Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 4, pp. 589593.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © V.A. Zhorin, M.R. Kiselev, V.I. Roldugin, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 4, pp. 571575.
OF SYSTEMS AND PROCESSES
Exothermic Processes in Aluminum–Polypropylene Mixtures
after High-Pressure Plastic Deformation
V. A. Zhorin, M. R. Kiselev, and V. I. Roldugin
Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
Received February 3, 2011
Abstract—The inﬂ uence of high-pressure plastic deformation on aluminum–polypropylene mixtures of differ-
ent compositions was examined by thermal analysis techniques. The thermokinetic characteristics of the process
were determined, and assumptions concerning the mechanism of the interaction of the components were made.
In was found earlier  that, under plastic deformation
at a pressure of 6–8 GPa in Bridgman anvil type high-
pressure devices, the 40–50-m ferrite and pearlite grains
in Steel 45 samples became aligned in the deformation
plane. In the initial stages of deformation, the material
acquired a banded structure comprised of 3–4-m-thick
pearlite (light) and ferrite (dark) bands. At higher degrees
of deformation the sizes of the heterogeneous areas
proved to be smaller than the resolution of an optical
Changes in the particle shape and size for heteroge-
neous mixtures, induced by high-pressure plastic defor-
mation, are accompanied by the appearance of freshly
exposed surfaces and formation of an extended interface.
High pressure provides a tight contact of heterogeneous
surfaces and is thereby conducive to interactions between
various reactive sites emerging on heterogeneous freshly
For example, plastic deformation at 2 GPa of mixtures
of powdered aluminum and copper with the particle size
of 20–30 m resulted in formation of solid solutions .
Heating of these samples was accompanied by intense
liberation of heat. In mixtures of polyethylene with met-
als, metal oxides, and organic compounds, the interaction
of the components at the interface formed under high-
pressure plastic deformation caused signiﬁ cant changes in
the polymer melting parameters [3–5], and for mixtures of
polypropylene with maleimide, formation of grafted co-
polymers was observed . An intense liberation of heat
was observed during heating of polyethylene–KMnO
mixtures subjected to plastic deformation at 2 GPa .
Thus, high-pressure plastic deformation of mixtures of
different components not only leads to reactions between
these components immediately during deformation but
also stimulates thermally-initiated exothermic processes
in the deformed mixtures.
As known, due to high reactivity of the freshly ex-
posed surface of aluminum, a passivating surface oxide
ﬁ lm on aluminum can be easily formed. Examinations
of the interaction of reactive aluminum atoms with vari-
ous components are possible only if the freshly exposed
metal surface will be prevented from coming in contact
with atmospheric oxygen. To this end, it is expedient to
subject mixtures of powdered aluminum with particular
components to high-pressure plastic deformation. Defor-
mation will lead to formation of a freshly exposed surface,
and high pressure will provide tight contact between the
mixture components, thereby preventing the access of
oxygen to reactive atoms on the freshly exposed surface.
As shown earlier , the deformation at 2 GPa leads
to inhibition of diffusion of oxygen into polypropylene,
as manifested in twofold deceleration of thermal oxida-