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Development the technology of obtaining microcrystalline cellulose from the hemp fibers

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A new, environmentally cleaner, technology of obtaining microcrystalline cellulose of fibers of hemp was proposed. The various stages of obtaining microcrystalline cellulose were studied and the optimum values of technological parameters of alkali extraction of hemp fibers, organosolv pulping, chelation and hydrolysis of cellulose were defined. It was determined that the consistent treatment of fibers of hemp by extraction of 5 % KOH solution during 210 minutes at the temperature of 95 °C, performic cooking in a mixture of 85 % formic acid and 30 % of hydrogen peroxide in the ratio of 60:40 of volume % at 100 °C during 210 min, chelation by the solution of trilon B of the concentration of 10 g/l during 30 min at 50 °C and hydrolysis by a mixture of 98 % acetic acid and 30 % of hydrogen peroxide solution in the ratio of 70:30 of volume %, allows obtaining microcrystalline cellulose in the form of white powder with a degree of polymerization 80 and the content of sulfate ash of 0.10 %. Using the methods of scanning electronic microscopy, thermogravimentric analysis and X-ray diffraction confirmed that the consistent multistage chemical treatment increases the content of crystalline part of cellulose by the removal of extractive and mineral substances, hemicelllulose and amorphous fraction of cellulose of the fibers of hemp. Application of the proposed technology of obtaining microcrystalline cellulose from the fibers of hemp is environmentally more friendly and enables to reduce significantly the cost of finished products by using national, annually renewable plant raw materials compared to imported cotton or pine cellulose. © 2016 Valerii Barbash, Mariia Karakutsa, Irina Trembus, Olha Yashchenko.
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Technology organic and inorganic substances
51
© V. Barbash, M. Karakutsa, I. Trembus, O. Yaschenko, 2016
18. Cibul’s’ka, L. V. Multifunctional additive based on the 5-amino-1,2,4-dithiazole-3-thione [Text] / L. V. Cibul’s’ka, І. M. Vasil’kevich,
V. V. Fіlіnova. – Mastil’nі materіali, 1997. – 182 p.
19. Pat. USA 3862942. Preparation of 2,4,6-tris(hydroxybenzylthio)triazines [Text] / Grilles J. – Ref. J. Chem, 1975. – 22H243.
20. Sanin, P. I. Installation for the oxidation of organic liquids with the automatic compensation and registration of consumable oxygen
[Text] / P. I. Sanin, L. F. Chernjavskaja, V. V. Sher // Neftehimija. – 1966. – Vol. 6. – P. 112114.
DEVELOPMENT
THE TECHNOLOGY
OF OBTAINING
MICROCRYSTALLINE
CELLULOSE FROM THE
HEMP FIBERS
V. Barbash
PhD, Associate Professor*
Е-mail: v.barbash@kpi.ua
M. Karakutsa*
Е-mail: mary-skies@yandex.ua
I. Trembus
PhD, Associate Professor*
Е-mail: lanos0790@yandex.ru
O. Yaschenko
Postgraduate Student*
Е-mail: voliav@ukr.net
*Department of ecology and plant polymer technologies
National Technical University of Ukraine
“Kyiv Polytechnic Institute”
Peremohy ave., 37, Kyiv, Ukraine, 03056
Досліджено різні стадії обробки волокон
конопель у процесі одержання мікрокристаліч-
ної целюлози. Визначено оптимальні умови про-
ведення лужної екстракції волокон конопель,
органосольвентного варіння, хелатування і гід-
ролізу целюлози. Встановлено, що проведення
вказаних стадій обробки за оптимальних зна-
чень технологічних параметрів призводить до
отримання мікрокристалічної целюлози, яка за
вмістом сульфатної золи і ступенем полімери-
зації відповідає вимогам стандарту
Ключові слова: мікрокристалічна целюлоза,
волокно конопель, екстракція, гідроліз, рентге-
нівська дифракція, термогравіметричний аналіз
Исследованы различные стадии обработки
волокон конопли в процессе получения микро-
кристаллической целлюлозы. Определены
оптимальные условия проведения щелочной
экстракции волокон конопли, органосольвент-
ной варки, хелатирования и гидролиза целлюло-
зы. Установлено, что проведение указанных
стадий обработки при оптимальных значени-
ях технологических параметров приводит к
получению микрокристаллической целлюлозы,
которая по содержанию сульфатной золы и
степенью полимеризации соответствует тре-
бованиям стандарта
Ключевые слова: микрокристаллическая цел-
люлоза, волокно конопли, экстракция, гидролиз,
рентгеновская дифракция, термогравиметриче-
ский анализ
UDC 676.166+661.123
DOI: 10.15587/1729-4061.2016.71275
1. Introduction
The number of studies of new promising materials
based on natural polymers has increased significantly
lately, in particular cellulose, which is related to economic
and ecological necessity of replacing natural exhaustible
sources of carbohydrates (oil, coal) to renewable plant raw
materials. Due to its valuable properties, cellulose suc-
cessfully finds its application not only in paper industry
but in other industrial areas, such as chemical, food, phar-
maceutical, cosmetic. One of the most promising products
of cellulose chemical processing is the microcrystalline
cellulose (MCC), which has high content of the ordered
part of cellulose with crystallographic orientation of the
macromolecules [1, 2], the maximum degree of crystallin-
ity, high density and specific surface [3].
MCC is characterized by chemical resistance, insolu-
bility in water and organic solvents, absence of taste, smell and
color that allow using it as a filler, stabilizer and emulsifier in
food processing, cosmetic and pharmaceutical industries [4].
The main raw material for obtaining microcrystalline
cellulose remains high-quality cellulose produced from
wood and cotton. The countries that have no available
stocks of wood and cotton as the re sources of fibers for ob-
taining MCC, ca n consider non-wood plant raw materials,
such as bast plants, which have more homogeneous long
cells, such as fibers of flax, hemp, kenaf [5].
One of the most profitable crops among those plants
in Ukraine remains hemp. Favorable weather conditions, a
large reserve of fertile lands, existing human and industri-
al potential promote the cultivation of hemp in Ukraine.
Taking into account that a hectare of hemp produces the
weight gain of 6 m3 per year, while deciduous trees do only
up to 3.2 m3, the change of wood to hemp during the pro-
cessing of cellulose is considered advisable economically
and ecologically as well [6].
Eastern-European Journal of Enterprise Technologies ISSN 1729-3774 3/6 ( 81 ) 2016
52
2. Analysis of scientific literature and the problem statement
There are different methods of MCC obtaining to pro-
vide a required complex of its properties, such as mechanical
(grinding), thermo-mechanical, chemical (hydrolysis), pre-
cipitation the cellulose from the solution in a powder form [7].
The majority of methods of MCC obtaining in the industry
are based on the effect of different chemical reagents on the
prepared beforehand plant raw materials that provide the
transfer of the bulk of lignin, hemicelluloses, extractive and
mineral substances to the solution. Cellulose indexes obta ined
as a result of chemical treatment, depend on the quantity
and sequence of stages of MCC obtaining, the values of their
technological parameters, the type of plant raw materials and
chemical reagents used in the process of its manufacturing.
The majority of existing industrial chemical methods of MCC
obtaining are characterized by pollution of the environment,
associated with the use of environmentally harmful chemi-
cals, including sulfuric and chlorine-containing reagents [8].
In industrial conditions, MCC is obtained mostly by
the chemical method, particularly by hydrolysis of technical
cellulose with solutions of various chemicals (acids, alkalis,
salts, acidic peroxide) that can destroy the structure of the
cell’s wall [4, 9]. During such a processing, the partial de-
struction of lignin and hemicelluloses occurs, as well as the
partial destruction of the cellulose macromolecules with the
removal of the amorphous fraction, which helps to increase
specific surface and sorption properties of MCC relative to
the original raw material [7].
The classic method to obtain MCC is considered to be in
the for m of white powder with the help of hydrolysis of natural
or technical cellulose with 2.5 n. hydrochloric acid at 105 °C
to form cellulose with a degree of polymerization [10].
To reduce the ecological load on the environment, in
recent years organic solvent methods of obtaining cellulose
have been actively developed, in particular using the solu-
tions of hydrogen peroxide and acetic acid [11]. The known
method of obtaining cellulose of low-ash raw materials
(straw and rice husks), which includes preliminary alkali
extraction with further oxidative organosolv cooking by the
solution of peracetic and acetic acids and hydrogen peroxide
in various ratios [12].
In earlier papers [13–15], the influence of preliminary
alkaline and acid processing of flax and hemp fibers on cellu-
lose indexes was studied and it was shown that the increased
content of mineral substances in fibers of non-wood plant
raw materials, compared to wood raw materials, creates
the necessity to carry out additional stages of processing to
reduce the ash content in MCC to the level of the standard
requirements. However, the designed technological modes
require further study of the conditions of various stages of
hemp fibers treatment and determining optimal technolog-
ical parameters of obtaining microcrystalline cellulose [16].
3. The purpose and objectives of the study
The aim of this work is to develop technology obtaining
of microcrystalline cellulose from fibers of the hemp, which
is suitable for use in the pharmaceutical industry.
To achieve the specified goal, the following tasks are set:
– to study the influence of the main technological pa-
rameters (concentration of reagents, temperature, duration)
of various stages of the hemp fibres treatment on the indexes
of quality of the obtained pulps;
– to analyze the changes of structural characteristics of
pulps from hemp fibers by physical and chemical methods of
research.
4. Materials and methods of the research of the process of
obtaining microcrystalline cellulose from hemp fibers
To obtain microcrystal li ne cellulose, in this paper we stud-
ied the hemp fibers of the 2012 crop from Chernigov Region
(Ukraine), which had the following chemical composition:
cellulose – 46.2 %; lignin – 17.0 %; resins, fats, waxes – 1.4 %;
pentosans – 20.2 %; ash – 1.44 %; sulfate ash – 1.63 % to the
weight of absolutely dry raw material (a. d. m.).
Fibers of hemp were separated from impurities (scutch,
leaves, grass), ground to the size of 3...5 mm and stored in exica-
tors to maintain constant humidity and chemical composition.
The volume of scutch in the fibers of hemp did not exceed 5 %.
To reduce the content of mineral substances, we carried
out preliminary extraction of the ground fibers of hemp with
KOH solutions of different concentrations. To do this, the
samples of ground fibers were placed in the heat-resistant
conic flasks, added with a solution of required concentration
and the f lasks were connected with reverse refrigerators. To
provide the process temperature of 95±2 °C, the flasks were
installed on the water bath. Alkali extraction was carried
out during 30…240 min, concentration of KOH solution
was 3, 5 and 7 % and liquid-to-solid ratio 10:1. After the end
of the processing, pulp was rinsed with distilled water to
neutral pH, dried in the open air and the quality indexes of
the pulp were identified according to standard methods [16].
On the second stage of hemp pulp treatment, we carried
out the cooking process of of hemp pulp in a mixture of
formic acid and Н2О2 in the ratio 40:60, 50:50 and 60:40
of volume % at liquid-to-solid ratio 10:1, at temperature of
100 °C during 60 ...210 min. The cooking process was car-
ried out in a heat-resistant conic flasks installed on asbestos
grids and connected with reverse refrigerators. After the end
of the cooking, the cellulose was rinsed with distilled water
to a neutral reaction, dried in the open air and the quality
indexes of the pulp were identified.
Chelation of obtained cellulose was carried out with a solu-
tion of trilon B with concentration 10 g/l with consumption of
10 % to the weight of a. d. m. during 30 min. under conditions
that are taken on the basis of the previous research [15].
To reduce the residual content of mineral substances
and the degree of polymerization of hemp MCC, hydrolysis
by the solution of CH2COOH and H2O2 in the ratio 50:50
during 90, 120 and 150 min. at liquid-to-solid ratio 10:1
and temperature of 95±2 °C was performed. The process of
hydrolysis was carried out in the heat-resistant conic f lasks
installed on the asbestos grids and connected with reverse
refrigerators. After completion of hydrolysis, MCC was
rinsed with distilled water to a neutral reaction, dried in the
open air and the quality indexes of the pulp were identified
according to standard methods [16].
Analysis of the change of structural characteristics of hemp
MCC, depending on the stage of their treatment in the process
of MCC obtaining, was investigated using scanning electronic
microscopy on REM-106 (SELMI, Ukraine) and X-ray struc-
tural analysis on the diff ractometer Ultima IV (Rigaku, Japan).
Technology organic and inorganic substances
53
The degree of crystallinity (DC) of samples was defined
by the fomula [17]:
200 am
200
I1
СК 100,
I
=⋅
(1)
where І200 is the reflex intensity (200) around 23 degrees;
Іam is the scattered intensity of amorphous phase around
18, 5 degrees.
The resistance of obtained MCC to thermal destruction,
compared with hemp cellulose, was studied by the thermo-
gravimetric analysis on the thermoanalyser Netzsch STA-409.
5. Physical and chemical studies of the changes in
structural characteristics of hemp pulp
The results of the extraction of hemp fibers by solutions
of KOH of different concentrations to reduce the content of
mineral substances are presented in Fig. 1.
a
b
Fig. 1. Dependence of quality indexes of the hemp pulp on
the concentration of KOH: a – ash content, %; b – sulfate
ash, %; KOH of concentration 3%; – KOH of
concentration 5 %; – KOH of concentration 7 %
As it is seen from the data shown in Fig. 1, the reduction
of ash and sulfated ash in hemp pulp occurs with the increase
of duration of the extraction compared to the original plant
raw material. It can be explained by the fact that during this
stage, mineral substances contained in the fiber are transferred
to the solution. Besides, there is a partial removal of hemicellu-
loses as a result of hydrolysis of low molecular weight fractions
of the cellulose. Therefore, to carried out the next stages of
treatment, hemp pulp was used after treatment it with a solu-
tion of KOH of concentration 5 % during 210 min.
In order to reduce the content of lignin and mineral sub-
stances on the second stage, the process of cooking cellulose by
the solution of performic acid was carried out (Table 1). As it is
seen from the data in Table 1, the increase the cooking duration
by the solution of performic acid reduces the content of ash and
sulfate ash in the hemp cellulose. Reducing the of yield of hemp
pulp is caused by the destruction of carbohydrate part and by
the transition of lignin, extractive substances, ash and low mo-
lecular carbohydrate compounds to the solution. There is also a
sharp change of the coloring of hemp fiber from brown to white.
This is due to the fact that performic acid not only destroys
a lignin molecule, acting on the aromatic rings of its molecules,
but causes destruction of hromoformic groups. In this case, as
it is seen by the values of cellulose yield, the destructive effect
of performic acid to the carbohydrate part is insignificant,
because the ions of hydronium Н3О+, which are formed in the
solution, practically do not interact with hydroxyl groups of
polysaccharides.
As it is seen from the data in Table 1, minimal residual
content of mineral substances in the hemp cellulose is obtained
under conditions of cooking by the solution of formic acid and
hydrogen peroxide in the ratio of 60:40 during 210 minutes.
The considered organosolv cooking is environmentally more
friendly in comparison to traditional sulphate or sulphite meth-
ods of obtaining cellulose, because harmful emissions of sul-
furic and chlorine-containing compounds are absent [18, 19].
The cellulose, obtained under such conditions, was used
on the next stage – chelation treatment with trilon B solution.
Due to the formation of complexes of trilon B [20] with most
of the cations of metals that are included into organic solvent
cellulose, the residual content of mineral substances is reduced,
which is important for further use of MCC in the pharmaceuti-
cal industry. Chelation treatment of organosolv hemp cellulose
allows obtaining cellulose with the ash content of 0.15 % and
the content of sulfated ash of 0.21 % that indicates the need to
further reduce the content of mineral substances in cellulose.
Table 1
Indexes of hemp cellulose after cooking in performic acid
Ratio
НСООН:Н2О2,
% volume
Duration
of cooking,
min
Yield of
pulp,
% of а.d.m.
Ash content,
% of а.d.m.
Sulfate ash,
% of а.d.m.
50:50
60 80,98 0,44 0,50
90 75,83 0,35 0,37
150 73,33 0,31 0,34
180 72,10 0,25 0,29
210 70,75 0,22 0,27
40:60 150 73,85 0,29 0,35
210 71,25 0,24 0,29
60:40 150 72,73 0,28 0,33
210 70,10 0,21 0,25
Eastern-European Journal of Enterprise Technologies ISSN 1729-3774 3/6 ( 81 ) 2016
54
In order to reduce the residual content of mineral substanc-
es and the degree of polymerization of hemp MCC, the hydroly-
sis of cellulose was carried out with the solution of CH3CООН
and Н2О2, the results of which are included in Table 2.
According to the results of the hydrolysis (Table 2), we see
that the processing of the fibers with a solution of СН3СООН
and Н2О2 causes further reduction of ash content and sulfated
ash, as well as the degree of polymerization and yield of the
hemp MCC. As it is seen from the data in Table 2, a consistent
implementation of various stages of the hemp fiber treatment al-
lows obtaining hemp MCC (sample 8), which complies with the
European standard by its physical appearance, pH of aqueous
extracts, the degree of polymerization and the ash content [16].
6. Physical and chemical analysis of structural changes of
the hemp pulp
The change of structural characteristics of the hemp
pulp depending on their stage of treatment in the process
of obtaining MCC could be followed on the photo of the
samples received by scanning microscopy (Fig. 2). As it is
seen from Fig. 2, a significant reduction of the length of
hemp fibers is observed in the process of converting cellu-
losic fibers, especially as a result of the process of hydro-
lysis. MCC fibers, obtained by the proposed technology,
have the length within 30...100 microns.
Confirmation of changes of the crystal structure that
occur at various stages of processing hemp fibres is ob-
tained by the X–ray structural analysis of diffractogram
of natural hemp fibers, pulp after alkaline extraction,
cooking and hydrolysis shown in Fig. 3.
As it is seen from Fig. 3, a consistent chemical treat-
ment of hemp fibers by the proposed technology leads to
the increase of crystallinity, the increase in the intensity
of the peak about 23 degrees. Calculated values of the
degree of crystallinity of the studied samples had the fol-
lowing values: 77.1 % – in the fibers of hemp, 84.8 % – in
MCC after alkaline extraction, 87.7 % – in cellulose after
cooking and 88.7 % – in MCC after hydrolysis.
The obtained data confirm the fact that the increase
of content of crystalline part of cellulose occurs during a
consistent multistage chemical treatment by removal of
extractive and mineral substances, hemicelluloses and amor-
phous part of cellulose from the plant raw materials. This
fact is also confirmed by the data of the thermogravimetric
analysis of cellulose and microcrystalline cellulose (Fig. 4).
As it is seen from the thermal gravimetric curves
shown in Fig. 4, microcrystalline cellulose loses
weight by 5–25 % less than the hemp cellulose after
cooking and chelation in the temperature range be-
tween 200–300 оС. This indicates that the CMC has
higher thermal stability in comparison with the hemp
cellulose after cooking and chelation, which is subject-
ed to heat destruction much faster due to the presence
of less resistant to the temperature amorphous part.
a
b
c
d
Fig. 2. Photos of SEM samples: aoriginal hemp fibers;
b – fibers after the extraction with a solution of KOH;
c – cellulose after cooking by performic acid;
d – MCC after hydrolysis
Table 2
Indexes of hemp MCC after hydrolysis
No. of
sample
Ratio
CH3CООН:Н2О2,
% volume
Hydrolysis
duration,
min
Ash con-
tent, %
Sulfate
ash, %
Degree of
polymer-
ization
1
50:50
120 0,13 0,19 210
2 150 0,09 0,15 180
3 180 0,07 0,12 150
4 210 0,07 0,12 115
5
70:30
120 0,12 0,17 160
6 150 0,08 0,13 130
7 180 0,06 0,11 100
8 210 0,05 0,10 80
Technology organic and inorganic substances
55
References
1. Audu-Peter, J. D. Physicochemical and Powder Properties of alpha- and microcrystalline-cellulose derived from sugar cane cobs
[Text] / Audu-Peter, J. D., Ojile, J. E., Bhatia, P. G. // Journal of Pharmacy & Bioresources. – 2004. – Vol. 1, Issue 1. – P. 41–45.
doi: 10.4314/jpb.v1i1.32047
2. El-Sakhawy, M. Physical and mechanical properties of microcrystalline cellulose prepared from agricultural residues [Text] / M. El-
Sakhawy, M. L. Hassan // Carbohydrate polymers. – 2007. – Vol. 67, Issue 1. – P. 1–10. doi: 10.1016/j.carbpol.2006.04.009
3. Cintil, J. Ch. Review of recent research in nanocellulose preparation from different lignocellulosic fibers [Text] / J. Ch. Cintil,
M. Lovely, Th. Sabu // Rev. Adv. Mater. Sci. – 2014. – Vol. 37. – P. 20–28.
4. Shlieout, G. Powder and mechanical properties of microcrystalline cellulose with different degrees of polymerization [Text] /
G. Shlieout, K. Arnold, G. Muller // AAPS PharmSciTech. – 2002. – Vol. 3, Issue 2. – Р. 45–54. doi: 10.1208/pt030211
5. Barbash, V. A. Mіkrokristalіchna celyuloza іz lubyanih roslin [Text] / V. A. Barbash // Naukovі vіstі NTUU “KPІ”. – 2013. –
Vol. 1. – P. 117–122.
6. Krotov, V. S. Novaya tehnologiya proizvodstva cellyulozy sohranit les i prirodu [Text] / V. S. Krotov, A. Ya. Frank, G. A. Ryzhik //
Hіmіchna promislovіst Ukraini. – 1995. – Vol. 1. – P. 2–5.
7. Stupinska, H. An environment-friendly method to prepare microcrystalline cellulose [Text] / H. Stupinska, E. Iller, Z. Zimek //
Fibres and textiles in Eastern January. – 2007. – Vol. 15. – P. 167–172.
8. Autlov, S. A. Microcrystalline cellulose. structure, properties and applications (review) [Text] / S. A. Autlov, N. G. Bazarnova,
E. J. Kushnir // Himija rastitel’nogo syr’ja. – 2013. – Vol. 3. – P. 33–41.
9. Ciolacu, D. Amorphous cellulose – structure and characterization [Text] / D. Ciolacu, F. Ciolacu, V. I. Popa // Cellulose Chem.
Technol. – 2011. – Vol. 45, Issue 1-2. – P. 13–21.
10. Vanhatalo, K. Effect of mild acid hydrolysis parameters on properties of microcrystalline cellulose [Text] / K. Vanhatalo,
O. P. Dahl // BioResourses. – 2014. – Vol. 9, Issue 3. – P. 4729–4740. doi: 10.15376/biores.9.3.4729-4740
11. RU Patent 2203995. Method for the microcrystalline cellulose producing [Text] / Danilov V. G., Yatsenko O. V., Kuznetsova S. A.,
Kuznetsov B. N. – Institut himii i himicheskoj tehnologii SO RAN. – Declareted: 09. 07.2002.
Fig. 3. X-ray structural difractograms of hemp fibers samples
(1), pulp after alkaline extraction (2), after cooking (3) and
MCC after hydrolysis (4)
7. Conclusions
1. The inf luence of the main technological param-
eters of various stages of treatment hemp fibres on
the indicators of the quality of the obtained pulps was
studied. It was found that increasing the concentration
of the solution of potassium hydroxide and the duration
of the stage of alkaline extraction significantly reduces
the content of mineral substances in the fibers of hemp.
It was shown that the increase in the content of formic
acid in the composition of cooking solution contributes
to further reduction of mineral substances in cellulose
as well as performing the stage of chelation with the
solution of trilon B. It was determined that the increase
of acetic acid in the mixture on the stage of hydrolysis al-
lows obtaining MCC from hemp fibers, which meets the
requirements of international standards. The proposed
technology of obtaining microcrystalline cellulose from
hemp fibers using organic substances does not contain
harmful sulfuric and chlorine-containing compounds
and therefore is environmentally more friendly.
2. The changes of structural characteristics of pulp
from hemp fibers with the use of scanning electronic mi-
croscopy, thermographic and X-ray structural analyses
were explored.
3. It was found that in the process of consistent
treatment of hemp fibers by the proposed stages: alkaline
extraction performic cooking chelation – hydro-
lysis, the reduction of length of the fibers of cellulose
to microsizes (up to 30–100 microns) occurs as well as
the gradual removal of amorphous fraction of cellulose,
which increases the degree of crystallinity from 77.1 %
to 88.7 % and increases the thermal stability of the ob-
tained microcrystalline cellulose by 5–25 %.
Fig. 4. Results of thermal gravimetric analysis of the hemp
cellulose after cooking and chelation () and MCC after
hydrolysis ()
Eastern-European Journal of Enterprise Technologies ISSN 1729-3774 3/6 ( 81 ) 2016
56
12. Vurasko, A. V. Appropriate technology of cellulose materials obtaining during agricultural wastes utilization [Text] / A. V. Vurasko,
B. N. Driker, E. A. Kozyrev // Chemistry of plant raw material. – 2006. – Vol. 4. – P. 5–10.
13. Barbash, V. A. Vplyv stadіi obrobky volokon lubyanih kultur na pokaznyky mіkrokrystalіchnoi tselyulozy [Text] / V. A. Barbash,
Yu. M. Nagorna // Naukovі vіstі NTUU «KPІ». – 2014. – Vol. 2. – P. 117–120.
14. Barbash, V. A. Influence of pre-treatment of flax fibers on cellulose properties [Text] / V. A. Barbash, Yu. A. Nahorna // Eastern-
European Journal of Enterprise Technologies. – 2014. – Vol. 4, Issue 6 (70). – P. 4–8. doi: 10.15587/1729-4061.2014.25934
15. Barbash, V. A. Development of technology of obtaining microcrystalline cellulose from flax fibres [Text] / V. A. Barbash // Eastern-
European Journal of Enterprise Technologies. – 2015. – Vol. 1, Issue 5 (73). – P. 42–46. doi: 10.15587/1729-4061.2015.36013
16. European Pharmacopoeia, 7th ed. [Text]. – Council of Europe, Strasbourg, 2010. – P. 1634–1637.
17. Costa, L. A. Extraction and characterization of cellulose nanocrystals from corn stover [Text] / L. A. Costa, A. F. Fonseca,
F. V. Pereira, J. I. Druzian // Cellulose Chemistry And Technology. – 2015. – Vol. 49. – P. 127133.
18. Ferraz, A. Formic acid/acetone-organosolv pulping of white-rotted Pinus radiata softwood [Text] / A. Ferraz, J. Rodriguez,
J. Freer, J. Baeza // Journal of Chemical Technology & Biotechnology. – 2000. Vol. 75, Issue 12. P. 1190–1196.
doi: 10.1002/1097-4660(200012)75:12<1190::aid-jctb342>3.3.co;2-b
19. Saberikhah, E. Organosolv pulping of wheat straw by glycerol [Text] / E. Saberikhah, J. M. Rovshandeh, P. Rezayati-Charani //
Cellulose Chemistry and Technology. – 2011. – Vol. 45, Issue 1-2. – P. 67–75.
20. Zharovskyi, F. H. Analytycheskaia Khymyia [Text] / F. H. Zharovskyi. – Kyiv: Vyscha shkola, 1982. – P. 472–474.

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... У наших роботах [14][15][16][17] показано вплив попередньої лужної та кислотної обробки конопель і льону на показники якості целюлози та МКЦ і встановлено, що підвищений вміст мінеральних речовин у різних представниках недеревної рослинної сировини порівняно з деревиною потребує проведення додаткових стадій обробки сировини для зниження зольності МКЦ до рівня вимог стандарту. Для визначення оптимальних значень технологічних параметрів отримання МКЦ із волокон конопель необхідне подальше вивчення умов проведення різних стадій їх обробки. ...
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