Transesterification

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transesterification

[¦trans·e¦ster·ə·fə′kā·shən]
(organic chemistry)
Conversion of an organic acid ester into another ester of that same acid.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Transesterification

 

the general name for the processes of alcoholysis (1), acidolysis (2), and ester (RCOOR’) interchange (3):

(1) RCOOR’ + R”OH ⇄ RCOOR” + R’OH

(2) RCOOR’ + R”COOH ⇄ R”COOR’ + RCOOH

(3) RCOOR’ + R”COOR”’ ⇄ RCOOR’” + R”COOR’

The catalysts of transesterification are acids (HCl, HBr, and H3PO4), BF3, and salts of Zn and Co. A shift in the equilibrium toward the right is usually achieved by distillation of the more volatile alcohol (R’OH), acid (RCOOH), or ester.

Transesterification is widely used in preparative organic chemistry and the chemical industry. Thus, bis-β-hydroxyethyl terephthalate, which yields polyethylene terephthalate upon heating to 275°–290°C under vacuum, is obtained from dimethyl terephthalate and ethylene glycol. Transesterification is one of the industrial methods of producing polycarbonates.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Bhuyar, Transesterified Hingan (Balanites) oil as a fuel for compression ignition engines, Biomass Bioenergy, 33, 108 (2009).
Thus, the role of biomass-derived, diesel-like fuels (biodiesel) such as transesterified esters, hydrogenated vegetable oils (HVO), and other synthetic biofuels is set to increase.
Unlike the current alternatives to trans fats, such as tropical oils, fully hydrogenated oils and transesterified oils containing a high amount of saturated fats, organogels can be prepared with a variety of oils that contain mono- and polyunsaturated fats.
Margarine is usually prepared from vegetable fats, the feedstock may originate from partially hydrogenated, interesterified and transesterified. Different categories of margarine are produced at industrial level e.g.
Durability of transesterified jute geotextiles, Geotextile and Geomembranes 35: 69-75.
After that, the oil samples were transesterified with methanol and ethanol separately, under reflux conditions, by using 6:1 in molar ratio of alcohol to oil and 0.5% of NaOH catalyst (m/m of oil).
Further, the n-hexane present in the reaction mixture was removed from transesterified canola oil on rotary evaporator under vacuum to get the concentrated product.
Fatty acids from each lipid fraction and five hundred milligrams of fat (total fatty acids) were transesterified following the method of Shehata et al.
Vetter, "Detection of 430 fatty acid methyl esters from a transesterified butter sample," Journal of the American Oil Chemical Society, vol.
After solvent extraction or physical extraction, these lipids of microalgae can then be further transesterified to biodiesels.
Extracted lipids were methylated and transesterified using sodium methoxide at pH 3, according to the method of Park and Goins [16].
(1984).Variables affecting the yield of fatty esters from transesterified vegetable oils.