Use in Lubricating Oils

The concentration of molybdenum disulphide dispersed in an oil may be as high as 60% or as low as 0.1%. At the higher concentrations the dispersions become pastes, and these will be considered in Section 13.4. 

A high proportion of the molybdenum disulphide used in lubrication is used in the form of dispersions in oil. In many cases the concentrations are less than 3%, 

They also reported a general reduction in sludge, varnish, wear and oil thickening due to oxidation, with no adverse effect in any of the test engines. The improvement in deposits was also confirmed by Muller and Bartz , who reported improved piston cleanliness. Further investigation suggested that this was due to an improvement in oxidation stability, but the way in which molybdenum disulphide can improve oxidation stability is not clear. Other beneficial mechanisms which have been suggested are improved dispersion of solid contaminants by the dispersant used to stabilise the molybdenum disulphide dispersion, and prevention of surface deposits by the formation of a molybdenum disulphide film. 

A later study by the Ford Motor Company ° investigated the use of a 1 % dispersion of molybdenum disulphide in the engine oil in standard Ford cars. The results showed fuel economy improvements between 0.8% and 4.7%, and subsequent more extensive studies confirmed improvements of over 3% with no adverse effects. 

Following such reports, molybdenum disulphide-containing engine oils became commercially available in the late nineteen-seventies. However, there is as yet no indication that any major vehicle manufacturer recommends the use of engine oils containing molybdenum disulphide. Almost all manufacturers recommend the American Petroleum Institute categories such as CF or SJ or their European ACEA equivalents, and none of these yet includes molybdenum disulphide. It seems 

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For use in lubrication oils Ca salts of isostearyl ether carboxylic acids are described as multifunctional additives to achieve a good water tolerance of the oil and good antiwear characteristics [182]. 

Other variants that are used in lubricating oils are sulfurized olefin compositions (69). An example for poly(isobutyl-l,2-dithiol-e-4-cyclopentene-3-thione) compounds is shown in Figure 6.10. 

These branched alcohol products are also useful in solvents, plasticizers, and monomers. For example, isobutyl alcohol is converted into the acetate ester, which is used extensively as a lacquer solvent. Isobutyl alcohol is also used in lubricating oils and in the production of amide resins. Propyl alcohol (59 million kg/yr) is used heavily in herbicide syntheses and in solvents for coatings and inks. 

Use In lubricating-oil additives for ashless dispersant processing, rolling, and compressor oils caulks, sealants, adhesives as an elastomeric process aid and cling improver in cling films. 

BHT is the largest single volume antioxidant used in plastics and rubbers especially for poly-olefins, such as, PE and PP. It is also used in lubricating oils. 

USE In lubricating oils, as solvent evaporation retarder in paint removers. Amide as anti -foam in the manuf of detet -gents, in floor polishes, in dripless candles. 

The residue is a mixture of higher hydrocarbons. The liquid components are obtained by vacuum distillation and used in lubricating oils. The solid components (paraffin wax) are obtained by solvent extraction. The final residue is a black tar containing free carbon (asphalt or bitumen). 

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