Russian Journal of Applied Chemistry, Vol. 77, No. 5, 2004, pp. 842 845. Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 5,
2004, pp. 847 850.
Original Russian Text Copyright
2004 by Akhmetkhanov, Kolesov, Kadyrov, Karmilov, Zaikov.
MACROMOLECULAR CHEMISTRY
AND POLYMERIC MATERIALS
Preparation of Metal Carboxylates and Their Stabilizing
Performance under Intense High-Pressure Shear Treatment
R. M. Akhmetkhanov, S. V. Kolesov, R. G. Kadyrov,
A. Yu. Karmilov, and G. E. Zaikov
Bashkir State University, Ufa, Bashkortostan, Russia
Institute of Synthetic Polymeric Materials, Russian Academy of Sciences, Moscow, Russia
Institute of Biophysical Chemistry, Russian Academy of Sciences, Moscow, Russia
Received October 28, 2003
Abstract Solid-phase synthesis of certain metal carboxylates and their effect on stabilization of polyvinyl
chloride under intense high-pressure shear treatment were studied.
Metal carboxylates are widely used as thermal
stabilizers and lubricants in development of new ma-
terials and goods based on polyvinyl chloride (PVC)
[1]. The main method of industrial production of
metal carboxylates is the exchange reaction between
aqueous solution of metal chloride or nitrate and sodi-
um carboxylate, e.g., stearate, at elevated tempera-
tures. It is characterized by a large amount of waste-
water, the need in additional operations to isolate
target products, etc. [2]. In known methods of solid-
phase synthesis of metal carboxylates [3, 4], sophist-
icated and power-consuming devices with abrasive,
cutting, and impact action are used. The product
yields in such procedures are usually low.
Academy of Sciences [6]. The yield of metal car-
boxylates was determined analytically in accordance
with TU (Technical Specifications) 6-09-4104 87
from the residual content of carboxylic acids in the
reaction mixture and by IR spectrometry on a Bruker
IFS-88 spectrometer from the intensity of the absorp-
1
tion bands within the 1400 1650 cm range depend-
ing on metal. Pure grade stearic, lauric, and palmitic
acids and calcium, barium, cadmium(II), lead(II), and
zinc(II) oxides or their binary mixtures, and sodium
and potassium carbonates were used. The method of
determination of the PVC dehydrochlorination rate
was similar to that described in [7]. The thermal sta-
bility time of polymeric compositions was determined
in accordance with GOST (State Standard) 14041 91.
A new method of solid-phase synthesis of chemical
materials and processing and modification of poly-
mers under intense high-pressure shear treatment
(IHPST) at elevated temperatures in special dispersers
is being actively developed today [5, 6]. Under
IHPST, various chemical reactions can proceed in
polymers: change of supramolecular structure, disin-
tegration, and increase in specific surface area of the
material treated with formation of a superfine powder.
The IHPST method has no disadvantages character-
istic for other methods of metal carboxylate synthesis
and provides high yield of the reaction products and
short reaction time; no catalysts are required. The
specific feature of solid-phase reactions with IHPST is
that the combined effect of high pressure and shear
strain brings solid substances to the plastic flow state.
In the process, a great amount of structural defects
is formed in the substance, electronic properties of
molecules change, and the activation barrier of reac-
tions decreases [8].
The goal of this work is to perform solid-phase
synthesis of certain metal carboxylates and to study
polyvinyl chloride (PVC) stabilization with these car-
boxylates under IHPST.
The solid-phase synthesis of metal carboxylates
proceeds by the reactions
EXPERIMENTAL
MO + 2RCO2H
M(RCO2)2 + H2O,
The solid-phase synthesis of metal carboxylates
and processing of polyvinyl chloride compositions
under IHPST were performed in a rotary disperser
designed at the Institute of Chemical Physics, Russian
M2CO3 + 2RCO2H
2M (RCO2) + H2O + CO2,
where M = Ca, Ba, Zn, Cd, Pb; M = K, Na; R =
C H , C H , C H .
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1070-4272/04/7705-0842 2004 MAIK Nauka/Interperiodica