Tetrasulphide

Polysulphide rubbers. Ethylene dichloride and excess of sodium tetrasulphide when heated together give a polymeric polysulphide, Thiokol A, with properties resembling those of rubber ... 

Prepare a saturated solution of sodium sulphide, preferably from the fused technical sodium polysulphide, and saturate it with sulphur the sulphur content should approximate to that of sodium tetrasulphide. To 50 ml. of the saturated sodium tetrasulphide solution contained in a 500 ml. round-bottomed flask provided with a reflux condenser, add 12 -5 ml. of ethylene dichloride, followed by 1 g. of magnesium oxide to act as catalyst. Heat the mixture until the ethylene dichloride commences to reflux and remove the flame. An exothermic reaction sets in and small particles of Thiokol are formed at the interface between the tetrasulphide solution and the ethylene chloride these float to the surface, agglomerate, and then sink to the bottom of the flask. Decant the hquid, and wash the sohd several times with water. Remove the Thiokol with forceps or tongs and test its rubber-like properties (stretching, etc.). 

By varying the value of the ranking x in the polysulphide Na2S. The tetrasulphide is necessary to obtain a rubber with ethylene dichloride, but disulphides may be used with other dichlorides. 

A hydrocarbon of the ethylene series, containing two double bonds in the molecule. Dipentamethylene Thiuram Tetrasulphide DPTT, accelerator. 

Addition of bis-(3-triethoxysilylpropyl)-tetrasulphide plus accelerator and sulphur can counter loss of crosslinking. Accelerator systems which respond to this antireversion agent are the thiazoles and the sulphenamides. Thiurams do not respond. For cure state equilibrium to be maintained the proportions of the three constituents (sulphur, accelerator and antireversion agent) are adjusted to give a constant modulus. 

The only odour-intensive species conclusively identified in the odorous emission of water reclamation works were dimethyl -disulphide, -trisulphide and -tetrasulphide. 

Virtually nothing is known about the lithium poly sulphides. Sodium tetrasulphide is the highest stable sodium polysulphide, although higher ones may be present in... 

A. Rule and J. S. Price also noted that when metallic sodium is added to an alcoholic soln. of sodium tetrasulphide, there is an immediate separation of yellow crystals of the disulphide. 

According to A. Rule and J. S, Price, anhydrous sodium tetrasulphide is a... 

The main polysulphide products are trisulphide, tetrasulphide and pentasulphide, but on account of the tendency of the polysulphides to decompose, yielding thiosulj hate and hydrogen sulphide, the quantity of thiosulphate usually exceeds that indicated in the equation.7 Loss of sulphur by the thiosulphate yields sulphite.8 The so-called lime-sulphur washes, used as insecticides in agricultural work, are obtained by treating sulphur with milk of lime in this way.9... 

The tetrasulphide may be precipitated by the addition of alcohol, and by concentration of the mother-liquor the pcntasulphide, N2S5, and the hexasulphamide, SGNII2, may be obtained. 

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