Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 9, pp. 1399−1403.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © T.N. Poyarkova, Yu.I. Prokof’ev, G.V. Kudrina, A.V. Tarasova, E.V. Sotnikova, 2012, published in Zhurnal Prikladnoi Khimii, 2012,
Vol. 85, No. 9, pp. 1487−1492.
AND INDUSTRIAL ORGANIC CHEMISTRY
Inﬂ uence of Temperature, pH, and Time of Base Hydrolysis
on Variation of the Fatty Acid Composition of Soapstock
T. N. Poyarkova
, Yu. I. Prokof’ev
, G. V. Kudrina
, A. V. Tarasova
, and E. V. Sotnikova
Voronezh State University, Voronezh, Russia
Bunin Elets State University, Elets, Lipetsk oblast, Russia
Voronezh State University of Engineering Technologies, Voronezh, Russia
Moscow State Automotive Institute, Moscow, Russia
Received June 26, 2012
Abstract—Seven samples of surfactants were prepared from soapstock (waste from sunﬂ ower-seed oil production)
under different conditions of base hydrolysis. The surfactant properties of the products at the solution–air boundary
(surface activity, adsorption layer thickness, molecular area, work of adsorption, limiting adsorption) were studied.
The production of sunﬂ ower-seed oil in Russia
considerably increased in the recent years. The
main waste formed in the step of its alkali reﬁ ning
(neutralization) is soapstock containing fats, fatty
acids and their salts (soaps), phospholipids, coloring
substances, etc. . The soapstock, formed annually in
an amount of 150 thousand tons, ﬁ nds no efﬁ cient use yet.
It is well known that surfactants play an important role
in many processes. They ensure efﬁ cient emulsiﬁ cation,
dispersion, plasticization, structuring, and control of
rheological and other properties of various systems. Ionic
surfactants based on saturated and unsaturated higher
carboxylic acids and their salts are widely used today.
They are components of technical soaps and synthetic
detergents . However, in the synthesis of soaps it is
undesirable to use fat products containing unsaturated
compounds , because in the course of storage and
service they undergo oxidation, with the soap degrading
and becoming rancid. In the past years, petrochemical
products as raw materials for surfactant production
appreciably replaced traditional raw materials (natural
fats and soaps). However, because of short supply of
many petrochemical products, surfactant producers
again turn to vegetable raw materials (castor, rapeseed,
sunﬂ ower-seed, olive, cottonseed oils, by-products and
wastes from oil production).
As we showed in , the fatty acid composition of
soapstock changes after the base hydrolysis. According
to the preliminary data of , the content of unsaturated
acids (e.g., linoleic and linolenic acids) in the initial
soapstock was about 63.4% in total, whereas after
the hydrolysis it was as low as 33.6%. Hence, base
hydrolysis of soapstock leads to a noticeable decrease in
the amount of unsaturated compounds in it.
In this study we examined the effect of temperature,
pH, and time of base hydrolysis on variation of the
fatty acid composition of soapstock with the aim to
ﬁ nd optimal conditions ensuring minimal content of
unsaturated acids in the soapstock.
The investigation object was the soapstock formed
in the course of processing of vegetable oils in the
reﬁ ning step in the oil extraction shop of the EFKO
plant (Alekseevka, Belgorod oblast).
The base hydrolysis of fats and fatty acids in the