Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 4/28/2000
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Oxidative and low temperature properties of a series of vegetable oils (VO) were studied for their usefulness as base fluids in lube formulation. The major drawbacks of VO are low oxidative stability due to polyunsaturation in the triacylglycerol structure and poor low temperature properties. A combination of Pressurized Differential Scanning Calorimeter (PDSC) and Thin film Micro-oxidation was used to study the relative thermal and oxidative behavior. The results were discussed in terms of the structural differences obtained from quantitative 1H and 13C NMR spectroscopy. Quantitation of each fatty acid was carried out by evaluation of particular peaks. Terminal -Me proton, divinyl proton, allyl proton, omega-2 carbon, olefin carbon, etc. are useful to explain the variations in thermal (% evaporation, % insoluble deposit) and kinetic (Ea, k) properties. A detailed Gel Permeation Chromatography (GPC) of the oil soluble oxidized fraction gives significant insight into the rate and extent of oxypolymeric compound formation and buildup of oil insoluble deposits. Scanning Electron Microscopy (SEM) details the dimension and morphology of high temperature VO deposits obtained on activated metal catalyst. A clear understanding of the rate and nature of deposit formation would help in subsequent studies on antioxidant (AO) additive response. Effect of a pour point depressant (PPD) and diluents was studied as external parameters influencing low temperature properties. Conclusions on thermal, oxidative, and low temperature behavior are made in terms of structural diversity of the vegetable oils used in the study.