Silicon disulphide

Silicon disulphide forms fibrous crystalline macromolecules with a structure intermediate between that of CO2, with its individual molecules, and the three-dimensional SiOg. In it the sulphur atoms are arranged tetrahedrally round the Si atoms (Zintl and Loosen, 1935) ... 

The orthosilicates (93) of D-glucose, D-fructose, and D-galactose were obtained in 30—40% yields by treatment of two molar equivalents of the sugar with silicon disulphide in DMF, whereas the orthosilicates (94) were obtained when four molar equivalents of the sugar were used. ... 

S2C12, a by-product in the manufacture of carbon tetrachloride from carbon disulphide. Was used, dissolved in solvent naphtha, in the vulcanising of mbber by the cold cure process and the vapour cure process. The process was fraught with health and safety problems and has been superseded by low temperature accelerators and room temperature vulcanising (RTV) systems for silicone and polyurethane. 

Ethylbenzene styrene Carbon disulphide 5% nitrile silicone rubber on Celite 545 at 135°C Flame ionisation 1 Omg L1 [642]... 

The initial properties of bonded films as applied vary considerably depending on the type of binder, the ratio of binder to molybdenum disulphide and other components, the nature of the drying or curing process, and the way in which the film was applied, in particular there is a wide variation in hardness from very soft (silicones and alkyds) to very hard (metals and ceramics), and this has important implications for the way in which a film is used and even the purpose for which it is used. 

Gangopadhyay et al investigated the use of graphite intercalated with nickel chloride NiClj to lubricate silicon nitride or alumina sliding against a steel counterface. The lubricant was quite effective, reducing the coefficient of friction from 0.5 to 0.17 for silicon nitride, and from 0.55 to 0.18 for alumina. There is no obvious reason to expect that the behaviour of molybdenum disulphide would be significantly different. 

In fact Van Wyk ° used something similar to a composite structure for the lubrication of silicon nitride and alumina in plain spherical bearings. He incorporated a 90% molybdenum disulphide/8% molybdenum/2% tantalum compact in holes drilled in the surface of the alumina outer ring, and the details have been described in Chapter 8. The system was very successful, giving a forty times increase in wear life. 

Molybdenum disulphide has been used in greases based on other oils, as well as mineral oils and esters, but probably the only other common type is silicone. Silicone greases are usable to over 250°C, but they are poor lubricants under boundary lubrication conditions. Addition of molybdenum disulphide gives a useful... 

Some commercial greases have also been produced which are based on a perfluorinated polyether oil with added molybdenum disulphide. They can be used for even higher temperatures than the silicone-based greases, but are much more expensive and would normally only be used on small components. They have the further advantage of excellent resistance to chemical attack. 

Carbon disulphide Phosphorus trichloride Silicon tetrachloride Stannic chloride Titanium tetrachloride... 

Liquids agreeing with (3) are called normal liquids they include benzene and other hydrocarbons (aliphatic and aromatic), ether, carbon tetrachloride, carbon disulphide, ethyl iodide, nickel carbonyl, sulphuryl chloride, sulphur chloride, phosphorus trichloride, phosphorus oxychloride, silicon tetrachloride, and nitrogen dioxide. 

Chloroacetophenone is soluble in alcohol, benzene (40% by weight), ether and carbon disulphide, as well as in many of the other war gases. For instance, phosgene dissolves 9 5% by weight, and cyanogen chloride 63% by weight. It is, however, very slightly soluble in titanium tetrachloride, silicon tetrachloride or water (i gm. in 1,000 ml.). 

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