Polysulfides are a class of chemical compounds derived from anionic chains of sulfur atoms.
[2] The alkali metal polysulfides arise by treatment of a solution of the sulfide with elemental sulfur, e.g. sodium sulfide to sodium polysulfide: S2−+ n S → S2−n+1 In some cases, these anions have been obtained as organic salts, which are soluble in organic solvents.
[6] In commerce, the term "polysulfide" usually refers to a class of polymers with alternating chains of several sulfur atoms and hydrocarbons.
Because of their solvent resistance, these materials find use as sealants to fill the joints in pavement, automotive window glass, and aircraft structures.
Charles Goodyear's discovery of vulcanization, involving the heating of polyisoprene with sulfur, was revolutionary because it converted a sticky and almost useless material into an elastomer that could be fabricated into useful products.
In addition to water and ammonia, the clouds in the atmospheres of the gas giant planets contain ammonium sulfides.