Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 2, pp. 269−272.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © A.V. Pestov, Yu.S. Petrova, A.V. Bukharova, L.K. Neudachina, O.V. Koryakova, E.G. Matochkina, M.I. Kodess, Yu.G. Yatluk, 2013,
published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 2, pp. 290−293.
AND POLYMERIC MATERIALS
Dedicated to the memory of L. A. Nud’ga, a leading scientist in the ﬁ eld of Russian chitinology
Synthesis in a Gel and Sorption Properties
of N-2-Sulfoethyl Chitosan
A. V. Pestov
, Yu. S. Petrova
, A. V. Bukharova
, L. K. Neudachina
O. V. Koryakova
, E. G. Matochkina
, M. I. Kodess
, and Yu. G. Yatluk
Postovskii Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences, Yekaterinburg, Russia
Yeltsin Ural Federal University, Yekaterinburg, Russia
Received September 28, 2012
Abstract—A new procedure was developed for preparation of chelate amino-containing polymer N-2-sulfoethyl
chitosan by synthesis in a gel through the reaction between chitosan and sodium 2-bromoethanesulfonate, yielding
a polymer with the degree of substitution of up to 0.5. The structure of the resulting polymers was conﬁ rmed by
H NMR spectroscopy. The sorption characteristics with respect to transition and alkaline-earth metal ions were
determined for the cross-linked polymers.
Sulfoethylation of polymers represents a productive
procedure for polymer-analogous transformations, since
incorporation of a strong acid residue into the macromol-
ecule substantially modiﬁ es the properties of the initial
polymer. For example, 2-sulfoetylation of synthetic
polymers allows preparation of stationary phases for
HPLC [1, 2], ion-conducting membranes , catalysts
[4, 5], and antimicrobial agents . In the case of natu-
ral polymers, modiﬁ cation with 2-sulfoethyl groups has
gained wider acceptance as a method of preparation of
products suitable for manufacture of membranes intended
for various applications [7, 8], biopolymeric surfactants
[9, 10], and 3d-metal ion sorbents [11, 12]. Modiﬁ ca-
tion signiﬁ cantly affects the bioactive properties of the
initial polymer matrices; the modiﬁ ed polymers exhibit
antimutagenic [13–16], immunomodulating , and
anticoagulant  activity.
Chitosan is a linear amino polysaccharide whose struc-
ture is nearly identical to that of cellulose, except for the
fact that the pyranose ring bears an amino, instead of a
hydroxy, group on the C-2 position, whereby it acquires
high complexing power with respect to metal ions. The
presence of highly reactive amino and hydroxy groups
in chitosan allows for easy modiﬁ cation and extends the
application range of the polymer.
Sulfoethylation of chitosan and carboxymethylated
chitosan with sodium 2-chloroethanesulfonate [18, 19]
and sodium vinyl sulfonate  in a strongly alkaline
medium leads to nonselective N,O-substituted product.
Here, we developed a procedure for synthesis of
N-2-sulfoethyl chitosan (SEC), a promising derivative
of the amino-containing polymer of natural origin, and
examined its sorption properties with respect to transition
and alkaline-earth metal ions.
We used chitosan available from Sonat (degree of
deacetylation 0.84, molecular weight 250 kDa, ash resi-
due 0.19%). The degree of deacetylation was determined
H NMR spectroscopy, and the molecular weight,
viscometrically ; sodium 2-bromoethanesulfonate
was available from Alfa Aesar and used without further
For C,H,N analysis served a Perkin Elmer automatic
analyzer. The diffuse reﬂ ection IR spectra were measured