1120
KUZNETSOVA et al.
cessible, and hydrolysis should accelerate. This is
apparently the case in acid solutions of DMAEM in
which the monomer salts are strongly associated. In
alkaline solutions, DMAEM is associated to a lesser
extent (Fig. 6), and the effect of adding polymers is
insignificant.
CONCLUSIONS
(1) An increase in the monomer concentration and
addition of cationic surfactants result in sharp decel-
eration of the base hydrolysis of N, N-dimethylamino-
ethyl methacrylate.
The presumed role of association of DMAEM and
its salts was confirmed by experiments with addition
of surfactants (Fig. 2). Cationic surfactants added to
10% DMAEM solutions noticeably decelerated (tetra-
butylammonium bromide) or fully suppressed (cetyl-
trimethylammonium bromide) the hydrolysis. Anionic
and nonionic surfactants did not noticeably affect the
reaction rate. Thus, cationic micelles appearing in
solutions prevent the hydrolysis, which is probably
due to the capability of the cationic monomer to be
incorporated into such micelles. In the case of ani-
onic and nonionic micelles, penetration of the mono-
mer inside the micelles is hindered, and, therefore,
these surfactants do not affect the hydrolysis of
DMAEM and its salts.
(2) Acid hydrolysis of N, N-dimethylaminoethyl
methacrylate salts is decelerated with increasing solu-
tion concentration and accelerated on adding anionic
and cationic polymers; quaternary salts are hydrolyzed
more readily than tertiary salts, and their activity
decreases in the order N, N, N-trimethylammonioethyl
methacrylate chloride > N-benzyl-N, N-dimethylam-
monioethyl methacrylate chloride > N, N, N-trimethyl-
ammonioethyl methacrylate methyl sulfate.
(3) The hydrolysis data and concentration depen-
dences of the viscosity of N, N-dimethylaminoethyl
methacrylate salt solutions suggest that association of
the monomers exerts a passivating effect on the hy-
drolysis.
EXPERIMENTAL
REFERENCES
Tertiary salts of DMAEM were prepared by addi-
tion of equivalent amounts of appropriate acids to
aqueous solutions of the monomer. Quaternary salts
were prepared in acetone or benzene by alkylation of
DMAEM with dimethyl sulfate, methyl chloride, or
benzyl chloride.
1. Askarov, M.A., Mukhitdinova, N.A., and Nazarov, A.,
Polimerizatsiya aminoalkilakrilatov (Polymerization of
Aminoalkyl Acrylates), Tashkent: Fan, 1977.
2. Kazantsev, O.A., Zil’berman, E.N., Salov, V.N., and
Krasnov, V.L., Zh. Prikl. Khim., 1987, vol. 60, no. 9,
pp. 2142 2145.
The hydrolytic stability of the monomers was
studied at 15 70 C at a monomer concentration of
10 90 wt %. The spontaneous polymerization was
excluded by adding hydroquinone (0.5 wt % relative
to the monomer). The progress of hydrolysis was
monitored by alkali titration, and the content of C=C
bonds was determined by bromide bromate titration.
The specific viscosity of aqueous solutions of the
monomers was determined with an Ubbelohde vis-
3. Kazantsev, O.A., Shirshin, K.V., Danov, S.M., and
Kazakov, S.A., Zh. Prikl. Khim., 1998, vol. 71, no. 2,
pp. 304 307.
4. Tur’yan, Ya.I., Ignat’eva, F.K., Korshunov, M.A., and
Mikhlin, V.S., Usp. Khim., 1976, vol. 45, no. 2,
pp. 224 250.
5. Ingold, C.K., Structure and Mechanism in Organic
Chemistry, Ithaca: Cornell Univ. Press, 1969.
6. Efimova, D.Yu., Shibalovich, V.G., and Nikolaev, A.F.,
cometer (d 0.56, 0.73, or 0.99 mm depending on the
c
Zh. Prikl. Khim., 2000, vol. 73, no. 5, pp. 815 819.
viscosity of the initial solution) at 25 C. When study-
ing the hydrolysis of DMAEM DMS, the methanol
concentration was estimated by gas liquid chromatog-
raphy (Tsvet-100 device, flame-ionization detector,
2000 3-mm steel column, stationary phase 10%
PEGA on Chromaton N-AW, carrier gas nitrogen,
7. Egorov, V.V., Zaitsev, S.Yu., and Zubov, V.P., Vyso-
komol. Soedin., Ser. A, 1991, vol. 33, no. 8, pp. 1587
1608.
8. Shibalovich, V.G., Efimova, D.Yu., and Nikolaev, A.F.,
Plast. Massy, 2000, no. 3, pp. 25 27.
3
3
1
flow rate 2 10
m h , vaporizer temperature
9. Egorov, V.V., Kolloidn. Zh., 1992, vol. 54, no. 1,
200 C, column temperature 100 C).
pp. 47 51.
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