Polysulfide


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Polysulfide

A thermosetting resin, used as a building sealant.

Polysulfide

 

a derivative of hydrogen polysulfide, H2Sx where x = 2–9. Polysulfides are solids, ranging in color from light yellow to brownish red, with a specific, unpleasant odor.

Polysulfides of ammonia, alkali metals, and alkaline-earth metals are known—for example, potassium forms K2S2, K2S3, K2S4, K2S5, and K2S6. Sulfur atoms are arranged in an —S—S—S— chain in polysulfide molecules. The melting point of polysulfides is lower than that of sulfides. For example, the melting point of K2S is 835°C, whereas that of K2S6 is 183°C. Polysulfides are chemically very unstable; they decompose upon heating to form sulfides. In the presence of acids they liberate H2Sx which decomposes immediately into H2S and S.

Polysulfides are produced by fusing sulfides, hydroxides, or carbonates with sulfur; sulfur may be added to an aqueous sulfide solution. Polysulfides of calcium and barium are used against agricultural pests. Barium polysulfide is an effective depilatory.

References in periodicals archive ?
According to Joutseno Mill Manager Risto Joronen, who was also the director for this development project with ANDRITZ, the use of polysulfide cooking liquor enables the mill to improve certain pulp qualities, which benefits papermakers.
Recent introductions in the rubber industry, highlighted on page 6, include NXT LowV silane and NXT Ultra-LowV silane coupling agents from GE Advanced Materials, said to help decrease ethanol emissions up to 90% compared to polysulfide silanes.
Tenders are invited for Sealant polysulfide black two-component for the production of insulating glass - 6000l.
There are few reports concerning intrinsic self-healing epoxy resins; for instance, Lei and collaborators reported the use of a polysulfide aliphatic diglycidylether in the preparation of self-healing remoldable epoxy resins [23].
com), Macungie, PA, a manufacturer of silicone rubbers, polyurethane rubbers and plastics, rigid and flexible urethane foams, epoxies, polysulfide rubbers, adhesives, coatings, release agents and other material technologies, announced the opening of its production facility in Macungie, PA.
Until now, there has been no such method, but the new sulphur-limonene polysulfide addresses this urgent need.
Common additives used in the process include emulsified vegetable oil or calcium polysulfide.
There are five categories of sealant products made in China: silicone (SR), polyurethane (PU), polysulfide (PS), acrylic (AC), and other.
After the Mooney viscosities have reached the maximum value, the compounds show some sort of reversion which could be linked to a change within the polysulfide linkages.