High pressure viscosity behaviour of tris(2-ethylhexyl) trimellitate up to 150 MPa

Abstract

This article presents a study on the viscous behaviour at high pressure of a synthetic oil, tris(2-ethylhexyl) trimellitate (TOTM). This fluid is being recommended as potential industrial reference material for high viscosity-high pressure measurements. Here we report new experimental viscosity values for TOTM at temperatures from 278.15 K to 373.15 K and at pressures to 150 MPa with a maximum viscosity of 2570 mPa s. The measurements have been performed using a high pressure falling-body apparatus and a Couette rotational viscometer. The experimental values obtained in this work are included in the database of a multinational project used recently to develop a reference correlation for TOTM (Wakeham et al., 2017). The universal viscosity-pressure coefficient of this fluid has been evaluated and compared with other oils, finding that it is close to the literature values of mineral oils. Moreover, we perform an analysis of the dependency of viscosity on pressure and temperature based on the density scaling concept.