Нурланова А.Е., Карипуллаева А.С., Аликулов А.Ж., Токтабаева А.К., Мун Г.А.
Казахский национальный университет имени аль-Фараби, г. Алматы, Казахстан
Создание, характеристика и модификация сополимеров на основе N-(2-
винилoксиэтил)-N-(2-циaнoэтил) амина
В данной работе были получены новые сополимеры на основе N-(2-винилoксиэтил)-
N-(2-циaнoэтил) амина (ВОЭЦЭА) и N-изoпpoпилaкрилaмида (НИПAAм) путем
радикальной сополимеризации с использованием в качестве инициатора динитрила
азоизомасляной кислоты в спиртовом растворе при температуре 60°С. Были исследованы
их структуры и физико-химические свойства с помощью FT-IR спектрометра и
термогравиметрических анализов. Модификация нитрильных групп была проведена в
ХИМИЯ ЖӘНЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯ БОЙЫНША IX ХАЛЫҚАРАЛЫҚ БІРІМЖАНОВ СЪЕЗІНІҢ ЕҢБЕКТЕРІ
482
спиртовом растворе NH
2
OH
HCl – NaOH при температуе 80°C. Структуры
модифицированных сополимеров были исследованы на FT-IR спектрометре.
Ключевые слова: N-изoпpoпилaкpилaмид (HИПААм), N-(2-винилоксиэтил)-N-(2-
цианоэтил)
амин
(ВОЭЦЭА),
модифицирование
функциональных
групп,
амидоксилирование, очистка воды, FT-IR, ТГА.
Introduction
Functional copolymers obtained by modification of existing polymers are attractive
materials because of their good separation properties. Interest in water treatment is receiving
increasing globally attention due to the diminishing natural resources of fresh water and the
shortage in many remote areas. It is well known that the major portion of whole water on the
earth (96%) is in a form of salty water present in the oceans of the world and not usable for
human consumption. Another 3% of water locked up in the glaciers and ice, leaving 1%
available for human consumption. Various polymeric materials taking a variety of physical
forms can be used and applied in a large number of water treatment applications. In particular,
synthesis of copolymers in the form of membranes, hydrogels and adsorbents can be used in
water purification systems, including the removal of ions, particles, organic compounds and
microorganism [1]. Polymers with specific functional groups can be obtained by changing some
groups on existing polymers or copolymers with suitable reactants. It has been determined that
the polymers containing amidoxime groups have a great tendency to form a complex with metal
ions. Since there are no easily available monomers with pendant amidoxime groups, these types
of polymers were synthesized by polymer-polymer conversion reactions with hydroxylamine
hydrochloride [2]. In this study it is aimed to prepare copolymers of N-(2-vіnуlоxуеthyl)-N-(2-
cуanоеthyl) amine (VOECEA) and N-isopropylacrylamide (NIPAAm) with the anticipation of
preparing amidoximated copolymers.
Experimental
Synthesis of copolymers. N-(2-vinyloxyethyl)-N-(2-cyanoethyl) amine (VOECEA) used in
this study was synthesized at Institute of Chemical Sciences named after A.B. Bekturov by
mixing of monoethanolamine vinyl ether and acrylonitrile at room temperature for 6 hours.
Target monomer rectified from spare parts of N-(2-vinyloxyethyl)-N, N-di-(2-cyanoethyl) amine
by vacuum distillation [3]. N-isopropylacrylamide (NIPAAm) with 97% purity was obtained
from «Sigma-Aldrich» and used without further purification. AIBN and hydroxylamine
hydrochloride were obtained from Merck and used as received.
VOECEA and NIPAAm copolymers were prepared by radical copolymerization. Synthesis
was carried out in a sealed glass molybdenum ampoules at 60ºС and saturated with argon.
Azobisisobutyronitrile was used as an initiator and the solvent was an ethanol. The reaction was
carried out for 2,5 h, 5 h and 10 hours. The obtained copolymers were precipitated in boiled
water, washed and then dried in vacuo.
Characterization. In order to characterize the structures of obtained copolymers a detailed
FT-IR analysis was made. KBr pellets were prepared from these powder and spectra were taken
with Perkin Elmer FT-IR Spectrophotometer. The thermal characterization was performed by
using Perkin Elmer Pyris model Thermogravimetric Analyzer.
Modification. Obtained copolymers were reacted with the methanol solution of
hydroxylamine ( 1:1 in NH
2
OH HCl – NaOH ) at 80°C. After amidoximation reaction was
completed, the amidoximated copolymers were precipitated in n-hexane and dried at 30°C in a
vacuum oven. The conversion to amidoxime group was determined by following the changes in
nitrile group of VOECEA from FT-IR spectra.
ХИМИЯ ЖӘНЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯ БОЙЫНША IX ХАЛЫҚАРАЛЫҚ БІРІМЖАНОВ СЪЕЗІНІҢ ЕҢБЕКТЕРІ
483
Results and discussion
FT-IR and thermal analysis. To characterize the structures of copolymers based on N-(2-
vinyloxyethyl)-N-(2-cyanoethyl) amine and N-isopropylacrylamide (VOECEA-co-NIPAAm) a
detailed FT-IR analysis was recorded. The structural formulas of VOECEA and NIPAAm are
shown in Figure 1.
CH
2
CH
O
CH
2
CH
2
NH
CH
2
CH
2
C
N
CH
2
CH
C
O
NH
CH
CH
3
CH
3
VOECEA
NIPAAm
Figure 1 – The structural formulas of VOECEA and NIPAAm
Figure 2 shows FT-IR spectrum of pure VOECEA. Spectrum was taken on KBr pellets by
using Perkin Elmer FT-IR Spectrophotometer. In the FT-IR spectrum of VOECEA it is clearly
seen a sharp band peak at 2247.87 cm
-1
for the nitrile (C≡N) group. There are bands for C-O-C
ether group stretching vibrations between 998-1074 cm
-1
.
Administrator 04
Name
Sample 004 By Administrator Date Wednesday, June 22 2016
Description
4000
400
3500
3000
2500
2000
1500
1000
500
0.9
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
cm-1
1198.15cm-1
1620.06cm-1
1 6 3 5 .3 7 c m -1
1321.74cm-1
825.25cm-1
1138.53cm-1
2931.56cm-1
970.27cm-1
1074.73cm-1
1465.88cm-1
2847.74cm-1
1038.69cm-1
2247.87cm-1
998.68cm-1
764.56cm-1
1421.55cm-1
1370.28cm-1
1354.77cm-1
3329.87cm-1
3117.74cm-1
3044.73cm-1
608.75cm-1
503.53cm-1
1915.35cm-1
Figure 2 – FT-IR spectrum of VOECEA
The FT-IR spectrum of pure poly-N-isopropylacrylamide (PNIPAAm) is shown in Figure
3. The FT-IR spectrum of PNIPAAm shows the characteristic amide I (1629 cm
-1
) and amide II
(1534.55 cm
-1
) bands. The two isopropyl methyl groups are seen at 1366.17 cm
-1
and 1385.51
cm
-1
, respectively.
ХИМИЯ ЖӘНЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯ БОЙЫНША IX ХАЛЫҚАРАЛЫҚ БІРІМЖАНОВ СЪЕЗІНІҢ ЕҢБЕКТЕРІ
484
5
0
2
.4
6
8
7
5
.9
2
9
1
8
.3
2
9
7
9
.5
8
1
1
2
5
.6
5
1
1
7
0
.6
8
1
3
6
6
.1
7
1
3
8
5
.5
1
1
4
5
7
.4
2
1
5
3
4
.5
5
1
6
2
9
.8
4
1
7
3
3
.5
1
2
8
6
4
.4
0
2
9
2
5
.6
5
2
9
6
3
.3
5
3
0
6
7
.0
2
3
2
7
9
.0
6
0.00 5
0.01 0
0.01 5
0.02 0
0.02 5
0.03 0
0.03 5
0.04 0
0.04 5
0.05 0
0.05 5
0.06 0
0.06 5
A
b
s
o
rb
a
n
c
e
500
100 0
150 0
200 0
250 0
300 0
350 0
400 0
W av enu mber s ( c m- 1)
Figure 3 – FT-IR spectrum of PNIPAAm
In the Figure 4 are shown the FT-IR spectra of copolymers based on VOECEA and
NIPAAm. In the FT-IR spectra of copolymers with different feed compositions the bands
belonging to both monomers can be seen, such as between 3200-3300 cm
-1
for N-H groups and
characteristic observed bands of both VOECEA and NIPAAm are also present in the spectra of
copolymers: 2247 cm
-1
for C≡N stretching (weakly visible in 30:70 composition) and 1530-1640
cm
-1
for C=O stretching. The peaks at 1366 cm
-1
and 1385 cm
-1
which indicate isopropyl methyl
groups in PNIPAAm shift to 1363 cm
-1
, 1361 cm
-1
, 1356 cm
-1
in VOECEA-co-NIPAAm 30:70,
50:50, 60:40, respectively.
a
- 0.00
0.05
0.10
0.15
0.20
A
b
s
b
- 0.00
0.05
0.10
0.15
0.20
A
b
s
c
0.00
0.05
0.10
A
b
s
500
100 0
150 0
200 0
250 0
300 0
350 0
W av enu mber s ( c m- 1)
Figure 4 – The FT-IR spectra of VOECEA-co-NIPAAm copolymers (a) 60:40, (b) 50:50,
(c)30:70
In the Figure 5 are shown the dynamic thermograms of copolymers based on N-(2-
vinyloxyethyl)-N-(2-cyanoethyl) amine and N-isopropylacrylamide (VOECEA- co-NIPAAm). A
significant weight loss is observed about 90% around 430-440°C, which can be associated with
the degradation of the NIPAAm groups. A small weight loss is seen in all curves less than 10%
ХИМИЯ ЖӘНЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯ БОЙЫНША IX ХАЛЫҚАРАЛЫҚ БІРІМЖАНОВ СЪЕЗІНІҢ ЕҢБЕКТЕРІ
485
around 100°C, which might be due to some humidity (ethanol) present in the structure of the
copolymers. For all copolymers VOECEA-co-NIPAAm with different compositions there are a
smaller weight loss about 20% around 250°C. These weight losses might be associated to the
degradation of VOECEA groups.
Figure 5 - The dynamic thermograms of VOECEA- co-NIPAAM copolymers
As indicated in the experimental section the conversion of nitrile groups into amidoxime
structures is shown in Figure 6. In order to follow the course of the above reaction FT-IR
analysis was made. Practically the conversion is 99% and C≡N groups in copolymers were
transformed into amidoxime groups in 24 h.
2
2
4
7
.9
4
a
0.00
0.05
0.10
0.15
0.20
A
b
s
9
2
5
.1
9
b
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
A
b
s
500
100 0
150 0
200 0
250 0
300 0
350 0
W av enu mber s ( c m- 1)
Figure 6 – The FT-IR spectra of (a) unmodified, (b) modified VOECEA-co-NIPAAm
copolymers
ХИМИЯ ЖӘНЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯ БОЙЫНША IX ХАЛЫҚАРАЛЫҚ БІРІМЖАНОВ СЪЕЗІНІҢ ЕҢБЕКТЕРІ
486
Figure 6 shows the FT-IR spectra of VOECEA-co-NIPAAm together with unmodified and
modified copolymers. After the amidoximation reaction the characteristic bands of VOECEA,
which was mentioned earlier have been observed to change. After successful conversion of
nitrile groups to amidoxime groups the peak at 2247 cm
-1
disappears and the new formation of
N-O band can be reflected by the bond at 925 cm
-1
, which further verifies the formation of
amidoxime group [4].
Conclusion
A new polymer containing amidoxime group was synthesized with the anticipation of
enhanced metal ion uptake capacity. For this purpose, N-(2-vinyloxyethyl)-N-(2-cyanoethyl)
amine (VOECEA) monomer was synthesized by mixing of monoethanolamine vinyl ether and
acrylonitrile. The copolymers based on VOECEA and N-isopropylacrylamide (NIPAAm) were
synthesized by free radical polymerization reaction using AIBN as the initiator. The copolymers
obtained was reacted with hydroxylamine to obtain a copolymers containing an amidoxime
group and after 24 h reaction time 99% conversion has been reached. These results clearly show
the disappearance of original nitrile group and new formation of amidoxime group through the
treatment with hydroxylamine under specified reaction condition. It is well known that
adsorbents containing amidoxime groups have high adsorption capacity for the recovery of
uranyl from seawater, radioactive waste water and nuclear industry effluent [5]. Adsorption
capacity of these copolymers will be the subject of another publication.
References
1
Strathmann H. Ion-exchange membrane separation processes. Amsterdam: Elsevier;
2004, 360.
2
F. Arranz, M. Sanchez-Chaves, M.M. Gallego, Angew. Makromol. Chem. 218 (1994)
183.
3
Mukhametkanova A.M., Praliev K.D., Mun G.A., Yu.V.K. Journal of Scientific and
Technical Society "Kaxak", 2016, № 1 (52), 55.
4
S. Chen, W. Shen, F. Yu, W. Hu, H. Wang, Preparation of amidoximated bacterial
cellulose and its adsorption mechanism for Cu
2+
and Pb
2+
, J. Appl. Polym. Sci. (2010).
5
Akkas P., Seko N., Tamada M., Guven O., Adsorption efficiency of a new adsorbent
towards uranium and vanadium ions at low concentrations, Seperation Science and Technology,
Vol. 39, No. 7, pp. 1631–1643, 2004.
ХИМИЯ ЖӘНЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯ БОЙЫНША IX ХАЛЫҚАРАЛЫҚ БІРІМЖАНОВ СЪЕЗІНІҢ ЕҢБЕКТЕРІ
487
УДК 544.18
1
Оспанова А.К.,
2
Омарова Р.А.,
1
Савденбекова Б.Е.*
1
Казахский национальный университет им. аль-Фараби, г. Алматы, Казахстан
2
Казахский национальный медицинский университет им. С.Д. Асфендирова г. Алматы,
Казахстан
* Email:
balzhan.savdenbekova@gmail.com
Квантовохимическое исследование структуры и прогноз участия функциональных
групп хлоргексидина при получении антибактериальных нанопокрытий в
мультислоях
Проведено квантовохимическое исследование cтруктуры хлоргексидина, рассчитаны
основные дескрипторы реакционной способности, а также соответствующие дескрипторы
двух его бромзамещенных производных. Установлено, что атомы азота хлоргексидина
могут быть потенциальными центрами электростатического взаимодействия в полислоях
или участвовать в образовании водородных связей с полиэлектролитами в бислоях
антибактериальных нанопокрытий.
Ключевые слова: хлоргексидин, квантовхимические исследования, структура,
дескрипторы, активные центры, мультислои, антибактериальные нанопокрытия.
1
Оспанова .Ә.Қ.,
2
Омарова Р.А.,
1
Савденбекова Б.Е.
Әл-Фараби атындағы Қазақ ұлттық университеті, Алматы қ., Қазақстан
С.Д. Асфендиров атындағы Қазақ ұлттық медициналық университеті, Алматы қ.,
Қазақстан
Мультиқабаттарда антибактериалды наножабындарды алу кезінде хлоргексидиннің
функционалды топтарының қатысуын болжау және құрылымын квантохимиялық
зерттеу
Хлоргексидиннің құрылысына квантты химиялық зерттеу жүргізілді, реакциялық
қабілетінің негізгі дескрипторы мен оның бром орын басқан туындыларының сәйкесінше
дескрипторлары есептелінді. Полиқабаттарда хлоргексидиннің молекуласындағы азот
атомы электростатикалық әрекеттесуде потенциалды орталықтар болуы немесе
антибактериалды наножабындардың биқабаттарында полиэлектролиттермен сутекті
байланыс түзуге қатысуы мүмкін екендігі анықталды.
Түйінді сөздер: хлоргексидин, квантты химиялық зерттеу, құрылыс, дескрипторлар,
активті орталықтар, мультиқабаттар, антибактериалды наножабын.
1
Оspanova А.К.,
2
Оmarova R.А.,
1
Savdenbekova B.Е.
Al-Farabi Kazakh national university, Almaty, Kazakhstan
S.D. Asfendiyarov Kazakh national medical university, Almaty, Kazakhstan
Quantum-chemical study of the structure and prediction of the participation of the
functional groups of chlorhexidine in the preparation of antimicrobial nanocoating in
multilayers
Conducted quantum-chemical study of the structure of chlorhexidine. calculate the main
descriptors of reactivity, as well as the corresponding descriptors its two brominated derivatives.
ХИМИЯ ЖӘНЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯ БОЙЫНША IX ХАЛЫҚАРАЛЫҚ БІРІМЖАНОВ СЪЕЗІНІҢ ЕҢБЕКТЕРІ
488
It was found that nitrogen atoms of chlorhexidine may be potential centers of electrostatic
interactions in polylayers or participate in the formation of hydrogen bonds with the
polyelectrolyte in the bilayers of antibacterial nanocoating.
Keywords: chlorhexidine, quantum-chemical research, structure, descriptors, active
centers, multilayers, antimicrobial nanocoating.
Введение
Полиэлектролитные
нанокомпозиты,
мультислои,
получаемые
методом
поочередного наслаивания противоположно заряженных полиэлектролитов на
определенные дисперсные частицы или твердые носители, представляют собой новое
перспективное направление быстро развивающейся области
— полимерной
нанотехнологии. Исследования в этой области позволяют получать композитные
многофункциональные материалы с заданными свойствами [1-4]. Основной задачей
многих исследований является разработка оптимальных условий получения
антибактериальных полиэлектролитных мультислоев путем предварительного квантово-
химического расчетного метода определения активных центров закрепления биоактивных
соединений на поверхности носителя. На основании полученных данных можно провести
мультислойную сборку полислоев путем формирования химических связей между
функциональными группами полимеров в зависимости от рН среды и температуры. Такой
подход к получению полислоев с активной противомикробной поверхностью сочетает в
себе прогнозируемый теоретический путь реакции и его экспериментальное
осуществление, что значительно облегчит выполнение поставленных задач во многих
отраслях
медицины
и
новых
биотехнологиях.
Полученные
мультислои
с
антибактериальными свойствами могут быть использованы для медико-биологических и
имплантируемых систем.
Эксперимент
В данной работе в качестве антибактериального агента был использован
хлоргексидин. Хлоргексидин - лекарственный препарат,
антисептик
. Химическое
название: 1,6-Ди-(пара-хлорфенилгуанидо)-гексан. Выпускается в виде би
глюконата
(Chlorhexidini bigluconas). В химическом отношении является дихлорсодержащим
производным
бигуанида
. По структуре весьма близок к
бигумалю
. Механизм действия
хлоргексидина заключается во взаимодействии с фосфатными группами на поверхности
клетки, вследствие чего возникает смещение осмотического равновесия, нарушение
целостности и гибель клеток бактерий.
С целью выявления особенностей геометрического и электронного строения
выбранного для исследований лекарственного препарата хлогексидина были рассчитаны
его основные дескрипторы реакционной способности, а также соответствующие
дескрипторы двух его бромзамещенных производных, которые могут быть
потенциальными антибактериальными агентами при получении мультислоев для медико-
биологических изделий. Для оптимизации геометрии и расчета дескрипторов использован
квантово-химический метод РМ3 в полуэмпирическом приближении, входящий в
программный пакет HyperChem версии 8 [5-7]. Для расчетов использовалось приближение
Флэтчера-Ривса [8, 9]. Некоторые из межатомных расстояний в модельных молекулах
(те, на которых в наибольшей степени сказалось замещение атома хлора, на атомы брома)
представлены в таблице 1. Точность расчетов межатомных расстояний составляет 0,02 Å.
Достарыңызбен бөлісу: |