Submitted to: European Symposium on Industrial Crops and Products
Publication Type: Abstract Only
Publication Acceptance Date: 3/25/1999
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Market potential for biodegradable lubricants is expected to grow with the increase of environmental regulations. Biodegradability is a property of lubricant basestock (80% of total lubricant), and presents an opportunity for veg. oils to be utilized at large scale. Applicability of a given base- stock is determined by viscometrics, oxidative stability, deposit formation, volatility, low temp. solidification, hydrolytic stability, solvency, miscibility and seal compatibility. Major concerns for veg. oils are their low oxidative stability and poor low temp. performance. Oxidative stability tests using Pressurized Differential Scanning, Oxidative Stability Index and Microoxidation (heating thin film of oil on metal surface under controlled air flow) showed that veg. oils perform not as well as their main biodegradable competitors, such as polyol esters, poly alpha olefins and isoalkyl adipates. Methylene interrupted polyunsaturation is the main factor causing unacceptable oxidative stability. Presence of multiple reactive sites in triglyceride molecules results in oxidative gelation under microoxidation conditions, unlike other fluids. Volatilities of those fluids were much higher than those of veg. oils. Low temp. behavior was monitored using pour point measurement and extended cold storage tests. Presence of saturated fatty acids and high molecular weight of triglycerides were main reasons of rapid crystalli- zation. Veg. oils were modified chemically to reduce their Iodine Value and improve viscometric properties without compromising biodegradability. Although oxidative stability testing did not show desired improvement, low temp. properties in many respects was better than that of original oils.