and the coefficient of stiffness or (young's modulus) E have been found to increase gradully with increasing the carbon black concentrations of both types. The fracture stress of and the fracture strain & exhibited peak values at certain concentrations (50 phr for HAF and 75 phr for GPF). The reduction in of and & at large concentrations of carbon black was considered as a result of dilution of effect due to the diminishing of the volume fraction of the polymer in the composite, where there is no enough polymer matrix to hold the filler particles together. Meanwhile, all the stress- strain parameters mentioned above have been found to decrease with increasing the working temperature. The activation energy of fracture have been found to decrease with increasing the concentration of carbon black. This observation was explained on the basis of the fact that the fracture in the interfaces between polymer and carbon aggregates need less energy than fracture in the polymer.