Why Sulfur Blooming Is Undesirable In The Rubber Industry?

Rubber is the main raw material in the manufacturing of tires. Industry uses both natural and synthetic rubber for the purpose. 

To maintain the quality of rubber sulfur content is one of the most important parameters. 

Raw rubber is a hydrocarbon in nature and is a thermoplastic. in order to eliminate the dundesirable property of malodorousness, treating rubber with sulfur, other accelerators, and antioxidants are necessary. Which in turn help to prolong the life of rubber product, tire in this case. 

However, being crystalline organic sulfur is somewhat soluble in polymers (rubber). Mixing ordinary sulfur to the natural rubber will be of no use as it will dissolve during the hot mixing process. Later after cool-down, it will form the crystalize surface, causing the sulfur to bloom. This might not affect the function of the rubber product but it will mess up the appearance of the product. 

To prevent this undesirable effect of sulfur blooming, insoluble sulfur is used in Rubber. Being a homopolymer, it forms a long chain compound, which eliminates the chance of blooming by keeping the sulfur inside and not allowing it to crystalize on the surface of the rubber.