Location: Bio-oils Research Unit
Title: Synthesis of chloro alkoxy and alkoxy derivatives of methyl oleate Authors
Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 25, 2013
Publication Date: May 30, 2013
Citation: Lowery, B.A., Andersh, B., Isbell, T. 2013. Synthesis of chloro alkoxy and alkoxy derivatives of methyl oleate. Journal of the American Oil Chemists' Society. 90(6):911-917. Interpretive Summary: This research demonstrated that highly modified oils could be made using new chemical reactions and these compounds may be useful in lubricants. Oils made from fatty acids often had poor cold temperature performance and degraded in the presence of oxygen at high temperatures (physical properties). The physical property performance can be improved by chemically modifying the oil to reduce or remove parts of the molecule responsible for poor performance. This work develops a method to chemically modify an oil and targets those chemical parts of the molecule that have weak performance. The final molecules were made in a modest yield and a number of pathways to make them were explored. This research will be used as a guide for further work that explores the modification of oils to improve their physical property performance.
Technical Abstract: Vegetable oil based lubricants typically have improved lubricity and biodegradability over their mineral oil based counterparts. However, vegetable oil lubricants often fail to meet the performance standards of mineral based oils with respect to cold temperature and resistance to oxidation. Olefins are an oxidatively weak point for vegetable based compounds. Removal of the olefin in a vegetable based lubricant through functionalization may increase resistance to oxidation. If the added functionality also causes branching of the alkyl chain, cold temperature properties may be improved. Any chemical modifications considered must be scalable and cost-effective to be useful in a commercial application. In this study, methyl oleate was functionalized into a chloroalkoxy derivative. Sodium hypochlorite (household bleach) and calcium hypochlorite were both used to generate hypochlorous acid in situ. Hypochlorous acid and a series of alcohols (methanol, ethanol, butanol) were reacted with methyl oleate to make chloroalkoxy compounds in 29.8 – 77.9% yields. In an effort to make a branched saturated ether, we removed the chlorine moiety of the chloroalkoxy compounds. Dehalogenation was achieved under basic conditions over a Pd/C catalyst in 2-propanol. Reaction times increased substantially as the size of the adjacent alkoxy group increased. Reaction rate could be improved by heating the reactions above 100 deg C in a pressure reactor. Increased reaction temperature also resulted in increased ketone side products from the competing elimination reactions. Saturated ether yields were 4.1 – 43.2%.