5 - Synthetic oils

Abstract

Synthetic oils are oligomers prepared by polymerization of selected monomers or similar oily fluids manufactured from other raw materials by chemical synthesis. The chapter explores synthetic oils. The wide variety of hydraulic applications poses a multitude of exacting physical and chemical requirements on the hydraulic fluid. To what extent the individual fluids satisfy these demands is decisive for the normal area of application, temperature limitations, etc. of each individual fluid. Although mineral oil-based products still display the most satisfactory balance of properties for the vast majority of hydraulic applications, there are nevertheless many critical systems for which a specialized synthetic fluid may represent a preferable choice. It discusses the various types of synthetic oils. These are synthetic hydrocarbons, ployethers, organic esters, phosphate esters, silicones, and fluoroethers. Synthetic oils are normally classified in accordance with their chemical composition. In general, synthetic oils display superior performance, compared to mineral oil-based fluids in many respects. They are better in respect to thermal stability, oxidation stability, viscosity, low temperature fluidity, operational temperature limits, and fire resistance etc. According to the chemical composition of synthetic oils, the individual synthetic media nevertheless possess greatly differing properties and in some cases mineral oil-based fluids may be advantageous.