ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 1, pp. 138−142. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © V.G. Kurbatov, E.A. Indeikin, 2015, published in Zhurnal Prikladnoi Khimii, 2015, Vol. 88, No. 1, pp. 149−153.
Inﬂ uence of the Polyaniline Structure
on the Properties of Epoxy Compounds and Materials
V. G. Kurbatov and E. A. Indeikin
Yaroslavl State Technical University, Moskovskii pr. 88, Yaroslavl, 150023 Russia
Received August 20, 2014
Abstract—Rheological properties of epoxy compounds containing pernigraniline and emeraldine forms of poly-
aniline were studied. The emeraldine form of polyaniline catalyzes the curing of epoxy compounds. The inﬂ u-
ence of the emeraldine and pernigraniline forms of polyaniline on the glass transition point of epoxy polymeric
materials was determined. The elastic and deformation properties of the epoxy polymeric materials were studied.
At up to 0.28 wt % content of the emeraldine form of polyaniline, the elastic modulus and ultimate strength in-
crease. Introduction of the pernigraniline form of polyaniline leads to a decrease in the elastic modulus and to an
insigniﬁ cant increase in the ultimate strength of the epoxy polymeric materials.
It has been shown that polyaniline (PANi) additions
enhance the physicomechanical properties of epoxy
composites [1, 2]. The inﬂ uence of the PANi particle
morphology on the physicomechanical properties of
epoxy materials was also evaluated [3, 4].
It is known  that PANi has three different forms
which can transform into each other under the action of
various factors. Such transformations are accompanied
by changes in the polymer structure.
Therefore, the PANi-modiﬁ ed amine curing agents
(ACAs) prepared according to  can undergo changes
in the course of storage, associated with the transforma-
tion of one PANi form into another. Such transformations
can occur under the action of oxidants, e.g., atmospheric
oxygen, and reductants, e.g., ACA.
Changes in the structure of the modifying additive will
undoubtedly inﬂ uence the operation properties of epoxy
Thus, it is necessary to study how the PANi structure
inﬂ uences the properties of epoxy compounds and poly-
meric materials based on them.
Experiments were performed with ED-20 epoxy
oligomer (EO) with the main characteristics corresponding
to GOST (State Standard) 10587–76. Dytek-A Amine
curing agent (99.9% DuPont) with the H equivalent of
29 g was used as cross-linking agent. The ratio of EO
and ACA in the compound ready for use was calculated
from the epoxy and H equivalents. Pernigraniline and
emeraldine forms of PANi, prepared directly by the
authors, were used for ACA modiﬁ cation. The ACA
modiﬁ cation was performed by the procedure developed
previously . The PANi content of the material was
varied from 0 to 0.76 wt %.
The curing of the PANi-modiﬁ ed epoxy compounds
was studied by the sol–gel analysis method . The
method for determining the degree of coating curing from
the sol and gel fraction content of the ﬁ lm is based on the
capability of the soluble fraction of the ﬁ lm (sol fraction),
not bound in the polymer network (gel fraction), to be
washed out with an organic solvent. The method consists
in quantitative determination of the sol fraction content
with a Soxhlet extractor operating in the automatic mode.
The compound was applied onto glass plates by single-
layer casting. Curing was performed at 60–62°С for 6 h.
The glass plates with the cured coating were weighed with
an accuracy of 0.0001 g. After that, they were placed in
ﬁ lter paper envelopes, preliminarily weighed and marked
with graphite pencil. The specimens were then extracted