Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 10, pp. 1610−1616.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © L.R. Saﬁ na, Kh.E. Kharlampidi, D.Kh. Saﬁ n, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 10, pp. 1679−1686.
AND POLYMERIC MATERIALS
Molecular-Weight Characteristics and Deemulsifying
Activity of Oligourethanes Based on Alkylene Oxide
Block Copolymers and Propylene Oxide Homopolymers
Prepared in the Presence of a Double Metal Cyanide Catalyst
L. R. Saﬁ na
, Kh. E. Kharlampidi
, and D. Kh. Saﬁ n
Kazan National Research University of Technology, Kazan, Tatarstan, Russia
Nizhnekamskneftekhim Public Joint-Stock Company, Nizhnekamsk, Tatarstan, Russia
e-mail: Saﬁ nDH@nknh.ru
Received July 26, 2012
Abstract—The molecular-weight characteristics of Laprol 6003-2B-18, of oligourethanes based on it, and of a
new series of propylene oxide homopolymers prepared using a double metal cyanide catalyst were determined.
This catalyst allows synthesis of polyethers whose molecular-weight distribution width smoothly varies with the
molecular weight. The polyethers were tested for the deemulsifying activity. The tests showed that high-molecular-
weight polyethers ensure high degree of dehydration of crude oil emulsions.
Nonionic surfactants (NSAs), namely, polyethers
(PEs) based on homopolymers and block copolymers of
propylene oxide (PO) and ethylene oxide (EO), are widely
used as active base of deemulsifying formulations for
crude oil extraction and pretreatment. The trend toward a
steady increase in the water content of the crude oil being
extracted and toward formation of stable water–oil emul-
sions makes it necessary to constantly improve deemul-
siﬁ er formulations. For example, wide introduction of
polyfunctional high-molecular-weight PEs into practical
use as active bases of deemulsiﬁ ers was aimed at solving
speciﬁ cally this problem. The majority of these reagents
are oligourethanes of PO–EO block copolymers [1–5].
However, papers [1–5] do not discuss the mechanisms
of oligourethane formation and speciﬁ c features of their
structure; only the surfactant properties and deemulsifying
activity of PEs are compared.
It is commonly believed today that the deemulsifying
properties of PEs are enhanced with an increase in their
molecular weight. This particularly concerns polyfunc-
tional PO–EO block copolymers. At the same time, the
molecular weight of available oligourethanes derived
from block copolymers and branched PEs actually var-
ies in a narrow range, 5000–50
000 [3–7]. Therefore, it
is of theoretical and practical interest to examine speciﬁ c
structural features of PEs and trends in variation of their
deemulsifying activity with variation of their molecular
weight in a wide range.
The investigation objects were PO–EO block copoly-
mer Laprol 6003-2B-18 and oligourethanes based on it,
prepared at varied ratio of toluene diisocyanate (TDI) and
the block copolymer, and also new high-molecular-weight
PO homopolymers prepared from glycerol and xylitol
prepolymers (molecular weight 1000) using double metal
cyanide catalysts (DMCCs).
Laprol 6003-2B-18 samples were taken from commer-
cial batches produced in accordance with TU (Technical
Speciﬁ cations) 2226-020-10488057–94. Some physico-
chemical characteristics of the PO–EO block copolymer
are given in Table 1. Laprol 6003-2B-18 is prepared by
anionic polymerization of PO and EO. The nature of