The desire to replace petroleum-based materials with environmentally friendly and sustainable alternatives has stimulated the development of vegetable oil-based materials as biolubricants. Our studies have focused on molecules that might be produced by biosynthesis of genetically-altered oilseed plants with limited post-harvest modification. Various fatty esters based on oleic acid and ricinoleic acid, were synthesized as potential biolubricants. These include oleate esters of isopropanol, oleyl alcohol and normal alcohols of 1-12 carbons chain lengths; ricinoleate esters of isopropanol and normal alcohols of 1-5 carbons chain lengths; ricinoleate esters acylated in their 12-positions with various acids; oleate esters of ethylene glycol, 1,2-propanediol, 2,3-butanediol, and pentaerythritol. The 12-methyltetradecanoate and decanoate esters of selected polyols were also made. The melting points and viscosities of these esters were documented. Some of these compounds showed melting points and viscosities suitable for uses as biolubricants. 2,3-Butanediol monooleate, butyl ricinoleate and various ricinoleate esters acylated at the 12 positions with short-chain acids were particularly promising. Some of these esters were measured for their boundary lubrication properties with a microtribometer. Seemingly, the lubricities of these esters were affected by their chemical structures. A possible explanation of the lubricity effects based on molecular packing of these compounds on metal surfaces was proposed.
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