ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 4, pp. 676!681. + Pleiades Publishing, Ltd., 2008.
Original Russian Text + S.E. Shakhovets, A.N. Ovechko, B.L. Smirnov, V.V. Bogdanov, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81,
No. 4, pp. 640 ! 644.
AND POLYMERIC MATERIALS
Influence of the Parameters of Integrated
on the Physicochemical Properties
of Vulcanized Rubbers
S. E. Shakhovets, A. N. Ovechko, B. L. Smirnov, and V. V. Bogdanov
St. Petersburg State Institute of Technology (Technical University), St. Petersburg, Russia
ELAST-Tekhnologii Open Joint-Stock Company, St. Petersburg, Russia
Received May 23, 2007
Abstract-The influence of integrated reclaiming of vulcanized rubbers, combining the high-temperature
mechanothermochemical and steam degradation methods, on the properties of reclaims was elucidated.
The existing methods for reclaiming of vulcanized
rubber are underlain by breaking the cross-links.
The available experience suggests that it is expedient
to combine high-temperature mechanothermochemical
and steam degradation methods in reclaiming [1, 2].
This not only provides a more extensive impact on
the material being reclaimed but also excludes [harsh]
modes of the process, resulting in an undesirably deep
From the economical viewpoint, the reclaiming
technology is acceptable only if implemented in
the continuous mode. This requirement can be satis-
fied with worm-gear machines. This inevitably gener-
ates a problem of intensive cooling of the equipment.
At the same time, the closed design of worm-gear
machines allows introduction into the processing zone
of water which can, in parallel, act as a coolant and,
via vaporization, as a degrading agent (the role of
the latter can also be played by other substances, in-
cluding those occurring in the liquid phase). Special
worm-gear machines were designed for implementa-
tion of such processes . They exhibit high perfor-
mance characteristics with tire crumb as the raw ma-
terial. The reason is twofold: This avoids emergency
operation modes for the equipment in cases when
foreign inclusions from vulcanized rubber pieces get
into working heads, and the interface surface area
between the material and the operating elements of
the equipment is substantially increased, thereby pro-
viding uniform warming and uniform external impact
on the material.
We estimated here the efficiency of the suggested
procedure by analyzing how the integrated mechano-
thermochemical reclaiming affects the physicochem-
ical properties of vulcanized rubbers.
General information about the investigation meth-
ods we used is presented in the scheme. Below, some
testing techniques and the facilities are specified.
The tire material undergoes numerous physico-
chemical changes during exploitation and subsequent
processing. We examined here the changes in the mo-
lecular composition; micro- and macrostructures of
the rubbers in the tire rubber formulation and their
chemical structure; microaggregation states governed
by the nature of interaction of rubbers with the fill-
ing agent; vulcanization network density; and the ex-
tent of degradation in different stages of the tire pro-
Our study was concerned with the material of
the treads of automobile tires manufactured in Russia
and other countries, both fresh and spent (climatic
zones of the Russian Federation and the Western
Europe); different size fractions of the tire rubber
crumb, as well as the reclaim obtained in the com-