Influence of concentration and chain surfactants in the tribological properties of microemulsion systems for cut fluids
Epoxidized Vegetal Oil, Tribological Tests, Microemulsion W/O, Cutting Fluid Concentration
Development of new cut fluids constitutes an important field of scientific and technological activity. A large portion of the fluids (Petroleum) that non-renovable is consumed. Recently, a microemulsion system has been studied as an alternative to improve lubricity and anti-wear effectiveness. Thus, this study aimed to develop, characterize and evaluate the performance of tribo colloidal system for use in cutting fuidos using an HFRR (High Frequency Reciprocating Rig) tribometer, consisting of a plane type ball wear test. Biolubricants were characterized in terms of density, acidity, iodo index, oxirane index, viscosity. In microemulsion systems were evaluated by small-angle X-ray scattering (SAXS), particle size and viscosity. Based on the results showed above, it is possible to conclude that: the physicochemical properties analyzed are suitable for the fluid lubricant; the lowest concentration of surfactant (1%) presented lower friction and WSD coefficients in the studied emulsions. Once that the surfactant in the medium stabilized the emulsion, forming smaller droplets. The emulsions with 5% surfactant showed higher friction and WSD coefficients values. This occurs because the surfactant competes with the oil on the surface, decreasing the lubricity in the medium. The highest concentrations of epoxidized oil showed a slow and unstable film with greater values of the coefficient of friction and WSD. Therefore, the emulsions that showed the best tribological performance to cutting fluid emulsion were the emulsions with 5% and 10% of epoxidized oil and 1% of surfactant concentration.