Synthetic lubricants are widely used for applications that require high-thermal and oxidative stability. In order to facilitate new designs and applications for these fluids we are measuring a suite of thermophysical and transport properties for lubricant base fluids and mixtures. As part of the property measurements, here we report the global thermal decomposition kinetics of four polyol ester lubricant base oils, in addition to a fully qualified (MIL-PRF-23699F) commercial formulation. The fluids were heated in stainless steel ampule reactors and the extent of decomposition was measured by gas chromatography (GC) with flame ionization detection, from which psuedo-first-order rate constants were derived. The rate constants for decomposition ranged from 1e-08 1/s at 500 K to 2e-04 1/s at 675 K. Arrhenius parameters across this temperature regime are also reported. Other techniques for chemical characterization applied in this work include GC with mass specrometry, NMR spectroscopy and Karl Fischer titration.
Citation: Energy and Fuels
Pub Type: Journals
aviation lubricants, polyol esters, global decomposition kinetics