Use of by-product sulfur from petroleum refinery as vulcanizing agent in natural rubber

Sulfur is typically required for rubber vulcanization in order to achieve enhanced mechanical strength and elastic behavior. Basically, the sulfur used in rubber industry originates from natural resource and petroleum-based refinery. The petroleum-based sulfur (PS) generally treated as by-product from refinery process was investigated in this work. Its influence on cure characteristics, viscoelastic properties as well as crosslink density was compared with conventional rhombic sulfur. Results obtained reveal inferiority in mechanical properties of the system with as-received PS. By reducing average particle size of as-received PS via a ball-milling process under optimal milling conditions, the ground PS (GPS) exhibits significant improvement in mechanical properties of rubber vulcanizates to be comparable to the conventional rhombic sulfur.