1070-4272/04/7705-0736C2004 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 77, No. 5, 2004, pp. 736!738. Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 5,
2004, pp. 740!742.
Original Russian Text Copyright + 2004 by Kurlykin, Novoselov, Sashina.
OF SYSTEMS AND PROCESSES
Thermochemistry of Dissolution of Glucose in Binary Systems
N-Methylmorpholine N-Oxide Monohydrate!Aprotic Solvent
M. P. Kurlykin, N. P. Novoselov, and E. S. Sashina
St. Petersburg State University of Technology and Design, St. Petersburg, Russia
Received March 4, 2003; in final form, January 2004
Abstract-Glucose enthalpies of solution in binary systems N-methylmorpholine N-oxide monohydrate3
aprotic solvent at 75oC are measured.
Since cellulose is the most abundant steadily re-
newable native polymer, the problem of its dissolution
is topical for more than 150 years all over the world.
Numerous works in this area are stimulated by the
need in processing cellulose fibers through dissolu-
tion, to manufacture fibers and films of various pur-
poses. The difficulty of the problem of cellulose dis-
solution originates from complexity of the structure of
its elementary unit bearing hydroxy groups of various
natures, and also from the structure of the cellulose
macromolecule consisting of crystalline and amorph-
ous regions of different reactivities.
To understand the mechanism of interaction of cel-
lulose macromolecules with solvents, it is advisable to
study the reactivity of functional groups of its ele-
mentary unit (a-D-glucose) under various conditions.
In this case, it is rational to perform the study with
solvents that dissolve cellulose to form solutions suit-
able for subsequent processing . The capability
of individual or mixed solvents to dissolve cellulose
can be predicted using the calorimetric method. Not
disclosing the nature of interparticle interaction, ther-
mochemical data reveal whether or not components of
a mixture are involved in chemical interaction.
The goal of this work is to study dissolution of
a-D-glucose as a model for the cellulose unit in
solvents based on N-methylmorpholine N-oxide mono-
hydrate (MMO). The decision on the solvent was
caused by the fact that MMO is of great practical
interest in view of cellulose dissolution . Also we
used binary mixtures of MMO with co-solvents. The
use of such binary mixtures allows preparation of cel-
lulose solutions suitable for manufacture of speciality
fibers and films, making these processes more cost-
The enthalpies of solution were determined at 75oC
on a Calvet adiabatic calorimeter (calorimetric vessel
volume 75 ml) to within 2.5%. As co-solvents for
MMO we used dimethyl sulfoxide (DMSO), dimeth-
ylformamide (DMF), and dimethylacetamide (DMAA)
(all of chemically pure grade). The solvents were
dried over a zeolite. The composition of MMO was
controlled by the melting point (72373oC) and also
using Fischer titration. In experiments we used glu-
cose (chemically pure grade) with mp 146oC.
The solvency of DMSO, DMF, and DMAA at
75oC with respect to glucose amounts to 15320%.
The solubility of glucose in pure MMO is about 2%
at 75oC. Therefore, in this work we studied solutions
of glucose in binary mixtures with a concentration
no more than 2%.
Our results (Table 1) showed that the enthalpy of
glucose solution in DMSO, DMF, and DMAA at
75oC is independent of the glucose concentration.
Table 1. Glucose enthalpies of solution in aprotic solvents
Solvent ³ Glucose concentration, wt % ³ DH
DMSO ³ 2.2 ³ 61.5
³ 4.3 ³ 60.0
³ 6.1 ³ 58.9
³ 8.7 ³ 60.0
³ 10.2 ³ 59.1
DMF ³ 2.1 ³ 99.9
³ 4.2 ³ 101.2
³ 6.1 ³ 102.7
³ 8.4 ³ 98.7
³ 10.1 ³ 99.2
DMAA ³ 2.1 ³ 115.3
³ 4.3 ³ 117.5
³ 6.0 ³ 114.0
³ 8.3 ³ 113.8
³ 10.0 ³ 114.1