ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 7, pp. 1138!1142. + Pleiades Publishing, Inc., 2006.
Original Russian Text + T.K. Dzhumadilov, I.S. Saparbekova, B.M. Butin, E.A. Bekturov, 2006, published in Zhurnal Prikladnoi Khimii, 2006, Vol. 79,
No. 7, pp. 1148!1152.
AND POLYMERIC MATERIALS
Influence of the Molecular Weight of a Polymer
on the Phase Diagram of the System Polyethylene
T. K. Dzhumadilov, I. S. Saparbekova, B. M. Butin, and E. A. Bekturov
Kazakhstan State Woman’s Pedagogical Institute, Ministry of Education and Science of Kazakhstan Republic,
Bekturov Institute of Chemical Sciences, Ministry of Education and Science of Kazakhstan Republic,
Received November 18, 2005
Abstract-The melting points of the polyethylene glycol!NaBPh
system synthesized in ethanol were
determined by optical microscopy. The influence of the molecular weight of polyethylene glycol on the phase
formation in the system was studied.
Molecular complexes of alkali and alkaline-earth
metal salts with nonionic polymers containing hetero-
atoms are known to be ion-conducting materials [1, 2].
A wide variety of problems concerning the influ-
ence of various factors, such as flexibility of macro-
molecules, nature of heteroatoms in polymers, and
type of cations and ions constituting the low-molecu-
lar-weight salts, on the ionic conductivity and struc-
ture of the complexes was considered previously .
At the same time, the effect exerted by the nature of
the medium on the composition, morphology, and
structure of complexes is as yet insufficiently studied.
In the previous studies, the possibility of formation
of various complexes was demonstrated for the system
polyethylene glycol (PEG)3sodium tetraphenylborate
in organic solvents. The composition and structure of
solid complexes formed in the solvent and their
change upon solvent removal remain unclear.
At the same time, a study of the composition and
structure of solid complexes and the features of their
formation in organic solvents of different nature is
of great significance for the development of processes
for preparation of individual complexes or their
In this connection, the features of formation of
polyethylene glycol complexes in protonic solvents of
linear and branched structure were studied previously
by optical microscopy and X-ray diffraction analysis.
The results obtained confirmed the formation of sev-
eral complexes in the above media [4, 5]. It was es-
tablished in these studies that the number of the
formed complexes decreases as the structure of alcohol
becomes more complex, i.e., in going from linear to
branched alcohols. However, the effect exerted by
the molecular weight of the polymer on the structure
of complexes composed of polyethylene glycol and
sodium tetraphenylborate was not considered.
In this study we examined how the length of the
PEG macromolecule chain affects the composition
and structure of the PEG3sodium teraphenylborate
complexes formed in ethanol. Taking the PEG3
system as example, we studied the features of
the interaction of alkali metal salts with the polyether
of a varied molecular weight (MW).
Sodium tetraphenylborate NaB(C
ally pure grade) was used in the study after additional
drying. Polyehtylene glycols with molecular weights
(MWs) of 2000, 4000, 15000, 40000, and 100000
(Schuchardt, Germany) were used after drying in a
rough vacuum. Ethanol was purified by the method
described in .
The complexes were synthesized by mixing solu-
tions of individual components under the standard
conditions. The solvent was evaporated in a vacuum