Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 10, pp. 1509−1513.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © N.P. Shapkin, L.B. Leont’ev, A.L. Leont’ev, V.V. Korochentsev, A.L. Shkuratov, 2012, published in Zhurnal Prikladnoi Khimii, 2012,
Vol. 85, No. 10, pp. 1570−1576.
AND INDUSTRIAL INORGANIC CHEMISTRY
Organomodiﬁ ed Aluminosilicates as Friction Geomodiﬁ ers
N. P. Shapkin, L. B. Leont’ev, A. L. Leont’ev,
V. V. Korochentsev, and A. L. Shkuratov
Far-Eastern Federal University, Vladivostok, Russia
Received May 12, 2012
Abstract—Effect of the composition of chitosan-modiﬁ ed natural silicates on tribotechnical characteristics of
additives and formation of a surface layer in friction of surfaces was studied. The following composites were found
to be the most promising: 90% serpentine + 10% chitosan-modiﬁ ed vermiculite; chitosan-modiﬁ ed serpentine;
and 90% serpentine + 10% vermiculite. These composites provided the minimum friction coefﬁ cients due to
introduction of polymeric chitosan into the interlayer space of an aluminosilicate. It was shown that introduction of
10% chitosan-modiﬁ ed layered silicate leads to formation of an organosilicate coating on the surface of chromium-
plated steel. The composition and structure of the coating were determined by X-ray photoelectron spectroscopy
and atomic-force microscopy.
Layered hydrosilicates and, in particular, serpentinite
are rather promising materials to be used as additives
to lubricants [1, 2]. There are a rather large number
of preparations based on these compounds [3, 4]. As,
however, shown by more in-depth studies, introduction
of aluminosilicates can adversely affect the properties of
tribotechnical composites .
Introduction of polymers into tribotechnical
composites can markedly improve their technical
characteristics . The surface of the hydrosilicates
used in the composites is weakly acidic, which is known
to impair the quality of tribotechnical composites. As
a rule, one of components of a composite is a base. In
particular, these may be fatty acid salts of alkali metals.
In this context, use of chitosan having amino groups
in its side chain as a macromolecular component of
lubricating composites may be of particular interest.
Therefore, chitosan was used in this study as a modifying
compound for new tribotechnical composites.
One of the components, vermiculite, has a composition
O. Serpentinite has the
following elementary composition (%): SiO
MgO 28.5, Fe
17.5, CaO 2.6, MnO 2.3, H
O 11.2; its
empirical formula is 4.5MgO·0.7Fe
O. The grain size of serpentinite (prior to
its being treated in a disperser) is in the range 1–10 μm.
Aluminosilicate of natural origin has the following
elemental composition (%): SiO
MgO 13.1, Fe
19.1, CaO 15.3, Na
O 0.6, K
MnO 0.2, TiO
O 0.6; empirical formula
. The grain size
of the silicate (prior to its being treated in a disperser) is
in the range 1–20 μm.
The natural polysaccharide has a molecular mass not
exceeding 200 000 Da and the following characteristics:
content in a 2% aqueous solution of acetic acid (%):
C 41.8, N 7.5, and H
O 8.8; degree of deacetylation
84.0%; viscosity of a 1% solution in 2% aqueous
solution of acetic acid, 88.0 mmg s
; empirical formula
of the natural polysaccharide (C
We modiﬁ ed the aluminosilicate of natural origin
with the polysaccharide as follows: a 1% solution of the
polysaccharide was prepared by its dissolution in 2%
acetic acid. Further, a ground silicate was introduced
into the polysaccharide solution in an amount of 100 g