Polysulfides are a group of chemical compounds made up of sulfur atom chains which posses solvent, chemical, and weather resistance in addition to flexibility and tensile strength. These compounds are primarily used as additives in the production of rubbers, sealants, and adhesives. Various attractive properties make polysulfide-based products ideal in civil engineering, aeronautic, and domestic applications where exposure to fuels, lubricants, and detergents preclude other products. The inherent flexibility and resistance to weathering of polysulfide sealants is highly beneficial in the marine, swimming pool, and construction industries. Notwithstanding the many beneficial applications of polysulfide products, care should be taken when using them on certain plastics as they are known to degrade PVC and ABS items.
Polysulfide was first identified in 1926 by American chemist Joseph C. Patrick. The compound first gained a formal commercial identity in 1929 when it was given the trade name Thiokol which has since become a generic standard for polysulfides. The extensive list of useful characteristics quickly made polysulfides popular as a base product for a large selection of adhesives, sealants, and rubber products. These properties include good shear and tear strength, high levels of chemical and solvent resistance, excellent weather resistance, and a finish easy to shape, sand, and paint. Products based on polysulfides are also able to with stand repeated flexing and impact, thermal cycling, and posses good anti-corrosive characteristics.
These characteristics make polysulfide sealants a marine engineering and repair standard with many products carrying extensive guarantees. The sealants and adhesives may be used below the waterline in salt water with no loss of integrity to the seal. The flexibility of the products also means that they handle continuous hull flexure well. These sealing agents are frequently used in the swimming pool industry for the same reason. Joints between decks, paving, and walkways benefit from the weathering, impact, and flex resistance of polysulfide sealants as well.
Sealants and rubber products based on polysulfides are extensively used in environments such as the aviation and construction industries due to their mechanical strength and resistance to degradation by gasoline, diesel, jet fuel, and lubricants. The products also make excellent sealants and insulators for plate glass windows and doors. Specialized grades of polysulfide rubber are even used as impression materials in the field of dental technology. One downside of these products, however, is their inclination to cause some plastics to become brittle and crack. This is particularly true of ABS and PVC plastics; polysulfide products should not be used on these materials.