1070-4272/01/7405-0818$25.00C2001 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 74, No. 5, 2001, pp. 818!821. Translated from Zhurnal Prikladnoi Khimii, Vol. 74, No. 5,
2001, pp. 793!796.
Original Russian Text Copyright + 2001 by Igrunova, Sirotinkin, Uspenskaya.
AND POLYMERIC MATERIALS
Synthesis and Absorption Power of New Polyelectrolyte
Tetrazole-Containing Acrylic Hydrogels
A. V. Igrunova, N. V. Sirotinkin, and M. V. Uspenskaya
St. Petersburg State Technological Institute, St. Petersburg, Russia
Received December 21, 2000; in final form, February 2001
Abstract-The kinetic features of formation and equilibrium swelling in water and aqueous solutions of
metals were considered for new hydrogels based on acrylic acid and methylenebisacrylamide modified with
2-methyl-5-vinyltetrazole in the polymerization stage. The influence of the concentration of the reactants
on the gelation rate and the degree of equilibrium swelling was studied, as well as the influence of 2-methyl-
5-vinyltetrazole on the properties of the copolymers prepared. Possible application fields for the new hy-
drogels were proposed.
Polyacrylate hydrogels find wide application owing
to their unique water-absorbing and immobilizing
power with respect to various media. These properties
are of special value in the context of the present-day
problems of biological medicine and ecology [1, 2].
Incorporation into the polymer structure of complex-
ones, in particular, nitrogen-containing heterocyclic
moieties, intensifies the absorption of aqueous solu-
tions of electrolytes . High complexing power of
the tetrazole ring with respect to heavy and noble
metal ions makes these gels suitable for water treat-
ment application. The immunobiological activity of
polyvinyltetrazoles and copolymers of vinyltetrazoles
with acrylic acid (AA) makes these hydrogels promis-
ing for application in living bodies [4, 5].
The aim of this work is to study the kinetic features
of gelation and the behavior of the gels in electrolyte
solutions, as well as to analyze the mechanism of
formation and interaction of the gel prepared with
solutions of salts of copper, cobalt, nickel, and other
Network copolymers were prepared by radical
polymerization of AA partially neutralized with sodi-
um hydroxide (degree of neutralization a = 0.830.9),
2-methyl-5-vinyltetrazole (MVT), and methylenebis-
acrylamide (MBAA) as cross-linking agents in an
aqueous solution at 40360oC. The initiator was the
(TMED) redox system. The initial concentrations of
the reactants in polymerization were as follows:
monomer 30, MVT 0370 wt % of the AA mass, and
MBAA 030.9 wt % of the monomer mass. Prior to
fied by vacuum distillation (bp 80oC at 20 mm Hg).
The other reactants, as well as their purification and
copolymerization procedures, were characterized in
. Polymerization was carried out in ampules; the
reaction mixture was deoxygenated prior to adding the
initiator by passing argon through the solution for
233 min. A specific feature of the experiment was
freezing of AA in a refrigerator at 335oC prior to the
The kinetic parameter to be measured was the gela-
tion time as estimated from the time of the onset of
the fluidity loss by the reaction mixture.
The gel structure was investigated by
spectroscopy and differential thermal analysis (DTA).
The presence of the tetrazole moiety in the polymer
was judged from the peaks in the IR spectrum at n
1100, 1208, and 1635 cm
(tetrazole ring vibrations).
The resulting copolymers are thermally stable, as
evidenced by the thermal oxidation analysis data as
processed by the Freeman and Carrol’s method (E
420 kJ mol
The copolymers synthesized were kept in distilled
water to remove the sol fraction. The equilibrium
swelling of the gels and the swelling kinetics were
studied by the standard gravimetric method. The
degree of equilibrium swelling was calculated by the
equation Q =(m
, where m
, g, is the mass
Synthesized at the St. Petersburg State Technological Institute.