Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 9, pp. 1673−1685. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © A.A. Fedorov, Yu.S. Chekryshkin, O.V. Rudometova, Zh.A. Vnutskikh, 2008, published in Khimicheskaya Promyshlennost’, 2008,
Vol. 85, No. 4, pp. 163−180.
TECHNOLOGY OF ORGANIC
AND INORGANIC CHEMISTRY
Application of Inorganic Compounds
at the Thermal Processing of Polyvinylchloride
A. A. Fedorov, Yu. S. Chekryshkin, O. V. Rudometova, and Zh. A. Vnutskikh
Institute of Technical Chemistry, Ural Branch, Russian Academy of Sciences, Perm, Russia
Received March 4, 2008
Abstract—A review of publications on the effect of various inorganic additives (metals oxides, hydroxides,
chlorides and carbonates) on the process of dehydrochlorination and pyrolysis at the thermal processing of
polyvinylchloride (PVC). A decrease in temperature of the PVC dehydrochlorination step is noted at processing in
the presence of chromium, iron, cobalt, copper and molybdenum oxides. Aluminum, titanium, circonium, cerium
and lead oxides do not change temperature of beginning of PVC destruction. No effect noted of the oxides at the
second step of PVC destruction.
Demand for plastics grows continuously due to their
wide application and relatively low cost; respectively,
their manufacturing and amount of side products grow.
Polyvinylchloride (PVC) plays key role in the plastics
industry for 40 years and remains to be the basic polymer
and a source of huge amount of wastes. For example, in
West Europe the amount of PVC in municipal wastes is
estimated as 2 million tons per year .
Combustion of municipal wastes became an alternative
to the technology of their concealment at the waste dump.
In Japan in 2004 appeared more than 10 million ton of
wastes, and approximately 40% of this amount was either
concealed or combusted . However, combustion leads
to the liberation of substances that can bring more harm
to environment than concealment or radioactive wastes.
The processes of combustion whole and not controlled
combustion of wastes in particular leads to formation
of hazard substances, e.g., soot, smoke, benzene,
dioxins, acid gases, heavy metals, aliphatic and aromatic
For the processing of wastes of synthetic polymer
materials the most often is used the method of pyrolysis.
However, thermal pyrolysis of PVC wastes liberates
hydrogen chloride and chlorine-containing organic
compounds are formed, therefore appears a problem of
corrosion at the use of chlorine-contaning plastics as raw
material for blast and coke furnaces at steel manufacturing
[7, 8]. Chlorinated hydrocarbons can be precursors of
even more toxic substances such as polychlorinated
dibenzodioxines, dibenzofurans and polychlorobiphenyls
Behavior of PVC at thermal decomposition has been
widely studied basing on the composition of the products
and kinetics of destruction [10−16]. All explorers suggest
that thermal decomposition of PVC proceeds in two steps,
starting with the splitting hydrogen chloride off. This
process is propagated along the polymer chain and leads
to formation of polyenes that are responsible for the color
of the destructed polymer. In the ﬁ rst step, at 200−360°C,
is liberated hydrogen chloride and approximately 15% of
the formed therewith polyene is converted into benzene
and other aromatic compounds [17, 18] via intramolecular
cyclization of the polyene segments  with formation
of cyclohexene and cyclohexadiene remaining in this step
introduced to aliphatic matrix. The hydrogen chloride
liberated in the ﬁ rst step works as a catalyst for the
further reactions of decomposition . In the second
step, at 360−500°C, the polyene frame exerts structural
decomposition leading to formation of alkylaromatic
and fused aromatic compounds (toluene, naphthalene,
indene, anthracene, o-xylene and various chlorobenzenes)
together with a small amount of hydrogen chloride and
benzene . During this step the polymer net formed at
the condensation of polyene is damaged, that promotes
aromatization of cyclohexene and cyclohexadiene rings.
The main reactions in the second step are cis-trans
isomerization, aromatization and stitching .