Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 11/14/2001
Publication Date: 11/14/2001
Citation: ISBELL, T., WINCHELL, M.L., CERMAK, S.C. SYNTHESIS AND PHYSICAL PROPERTIES OF LESQUERELLA OIL ESTOLIDES. ANNUAL MEETING AND EXPO OF THE AMERICAN OIL CHEMISTS' SOCIETY. 2001. Interpretive Summary:
Technical Abstract: Lesquerella is a developing oilseed crop grown in the desert Southwest of the United States. Lesquerella produces a small seed that contains 23-26% oil of which 45-55% is lesquerolic acid, a homolog of ricinoleic acid. The success of lesquerella will be dependent on new uses for the unique triglyceride structure of lesquerella, which is essentially a dihydroxy substituted oil as compared to castor which is high in triricinolein. In an effort to examine potential lubricant applications for lesquerella oil, the hydroxy moiety of the oil was capped with various saturated and unsaturated fatty acids to from estolide triglycerides. Castor oil estolides were also synthesized in a similar fashion. Conditions where triglycerides had one, two, and completely capped hydroxyl functionalities were determined. A range of temperatures of 150- 250 C were examined where the reaction was placed under vacuum to remove liberated water from the mixture. The resulting lesquerella estolides ranged from no capping (EN=0) to completely capped (EN=1.89). The optimum conditions for estolide formation were found to be a reaction run under vacuum at 200 C with no catalyst and a reactions time of 24 h. Higher temperatures gave shorter reaction times but promoted acyl exchange on the glycerol and dehydration of the estolide to polyenes. Pour points, viscosity, viscosity index, and oxidative stability were determined on both castor and lesquerella estolides. Estolides had pour points of -15 to -39 C and cloud points of -5 to -45 C. Viscosities ranged from 100 to 216 cSt at 40 C with viscosity indices between 115 and 191.