Poly(arylene ether ketone)s with pendant porphyrins: Synthesis and investigation on optical limiting properties

Article abstract of DOI:10.1039/c5ra05453b

This paper describes the synthesis and characterization of a novel series of poly(arylene ether ketone)s bearing porphyrin pendants, along with the demonstration of their nonlinear optical and optical limiting properties at 532 nm in both THF and films. T

Full text of DOI:10.1039/c5ra05453b

RSC Advances
View Article Online
View Journal | View Issue
PAPER
Poly(arylene ether ketone)s with pendant
porphyrins: synthesis and investigation on optical
Cite this: RSC Adv., 2015, 5, 48311
limiting properties†
a
a
b
a
a
a
Yinlong Du, Kai Zhu, Yu Fang, Shuling Zhang, Xingrui Zhang, Yaning Lu,
a
b
a
Yanchao Yang, Yinglin Song and Guibin Wang*
This paper describes the synthesis and characterization of a novel series of poly(arylene ether ketone)s
bearing porphyrin pendants, along with the demonstration of their nonlinear optical and optical limiting
properties at 532 nm in both THF and films. The incorporation of pendant porphyrins was done through
a modified esterification using a copoly(arylene ether ketone) with free carboxyl groups and mono-
hydroxyphenyl porphyrins with different substituents and center metal. The introduction of porphyrin in
1
the polymer was confirmed by IR,
H NMR, UV-vis, fluorescence spectroscopies, and WAXD.
Investigation of thermal properties indicated that the poly(arylene ether ketone)s with porphyrin
pendants possessed higher T s, and slightly lower decomposition temperatures than the starting
g
copolymers. The results of optical limiting and Z-scan measurements demonstrated that the
Received 27th March 2015
Accepted 21st May 2015
porphyrinated poly(arylene ether ketone)s exhibited strong optical limiting responses and nonlinear
ꢀ9
ꢀ1
absorption properties with the nonlinear absorption coefficient b in the order of 10
(m W )
DOI: 10.1039/c5ra05453b
magnitude. The effects of pendant porphyrin structure on the thermal, mechanical, linear and nonlinear
www.rsc.org/advances
optical properties of the poly(arylene ether ketone)s were investigated in detail.
as porphyrins and phthalocyanines have exhibited superior
optical limiting properties due to the occurrence of reverse
Introduction
The rapid advance of laser technology injects new opportunities saturable absorption (RSA) process, which involves an excited
into photonic, medical, and military applications, as well as the state absorption with cross section (sex) exceeding that of the
9,10
development of nonlinear optical (NLO) materials and devices ground state absorption (s
0
) under photoexcitation. Porphy-
for applications such as optical data storage, information rins have been the most intensively studied NLO compounds
1–3
11
process, and optical limiting. Within the scope of nonlinear since their RSA effect was rst reported by Blau et al. The
optics, optical limiting (OL) materials which effectively atten- structural changes consisting of the variation of peripheral
uate damaging laser pulses for protecting delicate optical substituents, central metals, and the type of axial ligands give
sensors and human eyes from exposure to intense light beams, rise to their adjustable optical properties, rendering porphyrins
while exhibit high transmittance for low intensity ambient light still among the most promising materials toward optical
4–6
9,10,12
have been extensively investigated. In general, the perfor- limiting.
As it is difficult to fabricate optical devices with
mance specications for an ideal optical limiter require fast single porphyrin molecule or solution, a variety of polymers
response time, broad-band spectral response range, large have been selected as solid state matrices over the past decades.
nonlinearities, low limiting threshold, and high linear trans- However, the direct introduction of porphyrins into polymers
7,8
mittance in the absence of intense light. Furthermore, ease of usually bring about aggregation and poor dispersion, resulting
processing, good mechanical strength and thermal stabilities in undesirable performance. To solve these problems, previous
are also necessary for practical applications of OL materials.
Among the widely investigated materials for optical limiting, porphyrin polymers by covalent attachment for the purpose of
17,18
efforts have been devoted to the design and preparation of
1
3,14
15,16
organic compounds with extended p conjugated systems such photovoltaic,
electrospinning,
nonlinear optics,
19
20,21
22
semiconducting, gas storage,
and photosensitizer. Up to
now, in spite of the wide variety of polymers that incorporate
porphyrin units, few of them have been considered as an ideal
material capable of protecting delicate optical devices due to
their inferior thermal stabilities and corrosion resistance,
which make them vulnerable to high energy density laser. In
view of this issue, it is critically important to explore and
a
College of Chemistry, Key Laboratory of High Performance Plastics, Ministry of
Education, Jilin University, Changchun 130012, China. E-mail: wgb@jlu.edu.cn
b
College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006,
China
†
Electronic supplementary information (ESI) available. See DOI:
0.1039/c5ra05453b
1
This journal is © The Royal Society of Chemistry 2015
RSC Adv., 2015, 5, 48311–48322 | 48311

View Article Online
RSC Advances
Paper
1
evaluate high performance (especially good thermal resistance) transmission. H NMR was recorded on a Bruker 510 NMR
polymers in the eld of NLO materials. spectrometer (500 MHz) in CDCl with tetramethylsilane as a
3
Poly(arylene ether ketone)s (PAEKs) are an important species reference. Mass spectra (MS) were performed on an AXIMA-CFR
of high performance thermoplastics characterized by their laser desorption ionization ying time spectrometer
outstanding chemical, nonammable, thermal, and mechan- (COMPACT). Gel permeation chromatograms (GPC) using
23–26
ical properties.
The semi-crystalline nature, poor solubility, polystyrene as a standard were obtained on a Waters 410
and low glass transition temperature of the original poly(ether instrument with tetrahydrofuran (THF) as an eluent at a ow
ꢀ
1
ether ketone) have been improved by means of modifying rate of 1 mL min . The crystallization behavior was investi-
27–30
molecular segment structure.
Currently, this class of gated by Rigaku D/max-2500 X-ray diffractometer with CuKa
advanced materials is receiving extensive attention for potential radiation (l ¼ 0.154 nm) as the X-ray source. Energy dispersive
3
1,32
applications on ber reinforced composites,
proton/anion spectroscopic (EDS) data was collected on Nova Nano (FEI)
and low dielectric constant mate- scanning electron microscope (SEM) 450 equipped with energy
However, synthesis and properties of PAEKs incorpo- dispersive spectroscopy. Differential scanning calorimetry (DSC)
rating NLO chromophores have scarcely been reported. Since measurements were performed on a Mettler-Toledo DSC 821e
33–37
exchange membrane,
38,39
rials.
ꢁ
ꢀ1
PAEKs combine rigidity, exibility and good thermal resistance, instrument at a heating rate of 20 C min under a nitrogen
we expect them to be promising substituents for poly(methyl atmosphere. Thermogravimetric analysis (TGA) was performed
4
0,41
methacrylate) as optical limiting materials.
on a Perkin Elmer Pyris 1 TGA analyzer; the samples were con-
ꢁ
ꢀ1
This work reports the synthesis and characterization of tained in open platinum pans at a heating rate of 10 C min
poly(arylene ether ketone)s having porphyrin pendant units under nitrogen. UV-vis absorption and uorescence emission
anchored at the sidechains via a exible alkyl chain, along with spectra were recorded on a UV2501-PC spectrophotometer and
their optical properties, thermal stabilities, and mechanical Shimadzu RF-3501 uorescence spectrophotometer, respec-
properties. To avoid the complicated procedures of synthesizing tively. The mechanical properties of polymer lms (rectangular
3
the corresponding porphyrin monomer and its possible low lms of 45.0 (length) ꢂ 5.0 (width) ꢂ 0.1 (thickness) mm , cast
reactivity as a bulky bisphenol monomer, the introduction of from THF solvents onto the glass plates, followed by heating at
0
ꢁ
porphyrin pendant groups was achieved through N,N -dicyclo- 60 C in vacuo), were evaluated at room temperature at a strain
ꢀ1
hexylcarbodiimide (DCC) and 4-(dimethylamino)pyridine (DMAP) rate of 10 mm min on a Shimadzu AG-I Universal Tester, and
catalyzed esterication reactions using a poly(arylene ether ketone) each lm was measured ve times in parallel.
with free carboxyl groups and asymmetric mono-hydroxyphenyl
The nonlinear optical (NLO) properties of the samples were
porphyrins. Their optical limiting properties were evaluated by evaluated by Z-scan technique using a Q-switched ns Nd:YAG
Z-scan and optical limiting measurements. Furthermore, the laser system continuum with linearly polarized 4 ns pulsed light
inuence factors, such as content, central metal, and peripheral at 10 Hz repetition rate and 532 nm wavelength. THF solution of
substituent of porphyrin moieties on the optical and thermal polymers was placed in a quartz cell with a thickness of 2 mm
properties of the polymers were comparatively investigated.
and placed at the focal point of a lens with a focal length of
0 cm, and moved along the axis of the incident beam
z direction). The measurements were carried out employing
4
(
Experimental section
Materials
open-aperture and closed-aperture congurations with the
input energy of 5.3 mJ. The incident and transmitted laser pulses
were monitored by utilizing two energy detectors, D1 and D2
(Rjp-765 energy probes, Laser Precision), which were linked to
an energy meter (Rj-7620 Energy Ratiometer, Laser Probe Inc.). A
computer was used to process the data coming from the energy
meter via a GPIB interface. The optical limiting properties were
performed using Z-scan technique with the same laser system as
in the nonlinear absorption experiments, where the intensity of
the incident energy is varied continuously and the output energy
is captured by a large aperture photodetector kept at a distance
of 10 cm from the samples; the samples were positioned in a
quartz cell of 5 mm thickness at the focal point, and curves of
output energy or transmittance vs. input energy were obtained.
0
1

-Naphthaldehyde (95%), p-tolualdehyde (97%) and 4,4 -(hexa-
ꢁ
uoroisopropylidene) diphenol (97%, mp 160–163 C) were
purchased from Sigma-Aldrich Chemical Company. 4-Hydroxy
benzaldehyde (98%), benzaldehyde (98%), and pyrrole (98%) were
purchased from Shanghai Chemical Factory and were distilled
prior to use. Diphenolic acid (98%) was provided by TCI Shanghai
0
Development Co. Ltd., China. 4,4 -Diuorobenzophenone (DFB)
was obtained from Changzhou Huashan Chemical, China and
0
further puried by recrystallization. N,N -Dicyclohexylcarbodiimide
(DCC) and 4-(dimethylamino)pyridine (DMAP) were supplied by
Sigma-Aldrich. Zinc acetate dihydrate (Zn(OAc) $2H O) and lead
2
2
acetate trihydrate (Pb(OAc) $3H O) were obtained from Sinopharm
2
2
Chemical Reagent Co. Ltd., China. Tetrahydrofuran (THF) and
N-methyl-2-pyrrolidinone (NMP) were distilled according to stan-
dard procedures before use.
Synthesis of 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin
42
This compound was synthesized by Adler's method. The crude
product was puried by silica-gel column chromatography
Instruments
using CHCl as eluent to collect the second fraction, then the
3
FTIR spectra (KBr pellets) were recorded on a Nicolet Impact solvent was evaporated and dried to yield bright purple crys-
10 Fourier transform infrared spectrophotometer in talline, 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (OH-TPP)
4
48312 | RSC Adv., 2015, 5, 48311–48322
This journal is © The Royal Society of Chemistry 2015

View Article Online
Paper
RSC Advances
ꢀ
1
(
1
(
8
yield: 6.2%). IR (KBr): vmax (cm ): 3408 (OH), 3314 (NH), 1607, 10,15,20-tritolylporphyrin (OH-TTP) (yield: 5.7%). Anal. calcd
1
510 (Ar), 1169 (Ar–O), 799 (Ar). H NMR (500 MHz, CDCl , TMS), d for (C H N O): C 83.90, H 5.39, N 8.33. Found: C 83.93, H 5.47,
ppm): 8.86 (s, 8H, pyrrolic-b-CH), 8.19–8.21 (m, 6H, ortho-C H ), N 8.35%. IR (KBr): vmax (cm ): 3423 (OH), 3312 (NH), 2935
3 47 36 4
ꢀ1
6
5
1
.04–8.06 (d, 2H, J ¼ 8.5 Hz, ortho-C H OH), 7.73–7.75 (m, 9H, (CH ), 1603, 1507 (Ar), 1159 (Ar–O), 801 (Ar). H NMR (500 MHz,
6
4
3
meta, para-C
H
6 5
), 7.13–7.16 (d, 2H, J ¼ 8.5 Hz, meta-C
6
H
4
OH), CDCl
3
, TMS), d (ppm): 8.85 (s, 8H, pyrrolic-b-CH), 8.07–8.10 (d,
), 8.01–8.04 (d, 2H, J ¼ 8.5 Hz, ortho-
OH), 7.53–7.55 (d, 6H, J ¼ 7.9 Hz, meta-C ), 7.10–7.13 (d,
OH), 2.69 (s, 9H, CH
), ꢀ2.78 (s, 2H,
O): m/z [M + H] : 631.25; NH). C NMR (125 MHz, CDCl , TMS), d (ppm): 146.65, 146.32,
145.81, 140.44, 139.35, 138.89, 137.31, 135.61, 134.51, 130.99,
29.24, 128.03, 127.73, 127.39, 120.09, 113.62, 21.48. MALDI-
13
ꢀ
2.78 (s, 2H, NH). C NMR (125 MHz, CDCl
3
, TMS), d (ppm): 6H, J ¼ 7.9 Hz, ortho-C
7 7
H
1
46.84, 145.89, 142.22, 140.46, 138.83, 135.63, 134.52, 129.98,
C
6
H
4
7 7
H
1
28.35, 127.80, 127.74, 127.65, 126.67, 126.63, 115.25, 113.63. 2H, J ¼ 8.5 Hz, meta-C
6
H
4
3
+
13
MALDI-TOF MS: calculated for (C44
H N
30 4
3
found: m/z ¼ 631.6.
1
+
TOF MS: calculated for (C H N O): m/z [M + H] ¼ 673.29;
4
7
36 4
Synthesis of 5-(4-hydroxyphenyl)-10,15,20-tritolylporphyrin
found: m/z ¼ 673.4.
Following a similar procedure to the preparation of OH-TPP,
4
-hydroxybenzaldehyde (3.053 g, 25 mmol), p-tolualdehyde
Synthesis of 5-(4-hydroxyphenyl)-10,15,20-
trinaphthylporphyrin
(9.011 g, 75 mmol) and pyrrole (6.8 mL, 100 mmol) was added
dropwise to 300 mL propionic acid in 30 min with stirring at
1
ꢁ
40 C. The mixture was reuxed for 1 h, most of propionic acid 4-Hydroxybenzaldehyde (3.053 g, 25 mmol), 1-naphthaldehyde
was removed under reduced pressure. The dark purple product (11.714 g, 75 mmol) and pyrrole (6.8 mL, 100 mmol) was added
was ltered and washed thoroughly with methanol until the dropwise to 250 mL propionic acid in 20 min with stirring at 126
ꢁ

ltrate became clear and the crude product was puried
C. The mixture was reuxed for 40 min, most of propionic acid
through column chromatography (CHCl ). The second fraction was distilled away under reduced pressure and allowed to cool
3
was collected and evaporated to give 5-(4-hydroxyphenyl)- overnight. The black precipitate was ltered and washed with
Scheme 1 Synthesis of PAEKs with porphyrin pendants.
This journal is © The Royal Society of Chemistry 2015
RSC Adv., 2015, 5, 48311–48322 | 48313

View Article Online
RSC Advances
Paper
methane, and the crude product was puried by column chro- (42 mL) and toluene (20 mL) in a three necked ask equipped
matography (CHCl : methane, 50 : 1, v : v) as eluent to collect the with a mechanical stirrer, a nitrogen inlet with a thermometer,
3
second fraction, bright purple crystalline 5-(4-hydroxyphenyl)- and a Dean–Stark trap with a condenser. The mixture was
ꢁ
1
0,15,20-trinaphthylporphyrin (OH-TNP) was obtained (yield: reuxed for 3 h at 130 C under nitrogen to remove the resulting
ꢁ
5.3%). Anal. calcd for (C56
H N
36 4
O): C 86.13, H 4.65, N 7.17. Found: water. The mixture was continued to react for 6 h at 160–170 C to
C 86.23, H 4.67, N 7.13%. IR (KBr): vmax (cm ): 3432 (OH), 3316 complete the polymerization. The viscous solution was poured
NH), 1608, 1505 (Ar), 1168 (Ar–O), 797 (Ar). H NMR (500 MHz, into deionized water to precipitate the brous polymer, which
CDCl
, TMS), d (ppm): 8.72–8.73 (d, 2H, J ¼ 4.7 Hz, pyrrolic-b-CH), was pulverized into powders, and washed thoroughly with boiling
.51–8.54 (m, 2H, pyrrolic-b-CH), 8.41–8.43 (m, 4H, pyrrolic-b- water and ethanol in sequence. The product was dissolved in 140
ꢀ
1
1
(
3
8
1
3
CH), ꢀ2.39 (s, 2H, NH). C NMR (125 MHz, CDCl , TMS), d mL THF, 10 mL concentrated HCl was added dropwise to the
3
(
ppm): 155.33, 139.26, 139.23, 136.73, 135.59, 134.48, 132.80, solution with stirring, the reaction was continued at room
132.68, 132.61, 131.36, 131.31, 131.14, 131.09, 130.98, 128.55, temperature for 8 h, ensuring that the potassium carboxylate were
1
27.71, 126.09, 124.06, 117.54, 113.58. MALDI-TOF MS: calculated completely converted to carboxyl groups. Then the polymer was
+
for (C56
36 4
H N O): m/z [M + H] ¼ 781.29; found: m/z ¼ 782.2.
precipitated in deionized water and washed, the product was
ꢁ
dried to constant weight under vacuum at 100 C for 24 h to
ꢀ1
give PAEK–COOH30%. Yield (92%). IR (KBr): vmax (cm ): 1732
Synthesis of poly(arylene ether ketone)s with carboxyl pendant
(O]C–OH), 1658 (Ar–C]O), 1594, 1502 (Ar), 1264 (Ar–O–Ar).
Poly(arylene ether ketone)s with different molar ratio (0.1, 0.3,
The synthesis of PAEK–COOH10% and PAEK–COOH50% were
0
.5) of carboxyl pendant (PAEK–COOHs) were synthesized via conducted using the same procedure, but with the monomer feed
0
0
copolymerization of 4,4 -diuorobenzophenone (DFB), 4,4 -(hexa- ratios of 6FBPA : DPA being 90 : 10 and 50 : 50, respectively.
uoroisopropylidene) diphenol and diphenolic acid as depicted

in Scheme 1. A typical synthetic procedure (PAEK–COOH30%)
0
Synthesis of poly(arylene ether ketone)s with porphyrin
pendant
was carried out as follows: 4,4 -diuorobenzophenone (4.364 g,
0
2
0 mmol), 4,4 -(hexauoroisopropylidene) diphenol (6FBPA)
(4.707 g, 14 mmol), diphenolic acid (DPA) (1.717 g, 6 mmol), and A general procedure to synthesis the porphyrin graed poly-
anhydrous K CO (3.455 g, 25 mmol) were dissolved in NMP (arylene ether ketone)s was illustrated as Scheme 1 and
2
3
Scheme 2 Synthesis of PAEK–COOH30%–ZnTPP and PAEK–COOH30%–PbTPP.
48314 | RSC Adv., 2015, 5, 48311–48322
This journal is © The Royal Society of Chemistry 2015

View Article Online
Paper
RSC Advances
conducted as follows: to a three-necked 100 mL ask tted with increased with the addition of DCC at rst and then decreased.
a funnel drop, magnetic stirrer and nitrogen inlet were added Finally, the intermediate reacted with porphyrins to yield the
1.5 g (0.9 mmol of COOH) PAEK–COOH30%, 1.13 g (1.8 mmol) target polymer and regenerate DMAP. Aer extraction in
OH-TPP and 30 mL anhydrous THF. Aer the copolymer was acetone for 48 h, the nal product was examined by layer
dissolved, 20 mL anhydrous THF solution of 0.227 g (1.1 mmol) chromatography (TLC) to conrm the absence of residual
DCC and 0.013 g (0.11 mmol) DMAP was dropwise added in 2 h porphyrins.
to avoid the formation of gel. The mixture was stirred at room
The molecular weights of the polymers were measured by
temperature for 72 h under nitrogen, the solution was ltered to GPC and displayed in Table 1, all the PAEKs were of high
remove the resultant white precipitate (dicyclohexylurea, DCU) molecular weight. The molecular weights of PAEKs with
and the purple ltrate was poured into ethanol to precipitate, porphyrin pendants are higher than those of the corresponding
then the polymer was dissolved/reprecipitate in THF/ethanol PAKE–COOH, indicating the successful graing of porphyrins.
before extraction in acetone to remove the porphyrin residues. However, PAEK–COOH30%–TNP has a lower Mn than PAEK–
ꢁ
Finally, the product was dried under vacuum at 80 C for 12 h, COOH30%–TPP and PAEK–COOH30%–TTP as a result of the
the purple polymer powders PAEK–COOH30%–TPP was bulkier OH-TNP, which further increased the steric hindrance
ꢀ1
prepared. IR (KBr): vmax (cm ): 3317 (NH), 1761 (O]C–O), 1658 and restricted the graing degree. PAEK–COOH series were only
Ar–C]O), 1594, 1502 (Ar), 1264 (Ar–O–Ar), 799 (Ar). soluble in polar solvents such as DMF and THF, aer esteri-
Following the same procedure, a series of poly(arylene ether cation, all the polymers with porphyrin pendants could be dis-
ketone)s with porphyrin pendants PAEK–COOH10%–TPP, solved in chloroform, suggesting the improved solubility.
PAEK–COOH50%–TPP, PAEK–COOH30%–TTP, and PAEK– The structure of PAEKs with porphyrin pendants was
COOH30%–TNP were synthesized with corresponding PAEK– conrmed by FTIR and H NMR spectroscopy. As shown in
(
1
COOH and feed ratios.
Fig. 1, the stretching vibration of the aromatic ketone C]O at
ꢀ1
ꢀ1
1
658 cm , skeleton vibration of benzene rings at 1594 cm
ꢀ
1
and 1501 cm , and stretching vibration of ether linkage at
1
Metallization of poly(arylene ether ketone)s with porphyrin
pendant
ꢀ
1
246 cm were observed for poly(arylene ether ketone)s. In
comparison with the spectrum of PAEK–COOH30%, the
Poly(arylene ether ketone)s with zinc-porphyrin and lead-
porphyrin pendant were synthesized using a similar method
according to previous literature as illustrated in Scheme 2.
PAEK–COOH30%–TPP (1.00 g) was dissolved in N,N -dime-
thylformamide (DMF) and stirred with excess Zn(OAc)
ꢀ1
absorption of carboxyl C]O at 1732 cm disappeared, a new
ꢀ1
absorption band at 1761 cm was detected in the spectra of
4
3
polymers with porphyrins pendant, which was ascribed to the
formation of ester bond. The existence of porphyrin moieties
was conrmed by the weak characteristic absorption at
0
2
$2H
2
O
ꢁ
(1.50 g) or Pb(OAc)
2
$3H
2
O (2.30 g) at 80 C for 4 h, the product
ꢀ1
ꢀ1
3
317 cm and 799 cm , corresponding to the internal –NH
was precipitated into a large amount of ice water, washed with
deionized water to remove unreacted acetate and isolated with
and porphyrin ring, respectively. However, aer complexation
2+
2+
with Zn or Pb the absorption band of –NH in porphyrin
moieties disappeared, indicating the complete metallization. It
should be noted that in the spectra of PAEK–COOH30%–TTP
and PAEK–COOH30%–TNP (Fig. S1†), the absorption of

ltration prior to being dried under vacuum to produce the

nal PAEK–COOH30%–ZnTPP (purple powders) and PAEK–
COOH30%–PbTPP (green powders).
ꢀ
1
residual carboxyl C]O at 1710 cm could be found compared
with the spectra of analogous PAEK–COOH30%–TPP, despite of
their identical reaction process. These results are consistent
with the GPC results of PAEK–COOH30%–TNP, which implied a
Results and discussion
Polymer synthesis and characterization
The poly(arylene ether ketone)s with porphyrin pendants were lower graing degree.
1
carried out by esterication of precursor copolymers (PAEK–
Fig. 2 shows the H NMR spectra of the PAEK–COOH30%
COOH) using DCC and DMAP to activate carboxylic acid and and PAEKs with three porphyrin pendants based on PAEK–
mono-hydroxyphenyl porphyrins in anhydrous THF (Scheme 1). COOH30%. The aromatic region of the polymers exhibited
By immediately adding DCC into the PAEK–COOH solution, a signals at 7.86, 7.43, and 7.25 ppm corresponding to protons a,
gel was rapidly formed and could not be dissolved even under c, and e, the integral ratio was calculated to coincide with the
44
heating conditions as previously reported. This is because the initial stoichiometric proportion. Signals from 7.03 to 7.12 ppm
carboxylic group of PAEK–COOH was prone to be converted to were assigned to protons around the ether linkage b and d,
acid anhydride through intermolecular dehydration by the while the signals from 2.03 to 2.45 ppm were assigned to
reaction of DCC in this system rather than intramolecular protons of aliphatic –CH – and –CH . Whereas for polymers
2 3
45
dehydration, resulting in crosslinking and the formation of with porphyrin pendants, the signals attributable to porphyrin
gel, which prevented the nucleophilic DMAP from attacking the moieties from 7.13 to 8.86 could be observed, which slightly
carbonyl group in the acid anhydride to form the intermediate. shied relative to those of OH-TPP (see Fig. S2†). In addition,
Therefore, this step was conducted by dropwise adding a THF the characteristic singlet of internal pyrrole –NH proton at
solution of DCC and DMAP to control the reaction rate, thus the ꢀ2.76 ppm appeared in PAEK–COOH30%–TPP, and dis-
2
+
2+
acid anhydride could react with DMAP to generate the inter- appeared aer the complexation with Zn and Pb as expected
mediate. The viscosity of the polymer solution gradually (see Fig. S3†).
This journal is © The Royal Society of Chemistry 2015
RSC Adv., 2015, 5, 48311–48322 | 48315

View Article Online
RSC Advances
Paper
Table 1 Molecular weight and optical properties of poly(arylene ether ketone)s
a
ꢀ1
a
w
ꢀ1
a
b
c
Polymer
M
n
(kg mol
)
M
(kg mol
)
PDI
Soret band (nm)
Emission bands (nm)
F
F
PAEK–COOH10%
PAEK–COOH30%
PAEK–COOH50%
PAEK–COOH10%–TPP
PAEK–COOH30%–TPP
PAEK–COOH50%–TPP
PAEK–COOH30%–ZnTPP
PAEK–COOH30%–PbTPP
PAEK–COOH30%–TTP
PAEK–COOH30%–TNP
53.5
57.4
39.4
68.9
75.9
68.6
83.2
78.3
62.4
61.8
95.0
95.7
79.8
129.5
151.8
107.7
144.8
150.3
138.6
107.8
1.78
1.67
2.03
1.88
2.00
1.57
1.74
1.92
2.22
1.74
418
418
418
423
466
420
422
651 708
649 708
649 708
600 649
0.087
0.091
0.101
0.089
651 709
652 707
0.131
0.103
a
b
c
Evaluated by GPC eluted with THF, using polystyrene as a standard. Excited at the maximum excitation wavelength. Determined using free base
47
TPP in benzene (F
F
¼ 0.11) as a standard according to the report.
ꢁ
shoulder was also observed at 2q ¼ 7.3 . The diffuse peaks of the
resultant PAEKs with porphyrin pendants manifested the good
compatibility of porphyrins with the poly(arylene ether ketone)
s, and the agglomeration of porphyrins was precluded due to
covalent linkage. Moreover, it is favorable to fabricate optical

lms since the incorporation of porphyrins in the sidechains
retained the amorphous nature of the polymer.
Thermal stabilities and mechanical properties
The thermal properties of these polymers were evaluated by
DSC and TGA in a nitrogen atmosphere as shown in Table 2, it
can be seen that all polymers with porphyrin pendants
possessed higher glass transition temperatures (T ) than their
g
precursor polymers PAEK–COOH. Generally, the conversion
Fig. 1 IR spectra of (a) PAEK–COOH30%, (b) PAEK–COOH30%–TPP, from polar groups to nonpolar groups in polymers results in a
c) PAEK–COOH50%–TPP, (d) PAEK–COOH30%–ZnTPP, and (e)
(
decrease in T
other hand, the presence of bulky pendant substituents would
conne the segmental motion, leading to an increase of T . In
this work, the bulkiness of porphyrin pendants seemed to play a
more important role, and the T markedly increased as the
g
due to the reduced intermolecular force. On the
PAEK–COOH30%–PbTPP.
g
To further corroborate the presence and distribution of
metal elements in a polymer matrix, energy dispersive spec-
trometry (EDS) was employed as it provides direct information
regarding the contents of the target elements. The mass frac-
tions (wt%) of Zn and Pb on the selected area of polymer lm
surface were found to be 2.3% and 6.95%, from which the wt%
of porphyrin were calculated to be 22.1% and 21.1%. The EDS
mapping photographs of PAEK–COOH30%–ZnTPP and PAEK–
COOH30%–PbTPP lms were shown in Fig. S4† at magnica-
tions of 800k. The well-dispersed red/green dots represented the
position of Zn/Pb element, indicating that porphyrins were
densely and uniformly distributed in the matrix, the agglom-
eration or phase separation was not observed in the lm
samples, despite of the extremely high porphyrin content.
The wide-angle X-ray diffraction proles of the neat PAEK–
COOH30% lm (Fig. 3) exhibited a typical pattern of amor-
g
porphyrin pendants content increased (Fig. 4a) It should be
noted that metallization further elevated the T value of PAEK–
g
ꢁ
COOH30%–TPP by 10 C approximately, similar situation has
been reported in polyimides containing metalporphyrins,
where the incorporation of Zn enhanced the rigidity of the
planar macrocyclic structure, thus impeded the segmental
46
motion at the same porphyrin content. Thermal stability is
vital to optical limiting materials due to the thermal effect
induced by laser. As illustrated in Fig. 5a, the TGA curves of the
polymers exhibited two degradation step. The rst weight loss
ꢁ
at about 140 C was associated with the degradation of carboxyl
or ester group, the PAEKs with porphyrin pendants showed
slightly more initial weight loss when compared with their
corresponding starting polymers PAEK–COOH, indicating the
weaker thermal stability of ester linkage. Fig. 5b shows the TGA
curves of poly(arylene ether ketone)s with different porphyrin
pendants based on PAEK–COOH30%. For the metal porphyrin
counterparts, no signicant distinction was detected in the
weight loss curves but a higher char yield due to the presence of
central metal. By contrast, PAEK–COOH30%–TTP showed a
ꢁ
phous polymers centered at 2q ¼ 16.3 and a shoulder at 2q ¼
ꢁ
6
.4 , the solid state pure OH-TPP sample displayed multiple
sharp diffraction peaks, suggesting a crystalline structure. The
position of the maximum for PAEK–COOH30%–TPP and PAEK–
COOH50%–TPP shied to a higher position at 2q ¼ 17.8 , a
ꢁ
48316 | RSC Adv., 2015, 5, 48311–48322
This journal is © The Royal Society of Chemistry 2015

View Article Online
Paper
RSC Advances
1
Fig. 2 H NMR spectra of (a) PAEK–COOH30%, (b) PAEK–COOH30%–TPP, (c) PAEK–COOH30%–TTP, (d) PAEK–COOH30%–TNP.
possessed Young's modulus from 2.03 to 2.14 GPa, tensile
strength from 67.4 to 72.4 MPa, and elongation at break from
12.7% to 24.1%. When the carboxyl groups were converted into
porphyrin pendants via esterication, their Young's modulus
and tensile strength decreased to some extent, one of the major
reasons was that the polar PAEK–COOHs had a stronger inter-
molecular force. The elongation at break of the polymers
decreased as well aer esterication, on one hand, the incor-
poration of rigid macrocyclic group in the polymer matrix
47
usually bring about brittleness. On the other hand, as
mentioned above, DCC/DMAP catalyzed esterication was likely
to result in a slight crosslinking structure in the current system
that decreased the elongation at break. From these results, it
can be stated that, the prepared poly(arylene ether ketone)s with
Fig. 3 WAXD profiles of (a) pure OH-TPP, (b) PAEK–COOH30%, (c) porphyrin pendants retained good thermal stabilities and
PAEK–COOH30%–TPP, (d) PAEK–COOH50%–TPP.
mechanical properties of high performance polymers, and
showed the application prospect as a new species of NLO
material.
much poorer thermal stability, which might be attributed to the
structure of tritolylporphyrin. The 5% and 10% decomposition
temperatures of the polymers are presented in Table 2, the
Photophysical properties
conclusion can be drawn that the incorporation of porphyrins The ground state absorption of the highly delocalized aromatic
slightly decreased the thermal stabilities of the starting copol- porphyrins is mostly conned to a few narrow regions, an
ymers, this phenomenon was in agreement with other polymers intense Soret band ascribed to p / p* transitions and several Q
44
wearing ester pendant groups.
bands from 500 nm to 700 nm, which can be modulated by the
The mechanical properties of the PAEK lms cast from THF central metal, the type of axial ligands, or the nature of the
are summarized in Table 2. The PAEKs with carboxyl group peripheral substituents as previously reported.9
–12
UV-vis
This journal is © The Royal Society of Chemistry 2015
RSC Adv., 2015, 5, 48311–48322 | 48317

View Article Online
RSC Advances
Paper
Table 2 Thermal and mechanical of poly(arylene ether ketone)s films
a
ꢁ
ꢁ
ꢁ
Polymer
T
g
( C)
T
d5 ( C)
T
d10 ( C)
Tensile modulus (GPa)
Tensile strength (MPa)
Elongation at break (%)
PAEK–COOH10%
PAEK–COOH30%
PAEK–COOH50%
PAEK–COOH10%–TPP
PAEK–COOH30%–TPP
PAEK–COOH50%–TPP
PAEK–COOH30%–ZnTPP
PAEK–COOH30%–PbTPP
PAEK–COOH30%–TTP
PAEK–COOH30%–TNP
165.6
169.5
171.8
175.2
197.2
212.9
206.7
209.2
185.0
184.5
547.8
472.8
434.4
514.2
481.2
455.4
488.6
484.0
397.9
415.7
576.6
539.4
502.5
557.9
526.6
482.1
546.1
536.4
466.6
508.5
2.03
2.11
2.14
2.09
1.82
1.84
2.01
1.88
2.03
1.97
67.4
67.8
72.4
64.2
60.6
61.2
64.2
62.5
63.3
63.8
24.1
19.3
12.7
7.2
8.7
8.0
7.5
8.3
6.4
5.8
a
ꢁ
ꢀ1
From the second heating trace of DSC measurements conducted at a heating rate of 20 C min
.
spectroscopy of the prepared polymers in chloroform was and the enlarged conjugation. PAEK with ZnTPP exhibited
employed to monitor the variation of their linear optical prop- emission band at 600 and 649 nm, whereas the incorporation of
2
+
erties. As shown in Fig. 6, all polymer solutions showed Pb completely quenched the uorescence of porphyrin due to
absorption before 300 nm due to the electron transitions of the heavy-atom effect, thus increased the efficiency in inter-
aromatic ketones in the backbone, but no absorption was system crossing from S1 to T . The relative uorescence
1
detected in PAEK–COOH30% in the visible region. PAEKs with quantum yields were determined by previously reported
TPP, TTP, and TNP pendants exhibited intense Soret bands at method, where a freshly prepared free base tetraphenylpor-
48
0 2
418, 420, and 422 nm (attributed to S –S transition), respec- phyrin (TPP) in air-saturated benzene was used as a standard.
tively. In the case of PAEKs with Zn-TPP and Pb-TPP pendants, As shown in Table 1, all polymers were excited at their
the Soret band shied to 423 and 466 nm. It is known that the maximum excitation wavelength, the quantum yields of the
complexation with metal ions result in a distinct shi in Soret PAEKs were similar with that of TPP in benzene (0.11), this
band and a reduction of Q bands due to the conguration observation demonstrated that no substantial electron inter-
interaction, the Q bands absorption of our polymers is consis- action from porphyrins to the polymer backbone occurred via
tent with this nature (Fig. S5†). PAEK–COOH30%–TPP exhibited ester linkage. Among the poly(arylene ether ketone)s with
four weak Q bands at 515, 550, 590, and 648 nm, whereas for porphyrin pendants, PAEK–COOH30%–TTP exhibited the
PAEK–COOH30%–ZnTPP and PAEK–COOH30%–PbTPP the Q highest quantum yield of 0.13.
bands reduced to two with a red shi.
Fluorescence measurements were performed on the poly-
mers at a low concentration (maximum absorption less than
Nonlinear optical and optical limiting properties
0.05) to avoid self-quenching. The emission spectra are given in The nonlinear optical behavior of the polymers in THF were
Fig. 7, PAEKs with TPP, TTP, and TNP pendants showed a measured by using Z-scan technique under open-aperture and
similar emission band in the red region at 650–710 nm attrib- closed-aperture conguration with 4 ns pulsed laser irradiation
uted to the porphyrin moieties. TTP and TNP pendants showed at 532 nm with an intensity of 5.3 mJ. To investigate the effect of
a minor red shi due to the presence of electron-donating group the porphyrin pendants on the NLO properties, open Z-scan
Fig. 4 (a) DSC curves of (1) PAEK–COOH10%, (2) PAEK–COOH10%–TPP, (3) PAEK–COOH30%, (4) PAEK–COOH30%–TPP, (5) PAEK–
COOH50%, and (6) PAEK–COOH50%–TPP. (b) DSC curves of (1) PAEK–COOH30%–TPP, (2) PAEK–COOH30%–ZnTPP, (3) PAEK–COOH30%–
PbTPP, (4) PAEK–COOH30%–TTP, and (5) PAEK–COOH30%–TNP.
48318 | RSC Adv., 2015, 5, 48311–48322
This journal is © The Royal Society of Chemistry 2015

View Article Online
Paper
RSC Advances
Fig. 5 (a) TGA analysis of PAEKs with different contents of porphyrin pendants. (b) TGA analysis of PAEKs with various porphyrin pendants based
on PAEK–COOH30%.
THF solution of PAEK–COOH30%, which had a linear trans-
mittance of 91%.
Fig. 9 represented the open Z-scan curves of PAEKs with
various porphyrin pendants based on PAEK–COOH30%. To
evaluate their NLO response by comparison, all samples were
adjusted to have the same linear transmittance of 65%. It was
observed that PAEKs with TPP and TTP pendants showed
similar proles with the normalized nonlinear transmittance of
0
1
.69 at the focus, the b values were determined to be 7.61 ꢂ
ꢀ10 ꢀ10 ꢀ1
0
and 7.5 ꢂ 10
m W from theoretical tting. Whereas
for PAEK–COOH30%–TNP, the transmittance decreased to 0.61
ꢀ
9
ꢀ1
with b of 1.21 ꢂ 10
m W , indicating a stronger NLO
response due to an extended conjugated system at the same
level of incident energy. When the Zn and Pb atom were
inserted to PAEK–COOH30%–TPP, the nonlinear absorption
Fig. 6 UV-vis absorption spectra of (a) PAEK–COOH30%, (b) PAEK–
COOH30%–TPP, (c) PAEK–COOH30%–ZnTPP, (d) PAEK–
COOH30%–PbTPP, (e) PAEK–COOH30%–TTP, and (f) PAEK– coefficient b signicantly increased by one order of magnitude,
COOH30%–TNP.
and the transmittance decreased to 0.6 and 0.4. It is well known
that the electrical conguration of the central ions plays an
important role on ISC and relaxation time, involving spin–orbit
experiments of PAEKs with porphyrins of different contents, coupling through coulombic exchange terms. Zn and Pb have
peripheral substituents, and central metal in THF were per-
formed by comparison. As shown in Fig. 8, the normalized
transmittance curves showed a symmetrical peak with respect
to the focus, indicating that the attachment of porphyrin
moieties endowed PAEKs nonlinear absorption, as the samples
exhibited a decreased transmittance when they were brought
closer to focus. The linear transmittance of PAEK–COOH10%–
TPP, PAEK–COOH30%–TPP, and PAEK–COOH50%–TPP were
determined to be 83%, 65%, and 56% at the same concentra-
ꢀ1
tion of 0.25 mg mL , respectively. The NLO properties in the ns
region can be described using a ve-level model RSA process: A
molecule of ground state (S
) by a laser pulse, aer that several competing process occurs,
such as radiationless relaxation, uorescence, and intersystem
crossing (ISC) from S to triplet state (T ) with a time constant
sISC) of nanoseconds. The latter has a large excited state
absorption cross section (s ), thus gives a strong nonlinear
0
) is excited to the rst singlet state
(S
1
1
1
(
ex
9,10,49
absorption to the incident laser beam.
The RSA curve of
Fig. 7 Fluorescence emission spectra of (a) PAEK–COOH30%–TPP,
PAEK–COOH50%–TPP showed the deepest valley due to the (b) PAEK–COOH30%–ZnTPP, (c) PAEK–COOH30%–PbTPP, (d)
PAEK–COOH30%–TTP, and (e) PAEK–COOH30%–TNP. Inset:
photographs of polymer solution under a hand-held UV-lamp with
largest porphyrin amount at the expense of the lowest linear
transmittance. While there was no NLO signal observed in the
lmax ¼ 365 nm.
This journal is © The Royal Society of Chemistry 2015
RSC Adv., 2015, 5, 48311–48322 | 48319

View Article Online
RSC Advances
Paper
ꢀ
1
m W , the tting obtained from the data of PAEK–COOH30%–
PbTPP is not perfect, this may be induced by the change of
beam at high pulse energy. These results were two orders of
magnitude larger than those of our previous work, where the
NLO properties of PAEKs incorporating porphyrins in the
50
backbones were investigated by 21 ps pulsed laser system. The
much larger b values in the present work were primarily
attributed to the longer laser pulse relative to sISC that allowed
1 1
the transformation from S to T .
In addition, closed-aperture Z-scan measurements demon-
strated the nonlinear refraction response in THF of PAEKs with
porphyrin pendants, which was not observed in those of PAEKs
with metal porphyrin pendants (Fig. S6†). The curves (peak-
valley) indicated that the nonlinear refraction of PAEK–
COOH30%–TPP resulted from the thermally induced self-
Fig. 8 Normalized open-Z scan curves of PAEK–COOH30%, PAEK–
COOH10%–TPP, PAEK–COOH30%–TPP, and PAEK–COOH50%–TPP
ꢀ1
at a concentration of 0.25 mg mL at 532 nm. Solid lines represents defocusing effect, suggesting a negative nonlinear refraction
theoretical fits.
coefficient (Table 3).
The optical limiting performances of the polymer were
measured in THF with the same laser system, the normalized
transmittance or output uence was plotted as functions of
ꢀ2
input uence (J cm ). The OL behavior of PAEK–COOH10%–
TPP, PAEK–COOH30%–TPP, and PAEK–COOH50%–TPP were
shown in Fig. S7† at the same concentration. It can be observed
that at low incident energy, the output increased linearly with
the input uence obeying Beer's law, as the incident energy
increased, the output uence signicantly deviated from line-
arity. PAEK–COOH50%–TPP showed the best OL performance
due to the largest porphyrin amount per unit volume, which was
consistent with their open Z-scan curves. The curves of
normalized transmittance versus input uence for PAEKs
bearing various porphyrin pendants based on PAEK–COOH30%
were gathered in Fig. 10, all the samples were adjusted to have
the same linear transmittance at 532 nm in THF. The results are
in agreement with the nonlinear absorption derived from Z-
scan measurements, following a similar trend that PAEK–
COOH30%–PbTPP showed the best OL performance with the
limiting threshold (incident uence at which the transmittance
Fig. 9 Open-Z scan curves of PAEKs with various porphyrin pendants
based on PAEK–COOH30% at the linear transmittance of 65%. Solid
lines represents theoretical fits.
ꢀ2
closed shells, which result in high ISC rates, high yields and falls to 50% of the linear transmittance) of 0.3 J cm . Generally,
long lifetime of triplet excited states, thus giving rise to the the OL property can be evaluated by the ratio of excited state
9
–11
enhanced RSA.
largest NLO response of all the samples with b of 3.9 ꢂ 10
PAEK–COOH30%–PbTPP exhibited the absorption cross section (sex) to the ground state absorption
ꢀ
9
cross section (s
0
) sex/s
0
¼ ln Tsat/ln T
0
, Tsat is the saturated
Table 3 Nonlinear optical properties of poly(arylene ether ketone)s with porphyrin pendants
a
Nonlinear optical values
ꢀ1
ꢀ2
(3)
b
Polymer
Transmittance
b (m W
)
n
2
(m W)
|c | (esu)
sex/s
0
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
10
10
10
10
10
10
10
ꢀ17
ꢀ17
ꢀ17
ꢀ11
PAEK–COOH10%–TPP
PAEK–COOH30%–TPP
PAEK–COOH50%–TPP
PAEK–COOH30%–ZnTPP
PAEK–COOH30%–PbTPP
PAEK–COOH30%–TTP
PAEK–COOH30%–TNP
83%
65%
56%
65%
65%
65%
65%
1.45 ꢂ 10
7.61 ꢂ 10
10.9 ꢂ 10
12.3 ꢂ 10
39 ꢂ 10
ꢀ1.5 ꢂ 10
ꢀ4.5 ꢂ 10
ꢀ3.5 ꢂ 10
3.56 ꢂ 10
1.09 ꢂ 10
8.52 ꢂ 10
3.91 ꢂ 10
1.24 ꢂ 10
8.14 ꢂ 10
1.58 ꢂ 10
1.6
1.8
1.8
2.6
3.7
2.0
2.4
ꢀ10
ꢀ11
ꢀ11
ꢀ10
ꢀ11
ꢀ10
ꢀ17
ꢀ17
7.5 ꢂ 10
12.1 ꢂ 10
ꢀ3.5 ꢂ 10
ꢀ6.5 ꢂ 10
a
Measured by Z-scan technique with 4 ns Nd:YAG laser system at 10 Hz and 532 nm, the values were determined by tting the experimental data.
b
ꢀ2
calculated by ln Tsat/ln T
0
, where Tsat is replaced by the transmittance at 1.4 J cm
.
48320 | RSC Adv., 2015, 5, 48311–48322
This journal is © The Royal Society of Chemistry 2015

View Article Online
Paper
RSC Advances
ꢀ
2
before 50 mJ cm , indicating remarkable OL effect. It is worth
mentioning that the polymers showed improved OL perfor-
mance in lms than those in THF, the limiting threshold was
ꢀ
2
found to be 0.3 J cm for PAEK–COOH30%–PbTPP, and the
THF solutions of PAEK–COOH30%–TPP and PAEK–COOH30%–
ZnTPP were unable to attenuate the incident energy to a
threshold. Whereas for lm samples, their limiting threshold
ꢀ
2
were determined to be 0.29, 0.30, and 0.15 J cm for PAEK–
COOH30%–TPP, PAEK–COOH30%–ZnTPP, and PAEK–
COOH30%–PbTPP, respectively. Hence, according to the
results, the PAEKs with porphyrin pendants possessed good
performance as optical limiting materials in both solution and
in solid state.
Fig. 10 Optical limiting responses of PAEKs with various porphyrin
pendants based on PAEK–COOH30% in THF.
Conclusions
A series of novel poly(arylene ether ketone)s with porphyrin
pendants of different structure were synthesized via an esteri-

cation reaction using DCC and DMAP to activate the carboxyl
groups. The porphyrin pendant moieties endowed PAEKs with
strong uorescent intensity, excellent solubility (particularly in
CHCl ), much higher Tg values, and lower decomposition
3
temperatures compared with the starting copolymers. More
importantly, the combination of porphyrin chromophores with
poly(arylene ether ketone)s retained the excellent nonlinear
optical properties and the good lm formability of each
component, as demonstrated by Z-scan technique and optical
limiting measurements. Poly(arylene ether ketone) with PbTPP
pendants showed the largest nonlinear optical coefficient b of
ꢀ
2
9
ꢀ1
3
0
.9 ꢂ 10
m W
and the lowest limiting threshold of
ꢀ
.3 J cm in THF. In addition, it was found the polymers in
homogeneous thin lm state exhibited enhanced OL perfor-
mance, which provides a new facile synthetic approach for
designing high performance polymer based optical limiter.
Fig. 11 Photographs of (a) PAEK–COOH30%, (b) PAEK–COOH30%–
TPP, (c) PAEK–COOH30%–ZnTPP, and (d) PAEK–COOH30%–PbTPP
films prepared by spin-coating and their OL responses.
Acknowledgements
This research was nancially supported by the PhD Program
Foundation of the Ministry of Education of China (no.
transmittance for high degrees of excitation. Although the
saturated transmittance is unable to reach in our experiment
20120061110017) and Changchun Science and Technology
Development Plan Program of China (2013050). We also
acknowledge the support from Prof. Yinglin Song of Soochow
University for the Z-scan and optical limiting measurements.
51
setup, we can use the method in some reports, where the
ꢀ
2
transmittance at maximum input uence (1.4 J cm ) is
employed to calculate the lowest bound for sex/s , and the
0
values are 1.8, 2.0, 2.4, 2.6, and 3.7 for the THF solution of PAEK
with TPP, TTP, TNP, ZnTPP, and PbTPP pendants, respectively.
The application of porphyrins in a practical optical limiting
device would inevitably require the homogeneous incorporation
in the solid state. Based on this consideration, we prepared thin
Notes and references
1
2
L. W. Tutt and A. Kost, Nature, 1992, 356, 225–226.
D. M. Burland, R. D. Miller and C. Walsh, Chem. Rev., 1994,
94, 31–75.

lms of PAEK–COOH30%–TPP, PAEK–COOH30%–ZnTPP, and
3
G. I. Stegeman, D. J. Hagan and L. Torner, Opt. Quantum
Electron., 1996, 28, 1691–1740.
PAEK–COOH30%–PbTPP using conventional spin-coating on
quartz glass substrates (diameter: 37 mm, thickness: 2 mm) to
preliminarily evaluate their OL performance. Their linear
transmittance were measured to be 55%, 68%, and 73%,
respectively. From Fig. 11, it can be observed that the trans-
mittance of PAEKs with porphyrin pendants started to decrease
4
5
C. W. Spangler, J. Mater. Chem., 1999, 9, 2013–2020.
T. J. Mckay, J. Staromlynska, P. Wilson and J. Davy, J. Appl.
Phys., 1999, 85, 1337–1341.
6
G. J. Zhou and W. Y. Wong, Chem. Soc. Rev., 2011, 40, 2541–
2566.
This journal is © The Royal Society of Chemistry 2015
RSC Adv., 2015, 5, 48311–48322 | 48321

View Article Online
RSC Advances
Paper
7
8
L. W. Tutt and T. F. Boggess, Prog. Quantum Electron., 1993, 29 J. F. Ding, F. T. Liu and M. Li, J. Polym. Sci., Part A: Polym.
7, 299–338. Chem., 2002, 40, 4205–4216.
D. G. McLean, R. L. Sutherland, M. C. Brant, 30 B. J. Liu, W. Hu and G. P. Robertson, J. Mater. Chem., 2008,
1
D. M. Brandelick, P. A. Fleitz and T. Pottenger, Opt. Lett.,
993, 18, 858–860.
18, 4675–4682.
1
31 W. J. Cantwell and J. Morton, Composites, 1991, 22, 347–362.
9
M. O. Senge, M. Fazekas, E. G. A. Notaras, W. J. Blau, 32 K. Friedrich, R. Walter, H. Voss and J. Karger-Kocsis,
M. Zawadzka, O. B. Locos and E. M. N. Mhuircheartaigh,
Composites, 1986, 17, 205–216.
Adv. Mater., 2007, 19, 2737–2774.
0 M. Calvete, G. Y. Yang and M. Hanack, Synth. Met., 2004, 141,
33 B. J. Liu, G. P. Robertson, D. S. Kim, M. D. Guiver, W. Hu and
Z. H. Jiang, Macromolecules, 2007, 40, 1934–1944.
34 B. Bae, T. Yoda, K. Miyatake, H. Uchida and M. Watanabe,
Angew. Chem., Int. Ed., 2010, 122, 327–330.
35 S. Gu, R. Cai and Y. Yan, Chem. Commun., 2011, 47, 2856–
2858.
36 Z. Zhao, J. Wang, S. Li and S. Zhang, J. Power Sources, 2011,
196, 4445–4450.
37 D. Y. Chen and M. A. Hickner, Macromolecules, 2013, 46,
9270–9278.
1
1
1
1
1
1
1
1
231–243.
1 W. Blau, H. Byrne, W. M. Dennis and J. M. Kelly, Opt.
Commun., 1985, 56, 25–29.
2 A. K. Harry, H. L. Anderson, G. B. Ross, S. Clark and
K. J. McEwan, Adv. Mater., 2001, 13, 652–656.
3 J. C. Feng, Q. H. Zhang, W. Li, Y. Li, M. J. Yang and Y. Cao, J.
Appl. Polym. Sci., 2008, 109, 2283–2290.
4 K. T. Nielsen, H. Spanggaard and F. C. Krebs,
Macromolecules, 2005, 38, 1180–1189.
38 G. Maier, Prog. Polym. Sci., 2001, 26, 3–65.
5 L. S. Wan, J. Wu and Z. K. Xu, Macromol. Rapid Commun., 39 Z. Geng, M. X. Huo, J. X. Mu, S. L. Zhang, Y. N. Lu, J. S. Luan,
2
006, 27, 1533–1538.
6 Y. Y. Lv, J. Wu, L. S. Wan and J. K. Xu, J. Phys. Chem. C, 2008,
12, 10609–10615.
P. F. Huo, Y. L. Du and G. B. Wang, J. Mater. Chem. C, 2014, 2,
1094–1103.
40 R. Westlund, E. Malmstrom, C. Lopes, J. Ohgren, T. Rodgers,
Y. Saito, S. Kawata, E. Glimsdal and M. Lindgren, Adv. Funct.
Mater., 2008, 18, 1939–1948.
1
7 T. E. O. Screen, K. B. Lawton, G. S. Wilson, N. Dolney,
R. Ispasoiu, T. Goodson, S. J. Martin, D. D. C. Bradley and
H. L. Anderson, J. Mater. Chem., 2001, 11, 312–320.
41 C. W. Spangler, J. Mater. Chem., 1999, 9, 2013–2020.
18 X. B. Huang, Q. Q. Shi, W. Q. Chen, C. L. Zhu, W. Y. Zhou, 42 A. D. Alder, F. R. Longo, J. D. Finarelli, J. Goldmacher,
Z. Zhao, X. M. Duan and X. W. Zhang, Macromolecules,
010, 43, 9620–9636.
9 R. A. Schmitz, P. A. Liddell, G. Kodis, M. J. Kenney,
J. Assour and L. Korakoff, J. Org. Chem., 1967, 32, 476.
43 L. J. Twyman, A. Ellis and P. J. Gittins, Macromolecules, 2011,
44, 6365–6369.
2
1
B. J. Brennan, N. V. Oster, T. A. Moore and D. Gust, Phys. 44 E. M. Maya, I. Garcia-Yoldi, A. E. Lozano, J. G. de la Campa
Chem. Chem. Phys., 2014, 16, 17569–17579. and J. de Abajo, Macromolecules, 2011, 44, 2780–2790.
0 V. S. P. K. Neti, X. F. Wu, S. G. Deng and L. Echegoyen, Polym. 45 Y. L. Luo, Q. P. Ran, S. S. Wu and J. Shen, J. Appl. Polym. Sci.,
Chem., 2013, 4, 4566–4569. 2008, 109, 3286–3291.
1 L. J. Feng, Q. Chen, J. H. Zhu, D. P. Liu, Y. C. Zhao and 46 W. Anannarukan, S. Tantayanon, D. Zhang, E. A. Aleman,
2
2
2
B. H. Han, Polym. Chem., 2014, 5, 3081–3088.
D. A. Modarelli and F. W. Harris, Polymer, 2006, 47, 4936–
2 A. L. Wirotius, E. Ibraboure, L. Scarpantonio,
4945.
M. Schappacher, N. D. McClenaghan and A. Deffieux, 47 L. J. Gao, F. G. Du, M. Xiao, S. J. Wang and Y. Z. Meng, J. Appl.
Polym. Chem., 2013, 4, 1903–1912. Polym. Sci., 2008, 108, 3626–3631.
3 T. E. Attwood, P. C. Dawson, J. L. Freeman, L. R. J. Hoy, 48 D. J. Quimby and F. R. Longo, J. Am. Chem. Soc., 1975, 97,
J. B. Rose and P. A. Staniland, Polymer, 1981, 22, 1096–1103. 5111–5117.
4 P. M. Hergenrother, B. J. Jensen and S. J. Havens, Polymer, 49 Y. Chen, M. Hanack, Y. Araki and O. Ito, Chem. Soc. Rev.,
2
2
1988, 29, 358–369.
2005, 34, 517–529.
2
2
2
5 J. B. Rose, Polymer, 1974, 15, 456–465.
6 A. Jonas and R. Legras, Polymer, 1991, 32, 2691–2706.
7 M. G. Dhara and S. Banerjee, Prog. Polym. Sci., 2010, 35,
50 Y. L. Du, S. L. Zhang, X. Jiang, K. Zhu, Z. Geng, Y. Fang,
P. F. Huo, C. Liu, Y. L. Song and G. B. Wang, J. Polym. Sci.,
Part A: Polym. Chem., 2014, 52, 1282–1290.
1
022–1077.
51 X. Y. Su, S. Y. Guang, C. W. Li, H. Y. Xu, X. Y. Liu, X. Wang
and Y. L. Song, Macromolecules, 2010, 43, 2840–2845.
2
8 B. J. Liu, G. B. Wang, W. Hu, Y. H. Jin, C. H. Chen, Z. H. Jiang,
W. J. Zhang, Z. W. Wu and Y. Wei, J. Polym. Sci., Part A:
Polym. Chem., 2002, 40, 3392–3398.
48322 | RSC Adv., 2015, 5, 48311–48322
This journal is © The Royal Society of Chemistry 2015