1070-4272/02/7510-1688 $27.00 C 2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 10, 2002, pp. 1688!1691. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 10, 2002,
Original Russian Text Copyright C 2002 by Lazareva, Shinkareva.
AND POLYMERIC MATERIALS
Rheological and Electrophysical Characteristics
of Solutions of Polyvinyl Alcohol and Water-Soluble
T. G. Lazareva and E. V. Shinkareva
Institute of General and Inorganic Chemistry, Belarussian National Academy of Sciences, Minsk, Belarus
Received December 5, 2001; in final form, March 2002
Abstract-The flow and viscosity curves of solutions of polyvinyl alcohol and water-soluble carboxymethyl
cellulose of various brands, and also of their mixtures are studied over the temperature range 30370oC.
Water-soluble polymer and, in particular, poly-
vinyl alcohol (PVA) and carboxymethyl cellulose
(Na-CMC) are widely used in the pulp-and-paper,
varnish-and-paint, and other branches of industry. In
the pulp-and-paper works, their 135% solutions are
used for paper sizing. In this context, it is of interest
to compare rheological characteristics of such solu-
tions, as dependent on the polymer brand and con-
centration and the solution temperature. A study of
the flow and viscosity curves as influenced by the
temperature and electric and magnetic fields is neces-
sary to evaluate the operational capacity of polymer
solutions [1, 2]. The rheological properties of polymer
solutions are also of interest for elucidating their
structural features related to the system of intermo-
lecular interactions, conformational transformations,
and stereoregularity. Finally, the initial parameters
of polymer solutions largely control the mechanical
and performance characteristics of the resulting prod-
ucts (coatings, fibers, special-purpose paper, paints,
Here we report generalized data on the rheological
properties of polyvinyl alcohol and water-soluble car-
boxymethyl cellulose of various brands and formula-
tions on their base.
Rheological measurements were carried out with
a Rheotest-2 rotary viscometer over wide the shear
from 1 to 1350 s
) and temperature ranges
(from 30 to 80oC). Mechanical action on the polymer
solutions was effected by rotation of the inner cylinder
of the rotary cell of the viscometer. The electrical
conductivity k and dielectric loss tangent tand were
determined on an E7-15 instrument at a frequency of
It was demonstrated experimentally that, in PVA
solutions, the shear stress t
linearly depends on the
shear rate D
over the concentration range 1320 wt %.
Such a dependence, known as the flow curve, is one
of the main rheological characteristics of fluid media.
The flow curves allow classification of liquids with
Newtonian or non-Newtonian fluids. For ordinary
(Newtonian) fluids, the dependences of the viscosity h
and shear stress t
on the shear rate D
are linear, and
h is independent of the shear rate and shear stress.
The viscosity of non-Newtonian fluids is not constant,
being dependent on the shear rate or stress .
In PVA solutions, the plots of h vs. D
in shape, depending on the PVA brand (Fig. 1). For
PVA manufactured in Japan, h at 30oC initially in-
creases and then level off (Fig. 1, curve 1). At 70oC,
the flow curves are similar in shape. It may be sug-
gested that, under shearing load at low shear rate,
Fig. 1. Viscosity h vs. shear rate D
in 16% PVA solutions.
PVA manufacture: (1) in Japan and (2! 4) in Russia (16/1).
Temperature (oC): (1, 2) 30, (3) 45, and (4) 70.