Estolides are bio‐based oils synthesized from fatty acids or from the reaction of fatty acids with vegetable oils. Estolides have many advantages as lubricant base oils, including excellent biodegradability and cold flow properties. Promising applications for estolides include bio‐lubricant base oils and in cosmetics. In this review, the synthesis of estolides from fatty acids using four different types of catalysts, namely, mineral acids, solid acids, lipases, and ionic liquids, is summarized. The summary includes the yield of estolide obtained from varying synthetic conditions (time, temperature, catalyst). Also reviewed are studies comparing the physical properties of estolides synthesized from refined fatty acids against those synthesized from fatty acid mixtures obtained from vegetable oils such as coconut, castor, Physaria, etc. By varying the structure of the fatty acids, estolides with a wide range of pour point, cloud point, and viscosity are synthesized to meet a wide range of application requirements. Currently, estolide products are being commercialized for personal care and lubricant base oils for automotive, industrial, and marine applications. The application areas and the demand for estolides is expected to grow as the drive for switching from petroleum to bio‐based products keeps growing.

中文翻译：

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脂肪酸甾醇：综述

雌二醇是从脂肪酸或脂肪酸与植物油反应合成的生物基油。雌二醇具有作为润滑剂基础油的许多优点，包括出色的生物降解性和冷流性能。雌激素的有前途的应用包括生物润滑剂基础油和化妆品中。在这篇综述中，总结了使用四种不同类型的催化剂由脂肪酸合成雌二醇的方法，即无机酸，固体酸，脂肪酶和离子液体。该摘要包括从不同的合成条件（时间，温度，催化剂）获得的依斯托利特的收率。还审查了比较由精制脂肪酸合成的雌二醇与由植物油如椰子，蓖麻，or属等获得的脂肪酸混合物合成的雌二醇的物理性质的研究。通过改变脂肪酸的结构，可以合成具有广泛的倾点，浊点和粘度的雌二醇，以满足广泛的应用需求。目前，依斯托利特产品已商业化用于个人护理产品，并用于汽车，工业和船舶应用的润滑油基础油。随着从石油产品向生物基产品转换的驱动力不断增长，预计应用领域和对雌二醇的需求将会增长。