Solutions of Water Sterically Specific Surfactants as Model Ecological Cutting Fluids

Abstract

From the large group of surfactants with branched chains, sulfosuccinate derivatives obtained based on 2-ethylhexyl alcohol were selected. The surfactant of reference was ethoxylated sulfosuccinate with an alkyl chain (C12-C14). Tests regarding foam-forming ability (V0) and foam stability (V10) for selected solutions of the three surfactants were performed. Foam stability of the solutions of sterically specific surfactants (P13, P14) decreased by up to a factor of ten as compared with the equivalent linear alkyl chain (P19). This was achieved with the high surface activity of the solutions of these compounds as represented by surface tension and wettability of the surface of the bearing steel. The consequence of the high surface activity of the compounds were low friction and wear in tribological tests at constant load and excellent anti-seizure properties. On the cooperating friction pairs, adsorption layers were formed, effectively separating the two materials and able to transfer the high loads [L. 3]. Summing up, there is the possibility of using solutions of sterically specific surfactants as model cutting fluids with low foaming ability.

Ecological Cutting Fluids

“…This is a dominant process and, in the case of molecules with a long alkyl chain, the concentration of surfactants in the surface phase is considerably higher than in the bulk phase. With an increase in concentration, surfactant molecules produce, in turn, monolayers, closed structures (micelles) and then mesophases in the surface phase [ 31 ]. All the structures are spatially arranged in such a way that hydrophilic parts are turned outwards so that any contact of the hydrophobic part with water is impossible.…”

“…For c > CMC the value of surface excess remains constant (plateau). The extension of the Zhu model is a four-region model which divides the isotherm into four regions differing in its slope [ 31 ]. A two-region model is sufficient for interpretation of the results.…”