Oxidatively stable industrial fluids based on soybean oil: 1. Synthesis of oxidatively stable industrial fluids; 2. A new antioxidant for stabilizing vegetable oils in industrial applications
Date
2000
Authors
Jiang, Yongyi
Major Professor
Advisor
Hammond, Earl G.
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
To increase the industrial use of soybean oil (SBO), the problem of its oxidative instability needs to be overcome. In our laboratory we tried to synthesize more oxidation-resistant SBO derivatives by combining fully hydrogenated SBO with short-chain esters, reducing the number of double bonds, and reducing the number of fatty acids per molecule. Not all attempts worked well. A triglyceride with two butyric acid and one long saturated fatty acid from SBO was made, but its melting point was too high to meet the requirement for industrial fluids. Attempts to esterify 2-ethylhexanoic acid with glycerol failed, presumably because of stearic inhibition. Mercaptoacetic acid additives of soybean oil seem to have favorable properties, but this approach was not thoroughly explored because others appeared more promising. Esterifying SBO fatty acids with di- or mono-hydroxy alcohols increased oxidative stability compared with glycerol esters. Ethylene glycol esters (EGE) were made from free fatty acids (FFA) of SBO by refluxing the FFA with ethylene glycol in benzene, using 1-2% p-toluenesulfonic acid as a catalyst. Methyl ester (ME) was also prepared by stirring SBO with methanol and 1% sodium methoxide. The melting point of EGE and ME was checked by differential scanning calorimetry (DSC), and their oxidative stability was compared with that of SBO by measuring their viscosity under conditions of a modified Active Oxygen Method (AOM) at 1050C, in the presence of colloidal copper and iron.
As expected the oxidative stability generally increased with a decrease in the number of fatty acid chains per molecule; that is, in the order of SBO
Series Number
Journal Issue
Is Version Of
Versions
Series
Academic or Administrative Unit
Type
thesis