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Glycerolysis of linseed oil: A compositional study
Author(s) -
Rheineck A. E.,
Bergseth R.,
Sreenivasan B.
Publication year - 1969
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02544364
Subject(s) - glyceride , linseed oil , chemistry , monoglyceride , solubility , catalysis , alcohol , sodium hydroxide , fatty acid , fatty alcohol , organic chemistry , sodium , chromatography
Sodium hydroxide catalyzed glycerolysis of linseed oil is greatly enhanced by increase in temperature but only moderately by increase in catalyst concentration. That the active catalyst under these conditions is the glyceroxide ion and not the hydroxide ion was confirmed by performing the reaction with freshly prepared sodium glyceroxide. In all cases alcohol solubility is reached before the reaction attains equilibrium. Component glycerides analysis at these points shows that the monoglycerides content at alcohol solubility is about 35% and at equilibrium about 45%. Further, there are about twice as many 1,3‐diglycerides as either 1,2‐diglycerides or triglycerides. Component fatty acid analysis of these individual glycerides shows that all the fatty acids of the parent oil are present in every one of these glyceride types and in about the same proportions. Monoglycerides in the early stages of reaction are richer in saturated fatty acids indicating that the catalyst attacks the primary alcoholic ester portion of glycerides first. Similarities in the fatty acid compositions of 1‐and 2‐monoglycerides at these early stages indicate that the latter are formed by acyl migration from the former. Based on these observations a mechanism for glycerolysis has been proposed.