What is soluble sulfur?

In general terms, sulfur recovery refers to soluble sulfur; the distinction between soluble and insoluble sulfur is based on whether it dissolves in CS2. Insoluble sulfur (IS) refers to sulfur that is insoluble in carbon disulfide, also known as polymeric sulfur. The insoluble sulfur product actually refers to a mixture of insoluble sulfur and soluble sulfur (ordinary sulfur). Compared to ordinary sulfur, using insoluble sulfur products as vulcanizing agents in rubber processing can prevent the occurrence of \"frosting\" in the rubber semi-finished products, ensure uniform vulcanization of the products, and increase the vulcanization speed. However, thermal effects, induction by alkaline substances (especially amines), improper storage time, as well as the formulation and processing of the rubber compound, can all cause insoluble sulfur to be reduced prematurely into ordinary low-molecular-weight soluble sulfur. If, due to various factors, the mass fraction of insoluble sulfur in the insoluble sulfur product drops below 60%, an excessive amount of soluble sulfur will be emitted toward the surface of the rubber compound, leading to scorching. This not only causes difficulties in rubber processing, but also severely reduces the uniformity of vulcanization quality and the adhesion between the rubber and steel wire or chemical fiber reinforcement materials, leading to an increase in the defect rate of rubber products. It also poses a risk of tire blowout while in use.