Anti-friction compounds

Anti-friction formulations containing Ryton resin and three other available anti-friction compounds were evaluated in journal bearing test... 

It was natural that the first efforts to develop uniform testing procedures for the selection of compatible materials should come out of the oxygen industry which has always been concerned about the use of lubricants (or anti-friction compounds, as they prefer to call them) in oxygen systems. The reasons for their concern include (1) the possible use of petroleum lubricants (2) the lack of assurance concerning the quality and uniformity of the available lubricating materials (3) the lack of consumer knowledge about the use and methods of application and (4) the lack of standard test specifications to qualify the suita-... 

Table III. Oxygen Industry Qualifications for Class I Anti-Friction Compounds for Gaseous Oxygen Systems at Pressures from 0-500 psi and at Temperatures up to 250°F [12]...

International Acetylene Association, "Recommendations on Anti-Friction Compounds for Use with Gaseous Oxygen," New York (February 1, 1956). 

Ryton PPS—Polyphenylene Sulfide Res- 45. ins—Properties and Uses of Anti-Friction Compounds, TSM-262, Phillips Petroleum Company, Bartlesville, OK, October 1974. 

The performance of soluble oils is made possible not only by their high specific heat and thermal conductivity but by their low viscosity, which permits good penetration into the very fine clearances around the cutting zone. Consequently, these fluids are used mainly where cooling is the primary requirement. Lubricating properties can be improved by polar additives, which are agents that enhance the oiliness or anti-friction characteristics. Further improvements can be effected by EP (extreme-pressure) additives, which are usually compounds of sulfur or chlorine. 

Many different organo-molybdenum sulphur compounds have been studied in this context, and some are listed in Table 9.7. All those listed have been found to have friction-reducing, anti-wear or extreme-pressure properties, and it is significant that several authors have reported that the presence of sulphur is essential. 

Electrostatic interactions resulting from the polarity of the carbon-fluorine bond play an important role in the binding of fluorinated biologically active compounds to their effectors [22] (discussed in detail in Sections 4.5 and 4.6) and for the me-sophase behavior of fluorinated liquid crystals [23] (Section 4.4). The consequences of the low polarizability of perfluorinated molecular substructures have been put into commercial use for chlorofluorocarbon (CFG) refrigerants, fire fighting chemicals, lubricants, polymers with anti-stick and low-friction properties, and fluorosur-factants. 

As for all additives, interactions with other additives in solution, Fig. 3.16, and competition for surface reaction sites together with the effect of environmental factors such as temperature, blow-by gases, water and fuel dilution have variable effects on the formation of the film. Because ZDDPs are much more widely used as antiwear performance additives compared to other classes of compounds, these additive effects will now be discussed in greater detail than has been the case for other classes of anti-wear/friction additives. In particular the influence of structure, concentration, dispersant, detergent, antioxidancy and friction modifier on friction and wear will be discussed. In addition the influence of NO c and H2O will be briefly illustrated. 

In addition to being good friction modifiers with anti-wear performance, organomolybdenum compounds are also excellent antioxidants at low concentrations, at or below 100 ppm Mo. In fact, over 50% of ILSAC GF-4 engine oils contain organomolybdenum compounds at or above 60 ppm Mo. 

Slow moving slides and tables in machine tools are subject to jerky motion due to alternating slipping and sticking of the sliding surfaces. Consequently, specially developed lubricants are required to prevent and/or reduce the stick-slip phenomenon. Slideway oils usually contain polar surface-active compounds, mostly fatty acid derivatives, together with anti-wear additives and oxidation inhibitors. The polar surface-active agents form oriented boundary layers which prevent adhesive friction. 

It was formd that boundary lubrication films composed of Fe(0H)0, Fe304, FeP04 and compounds containing P-O bonds were formed on the worn surface, which resulted in an excellent friction reduction and also anti-wear performance (23). 

Based on the characterization and analysis of the worn surfaces, it has been proposed that the anti-wear mechanism consists of the prepared compound boron-containing thiophosphite derivative reacting with the steel surface during the friction process to generate a protective film mainly composed of phosphate, sulfide, sulfate, organic amine, and B2O3 (25). 

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