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.

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.

References in periodicals archive ?
242] developed a high performance (pressure) liquid chromatography (HPLC) method for analysis of products of transesterification of triglycerides.
Biodiesel is made through a conventional chemical process called transesterification.
She says a factorial-design experiment was used in these trials to determine the effects of backpressure, melt residence time, and other process parameters on transesterification, AA, I.
Palm oil, like other vegetable oils, can be used to create biodiesel as either a simple, processed palm oil mixed with petroleum-based diesel, or processed through transesterification to create a palm oil methyl ester blend, which meets the international EN 14214 specification.
hydrolysis, transesterification, hydrogenation, oxidation, pulping) in which a chemical change in the substrate occurs.
com)-- Avandith Energy has chosen the B-60 Biodiesel processor for their pilot transesterification facility.
These approaches include preheating of theoil, micro-emulsion with solvent, dilution with diesel fuel, thermal cracking and Pyrolysis, transesterification [19,23,] and recently hydroesterification in a two-step enzyme-chemical procedure [24,25].
To achieve compatibility of the PEN and PET blend, it is necessary to induce and control the transesterification reaction between the two polymers.
The masterbatch is formed by melt mixing in the presence of a transesterification catalyst, a starch, a second biodegradable polyester, and a biodegradable polymer having pendant carboxylic acid groups such as ethylene/acrylic acid.
9% purity using an alkaline catalyst (KOH), transesterification yield was 98.
Transesterification (or alcoholysis) is a process of displacement of an alcohol group from an ester by another alcohol.
Many studies are being carried out on the transesterification of vegetable oil using conventional method of heating.