Poster presentation
210
PREPARATION AND RESEARCH OF MICROCRYSTALLINE
CELLULOSE AND NANOCELLULOSE FROM LICORICE ROOT
CELLULOSE
D.J. Ergashev, M.Q. Saidmuhammedova, A.A. Atakhanov
Institute of Polymer Chemistry and Physics, Uzbekistan Academy of Sciences,
Tashkent, Uzbekistan,
e-mail: polymer@academy.uz
In recent years, researches on the creation of new types of products and introduction
of production technologies in world practice are being carried out at a rapid pace.
At this point, microcrystalline cellulose (MCC) and nanocellulose (NC) derivatives,
a modified form of cellulose, which is considered the most widespread and renewable
natural
polymer on earth, are receiving great attention.
In this work, MCC and nanocellulose NC were obtained from licorice root cellulose
by acid hydrolysis method.
MCC extraction from licorice root cellulose was carried out under the conditions of 4
12% of nitric acid (HNO
3
), temperature 100-110°C, modulus 1:10, duration of
hydrolysis 30-90 minutes as a hydrolyzing agent.
The results of the conducted research show that with increasing acid concentration
and
duration of hydrolysis, the degree of polymerization of MCC, depending on the acid
concentration, the degree of polymerization (DP) of MCC obtained from licorice root
cellulose decreases from 500 to 250. It was observed that the yield decreased to 70%
and the degree of crystallization (DC) changed from 56% to 71%
in MCC obtained
from licorice root cellulose due to the hydrolysis of a certain part of the amorphous area
in the cellulose.
NC from licorice root cellulose were obtained by hydrolysis in aqueous solutions of
sulfuric acid (H
2
SO
4
) with different concentrations: acid concentration 40, 50, 55, 60,
65%, temperature 25-50°C, module 1:10 duration 60-120 minutes and It was carried out
under conditions consisting of ultrasonic dispersion for 30 min.
The results of the conducted research show that the DP of NC decreased from 360 to
150 due to the increase of acid concentration, hydrolysis temperature and duration of
hydrolysis, acceleration of the hydrolysis process. Due to the fact that a certain part of
the amorphous area of the cellulose structure in licorice
root cellulose undergoes
hydrolysis and passes into the solution, it was found that the output yield of NC
decreased and DC changed from 59% to 81% when
the acid concentration was
increased from 40% to 60%. A further increase in acid concentration had a negative
effect on the DC of the NC samples, that is, the degree of crystallinity of the NC sample
obtained in a 65% acid solution was 68%, which was explained by the increase. caused
by the effect of the acid concentration on the crystal structure of cellulose.
The possibility of obtaining MСС and NС from licorice root cellulose under different
conditions was studied and it was shown that the structure and properties of MСС and
NС depend on the hydrolysis conditions.
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