High pressure thermophysical behaviour of reference and new lubricants. Mineral, synthetic and vegetable oils and ionic liquids

Abstract

This PhD Thesis is devoted to the study of several thermophysical properties, over broad ranges of temperature and pressure, of mineral and semisynthetic reference lubricants, vegetable oils and developed biodegradable lubricants, as well as ionic liquids (ILs) for their use as hydraulic fluids, gear and two stroke lubricants. The first property studied was the density from 278.15 K to 398.15 K up to 120 MPa. Density was measured by means of two different vibrating tube densimeters from Anton Paar (Graz, Austria). Results for eight reference oils, two vegetable base oils and eleven biodegradable lubricants for different applications are provided. Moreover density data for seven ILs are provided. Density data of all the studied fluids were correlated by means of the Tammann-Tait equation and the isothermal compressibility, κT, and the coefficient of thermal expansivity, αT, were obtained.