Sodium poly sulphides

This group of synthetic elastomers is better known under the trade name ThiokoP. Polysulphide rubbers are condensation polymers of sodium poly sulphide and dichloro-compounds they have outstanding resistance to swelling by oils and solvents but tensile strength is... 

Virtually nothing is known about the lithium polysulphides, Sodiumtetrasulphide is the highest stable sodium poly sulphide, although higher ones may be present in... 

The most widely used method for the preparation of polysulphide polymers is the reaction of sodium poly sulphides with alkyl dichlorides ... 

It is convenient to include under Aromatic Amines the preparation of m-nitroaniline as an example of the selective reduction of one group in a polynitro compound. When m-diuitrobenzene is allowed to react with sodium poly-sulpliide (or ammonium sulphide) solution, only one of the nitro groups is reduced and m-nitroaniline results. Some sulphur separates, but the main reaction is represented by ... 

Now we know that such model is very simplified, because these resistors are non-linear and the partial conductivities depend on the applied current [7]. However, even this simplified model turned to be very useful—first of all, for the development of electrolytic processes for production of metals from chalcogenide (mainly poly sulphide) ores. Evidently, for the successful electrowinning of such metals as Sb, Tl, In, Cu, Ag and others from its sulphide, selenide or telluride compounds, the electronic (both semiconductor and metallic) conductivity must be suppressed. For that purpose. Prof. Velikanov proposed and realised, together with his numerous scholars, the additions of compounds with pure ionic conductivity, such as sulphides of sodium and potassium. By studying the conductivities in many binary molten systems, he was able to choose the optimal compositions with high... 

If the gas is passed over sodium peroxide, a violent reaction occurs both in the presence and the absence of air. If the peroxide is previously heated, the reaction is accompanied by flame, and if excess of air is present a loud detonation is produced. In the absence of air the products consist of sulphide and polys ulphide of sodium, together with a small amount of thiosulphate and sulphate in the presence of air very little sulphide is formed, sodium sulphate and free sulphur being obtained.7... 

Poly(p-phenylene sulphide) (commonly called poly(phenylene sulphide) or PPS) is the sulphur analogue of poly(p-phenylene oxide) and is prepared from p-dichlorobenzene and sodium sulphide ... 

Condensation reactions yielding cyclic and/or linear oligosulfides were studied by four research groups [89-93]. In 1863, Husemann [89] prepared an intermediate by condensation of 1,2-dibromoethane with sodium sulfide. By heating he obtained the cyclic dimer, dithiane, as a volatile degradation product. Mansfeld [90] reinvestigated this reaction and interpreted the intermediate as polymer, but he speculatively assigned the formula of a cyclic trimer. Husemann also prepared poly(methylene sulphide) from dibromomethane and sodium sulfide. Furthermore, he performed condensations of dibromomethane and dibromoethane, respectively, with sodium trithiocarbonate, which was easily obtained from sodium sulfide and carbon disulfide. He isolated a five-membered cyclic ethylene trithiocarbonate, but a polymeric methylene trithiocarbonate the molar mass of which remained obscure. 

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