Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: May 7, 2003
Publication Date: N/A
Technical Abstract: Vegetable based lubricants face many challenges in their development as potential lubricants. The three biggest hurdles are cost, oxidative stability and cold temperature properties (pour point, cloud point and cold temperature storage). Distinct advantages of vegetable oils are their excellent lubricity, low toxicity and ready biodegradability. One method to overcome the shortcomings of vegetable oils is through the development of formulation packages which improve oxidative stability and pour point (RBOT ~ 15 minutes to ~80 minutes and pour points from -10's to -20 deg C). These are significant improvements but still fall short of commercial mineral oil based lubricants which have RBOTs of 240 minutes and pour points of -36 deg C when fully formulated. A second method is to alter the chemical structure of the vegetable oil and impart desirable physical properties independent of formulation. Several vegetable oil modifications, branched esters and polyol esters, branched fatty esters, telomers and estolides have made improvements in physical properties. Over the last several years our lab has had significant breakthroughs in both oxidative stability and cold temperature properties of a developing class of estolides. These estolides now meet or exceed the mineral oil based lubricants currently in the market and yet are less costly than fully synthetic lubricants on the shelf. Synthetic advancements in estolide synthesis as well as its impact on physical properties, will be discussed.