Effect of Carbon Black/Bi2O3 Ratio on the Vulcanization Characteristic and Mechanical Properties of Rubber Compound

Abstract This study aims to determine the effect of Bi2O3 as a substitute for carbon black (CB) fillers on the characteristics of vulcanization and mechanical properties of rubber compounds. The comparison of CB/Bi2O3 used are 50/0, 45/5, 40/10, and 35/15. Rubber compounds are prepared using two‐rolls mill. The rubber vulcanizates are prepared using hydraulic press at 150 °C. Vulcanization characteristics are determined by the moving die rheometer. Rubber vulcanizates are evaluated from aspects of physical and mechanical properties (tensile strength, elongation, density, hardness), morphology (SEM), and heat aging. It is found that rubber compounds containing high amounts of Bi2O3 show higher torque and higher optimum vulcanization time. In addition, rubber compounds with high Bi2O3 content show higher density, tensile strength, and elongation.