Polysulfide


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Related to Polysulfide: polysulfide rubber, polysulfide impression material, calcium polysulfide

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 ?
Polysulfide Sealants Appendix I: Supplier Profiles - 3M - BASF(Shanghai) - Bostik (Shanghai) - Dow Corning (China) Holding - Guangzhou Baiyun Chemical Industry - Guibao - H.
After a few minutes of stirring, sodium polysulfide was formed and a dark yellow transparent solution was obtained, indicated as solution A in figure 7.
3M said that the addition of AC TECH's range of fast-curing polysulfide sealants expands its product presence in the aerospace market for the manufacture and maintenance of commercial and military aircraft.
Given that the caulking material is at least 30 years old, it may be degraded to the point that the PCBs, which were plasticizers in the original polysulfide polymer formulations, can be mobilized into solution.
The gasket is designed so that once the mounting screws are installed and torqued, compression squeezes some of the polyurethane gel to the outside edge of the antenna mount providing a small perimeter seal, thus eliminating the need for additional polysulfide sealing.
The use of traditional polysulfide silanes as the chemical coupling agents for coupling silica to rubber in tread compounds complicates and prolongs mixing, and generates ethanol throughout the production and life of the tire.
15-xxxx For Imaging Media (Photography)--The Effectiveness of Chemical Conversion of Silver Images Against Oxidation--Methods for Measuring describes tests that may be used to determine the degree to which metallic silver in processed film products has been converted to silver sulfide when the images have been treated with a polysulfide solution.
The Licht battery transforms sulfur into a conductor by immersing it in a solution of polysulfide.
But there's a trick involved: To get solid sulfur (an insulator at room temperature) to conduct electricity, Licht and Peramunage bathed it in an aqueous polysulfide solution saturated with sulfur.
The pod assembly is composed of numerous materials, including wrought and cast aluminum alloys; titanium forgings, plate, and rod; fiberglass-reinforced epoxy composites; silicone rubber seals and wiring harnesses; structural adhesives; polysulfide sealants; and aluminum honeycomb core.
The addition of AC TECH's range of fast-curing polysulfide sealants expands 3M's product presence in the aerospace market for the manufacture and maintenance of commercial and military aircraft.
On the basis of Application: - Glazing - Flooring and Joining - Sanitary and Kitchen - Others On the basis of type: - Silicone - Polyurethane - Polysulfide - Others On the basis of region: - North America - Europe - Asia-Pacific - RoWDownload the full report: https://www.