1070-4272/02/7503-0465$27.00C2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 3, 2002, pp. 465! 469. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 3,
2002, pp. 476!480.
Original Russian Text Copyright + 2002 by Kazantsev, Igolkin, Shirshin, Kuznetsova, Spirina, Malyshev.
AND POLYMERIC MATERIALS
of 2-Acrylamido-2-methylpropanesulfonic Acid
in Acidic Aqueous Solutions
O. A. Kazantsev, A. V. Igolkin, K. V. Shirshin, N. A. Kuznetsova,
A. N. Spirina, and A. P. Malyshev
Dzerzhinsk Branch, Nizhni Novgorod State Technical University, Dzerzhinsk, Nizhni Novgorod oblast, Russia
Received October 10, 2001
Abstract-Spontaneous polymerization of 2-acrylamido-2-methylpropanesulfonic acid in the presence of
inorganic and organic neutralizing agents in concentrated aqueous solutions is studied. The hypothesis of
redox mechanism of the process initiation is discussed.
Water-soluble copolymers based on 2-acrylamido-
2-methylpropanesulfonic acid (AMPSA) and its sodi-
um salt are used in oil production and as effective
flocculants and additives in paper production .
These products are prepared by free radical polymeri-
zation of the corresponding monomers using the tradi-
tional methods. For methacrylic monomers capable of
association (containing ionogenic groups, e.g., N,N-di-
alkylaminoethyl methacrylates, or mobile hydrogen
atoms, e.g., acrylamide), the methods for spontaneous
polymerization in concentrated aqueous solutions are
being extensively developed [2, 3]. The AMPSA
molecule contains an acid group and a monosub-
stituted amide group and therefore should also be
capable of spontaneous polymerization. Indeed, spon-
taneous polymerization of AMPSA in water was re-
ported in . At the same time, in the system N,N-di-
alkylaminoethyl methacrylate3AMPSA3water (no ini-
tiator) a homopolymer of amino methacrylate was
obtained, i.e., AMPSA molecules were not involved
in spontaneous polymerization .
It was demonstrated in preliminary experiments
that spontaneous polymerization leading to consump-
tion of C=C bonds and considerable increase in the
viscosity of the system goes at a noticeable rate at
a temperature above 20oC and pH <7 in concentrated
aqueous AMPSA solutions. As the reaction proceeds
by the free radical mechanism, it does not occur in the
presence of sufficiently large amounts of inhibitors.
Furthermore, the monomer solutions remain stable
after total neutralization of AMPSA with NaOH and
also in the case of excess NaOH.
In this work we studied the features of autoinitiated
radical polymerization of AMPSA in acidic aqueous
solutions. Figure 1 shows the kinetics of C=C bond
consumption in spontaneous polymerization of
AMPSA at various degrees of neutralization of the
sulfonic acid groups with NaOH. In the absence of
the neutralizing agent, the reaction proceeds slowly
(curve 7). The dependence of the initial polymeriza-
tion rate on the degree of neutralization K passes
through a maximum at K of about 50% (Fig. 2). At
larger conversions, the effect of this factor becomes
weaker: at the degree of neutralization of AMPSA
varied within 10395%, the conversion of the monomer
after 4 h varies within a narrow range from 75 to 88%
(Fig. 1). Considerably lower value was obtained only
in the absence of NaOH.
Fig. 1. C=C bond concentration A in the system AMPSA3
O as a function of time t. [AMPSA]
T=50oC; the same for Fig. 2. Molar ratio AMPSA : NaOH:
(1) 1 : 1.5, (2)1:1,(3) 1.1 : 1, (4)4:3,(5)4:1,(6)10:1,