Insoluble sulfur is a transparent, amorphous, chain-like elastic sulfur obtained by heating sulfur powder to boiling (444.6 degrees Celsius) and pour it in cold water to quench it. It can also be prepared by diluting the superheated sulfur vapor with inert gas and spraying it in cold water mist to cool below 90 degrees Celsius, or dissolving the sulfur block in ammonia and spraying and drying it immediately. Because most (65%-95%) are insoluble in carbon disulfide, it is called insoluble sulfur. Because it is insoluble in rubber, it is not easy to produce early vulcanization and sulfur injection in the rubber, and does not damage the adhesiveness of the rubber, which can eliminate the coating process, save gasoline, and clean the environment. At the vulcanization temperature, insoluble sulfur is converted to normal sulfur to exert its vulcanization effect on rubber. Generally used for particularly important products, such as steel wire tires, etc.
Insoluble sulfur, molecular formula: Su, is a non-toxic, flammable yellow powder, named because it is insoluble in carbon disulfide. It is made by thermal polymerization of ordinary sulfur. The number of sulfur atoms in the molecular chain is as high as 108 or more. It has the viscoelasticity and molecular weight distribution of a polymer. Therefore, it is also called elastic sulfur or polymerized sulfur, which is an inorganic polymer chemical raw material.