Isothermal Thermogravimetric Analysis of Soybean Oil Oxidation Correlated to Thin Film Micro-Oxidation Test Methods

Abstract

An isothermal thermogravimetric analysis (TGA) method was used to generate a model capable of predicting the results of the Thin Film Micro-Oxidation (TFMO) test in a soybean oil system. Utilizing a series of pseudorate constants and "activation energies", weight loss data from the TGA method can predict oxidation, polymerization, evaporation, and the formation of high molecular weight deposits, normally observed in the TFMO test. These parameters can be used in simple computer simulations which can calculate the weight of each component of a lubricant as it decomposes. This allows evaluation of lubricants without the difficult to obtain TFMO equipment, instead utilizing equipment available in most laboratories.

Ester basestock vaporisation from thin oil films

“…Most widespread standard tests RPVOT, TFOUT, Baader, Rancimat and others are not designed to quantify volatile losses. This capability has been utilised in thin film‐based microoxidation family of tests, such as Koehler Instruments K‐29200. However, test equipment employs a sample pan with rectangular profile and favours fluid accumulation around the brim.…”