Water-based hydraulic fluids with synthetic components

Nonflammable water-based hydraulic fluids are described, their applications are cited, and comparisons are made with mineral-oil-based fluids. The structures of HFAs, HFC and thickened HFAs fluids and the technical requirements imposed on water-based hydraulic fluids are indicated. The chemistry of synthetic water thickeners, their thickening effect an shear stability, as well as their technical properties according to the 6th Luxembourg Report, are explained and compared. Detailed consideration is given to the structure and mode of operation of thickeners for HFAs fluids or viscous high water based fluids. The physical chemistry of these hydophilic-hydrophobic thickeners, which form microemulsions in water, is considered, particularly when they are used together with emulsifiers.