Lubricant basestocks from vegetable oils

Oil Chemical Research. USDA l-ARS-NCAUR. 1815 N. U;liuersity Street, Peoria, IL 61604, USA Accepted 8 October 1999 Compared to the lubricants made of petroleum, vegetable-based lubricants are much more biodegradable but inferior in many other technical characteristics. The basestock typically contributes to more than 80% of lubricant and must meet performance criteria in such aspects as cleanliness, viscometric properties, volatility, oxidative and hydrolytic stability, deposit forming tendencies, solvency, miscibility or compatibility with system elastomers and other. For vegetable-based lubricants, oxidative stability and low temperature problems are considered the most critical. Thin film oxidation test was used to compare oxidative stabilities. Vegetable oils appear an order of magnitude less stable than mineral oils or synthetic biodegradable basestocks, such as isoalkyl adipates or poly alphaolefins. Low temperature performance of vegetable oils, namely pour points and cold storage, was also problematic. These problems can only partially be relieved by lubricant additives, thus vegetable oils have to be modified chemically to eliminate sites susceptible to oxidation and to disrupt formation of crystals at low temperatures. Published by Elsevier Science B.V.