Synthesis and radical copolymerization of 2‐(4‐((4‐isocyanophenyl)diazenyl)phenoxy)ethyl‐3‐phenylacrylate with maleic anhydride

Abstract

A monomer containing a photochromic group was synthesized by condensation of 4‐(2‐hydroxyethyloxy)‐4‐cyanoazobenzene with cinnamoyl chloride. The structure and composition of the monomer were established by FTIR, UV–Vis, 1H NMR spectroscopy, and elemental analysis. The values of chemical shifts, multiplicity, and integrated intensity of 1H signals in one‐dimensional NMR spectra of the monomer were determined, and the homo‐ and heteronuclear interactions were found. The crystal structure of 4‐(2‐hydroxyethyloxy)‐4‐cyanoazobenzene was established using X‐ray diffraction analysis. A copolymer containing photochromic mesogenic fragment was synthesized by radical copolymerization of 2‐(4‐((4‐isocyanophenyl)diazenyl)phenoxy)ethyl‐3‐phenylacrylate with maleic anhydride.

Full text

SPECIAL ISSUE: RESEARCH ARTICLE
Synthesis and radical copolymerization of
2-(4-((4-isocyanophenyl)diazenyl)phenoxy)ethyl-
3-phenylacrylate with maleic anhydride
Meiram Burkeyev
1
| Zhanarkul Satpaeva
1
| Yerkeblan Tazhbayev
1
|
Tulegen Seilkhanov
2
| David Havlicek
3,4
1
Faculty of Chemistry, Department of Organic
Chemistry and Polymers, Buketov Karaganda
University, Karagandy, Kazakhstan
2
Faculty of Natural Sciences, Department of
Chemistry and Biotechnology, Ualikhanov
Kokshetau State University, Kokshetau,
Kazakhstan
3
Faculty of Science, Department of Inorganic
Chemistry, Charles University, Praha 2, Czech
Republic
4
Faculty of Education, Charles University,
Praha 1, Czech Republic
Correspondence
Meiram Burkeyev, Buketov Karaganda State
University, Karaganda 100026, Kazakhstan.
Email: m_burkeev@mail.ru
Abstract
A monomer containing a photochromic group was synthesized by condensation of
4-(2-hydroxyethyloxy)-4-cyanoazobenzene with cinnamoyl chloride. The structure
and composition of the monomer were established by FTIR, UV–Vis,
1
H NMR spec-
troscopy, and elemental analysis. The values of chemical shifts, multiplicity, and inte-
grated intensity of 1H signals in one-dimensional NMR spectra of the monomer were
determined, and the homo- and heteronuclear interactions were found. The crystal
structure of 4-(2-hydroxyethyloxy)-4-cyanoazobenzene was established using X-ray
diffraction analysis. A copolymer containing photochromic mesogenic fragment was
synthesized by radical copolymerization of 2-(4-((4-isocyanophenyl)diazenyl)
phenoxy)ethyl-3-phenylacrylate with maleic anhydride.
KEYWORDS
4-(2-hydroxyethyloxy)-4-cyanoazobenzene, azobenzene, copolymer, cyanoazobenzene,
monomer
1|INTRODUCTION
Over the past few years, liquid crystal (LC) polymers, containing
mesogenic and photochromic groups, have attracted the attention of
researchers as one of the most promising light-controlled “smart
materials.”
1,2
Previously, the preparation of photochromic comb-shaped LC
polymers with photochromic azobenzene groups was carried out by
various authors.
3-6
As photoactive fragments, the derivatives of
azobenzene, cinnamates, and coumarin were used.
7,8
Among the existing three main structural modifications of LC
polymers—nematic, smectic, and cholesteric types—of particular inter-
est are cholesteric LC polymers with a spiral supramolecular structure
and unique optical properties: selective light reflection, high optical
activity, etc. These optical properties determine the area of their prac-
tical use as selective filters, polarizing light reflectors, color photo-
controlled films and coatings, systems for recording information,
etc..
9-11
A wide range of applications of LC polymers is predicted in.
12
In
particular, the stored holographic and digital information is due to the
transformation of mesophases. The first report of Wendorf and Eich
13
was devoted to the holographic effects of accumulation with an
azobenzene-containing compound. It was shown
14
for the first time
that the reconstructed image as obtained from coherent illumination
of the hologram is reversibly stored in the LCP cell. The hologram
remained unchanged after more than 2 years of storage at room
temperature.
Introduction of photochromic fragments, such as azobenzene dye
molecules undergoing cis-trans isomerization under the influence of
light, provides their photo-optical sensitivity and opens up the possi-
bility of obtaining a new photosensitive and photochromic polymers.
The photosensitive compounds undergoing photoisomerization con-
tain double bonds, for example, C C-stylbenes and helices,
azomethines, olefins, salicylidenanilines, and others.
15
Ruhmann
et al
16
described the synthesis of LC copolymethacrylates with an
azobenzene moiety. The ability of azo groups undergoing
Received: 19 November 2020 Revised: 11 February 2021 Accepted: 12 February 2021
DOI: 10.1002/pat.5274
Polym Adv Technol. 2021;1–8. wileyonlinelibrary.com/journal/pat © 2021 John Wiley & Sons Ltd. 1

photochemical trans-cis isomerization was shown. The cis-trans isom-
erization of azo groups is used in preparation of light-sensitive mate-
rials for recording and storing information.
16,17
In the present communication, we report the synthesis and study
of cyanoazobenzene compounds 2-(4-((4-isocyanophenyl)diazenyl)
phenoxy)ethyl-3-phenylacrylate, and its copolymer with a maleic
anhydride, containing the photochromic groups, which can be consid-
ered as the promising light-sensitive materials, was first synthesized.
2|MATERIALS AND METHODS
2.1 |Materials
4-Aminobenzonitrile (purity 98%) and cinnamoyl chloride (purity98%)
were purchased from Sigma Aldrich (Saint Luis, MO, USA) and used as
received. Sodium nitrite (NaNO
2
, purity99.7%, AppliChem GmbH),
sodium hydroxide (NaOH, purity97%), potassium carbonate (K
2
CO
3
,
purity99%), potassium iodide (KI), and phenol were purchased from
LaborFarm (Almaty, Kazakhstan). Maleic anhydride (purity99%, Fluka)
was purchased from Labtech (Moscow, Russia). All organic solvents
used in this study were purified by distillation.
2.2 |Synthesis of compounds containing
photochromic groups
Synthesis of 4-hydroxy-4-cyanoazobenzene (1) was provided by
Scheme 1 according to the procedure described in Reference 17.
Aqueous solution, 30 ml, of NaNO
2
(0.045 mol) was dropwise added
to 14 ml solution of 4-aminobenzonitrile (0.045 mol) and concen-
trated HCl at 5C. Then, at the same temperature, a solution of phenol
(0.050 mol) in aqueous NaOH (2 M, 75 ml) was added. The mixture
was mixed for 2 h. The resulting sediment was filtered and washed by
water up to a neutral state. The filtered product was recrystallized
from ethanol and dried in a vacuum oven.
Scheme 2 shows the synthesis of 4-(2-hydroxyethyloxy)-
4-cyanoazobenzene (2) according to the procedure described in Ref-
erence 18. 4-hydroxy-4-cyanoazobenzene, 4.8 g (0.02 mol), 1.62 g
(0.02 mol) of ethylene hydrochloride, 3.32 g (0.024 mol) of potassium
carbonate, and 0.332 mol KI (0.002 mol)were dissolved in 140 ml of
DMF in a two-throated flask. After complete dissolution of the solids
in DMF, the reaction mixture was boiled and intensively stirred for
24 h. The temperature was kept at 90C. In the final stage, the hot
reaction mixture was poured into 500 ml of ice water. A cherry-red
precipitate was formed. The precipitate was filtered, recrystallized
from 2-propanol, and dried in a vacuum oven up to constant weight.
The obtained target product is an orange-colored powder with a melt-
ing temperature of 160C.
2.3 |Synthesis of monomer
Synthesis of 2-(4-((4-isocyanophenyl)diazenyl)phenoxy)ethyl-3-phenylacrylate
(3) was performed by reacting 4-(2-hydroxyethyloxy)-4-cyanoazoxybenzene
(2) with cinnamoyl chloride in the presence of potassium carbonate
in DMF (Scheme 3). The reaction mixture was stirred on a magnetic
stirrer at a temperature of 60–70Cfor24h.Thesaltprecipitate
was filtered out, the monomer was precipitated with water, an
orange-colored product was filtered, washed several times with
water, and dried at room temperature. The yield of the monomer
product 3is 70% with a melting temperature of 174C.
2.4 |Synthesis of copolymer
A photochromic polymer 4was synthesized according to Scheme 4.
Monomer (3) and maleic anhydride were placed in an ampoule, dis-
solved in DMF, and an initiator AIBN (2%) was added. Then, the reac-
tion mixture was purged with argon for 15 min, the ampoule was
sealed, and placed in a thermostat heated to 80C. After completion
of the polymerization (after 48 h), the ampoule was cooled and
opened. The resulting copolymer was precipitated in ethyl alcohol.
2.5 |Methods
FTIR spectra were registered on a FSM-1201 spectrophotometer
(LLC Infraspek, Russia) in KBr pellets in the range of wave numbers
from 500to 400 cm
−1
.SCHEME 1 Synthesis of 4-hydroxy-4-cyanoazobenzene (1)
SCHEME 2 Synthesis of 4-(2-hydroxyethyloxy)-
4-cyanoazobenzene (2)
SCHEME 3 Synthesis of 2-(4-((4-isocyanophenyl)diazenyl)
phenoxy)ethyl-3-phenylacrylate (3)
2BURKEYEV ET AL.

The X-ray diffraction experiments were performed on Bruker D8
Venture Kappa Duo PHOTON100 by IμS micro-focus sealed tube
with MoKα(0.71073 Å) radiation at a temperature of 120(2)K.
Electronic absorption spectra were recorded on a UV-1800
Shimadzu dual-beam scanning spectrophotometer (Shimadzu, Kyoto,
Japan) in 10 mm thick quartz cuvettes. Spectra were obtained at
25 C, with resolution of 1 nm.
Chromatography-mass spectra were recorded on Agilent 7890A
instrument with a 5975C mass-selective detector inert MSD with Tropl-
Axis Detector G1371A (Agilent Technologies, Inc., Wilmington, USA).
NMR spectra were recorded on a JNN-ECA Jeol 400 spectrome-
ter using a DMSO-d
6
solvent (BrukerDaltonics, Japan).
Thermogravimetric(TG), differential thermal (DTG), and differen-
tial scanning calorimetric (DSC) analyses were carried out by using
DTA/DSC equipment (LabsysEVO, Setaram, France) in dynamic mode
in the temperature range of 30–500C at a heating rate of 10
0
С/min
in nitrogen atmosphere and air.
3|RESULTS AND DISCUSSION
The spatial structure of 4-(2-hydroxyethyloxy)-4-cyanoazobenzene
(2) was first established by X-ray diffraction analysis. The spatial struc-
ture and packaging of molecule 2are shown in Figures 1 and 2. The
physical and chemical constants of 4-(2-hydroxyethyloxy)-
4-cyanoazobenzene (2) coincide well with previously obtained data.
18
X-ray diffraction analysis of compound 2 (C
15
H
13
N
3
O
2
) and all
relevant crystallographic data are given in Table 1 and Figures 1 and
2. The structure was identified by direct methods (XT)
19
and refined
by full-matrix least squares based on F
2
(SHELXL2018).
20
The hydro-
gen atoms on carbon were fixed into idealized positions (riding model),
and hydrogen atoms on oxygen O1 and nitrogen N5 were found on
difference Fourier map and refined under rigid body assumption with
assigned temperature factors H
iso
(H) = 1.2 U
eq
.X-ray crystallographic
data have been deposited with the Cambridge Crystallographic Data
Centre (2053997) and can be obtained free of charge from the center
via its website (www.ccdc.cam.ac.uk/geststructures). X-ray diffraction
analysis showed that the 4-(2-hydroxyethyloxy)-4-cyanoazobenzene
(2) molecule is flat and the molecules are connected by intermolecular
hydrogen bonds between O1 and N5 atoms.
Synthesis of a monomer (3) was carried out by condensation
of4-(2-hydroxyethyloxy)-4-cyanoazobenzene (2) with cinnamoyl chlo-
ride in anhydrous 50 ml of DMF at 90–100C for 48 h as shown in
Scheme 3. The progress of the reaction and the purity of the obtained
compounds were monitored by thin-layer chromatography on Silufol
UV-254 plates. The monomer was isolated by column chromatogra-
phy on alumina. Photochromicazobenzene-containing monomer
3orange crystalline substance with a yield of 51%, m.p. = 172-174C.
The structure of the monomer (3) was confirmed by elemental analy-
sis, FTIR,
1
H NMR spectroscopy, and HPLC analysis.
C
24
H
19
N
3
O
3
(397.43) Calc. C 72.46 H 4.78 N 10.56.
Found. C 72.65 H 4.93 N 10.89.
The mass spectrum of the monomer –2-(4-((4-isocyanophenyl)
diazenyl)phenoxy)ethyl-3-phenylacrylate (3) is presented in Figure 3.
The retention time for the characteristic components of monomer
3 is 14.26 min (4-aminobenzonitrile) and 14.011 min (trans-Cinnamic
acid) with a probability of 90% and 96%, respectively.
The structure of compound 3 was confirmed by two-dimensional
NMR spectra (Figures 4-6). Spin–spin interactions were detected
using the COSY spectrum. Heteronuclear correlations of HC through
a single bond are established by means of the HMQC spectrum
(
1
H-
13
C).
From an analysis of
1
H NMR spectra of the monomer
2-(4-((4-isocyanophenyl)diazenyl)phenoxy)ethyl-3-phenylacrylate (3),
it is possible to assume the presence in the solution of several N CO
and CO CH CH rotational bonds C
6
H
5
isomers. Since the barriers
of these rotations are small, they can lead both to the registration of
spectra from several conformers and simply to a substantial broaden-
ing of the lines of the spectrum. In some cases, this did not allow the
unambiguous assignment of signals.
The
1
H NMR spectrum of monomer 3 shows two-proton doublet
signals at 3.72 and 4.07 ppm with the same
3
J 4.4 Hz of ethylene
SCHEME 4 Radical copolymerization of monomer (3) with maleic
anhydride
FIGURE 1 Spatial structure of
4-(2-hydroxyethyloxy)-4-cyanoazobenzene (2)
BURKEYEV ET AL.3

protons H
9,9
and H
8,8
, respectively. Due to the presence of protons with
close chemical shifts, the remaining protons appeared as multiplets at
6.5–6.8 (1H, H
21
), 7.09–7.12 (4H, H
2,6,25,27
), 7.32–7.67 (4H, H
22,24,26,28
),
7.84–7.92 (5H, H
3,5,17,19,22
), and 7.97–7.99 (2H, H
16,20
) ppm.
In the
13
C NMR spectrum of monomer 3, the signals of ethylene
carbon atoms appear at 59.95 (C
9
) and 70.69 (C
8
) ppm. The carbon
atoms of the cyanophenyl fragment resonate at 118.15 (C
18
), 119.04
(C
29
), 128.26 (C
16,20
), 134.25 (C
17,19
), and 154.60 (C
15
) ppm. The aro-
matic carbon atoms of the diazenylphenoxy group appear at 163.00 (C
1
),
115.75 (C
2,6
), 125.82 (C
3,5
), and 145.59 (C
4
) ppm. The carbon atoms of
the phenyl acrylate fragment resonate at 115.86 (C
21
), 128.98 (C
24,28
),
129.31 (C
25,27
), 135.64 (C
23
), 146.56 (C
22
), and 166.71 (C
11
)ppm.
The structure of compound 3was also confirmed by two-
dimensional NMR spectroscopy of COSY (
1
H-
1
H) and HMQC
(
1
H-
13
C), which allow to establish spin–spin interactions of homo- and
heteronuclear nature. The observed correlations in the molecule are
shown in Figure 4. In the spectra of
1
H-
1
H COSY compounds, spin–
spin correlations are observed through three proton bonds of neigh-
boring methylene–methylene and methine–methine groups H
8
–H
9
(3.71, 4.06 and 4.06, 3.71), H
21
–H
22
(6.52, 7.37 and 7.37, 6.52; 6.62,
7.63 and 7.63, 6.62), H
25,27
–H
26,28
(7.09, 7.87, and 7.87, 7.09), and
H
17,19
–H
16,20
(7.88, 7.95 and 7.95, 7.88) ppm (Figure 5). Heter-
onuclear interactions of protons with carbon atoms via a single bond
were established using
1
H-
13
C HMQC spectroscopy for the following
pairs present in the compound: H
9
–C
9
(3.71, 60.08), H
8
–C
8
(4.06,
70.71), H
2,6
–C
2,6
(7.12, 115.89), H
24,28
–C
24,28
(7.36, 129.18) and
H
17,19
–C
17,19
(7.96, 134.17) ppm (Figure 6).
Thus, the combination of FTIR,
1
H,
13
C NMR spectroscopy, and
chromatographic analysis confirms the structure of monomer 3 that
further was involved in copolymerization reaction with maleic anhy-
dride to obtain copolymer 4.
FIGURE 2 Packing molecule
4-(2-hydroxyethyloxy)-
4-cyanoazobenzene (2) in the crystal
TABLE 1 Experimental data for single-crystal X-ray diffraction
analysis of 4-(2-hydroxyethyloxy)-4-cyanobenzene (2)
Parameter 2
Formula C
15
H
13
N
3
O
2
Formula mass 267.28
Crystal system Monoclinic
Space group P2
1
/c (No. 14)
a/Å 5.9195(2)
b/Å 7.5642(3)
c/Å 28.0287(11)
α/90
β/92.340(1)
γ/90
V/Å
3
1253.97(8)
Z4
D
(calc)
/g ml
−1
1.416
μ
(MoKa)
/mm
−1
0.097
F
(000)
560
Crystal size/mm 0.04 ×0.19 ×0.48
Temperature/K 120(2)
Radiation/Å 0.71073
θ/(min-max) 2.8–27.5
Index ranges −7.7; −9.8; −36.36
(measured/unique/observed) 17,269/2890/2336
Data/restrains/parameters 2890/0/188
Goodness-of-fit on F
2
1.063
Final R, wR2 0.0410, 0.1106
R indices (all data) 0.0536, 0.1171
Largest diff. peak and hole 0.33, −0.25
4BURKEYEV ET AL.

UV spectra of maleic anhydride, monomer 3, and copolymer in
ethanol are compared in Figure 7.
The UV spectrum of monomer 3is characterized mainly by a low-
intensive band in the region of 255–260 nm. The band at λ
max
260 nm belongs to the symmetric π–π* junction of the aromatic ring
and is called KIV bands, which are caused by transitions in the ben-
zene ring. An increase in the absorption intensity in the K-band region
may be associated with an increase in the excited molecules. The
strong absorption band at λ
max
360–365 nm corresponds to the π–π*
transition and the n–π* transition in azochromophore.
21
Copolymer
2 also exhibits the absorption band at λ
max
360–365 nm. An increase
in absorption at 352–460 nm indicates photoisomerization from trans
to cis form. Consequently, light irradiation in this wavelength region
should cause photoisomerization from trans form to cis form and vice
versa.
22
The presence of a double C C bond renders the compounds
photochromic properties, when exposed to UV light, manifesting E/Z
isomerization. As seen from Figure 6, the wide and intense absorption
band in the region of 200–300 nm corresponds to the absorption
band of maleic anhydride. In the UV spectrum of copolymer 2, this
band disappears and confirms the involvement of maleic anhydride in
copolymer 2 composition. The strong absorption band at λ
max
360 nm
is characteristic of azochromophoric groups of copolymer 2.
It has been reported that azobenzene molecule aligns perpendicular
to the plane of linearly polarized light. Such photo-induced orientation
allows to write, erase, and rewrite optical information on the side chain
of LC or on amorphous polymer films containing azobenzene group.
15
According to TG and DTG data, decomposition of copolymer
4 takes place in the temperature range of 300 –370Сand is accom-
panied by weight loss (Figure 8). Full destruction of the sample is com-
pleted at 590C with total weight loss of 92.23%.
FIGURE 3 Chromatogram of the
monomer 2-(4-((4-isocyanophenyl)
diazenyl)phenoxy)ethyl-
3-phenylacrylate (3)
FIGURE 4 a) correlation (
1
H-
1
H) COSY, b) correlation (
1
H-
13
C) HMQC monomer - 2-(4-((4-isocyanophenyl)diazenyl)phenoxy)ethyl-
3-phenylacrylate (3)
BURKEYEV ET AL.5

FIGURE 5 NMR (
1
H-
1
H) COSY monomer spectrum - 2-(4-((4-isocyanatophenyl)biphenyl)phenoxy)ethyl-3-phenylacrylate (3)
FIGURE 6 NMR (
1
H-
13
C) HMQC monomer spectrum - 2-(4-((4-isocyanatophenyl)biphenyl)phenoxy)ethyl-3-phenylacrylate (3)
6BURKEYEV ET AL.

Onthecurveoftherateofmasslossinthetemperaturerange30–
250C, a slight change in speed is observed in the range from 7.25 to
3.2 mg/min. Starting from 300C, a sharp increase in speed is observed and
reaches its peak at 342C, and the value of the speed at this temperature is
1.7 mg/min. Then comes a gradual decrease, and at 400C the speed stabi-
lizes, but in some places, there is a slight change at 475, 530, and 575C.
An endothermic peak due to melting is observed on the DSC
curve at a temperature of 180C, while the substance mass does not
change. Then, there is an exothermic effect at a temperature of
≈350C, which is explained by the sample decomposition with the
release of volatile products and mass loss.
4|CONCLUSIONS
2-(4-((4-isocyanophenyl)diazenyl)phenoxy)ethyl-3-phenylacrylate con-
taining the photochromic groups as first synthesized with the condensation
reaction of 4-(2-hydroxyethyloxy)-4-cyanoazobenzene with cinnamoyl
chloride, thus, its composition and structure were characterized by FTIR,
UV–Vis,
1
H NMR spectroscopy, chromatography, XRD, and elemental
analysis. X-ray crystallographic data for 4-(2-hydroxyethyloxy)-
4-cyanoazobenzene have been deposited with the Cambridge Crystallo-
graphic Data Centre (2053997). The copolymer was synthesized by radi-
cal copolymerization of 2-(4-((4-isocyanophenyl)diazenyl)phenoxy)ethyl-
3-phenylacrylate with maleic anhydride. The optical properties of the
monomer and copolymer products were compared and the existence of
cis-trans isomerization of azobenzene groups under the influence of UV
radiation was detected. The thermal stability and phase transition tem-
perature in a copolymer of 2-(4-((4-isocyanophenyl)diazenyl)phenoxy)
ethyl-3-phenylacrylate with the maleic anhydride were determined using
the DTA/DSC.
CONFLICT OF INTEREST
The authors declare no potential conflict of interest.
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are openly available at
the end of this article.
ORCID
Meiram Burkeyev https://orcid.org/0000-0001-8084-4825
Zhanarkul Satpaeva https://orcid.org/0000-0003-0962-1148
Yerkeblan Tazhbayev https://orcid.org/0000-0003-4828-2521
Tulegen Seilkhanov https://orcid.org/0000-0003-0079-4755
David Havlicek https://orcid.org/0000-0002-8854-6213
REFERENCES
1. Shibaev VP. Liquid-crystalline polymers: past, present, and future.
Polym Sci Ser A. 2009;51:1131-1193.
2. Zhao Y, Ikeda T. Smart Light-Responsive Materials: Azobenzene –Con-
taining Polymers and Liquid Crystals. Hoboken, New Jersey: Wiley; 2009.
3. Shibaev VP, Yakovlev IV, Kostromin SG, Ivanov SA, Zverkova TI. Fea-
tures of optical recording of information on oriented films of liquid
crystalline comb-shaped polymer under the action of selective optical
irradiation. Polym Sci USSR Ser A. 1990;32:1478-1486.
4. Lasker L, Fisher T, Stumpe I, et al. Photoinduced optical anisotropy in
thin films of amorphous photochromic side chain polymers. Mol Cryst
Liq Cryst. 1994;246:347-350.
5. Shibaev VP. Some new physico-chemical aspects of side chain liquid
crystal polymers. Mol Cryst Liq Cryst. 1994;243:201-230.
6. Shibaev VP. Electrooptical and photooptical properties of polymer liq-
uid crystals. Int. J. Polym. Mater. Polym. Biomater. 2000;45(3):307-348.
7. Shibaev VP, Bobrovsky AY, Boiko NI. Photoactive liquid crystalline
polymer systems with light-controllable structure and optical proper-
ties. Prog Polym Sci. 2003;28(5):729-836.
8. Shibaev VP. Liquid-crystalline polymer systems: from the past to the
present. Polym Sci Ser A. 2014;56(6):727-762.
9. Ryabchun AV, Bobrovsky AY, Shibaev VP. Photoinduced reor-
ientation processes in thin films of photochromic LC polymers on sub-
strates with a photocontrollable command surface. Polym Sci Ser A.
2010;52(8):812-823.
10. Hsu CS. The application of side-chain liquid crystalline polymers. Prog
Polym Sci. 1997;22(4):829-871.
11. Shibaev VP, Bobrovsky AY, Boiko NI. New types of multifunctional
liquid crystalline photochromic copolymers for optical data recording
and storage. Macromol. Symp. 2001;174:319-332.
FIGURE 7 Comparative UV spectra of maleic anhydride (1),
copolymer 2, and monomer 3
FIGURE 8 Thermal characteristics of copolymer 4
BURKEYEV ET AL.7

12. Schmidt GW. In: McArdle CB, ed. Side Chain Liquid Crystal Polymers.
Glasgow/London, UK: Blackie; 1989:196.
13. Eich M, Wendorff JH. Erasable holograms in polymeric liquid crystals.
Die Makromol Chem Rapid Commun. 1987;8:467-471.
14. Eich M, Wendorff JH. Laser-induced gratings and spectroscopy in
monodomains of liquid-crystalline polymers. J Opt Soc Am B. 1990;7
(8):1428-1436.
15. Shibaev VP, Bobrovsky AY. Liquid crystalline polymers: development
trends and photocontrollable materials. Russ Chem Rev. 2017;86(11):
1024-1072.
16. Ruhmann R, Zschuppe V, Dittmer M, Wolff D. Synthesis and charac-
terization of some new photochromic side-chain liquid-crystalline
polymers. Die Makromol Chem. 1992;193:3073-3082.
17. Kamruzzaman M, Kurihara S. Photo alignment behaviour of poly-
ethene imine having cyano azobenzene side chain. Dhaka Univ. J. Sci.
2015;63(2):67-72.
18. Kuvshinova SA, Burimistrov VA, Fokin DS, Litov KM, Koifman OI.
4-(2-Hydroxyethyloxy)-4-cyanoazoxybenzene exhibiting liquid crystal-
line properties of the stationary phase for gas chromatography. Russian
patent №2381214. February 10, 2010, Bull. №4 (in Russian). https://
patentimages.storage.googleapis.com/0f/ac/0f/bcf9fe5ef399ca/RU238
1214C1.pdf
19. Sheldrick GM. SHELXT - Integrated space-group and crystal-structure
determination. ActaCryst. 2015;A71:3-8.
20. Sheldrick GM. Crystal structure refinement with SHELXL. Acta Cryst.
2015;C71:3-8.
21. Freiberg S, Labarthet FL, Rochon P, Natansohn A. Synthesis and char-
acterization of a series of azobenzene-containing side-chain liquid
crystalline polymers. Macromolecules. 2003;36:2680-2688.
22. Alam MZ, Ohmachi T, Ogata T, Nonaka T, Kurihara S. Photo-
isomerisation behaviour and photoinduced surface relief gratings on
azopolymer film by a monochromatic light irradiation. Opt Mater.
2006;29:365-370.
How to cite this article: Burkeyev M, Satpaeva Z,
Tazhbayev Y, Seilkhanov T, Havlicek D. Synthesis and radical
copolymerization of 2-(4-((4-isocyanophenyl)diazenyl)
phenoxy)ethyl-3-phenylacrylate with maleic anhydride. Polym
Adv Technol. 2021;1–8. https://doi.org/10.1002/pat.5274
8BURKEYEV ET AL.