Synthesis, characterization, thermal and optical properties of styrene derivatives having pendant p-substituted benzylic ether groups

Article abstract of DOI:10.1007/s10973-012-2893-2

The derivatives of styrene monomer, 4-chlorophenyl-4-vinylbenzyl ether (M1), 4-methoxyphenyl-4-vinylbenzyl ether (M2), 4-ethylphenyl-4-vinylbenzyl ether (M3) and 1-naphtylphenyl-4-vinylbenzyl ether (M4) were synthesized. The normal free radical polymeriza

Full text of DOI:10.1007/s10973-012-2893-2

J Therm Anal Calorim
DOI 10.1007/s10973-012-2893-2
Synthesis, characterization, thermal and optical properties
of styrene derivatives having pendant p-substituted benzylic
ether groups
¨
Ibrahim Erol Levent Ozcan Sedat Yurdakal
˙
•
•
Received: 3 May 2012 / Accepted: 11 December 2012
´
´
Ó Akademiai Kiado, Budapest, Hungary 2013
Abstract The derivatives of styrene monomer, 4-chlor-
ophenyl-4-vinylbenzyl ether (M1), 4-methoxyphenyl-4-
vinylbenzyl ether (M2), 4-ethylphenyl-4-vinylbenzyl ether
(M3) and 1-naphtylphenyl-4-vinylbenzyl ether (M4) were
synthesized. The normal free radical polymerization of
monomers in 1,4-dioxane were performed by using 2,20-
azobisisobutyronitrile as an initiator at 65 °C. The mono-
mers and their homopolymers were characterized by
FT-IR, NMR and elemental analyses measurements. The
thermal stability of polymers was investigated by thermo-
gravimetric and differential scanning calorimetric analysis.
Thermal degradation activation energies of the polymers
were calculated by the Ozawa and Kissinger methods. In
addition, photo-stability tests of the polymers under near-
UV irradiation were performed.
polymerized via both cationic and radical routes and even
with transition-metal complexes. It should be mentioned that
living polymers of styrene and some of its derivatives can
now be produced by living cationic and radical polymer-
izations progressed significantly in recent years.
4-Vinylbenzyl chloride (VBC), is one of the most impor-
tant and interesting dual functional monomer. Due to pres-
ence of benzylic chlorine group in the structure, a great
number of nucleophilic substitutions are made possible,
leaving the double bond undamaged and providing new
monomers that can be polymerized or copolymerized when
the experimental conditions are well chosen [2, 3]. In addi-
tion, VBC can be easily polymerized or copolymerized with
various initiators [4] and the obtained polymers are able to
react with various nucleophilic reagents, giving fairly good
yields in the process [5, 6].
Keywords Styrene derivatives ꢀ Benzylic ether ꢀ
A number of studies on thermal degradation kinetics of
polymers have been investigated from thermogravimetric
(TG) analysis and it is widely used as a method to investigate
the thermal degradation of polymers and to determine the
kinetic parameters [7, 8]. TheKissinger [9] and Ozawa’s [10]
methods are the most widely used methods for obtaining
activation energy (Ea) values of polymers. The isoconver-
sional methods require performing a series of experiments
at different temperature programs and the yield values of
effective activation energy as a function of conversion. More
often than not, the activation energy is found to vary with
the extent of conversion. The full potential of the isocon-
versional methods has been appreciated to Vyazovkin [11]
brought analysis of the Ea-dependences to the forefront and
demonstrated that they can be used for exploring the mech-
anisms of processes and for predicting kinetics.
Thermal properties ꢀ Activation energies ꢀ Photo-stability
Introduction
Styrene is widely used industrial monomer and its polymers
are used in many different areas such as; plastics, latex paints
and coatings, synthetic rubbers, polyesters and styrene alkyd
coatings [1]. It is produced mainly by catalytic dehydroge-
nation of ethyl benzene and is used mainly for production of
polystyrene (PST) and styrene copolymers. It is the second
most widely used monomer for production of food-contact
packaging polymers. Styrene and its derivatives are also
˙
¨
I. Erol (&) ꢀ L. Ozcan ꢀ S. Yurdakal
The general application areas of polymers are in out-
doors and under sun light which includes ca. 5 % of near-
UV radiation [12]. Therefore, it is important to synthesized
¨ ¨
Kimya Bolumu, Fen-Edebiyat Fakultesi, Afyon Kocatepe
Universitesi, Afyon 03200, Turkey
¨
¨
¨
e-mail: ierol@aku.edu.tr
123

˙
I. Erol et al.
Characterization techniques
photo-stabile polymers toward near-UV radiation. More-
over, photo-stability results could be used for determining
application areas of polymers.
Infrared spectra were measured by using a Perkin Elmer
Spectrum BX FT-IR spectrometer. 1H- and 13C-NMR
spectra were recorded in DMSO-d6 with tetramethylsilane
as the internal standard using on Bruker GmbH DPX-400
500 MHz spectrometer. Thermal data were obtained by
using a Shimadzu DSC-60 instrument and TGA-60 ther-
mobalance in nitrogen atmosphere. UV–Vis spectra were
measured by Shimadzu UV 1700-Pharma spectrophotom-
eter. Elemental analyses of polymers have been performed
by using Vario EL III Elementar CHNOS Analyser.
In the first part of this paper a synthetic approach, eth-
eration of different alcohols with reactive VBC, was
introduced and some general aspects of alcohol analogous
reactions were discussed. Afterwards, the synthesis of the
reactive prepolymers was described in more detail, fol-
lowed by a number of examples for the preparation of
PST’s with simple polymers which be used in model
studies and go step to step to more complex architectures
with more than one functional group. Then the synthesized
polymers were characterised and tested by thermal analysis
and photo-stability experiments.
Set-up and procedure of photo-stability experiments
A concentration of 85 mg L-1 in dimethyl formamide
(DMF) of each polymer was prepared and used for photo-
stability experiments. A quartz cuvette was used as a
photo-reactor. The volume and thickness of the reactor
were 3.5 mL and 1 cm, respectively. The irradiation source
was 2 fluorescent black lamps (Philips, 8 W) which irra-
diate at 365 nm. The distances of between each lamp and
from the lamp to the reactor were 2.0 and 4.5 cm,
respectively. The radiation energy impinging on the sample
had an average value of 2.5 mW cm-2. It was measured at
between 315 and 400 nm by using a radiometer (Delta
Ohm, DO 9,721). The photo-stability experiments have
been performed at room temperature, ca. 293 K. The
results were followed by using UV–Vis measurements.
Experimental
Materials
4-Vinylbenzyl chloride, 4-methoxyphenol, 4-chlorophenol,
1-naphthol, 4-ethylphenol, 1,4-dioxane, potassium car-
bonate, acetonitrile and anhydrous magnesium sulphate
were purchased from Sigma-Aldrich. 4-Vinylbenzyl
chloride was purified from the inhibitor by distillation.
2,20-Azobisisobutyronitrile was recrystallized from chlo-
roform–methanol. All the other chemicals were analytical
grade and used without any further purification.
The synthesis of monomers
Results and discussion
A typical procedure for the etheration reaction of some
alcohols with VBC was as follows: each alcohol and
K2CO3 (1:1, mol:mol) were dissolved in 20 mL of anhy-
drous acetonitrile at 25 °C, and then VBC (1.1 mol) was
added dropwise to the solution. The reaction mixture was
stirred at 65 °C for 12 h. The organic layer was washed
several times with diethyl ether and dried over MgSO4.
After removing diethyl ether, the monomers were crystal-
lized by using ethanol (yields: ca. 80–85 %).
As shown in Scheme 1, it was proposed a new route for
styrene monomers having pendant ether moieties. The
yields of the reactions in Scheme 1 are of medium quantity
(80–85 %). The etheration reaction of VBC with various
alcohols was also better examined using K2CO3 under the
same conditions.
Structure characterization of the polymers
The FT-IR spectra of the monomer (M1) and its polymer (P1)
are shown in Fig. 1. In the IR spectrum of P1 showed some
characteristic absorption peaks at 1,600 cm-1 (C=C in aro-
matic ring) and 1,260 cm-1 (C–O–C). During the poly-
merization of the monomers, the IR band at 1,620 cm-1
(C=C) disappeared. The main evidence of polymer forma-
tion is certainly the disappearance of some characteristic
signals of the double bond in the spectra and this fact was
effectively observed in our case.
Polymerization of monomers
Appropriate amounts of each monomer, 1,4-dioxane and
2,20-azobisisobutyronitrile (1 % of the weight of monomer)
were placed in a reaction tube and purged with nitrogen for
10 min. The sealed tube was kept at 65 °C for 24 h. The
reaction contents were poured dropwise into a large excess
of ethanol. The polymers were purified by reprecipitation
with ethanol from 1,4-dioxane solution and finally dried
under vacuum (conversion is ca. 90 %).
The 1H- and 13C-NMR spectra of P2 are shown in
1
Fig. 2. From H-NMR spectroscopy the formation of the
123

Properties of styrene derivatives
Scheme 1 Synthesis of
monomers and their polymers
CH2
CH3CN / K2CO3
12h, 5 °C
Ar
OH
Cl
+
6
CH2
OAr
CH2
CH
CH2
1,4_ Dioxane / AIBN
65 °C
24 h,
OAr
OAr
Where Ar:
Cl
OCH3
P1
P2
P4
C2H5
P3
Fig. 1 FT-IR spectra of (a) M1
and (b) P1
a
b
4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400
–1
Wavenumbers/cm
polymer is also clearly evident from the vanishing of the
two dublets at 5.24 and 5.65 ppm and one quartet at 6.72 of
the vinyl protons and the appearance of the broad signals at
1.8 and 1.3 ppm assigned to an aliphatic –CH and –CH2
groups. The signals of the aryl group are seen between 6.5
and 8.0 ppm. The methoxy protons appeared at 3.70 ppm.
The peak at 4.9 ppm is attributed to the methyleneoxy
protons. In the proton decoupled 13C-NMR spectrum of P2,
chemical shift assignments were made from the off-reso-
nance decoupled spectra of the polymer. The signals due to
carbons (–CH2– and –CH– in the polymeric chain) are
observed at 40 and 42 ppm. The aromatic carbons are
observed at 154.7–123.0 ppm. The methoxy carbons show
signals at 63.0 ppm. The peak at 73 ppm is attributed to the
methyleneoxy carbons. As summarized in Table 1, the
structures of the obtained polymers were confirmed by IR,
123

˙
I. Erol et al.
1
Fig. 2 (a) H-NMR and
(b) 13C-NMR Spectra of P2
a
b
8
7
6
5
4
3
2
1
0
Chemical shift/ppm
170
150
130
110
90
70
50
30
Chemical shift/ppm
1
Table 1 FT-IR, H-, 13C-NMR spectral data and elemental analysis results of the polymers
Polymer FT-IR spectral data
(film/cm-1
1H-NMR spectral data
(400 MHz, DMSO-d6, TMS)
13C-NMR spectral data
(400 MHz, DMSO-d6, TMS)
Elemental analysis results
C/% H/%
)
Calc. Found Calc. Found
73.62 74.29 5.35 5.39
P1
P2
2960(CH),
3035(ArCH),
1600(ArC=C), 1250
(PhCH2–O–Ph),
730(C–Cl).
d/ppm: 1.7 (ArCH2),
1.2(ArCH2CH), 4.8(ArOCH2)
6.5–7.4 (Aromatic-H)
d/ppm: 40, 42(CH2– and CH– in the
polymeric chain), 70
(ArOCH2),110–135 (Aromatic-C),
158(C–Cl)
2955(CH),
3070(ArCH),
1600(ArC=C), 1245
(PhCH2–O–Ph and
ArOCH3).
d/ppm: 1.7 (ArCH2),
1.3(ArCH2CH), 4.9(ArOCH2)
6.5–7.6 (Aromatic-H),
3.6(OCH3)
d/ppm: 41, 43(CH2– and CH–
in the polymeric chain), 71
(ArOCH2),110–135 (Aromatic-
C),158(ArOCH3)
79.97 80.51 6.71 6.75
P3
P4
2960(CH),
3065(ArCH),
1600(ArC=C), 1252
(PhCH2–O–Ph).
d/ppm: 0.8 and 1.2 (CH2 and
CH3), 1.7 (ArCH2),
1.2(ArCH2CH), 4.9(ArOCH2)
6.5–7.4 (Aromatic-H)
d/ppm: 18,23(CH3 and CH2), 40,
44(CH2– and CH– in the polymeric
chain), 73 (ArOCH2),110–135
(Aromatic-C), 158(C–Cl)
85.68 86.62 7.61 7.67
89.25 89.63 5.99 6.04
2962(CH),
3100(ArCH),
1600(ArC=C), 1250
(PhCH2–O–Ph).
d/ppm: 1.7 (ArCH2),
1.2(ArCH2CH), 5.1(ArOCH2)
6.5–8.2 (Aromatic-H)
d/ppm: 42, 44(CH2– and CH–
in the polymeric chain), 71
(ArOCH2),110–145 (Aromatic-C),
1H- and 13C-NMR spectra and elemental analyses results.
All the other spectroscopic signals for the macromolecule
appeared in a normal mode.
as DMF, EMK, DMSO, CH2Cl2 and 1,4-dioxane at room
temperature or upon heating. The solubility of the resulting
polymers is summarized in Table 2.
Solubility of the polymers
Physical parameters
The solubility of the polymers was tested in various
organic solvents at a concentration of 1 % (w/v). The new
polymers are readily soluble in highly polar solvents such
Some physical parameters density, inherent viscosity (ginh)
and solubility parameter (d) of the polymers were deter-
mined in the study. PST was used for comparison. The
123

Properties of styrene derivatives
CH2Cl2 as a solvent and n-hexane and ethanol as non-
solvent. The results, shown in Table 3, inherent viscosity
results of the synthesized polymers are similar to that of
PST but their density and solubility results are a little higher
than that of PST.
Table 2 Solubility data of the resulting polymers
Solvent
P1
P2
P3
P4
DMF
??
??
??
-
??
??
??
-
??
??
??
-
??
-
DMSO
1,4-Dioxane
n-Hexane
Dichloromethane
Diethylether
Methanol
THF
??
-
Thermal properties of the polymers
??
-
??
-
??
-
??
-
Tg’s of the polymers
-
-
-
-
Tg is one of the most essential properties of polymers,
dictating important features such as thermomechani-
cal behavior and processing conditions. From differential
scanning calorimetry measurements, the glass-transition
temperatures were obtained as midpoints of the glass-
transition region (see Fig. 3). The glass-transition temper-
atures of the polymers are listed in Table 3. It is to be
expected, therefore, that the flexible benzylic ether func-
tionality will cause a decrease in Tg compared to that of
pure PST. As shown in Table 3, the Tg of P4 was higher
than that of other synthesized polymers. This effect might
be attributable to bulky substituent groups; a polymer
bearing bulky side groups generally has a high glass tran-
sition temperature, because for such a chain the moving
segment is necessarily large [13]. On the other hand, a
polymer that has high attraction forces between the chains
will expand less readily than a noninteracting polymers,
therefore such an interacting polymer must be heated to a
higher temperature before the free volume becomes as
large as required at the glass transition temperature. The
glass-transition temperature of P4 is considerably higher
than that of the others, because the bulky naphthyl side
group apparently decreases the flexibility of the chain and
the free volume more than the other side group.
??
??
-
??
??
-?
-
??
??
-?
-
??
?-
-
EMK
Acetonitrile
Ethanol
-
-
??, Soluble at room temperature; ?-, swelling or party soluble at
room temperature; -?, swelling or party soluble by heating;
-, insoluble
Table 3 The physical parameters and glass transition temperatures of
polymers
Polymer
d/g cm-3
g
inh/dL g-1
D/(cal cm-3 1/2
)
Tg/°C
P1
1.12
1.14
1.13
1.08
1.05
0.67
0.71
0.70
0.74
0.71
10.52
9.74
64
53
P2
P3
10.05
10.11
9.35
56
P4
74
PST
105
P2
P3
8.00
6.00
Endothermic
Thermal stability of the polymers
P1
P4
4.00
2.00
0.00
The thermal stabilities of the polymers were investigated by
TG in a nitrogen stream at a heating rate of 20 °C min-1. In
Fig. 4, TG curves of the polymers are shown. While P1 and
P4 have nearly the same initial decomposition temperature
(ca. 315 °C), P2 decomposes relatively lower (ca. 305 °C).
P3 is more stable than that of other polymers and decom-
pose at ca. 320 °C. The reason why the new polymers are
less stable than PST (325 °C) is due to in the presence of
benzyl ether group in PST structure. The residues of syn-
thesized polymers obtained at 500 °C are very interestingly
much higher than PST. It is 28 % for P2, 25 % for P3, and
40 % for P1 and P4, but it is only % 2 for PST.
Exothermic
0.00
100.00
200.00
300.00
Temperature/°C
Fig. 3 DSC curves of the polymers
inherent viscosities of 1 % (w/v) solutions of the poly-
mers in 1,4-dioxane were determined at 25 °C using an
Ubbelohde viscometer. The densities of the polymers were
determined experimentally by the flotation method at 25 °C
using mixtures of methanol and formic acid as the floating
agent, and many glass beads of known densities. The sol-
ubility parameters of the polymers were determined by
using a titration method at 25 °C from a solubility test using
The degradation of all synthesized polymers occurred at
two stages. The first stage was observed at about a tem-
perature range of 309–380 °C, while the second stage
decomposition commenced at that of 408-484 °C. Pure
123

˙
I. Erol et al.
Fig. 4 TG curves of the
polymers heated in nitrogen
atmosphere at a heating rate
of 20 °C min-1
100.00
50.00
–0.00
P1
P2
P3
P4
–0.00
100.00
200.00
300.00
400.00
500.00
Temperature/°C
Table 4 Some TG results of the polymers
due to side groups, the TG at various heating rates is much
more convenient than ITG for the investigation of thermal
degradation kinetics. In this section, the degradation param-
eters of polymers are estimated by two methods. TG was used
toinvestigatetheactivationenergies. Thethermaldegradation
expression results differ based on the different assumptions
and derivatives, for example, bulk or powder, carrier gas, flow
rate, would directly affect the results of parameters [17, 18].
The different analysis methods are described. These methods
requireseveral TG curvesatdifferent heatingrates. Hence, the
dynamic thermogravimetric analysis in nitrogen of the poly-
mers has been performed at various heating rates 5, 10, 15 and
20 °C min-1. Figure 5 shows the TG curves at the different
heating rates of P2.
Polymer IDT Temperature for a mass
loss/°C
Residue at 500 °C/%
20 %
50 %
70 %
P1
314 360
460
451
455
460
400
–
40
28
25
40
2
P2
315 338
319 367
305 422
325 380
490
483
–
P3
P4
PST
450
IDT initial decomposition temperature/°C
PST is more stable than new polymers, since new polymers
have flexible side group as benzylic ether in the structure.
This group is can be transformed at lower temperatures into
stable benzylic intermediate products. This accelerates
degradation of new PST derivatives.
Using Kissinger’s method and the experimental data
recorded in the Fig. 5, the activation energy of the decom-
position of polymers was calculated from a straight line fit of
a plot of ln(b/T2p) versus 1,000/Tp. The value obtained from
Fig. 6 for the activation energy of P3 was 186 kJ mol-1. The
Ea value of P1, P2 and P4 from Kissinger plots were obtained
as 148, 139 and 152 kJ mol-1. The Ea value of PST is 190
kJ mol-1 [19]. DTG curve of the P3 are shown in Fig. 7.
From this information we can conclude that PST has higher
activation energy than the new polymers. Thus, the new
styrene polymer has low thermal resistance.
Some of the degradation characteristics are summarized
in Table 4. The results show that main-chain scission is an
important reaction in the degradation of polymers, at least
in the beginning. PST is a polymer which undergoes
depolymerization to afford the monomer by pyrolysis.
Numerous studies of the thermal degradation of PST have
been reported and the predominant mechanism is accepted
to be that of random chain scission followed by intermo-
lecular transfer, with smaller amounts of unzipping and
intramolecular transfer. Complete volatilization is usual
and, depending upon precise conditions, monomer yield
may be up to 40 %, with the balance made up mostly of
dimer and trimer. McNeill et al. [14], McNeill [15] and
Shapi and Hesso [16], give useful details of degradation
products for various sets of conditions.
According to Hay and Kemmish [20], degradation in poly-
mer with ether group is initiated by random homolytic scission
of the ether bonds in the polymer chains, however there is
conflicting evidence about which bond is more stable. The
radicals produced abstract hydrogen from adjacent phenylene
units, or terminate by combination to produce crosslinks. The
products of the scission, if sufficiently mobile will volatilize.
Cyclization to benzofuran derivatives can also occur.
Thermal decomposition kinetics
The results of the Ozawa analysis are given in Fig. 8,
which shows that the best fitting straight lines are nearly
parallel, indicating a constant activation energy range of
conversions analysed and confirming the validity of the
approach used. Activation energies corresponding to the
different conversions are listed in Table 5. Ea calculated
The activation energies on the thermal decomposition of
polymers were determined by thermogravimetric analysis. In
the case of thermal degradation of polymers, in which depo-
lymerization is competing with cyclization or crosslinking
123

Properties of styrene derivatives
Fig. 5 Thermal degradation
curves of P2 at different heating
rates
100.00
50.00
0.00
–1
20 °C min
–1
–1
5 °C min
10 °C min
–1
15 °C min
0.00
100.00
200.00
300.00
400.00
500.00
Temperature/°C
1.40
1.30
1.20
–9.8
–10
0.35
0.10
0.50
0.20
0.30
–10.2
–10.4
β
1.10
1.00
–10.6
0.90
0.80
β
0.55
0.45
0.25
1.62
0.15
–10.8
–11
1.32
1.42
1.52
–1 –1
1.72
10 T /K
–11.2
–11.4
Fig. 8 Ozawa plots of the logarithm of the heating rate (log b) versus
the reciprocal of the temperature (1/T) at different conversions for P4
1.56 1.57 1.58 1.59 1.6 1.61 1.62 1.63 1.64 1.65
–1
Ultraviolet stability of the polymers
3
10 /T /K
p
Fig. 6 Kissinger plot of P3 in nitrogen atmosphere
According to the UV–Vis spectra results of the polymers in
DMF, the maximum wavelength of the peaks are 274, 282
and 289 nm for P1, 292 nm for P2, 278 and 285 nm for P3,
and 283, 294 and 321 nm for P4.
0.00
5 °C/mmin
After using 10 h near-UV irradiation, no significant
decomposition (less than 1 %) of P1, P2 and P3 in DMF was
observed. However, the results showed that P4 is not stable
in the same experimental conditions and ca. 13 % photo-
decomposition of P4 was observed by following kmax values
at294 nm(seeFig. 9a). Figure 9b givesphoto-decomposition
of P4 in DMF during irradiation time. The values were deter-
mined by using decreasing values of absorbance at 294 nm.
This result could be explain by two different ways; (i) the
probable decomposition product of P4 is naphthalene which is
most stable intermediate (due to delocalisation) with respect
to other probable main intermediates of the other polymers
which are chlorobenzene, methoxybenzene and ethylbenzene,
therefore it could be removed very easily, (ii) only P4 has an
significant absorbance value at 365 nm, ca. 0.238. Due to the
experiments have been performed in homogenous media
and without using any catalyst, photodecomposition could
be occur only if the substrate could absorb the irradiate
10 °C/mmin
15 °C/mmin
20 °C/mmin
–0.50
–1.00
100.00
200.00
300.00
400.00
500.00
Temperature/°C
Fig. 7 DTG curves of P3 in nitrogen atmosphere
from the Ozawa method is superior to other methods for
complex degradation, since it does not use the reaction order
in the calculation of the decomposition activation energy.
Therefore, Ea calculated from the Ozawa method was
superior to the former methods for complex degradation.
123

˙
I. Erol et al.
Table 5 The apparent activation energies of polymers for different mass loss percentage values under thermal degradation in N2
Activation energy Ea/kJ mol-1
Sample
10 %
15 %
20 %
25 %
30 %
40 %
45 %
50 %
55 %
Average
P1
P2
P3
P4
164
41
170
118
161
122
168
128
157
167
150
80
160
175
276
175
138
188
230
165
133
185
207
176
128
180
195
166
148
181
184
177
151
142
191
154
157
61
149
176
Conclusions
0.8
a
0
1 h
0.7
0.6
0.5
0.4
The synthesis of new styrene monomers with pendant ben-
zylic ethers groups has been reported for the first time. The
structures of the monomer and polymer were characterized
with spectroscopic methods. It was obtained that the thermal
stability of new polymers was lower than that of PST. Glass
transition temperatures of the polymers were much more
less than PST. The activation energies of decomposition
were calculated with the Ozawa and Kissinger method.
Finally, it was observed that most the synthesized polymers
are quite stable under near-UV irradiation.
2 h
3 h
4 h
5 h
6 h
0.3
0.2
8 h
10 h
0.1
0
265 275 285 295 305 315 325 335 345 355
Acknowledgements Authors thank the Afyon Kocatepe University,
(BAP Project no: 10.FENED.05) for financial support.
Wavelength/nm
86
84
82
b
References
1. IARC Working Group on the Evaluation of Carcinogenic Risks to
Humans: Some Traditional Herbal Medicines, Some Mycotoxins,
Naphthalene and Styrene. in ‘‘IARC monograph evaluation of carcin-
ogenic risks to humans’’ Lyon: IARC Press; 2002. vol 82, p. 437–451.
2. Montheard JP, Jegat C, Camps M. Vinylbenzylchloride (chlo-
romethylstyrene), polymers, and copolymers: recent reactions
and applications. J Macromol Sci Rev Macromol Chem Phys.
1999;C39:135–74.
3. Dong JY, Manias E, Chung TC. Functionalized syndiotatic polysty-
rene polymers prepared by the combination of metallocene catalyst
and borane comonomer. Macromolecules. 2002;35:3439–47.
4. Yus M, Gomez C, Candela P. The first direct formation of an
organolithium reagent on a soluble polymer by chlorineelithium
exchange: functionalized linear polystyrene. Tetrahedron Lett.
2001;42:3977–9.
80
78
76
74
72
0
2
4
6
8
10
12
t/h
Fig. 9 a UV–Vis absorption spectra of P4 in DMF during the
photolysis (k = 365 nm) and b photo-decomposition of P4 in DMF
during irradiation time. The values were determined by using
decreasing values of absorbance at 294 nm
5. Worl LA, Jones WE, Strouse GF, Younathan JN, Danielson E,
Maxwell KA, Sykora M, Meyer TJ. Multiphoton, multielectron
transfer photochemistry in a soluble polymer. Inorg Chem. 1999;
38:2705–8.
radiation, in the present case it was at 365 nm [21]. Isobestic
point of P4 is at 284 nm. During the irradiation, the absor-
bance peaks at 283, 294 and 321 nm decreased, while the
absorbance coming before isobestic point increased. This
increase could be due to increasing amount of naphthalene
which probable main intermediate product of P4. Indeed, the
maximum peak absorbance of naphthalene is at 275 nm and
at this wavelength the increasing was observed from photo-
degradation of P4.
6. Kawashima N, Kameyama A, Nishikubo T, Nagai T. Synthesis
and photochemical reaction of polystyrene with pendent donor-
acceptor type norbornadienes containing carbamyl chromoph-
ores. React Funct Polym. 2003;55:75–88.
7. Tagle LH, Diaz FR. Thermogravimetric analysis of polymers
with indanic structure. J Therm Anal Calorim. 1992;38:2385–95.
8. Cais RE, O’Donell JH, Bovey FA. Copolymerization of styrene
with sulfur dioxide. Determination of the monomer sequence dis-
tribution by carbon-13 NMR. Macromolecules. 1977;10:254–60.
9. Kissinger HE. Reaction kinetics in differential thermal analysis.
Anal Chem. 1957;29:1702–6.
123

Properties of styrene derivatives
10. Ozawa T. A new method of analyzing thermogravimetric data.
Bull Chem Soc Jpn. 1965;38:1881–6.
11. Vyazovkin S, Sbirrazzuoli N. Isoconversional kinetic analysis of
thermally stimulated processes in polymers. Macromol Rapid
Commun. 2006;27:1515–32.
12. Schiavello M. Heterogeneous photocatalysis. New York: Wiley;
1995.
13. Shenhar R, Sanyal A, Uzun O, Rotello VM. Anthracene-func-
tionalized polystyrene random copolymers: effects of side-chain
modification on polymer structure and behavior. Macromole-
cules. 2004;37:92–8.
14. McNeill IC, Zulfiqar M, Kousar T. A detailed investigation of the
products of the thermal-degradation of polystyerene. Polym
Degrad Stab. 1990;28:131–51.
15. McNeill IC. Thermal degradation of polystyrene in different
environments. Angew Makromol Chem. 1997;247:179–95.
16. Shapi MM, Hesso A. Thermal-decomposition of polystyrene-
volatile compounds from large-scale pyrolysis. J Anal Appl
Pyrolysis. 1990;18:143–61.
17. Coskun M, Demirelli K, Erol I, Ahmedzade M. Thermal degra-
dation of poly[2-(3-aryl-3-methylcyclobutyl)-2-hydroxyethyl
methacrylate]. Polym Degrad Stab. 1998;61:493–7.
18. Erol I, Soykan C, Ilter Z, Ahmedzade M. Thermal degradation of
poly 2-[3-(6-tetralino)-3-methylcyclobutyl]-2-ketoethyl methac-
rylate. Polym Degrad Stab. 2003;81:287–95.
19. Yang M, Tsukame T, Saitoh H, Shibasaki Y. Investigation of the
thermal degradation mechanisms of poly(styrene-co-methacry-
lonitrile)s by flash pyrolysis and TG-FTIR measurements. Polym
Degrad Stab. 2000;67:479–89.
20. Hay JN, Kemmish DJ. Thermal-decomposition of poly(aryl ether
ketones). Polymer. 1987;28:2047–51.
21. Yurdakal S, Loddo V, Augugliaro V, Berber H, Palmisano G,
Palmisano L. Photocatalytic degradation of gemfibrozil in aque-
ous TiO2 suspensions: mechanism and kinetics. Catal Today.
2007;129:9–15.
123