Hydraulic fluids - Hydrocarbons and ester-polyesters

We remind you (cf. article ) that a hydraulic fluid must have a wide range of properties in order to perform its assigned functions. These properties are closely related to the structural state of the oils used.

After studying the influence of their chemical structure on their physico-chemical properties, properties on which their qualities of use depend, the main categories of hydraulic fluids are presented and compared.

This article focuses on the properties of hydrocarbons and ester-polyesters.

The articles that follow will look at :

• phosphoric esters ;

• halogenated organic derivatives and silicon ;

• polyphenyl ethers ;

• pyrazine derivatives and fluoroalkylphosphonitrilates.

To conclude this overview, the main additives and future developments will be presented.