Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 1, pp. 15−19.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © V.A. Zhorin, M.R. Kiselev, V.I. Roldugin, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 1, pp. 18−23.
AND INDUSTRIAL INORGANIC CHEMISTRY
Thermogravimetric Analysis of the Aluminum–Polypropylene
Mixtures after Plastic Deformation Under High Pressure
V. A. Zhorin, M. R. Kiselev, and V. I. Roldugin
Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
Received July 21, 2011
Abstract—The thermogravimetric analysis of the aluminum–polypropylene mixture of varied composition was
performed to determine the effect of plastic deformation under the high pressure. It was found that a loss of mass
by the mixed samples up to 400°С is due to decomposition of a polymer and the mass gain above 500°С, due to
It is known that aluminum has high chemical activity
and is widely used as a component of solid fuel. Under
normal conditions, the aluminum surface is covered with
a thin but solid layer of oxide, which prevents the interac-
tion of aluminum atoms with the reagents.
In [1, 2], mixtures of powdered aluminum with Teﬂ on
have been processed in a mechanical activator. In this
case, the spherical aluminum particles 3.6 μm in diameter
were deformed into petals with a thickness ranging from
several fractions to 1 μm. Thus, in the treated mixtures
there was formed the metal–polymer interface with
a freshly opened surface of metal particles as constitu-
ent. The shock-wave inﬂ uence on such mixtures caused
The freshly opened surfaces are also formed at
working of various friction units in the presence of oils
and greases. These processes are accompanied by heat
evolution. It is of interest to study the thermally initiated
processes of the interaction of the active metal atoms on
the freshly opened surface with the environment.
The plastic deformation of solids with different
types of chemical bonds can be performed on the high-
pressure equipment of the type of anvils. This treatment
causes powdered aluminum to compact into solid discs
with a characteristic metallic luster, which indicates the
formation of freshly opened surface. It was found that
in polypropylene (PP) subjected to plastic deformation
under the pressure 1–2 GPa the rate of thermal oxida-
tion decreases . The authors ascribed this effect to a
decrease in the diffusion rate of oxygen.
It is of interest to study the thermally initiated process-
es in mixtures of powdered aluminum with PP after the
plastic deformation under high pressure. This treatment
causes metal particles with the formed opened surface
to incorporate into a polymer matrix, thus making them
inaccessible to atmospheric oxygen. At the initial stage
of the heating of the metal–polymer mixtures, a polymer
will decompose to form highly active products, which
may enter into contact with the active aluminum atoms on
the freshly opened surfaces. The products being formed
may affect the behavior of aluminum at high temperatures
when the intense oxidation begins. The study is concerned
with the thermogravimetric analysis of the behavior of
the metal–polymer mixtures.
We studied powdered isotactic polypropylene (M
3.5 × 10
= 7.7 × 10
) and ASD-6 powdered alu-
minum (particle size 5–10 μm). Powdered components
of the required composition were mixed in a mortar.
The starting components and metal–polymer mixtures
were compressed under the pressure 1.0 GPa at room
temperature on anvils made of a hardened KhVG steel
(diameter of working surfaces 20 mm). The edge zone of
the samples (width 3 mm) was analyzed. The thickness