AbstractThe time taken to break under fixed load has been measured for three SBR–filler systems. Two SBR–HAF black systems were used, one vulcanized with sulfur and the other with dicumyl peroxide; the third system was an SBR–silica formulation. Measurements at several temperatures between 30 and 100°C. allowed the computation of an activation energy for the breaking process: 45 kcal./mole for all three systems. By measuring the tensile strength of the filled stock in air and vacuum at various temperatures, it was shown that the presence of oxygen seriously decreases the strength of the filled stock at high temperatures, an effect not present in the gum stock or in silicasilicone
展开▼
