Submitted to: Review Article
Publication Type: Review Article
Publication Acceptance Date: January 25, 2010
Publication Date: January 13, 2011
Citation: Isbell, T. 2011. Chemistry and physical properties of estolides. International Journal of Fats and Oils. 62(1):8-20. Interpretive Summary: An interpretative summary is not required for a Review Article.
Technical Abstract: Estolides are a developing class of natural and synthetic compounds that have been synthesized from hydroxy oils, like castor and lesquerella, or by the condensation of fatty acids across the olefin of a second fatty acid. Castor and lesquerella estolides are derived from either their triglycerides or their free fatty acids utilizing their hydroxyl moiety to establish the estolide bond. The triglyceride estolides have pour points of 9 to -36 deg C, but suffer poor oxidative stability with RPVOT times of 29–52 min even with 1% of an antioxidant package incorporated into the samples. In contrast to the triglyceride estolides of castor and lesquerella, the estolides from lesquerolic and ricinoleic acids have very good pour points of -36 to -54 deg C. Estolides derived from the acid catalyzed condensation of oleic acid with a variety of fatty acids can be made in good yield and possess a wide range of physical properties. Of particular interest are the saturated capped estolides of oleic that have both good low temperature properties (pour point -5 to -39 deg C) and good oxidative stability. Estolides from meadowfoam fatty acids do not have good low temperature properties, but have been extensively used in cosmetics where they provide good moisturizing properties.