DIALKYL CARBONATES AS LUBRICANT ADDITIVES

Authors: Kenar, James - Jim; KURTH, TODD - FORMER USDA EMPLOYEE

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 5/3/2006
Publication Date: 5/3/2006
Citation: Kenar, J.A., Kurth, T. 2006. Dialkyl carbonates as lubricant additives [abstract]. Annual Meeting and Expo of the American Oil Chemists' Society. p. 74.

Interpretive Summary:

Technical Abstract: It has been previously reported that dialkyl carbonates represent attractive lubricants, in part, to their ampiphilic nature and their decomposition to non-corrosive simple alcohols and carbon dioxide. Members of our labs previously examined such materials as additives for biodiesel applications and found them to be suitable lubricants. In this work, a series of symmetric and asymmetric dialkylcarbonates prepared from oleochemical alcohols were synthesized and examined for performance as lubricant additives in hexadecane. A standard 4-ball wear test was performed, the wear scars were examined, and the used hexadecane mixtures were examined for decomposition products. The results were compared to those for analogous fatty acid methyl esters of similar chain length. For cases where fatty acid methyl esters and the analogous dialkyl carbonate systems were available, it was found that the methyl esters performed better as evidenced by superior (smaller) wear scars. No alcohol decomposition products could be detected via GC for the dialkyl carbonates or fatty acid methyl esters. Asymmetric methyl fatty alkyl carbonates were synthesized to more closely explore the cause for this behavior. It was found that the asymmetric systems performed worse than the corresponding esters and alcohols containing the same number of carbons. These results suggest the inherent structure and/or electronics of the carbonate moiety does not lead to improved interaction of the polar headgroup with the metal surface.