Polysulfide

A thermosetting resin, used as a building sealant.

Polysulfide

a derivative of hydrogen polysulfide, H₂S_x 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 K₂S_6. 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 H₂S_x 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.

单词	polysulfide
释义	polysulfide pol·y·sul·fide P0430800 (pŏl′ē-sŭl′fīd)n. A sulfide compound containing at least two sulfur atoms per molecule. pol•y•sul•fide (ˌpɒl iˈsʌl faɪd) n. a sulfide whose molecules contain two or more atoms of sulfur. [1840–50] Polysulfide Polysulfide A thermosetting resin, used as a building sealant. Polysulfide a derivative of hydrogen polysulfide, H₂S_x 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 K₂S_6. 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 H₂S_x 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.
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polysulfide

pol·y·sul·fide

pol•y•sul•fide

Polysulfide

Polysulfide

Polysulfide