Abstract:8 capped estolides of oleic that have both good low temperature properties (pour point -5 to -39 o 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.
“…The hydroxyl functionality induces the formation of hydrogen bonding between the hydroxylated triglyceride molecules that increases the steric hindrance of the oil, leading to the formation of weakly bound dimers and trimers of the original triglycerides; hence, CO has a high viscosity of 260.4 cSt at 40°C [48]. Molecular weights (MWs) of oils have an effect on oil viscosity.…”
Section: Facts About Castor Oilmentioning
confidence: 99%
“…Estolides can be in the form of free acids, esters or could be found within the structure of triglycerides. Estolides usually form in most hydroxylated oils such as castor and Lesquerella oils [48]. Figure 4.( a ) Triglycerides found in CO (FA1, FA2 and FA3 represent FAs attached to the glycerol, when FA1 = R, FA2 = R, FA3 = R, i.e.…”
Section: Chemical Composition and Structure Of Castor Oilmentioning
Castor oil (CO) is an inedible vegetable oil (VO) that has been employed extensively as a bioresource material for the synthesis of biodegradable polymers, cosmetics, lubricants, biofuels, coatings and adhesives. It is used in medicine, pharmaceuticals and biorefineries, due to its versatile chemistry. However, there has been less focus on CO as an alternative to toxic and expensive solvents, and capping/stabilizing agents routinely used in nanoparticle syntheses. It provides a richer chemistry than edible VOs as a solvent for green syntheses of nanoparticles. CO, being the only rich source of ricinoleic acid (RA), has been used as a solvent, co-solvent, stabilizing agent and polyol for the formation of polymer–nanoparticle composites. RA is a suitable alternative to oleic acid used as a capping and/or stabilizing agent. Unlike oleic acid, it provides a facile route to the functionalization of surfaces of nanoparticles and the coating of nanoparticles with polymers. For applications requiring more polar organic solvents, RA is more preferred than oleic acid. In this review, we discuss the production, chemical and physical properties, triglyceride and fatty acid (FA) compositions and applications of CO, focusing on the use of CO and RA as well as other VOs and FAs in syntheses of nanoparticles and surface functionalization.
“…The hydroxyl functionality induces the formation of hydrogen bonding between the hydroxylated triglyceride molecules that increases the steric hindrance of the oil, leading to the formation of weakly bound dimers and trimers of the original triglycerides; hence, CO has a high viscosity of 260.4 cSt at 40°C [48]. Molecular weights (MWs) of oils have an effect on oil viscosity.…”
Section: Facts About Castor Oilmentioning
confidence: 99%
“…Estolides can be in the form of free acids, esters or could be found within the structure of triglycerides. Estolides usually form in most hydroxylated oils such as castor and Lesquerella oils [48]. Figure 4.( a ) Triglycerides found in CO (FA1, FA2 and FA3 represent FAs attached to the glycerol, when FA1 = R, FA2 = R, FA3 = R, i.e.…”
Section: Chemical Composition and Structure Of Castor Oilmentioning
Castor oil (CO) is an inedible vegetable oil (VO) that has been employed extensively as a bioresource material for the synthesis of biodegradable polymers, cosmetics, lubricants, biofuels, coatings and adhesives. It is used in medicine, pharmaceuticals and biorefineries, due to its versatile chemistry. However, there has been less focus on CO as an alternative to toxic and expensive solvents, and capping/stabilizing agents routinely used in nanoparticle syntheses. It provides a richer chemistry than edible VOs as a solvent for green syntheses of nanoparticles. CO, being the only rich source of ricinoleic acid (RA), has been used as a solvent, co-solvent, stabilizing agent and polyol for the formation of polymer–nanoparticle composites. RA is a suitable alternative to oleic acid used as a capping and/or stabilizing agent. Unlike oleic acid, it provides a facile route to the functionalization of surfaces of nanoparticles and the coating of nanoparticles with polymers. For applications requiring more polar organic solvents, RA is more preferred than oleic acid. In this review, we discuss the production, chemical and physical properties, triglyceride and fatty acid (FA) compositions and applications of CO, focusing on the use of CO and RA as well as other VOs and FAs in syntheses of nanoparticles and surface functionalization.
“…The extent of oligomerization of the molecule or the average number of fatty acids added to the base fatty acid is represented by estolide number (EN) (73,74). A series of saturated estolides were developed by Cermak and Isbell (73) in which oleic acid and saturated fatty acids ranging from butyric through stearic treated with 0.4 equivalents of perchloric acid at either 45 or 55°C produce complex estolides.…”
Lubricant oils are known to decrease the friction coefficient between two contacting surfaces. It is essential for the correct function of almost the totality of mechanical machinery working in the entire world. Lubricant oils consist of about 80% of oily base stocks which attributes to their properties of viscosity, stability, and pour point to the lubricant plus additives supplemented to improve these properties. Petroleum lubricants are usually environmentally unacceptable due to their low biodegradability and toxicity. These oils contaminate the air, soil, and drinking water and affect human and plant life to a great extent. Thus, the demand for environmentally acceptable lubricants is increasing along with the public concerns for a pollution-free environment. Plant oils are promising as base fluid for biolubricants because of their excellent lubricity, biodegradability, viscosity-temperature characteristics, and low volatility. The purpose of this paper is to present a survey of the current status of biolubricating oil. This research provides an overview on the synthesis, tribochemical behavior; the effect of structure on friction/wear, load-bearing capacity, resistance to rise in specimen temperature, and varying response of antiwear/extreme-pressure additives in the presence of vegetable oil/derivative structures has also been discussed. Though a significant number of papers have been published in this area, there is still much to explore. A proper selection of base oil and additives is therefore essential for an efficient synthesis of biolubricating oil.
“…Polyesters based on hydroxy fatty acids from vegetable oils, called estolides, present a variety of potential applications due to their biodegradability and improved characteristics including the higher thermal oxidative stability compared to the vegetable oils [4]. The chemical route for estolides synthesis involves high temperatures (205-210 °C) or strong acids as catalysts that can lead to colored and malodorous products, together with undesired products that are not particularly suitable for pharma and food industry and would require supplementary costs for purification [5].…”
Lipase-catalyzed synthesis of estolides starting from different saturated (C16 16OH, C18 12OH) and unsaturated (C18:1 9 cis 12-OH) hydroxy-fatty acids was investigated. For this reason, the catalytic efficiency of several native and immobilized lipases in different organic reaction media at temperatures up to 75 °C was studied. The formation of mono-and di-lactone as well as estolide's chain elongation depends on the type and source of lipase. The lipase from Pseudomonas stutzeri immobilized by cross-linking as cross-linked enzymes aggregates (CLEAs) was the best biocatalyst in terms of chain elongation. Estolides with polymerization degree up to 10 were obtained at substrate conversions higher than 80 %.
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