Synthesis and property of polyoxazolidone having fluorene moiety by polyaddition of diisocyanate and diepoxide

Article abstract of DOI:10.1002/pola.27181

Polyoxazolidones having fluorenyl group were synthesized by polyaddition of 9,9-diglycidyl fluorene with various diisocyanates. The polymer from 9,9-diglycidyl fluorene and methylenediphenyl 4,4′-diisocyanate was afforded in high yield although polydispersity of the polymer was found relatively broad. The IR spectrum of the obtained polymer showed two absorption in carbonyl region. One of them was assigned to the expected oxazolidone, while the other at 1710 cm^-1 appeared due to a carbonyl group of the isocyanurate moieties produced by cyclotrimerization of isocyanate. It is assumed that the cyclotrimerization would cause the broad polydispersity caused by the branched structure formed by isocyanurate. The polymers obtained with three kinds of diisocyanates (methylenediphenyl 4,4'-diisocyanate, 1,6-hexamethylene diisocyanate, 1,4-phenylene diisocyanate) showed high thermal stability, as their T_d10 was depended on the structure of diisocyanate. All polymers had high transparency in a visible region.

Full text of DOI:10.1002/pola.27181

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Synthesis and Property of Polyoxazolidone Having Fluorene Moiety
by Polyaddition of Diisocyanate and Diepoxide
Motohisa Azechi, Takeshi Endo
Molecular Engineering Institute, Kinki University, Kayanomori, Iizuka, Fukuoka 820–8555, Japan
Correspondence to: T. Endo (E-mail: tendo@moleng.fuk.kindai.ac.jp)
Received 16 October 2013; accepted 11 March 2014; published online 00 Month 2014
DOI: 10.1002/pola.27181
ABSTRACT: Polyoxazolidones having fluorenyl group were syn-
thesized by polyaddition of 9,9-diglycidyl fluorene with various
diisocyanates. The polymer from 9,9-diglycidyl fluorene and
methylenediphenyl 4,40-diisocyanate was afforded in high yield
although polydispersity of the polymer was found relatively
broad. The IR spectrum of the obtained polymer showed two
absorption in carbonyl region. One of them was assigned to
the expected oxazolidone, while the other at 1710 cm21
appeared due to a carbonyl group of the isocyanurate moieties
produced by cyclotrimerization of isocyanate. It is assumed
that the cyclotrimerization would cause the broad polydisper-
sity caused by the branched structure formed by isocyanurate.
The polymers obtained with three kinds of diisocyanates
(methylenediphenyl 4,4’-diisocyanate, 1,6-hexamethylene diiso-
cyanate, 1,4-phenylene diisocyanate) showed high thermal sta-
bility, as their Td10 was depended on the structure of
diisocyanate. All polymers had high transparency in a visible
C
V
region.
2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A:
Polym. Chem. 2014, 00, 000–000
KEYWORDS: cyclopolymerization; fluorene; oxazolidone; polyad-
dition; thermal properties; transparency
bridge. The methylene bridge forces the two phenyl rings to
be planar, thereby providing high overlaps of p orbitals.
Incorporating the rigid and bulky fluorene moiety to poly-
mers leads to enhanced thermal properties, solubility, and
optical properties. We expect that thermal property and opti-
cal property are improved further by introducing fluorene
unit to poly(oxazolidone).
INTRODUCTION Cycloaddition of the epoxide with isocyanate
gives 3,5-disubstituted-oxazolidin-2-one, known as oxazoli-
done.1–7 Oxazolidones were widely used in medicine as
drugs and pharmaceutical preparations, intermediates in the
paint and varnish industry, and lubricants. On the other
hand, oxazolidone structure is well known that their high
thermal stability is generally superior to those of carbodii-
mide, urea, and urethane.8,9 Since 1960s, this reaction has
ever been utilized for the synthesis of thermally stable poly-
mers, poly(oxazolidone)s, derived from bifunctional epoxides
and diisocyanates.10–14 So far, it has been reported on the
synthesis and thermal property of poly(oxazolidone)s
obtained from the corresponding bifunctional epoxides and
diisocyanates as monomer. Above all, Whitmore’s group
reported the synthesis and thermal stability of poly(oxazoli-
done)s prepared with as various diglycidyl ethers derivatives
and diisocyanates.13 According to this report, molecular
weights of the poly(oxazolidone)s were 1ꢀ340–4750 and the
poly(oxazolidone)s were stable up to 260 C by thermogravi-
metric analysis (TGA). However, further improvement of pol-
y(oxazolidone) has not been studied in recent years. Thus,
we focus on fluorene structure giving high thermal stability
and optical property.
In this work, we carried out synthesis of poly(oxazolidone)s
prepared from 9,9-diglycidyl fluorene and three diisocyanates
[methylenediphenyl 4,4’-diisocyanate (MDI), hexamethylene dii-
socyanate (HMDI), 1,4-phenylene diisocyanate) (PDI); Scheme
1] and report the effects of reaction conditions (monomer con-
centration, catalysis amount, and temperature) on the polyaddi-
tion of 9,9-diglycidyl fluorene with diisocyanates. Further, we
examined their thermal and optical properties.
EXPERIMENTAL
Materials
Fluorene was purchased from Sigma-Aldrich (St. Louis) and
recrystallized from methanol before use. Allyl chloride was
purchased from Wako Pure Chemical Industry (Osaka, Japan).
Sodium methoxide was purchased from Kanto Kagaku (Tokyo,
Japan). m-Chloroperbenzoic acid (m-CPBA) was purchased
from Wako Pure Chemical Industry. p-Tolyl isocyanate, MDI,
and HMDI were purchased from Tokyo Chemical Industry
The fluorene group contains two benzene rings that are con-
nected via a carbon–carbon bond and an adjacent methylene
C
V
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tetramethylsilane as an internal standard. IR spectra were
recorded on a Thermo Scientific NICOLET iS10 FTIR spec-
trometer equipped with a SMART iTR ATR sampling acces-
sory. Number average molecular weight (Mn) and
polydispersity (Mw/Mn) were estimated from size exclusion
chromatography, performed on
a Tosoh chromatograph
model HLC-8220GPC equipped with Tosoh TSKgel Super AW
2500 columns (6.0 mmI.D. 3 15 cm), TSKgel Super AW
3000 columns (6.0 mmI.D. 3 15 cm), and TSKgel Super AW
4000 columns (6.0 mmI.D. 3 15 cm), using N,N-dimethylfor-
mamide (DMF) containing 10 mM lithium bꢀromide as an elu-
ent at the flow rate of 0.5 mL min21 at 40 C. The molecular
weight calibration curve was obtained with polystyrene
standards. Differential scanning calorimetry (DSC) was car-
ried out with DSC-6200 (Seiko Instrument) using aluminum
pan under a 20 mL min21 N2 flow at the heating rate of
10 ꢀC min21. TGA was performed with TG-DTA 6200 (Seiko
Instrument) using aluminum pan under a 50 mL min21 N2
SCHEME 1 Polyaddition of 9,9-diglycidyl fluorene and
isocyanates.
(Tokyo, Japan) and distilled under reduced pressure. PDI was
purchased from Tokyo Chemical Industry and sublimated
under reduced pressure. Lithium bromide was purchased
from Kanto Kagaku dried under reduced pressure before use.
N-Methylpyrrolidone (NMP) was distilled over calcium
hydride (CaH2) under reduced pressure. Other solvents were
used without further purification.
21
ꢀ
flow at a heating rate of 10 C min
.
Measurements
Monomer Synthesis
The synthetic route of the monomer is shown in Scheme 2.
Nuclear magnetic resonance (NMR) measurements were
recorded on JEOL JNM ECS 400 in CDCl3 and DMSO-d6 with
SCHEME 2 Synthesis of 9,9-diglycidyl fluorene.
SCHEME 3 Model reaction of 9,9-diglycidyl fluorene and p-tolyl isocyanate.
TABLE 1 Polyaddition of 2 and MDIa
Yieldb (%)
Mn
Mw/Mn
c
c
Run
Temperature (ꢀC)
Time (h)
NMP (mL)
LiBr (mol %)
1
160
160
160
160
160
160
160
160
100
120
140
180
2
2
2
2
2
2
2
2
2
2
2
2
1.0
1.5
2.0
4.0
8.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
20
20
20
20
20
2
86
85
88
92
52
51
64
82
70
84
85
81
5,100
4,200
3,600
3,000
1,800
2,400
2,400
2,600
NDd
12.4
4.51
2.72
2.19
1.63
2.42
2.50
2.02
NDd
8.52
4.32
2.00
2
3
4
5
6
7
5
8
10
10
10
10
10
9
10
11
12
4,100
3,900
2,700
a
c
Reaction conditions: 2 and MDI 5 2 mmol, reaction time 5 2 h.
Methanol-insoluble part.
Estimated by GPC analysis (eluent : DMF, polystyrene standards).
ND, not determined.
b
d
2
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Synthesis of 9,9-Diglycidyl fluorene (2)
A solution of m-CPBA (22.0 g, 89.3 mmol, 70% purity) in
dichloromethane (300 mL) was added dropwise a solution
of 1 (10.0 g, 40.6 mmol) in dichloromethane (100 mL) at
room temperature. The white suspension thus formed was
stirred at room temperature for 24 h and then quenched by
addition of a saturated solution of Na2SO3 in water. The
product was extracted with dichloromethane. The combined
extracts were washed successively with saturated NaHCO3
solution and brine and dried with anhydrous Na2SO4, and fil-
tered and concentrated under reduced pressure. The residue
was purified by column chromatography with dichlorome-
thane and then recrystallization with n-hexane twice and 2
was obtained as a white crystalline (yield: 7.6 g, 27.3 mmol,
67%).
FIGURE 1 FTIR spectra of poly(oxazolidone) obtained at 160 ꢀC
for 2 h.
1H NMR (CDCl3): d 5 7.77 (m, 2H), 7.39–7.61 (m, 6H), 7.06
(s, 8H), 3.82 (m, 2H), 3.12 (dd, 1H), 2.91 (dd, 1H), 2.87 (m,
1H), 2.55 (m, 1H), 2.56 (s, 6H), 13C NMR (CDCl3): d 5 154.3,
146.4, 140.4, 135.7, 133.7, 129.5, 129.0, 128.2, 123.6, 123.9,
120.9, 118.1, 70.3, 51.3, 50.9, 44.6, 20.8 ppm.
Synthesis of 9,9-Diallyl fluorene (1)
In a round-bottom flask, fluorene (20 g, 120mmol), sodium
methoxide (19.5 g, 360 mmol), and DMSO (213 mL) were
added and stirred at room temperature for 30 min under
nitrogen. Then, allyl chloride (27.6 mL, 360 mmol) was added
dropwise to the mixture at room temperature. The reaction
mixture was stirred for 3 h, quenched with distilled water,
and extracted with n-hexane three times. The combined
organic layer was washed with distilled water and brine,
dried over anhydrous MgSO4, and filtered and concentrated
under reduced pressure. The residue was purified by column
chromatography (silica gel, eluted with n-hexane) and 1 was
obtained as colorless oil (yield: 26.5 g, 108.8 mmol, 90%).
Synthesis of Model Compound (3)
The synthetic route of the model compound is shown in
Scheme 3. 2 (279 mg, 1.0 mmol), p-tolyl isocyanate (266 mg,
2.0 mmol), and LiBr (18 mg, 0.2 mmol) were placed in a
Schlenk reaction tube. The flask was evacuated and then
filled with nitrogen gas. NMP (0.5 mL) was added to flask
under nitrogen atmosphere. The mixture was stirred at 160
ꢀC for 2 h. Then, the reaction mixture was cooled to room
temperature, diluted with ethyl acetate, and washed with
distilled water four times. The organic layer was dried over
anhydrous NaSO4, filtered, and concentrated under reduced
pressure. The resulting residue was recrystallization with
diethyl ether to isolate 3 as a slightly yellow solid (yield:
330 mg, 0.6 mmol, 60%).
1H NMR (CDCl3): d 5 7.68 (m, 2H), 7.39 (m, 2H), 7.29 (m,
4H), 5.24 (m, 2H), 4.77 (m, 4H), 2.69 (d, 4H), 13C NMR
(CDCl3): d 5 149.4, 140.9, 133.9, 127.3, 127.1, 123.8, 119.9,
117.7, 54.3, 43.7 ppm.
SCHEME 4 Plausible mechanism of isocyanurate formation in polymerization.
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RESULTS AND DISCUSSION
Synthesis of Oxazolidone Compound from 2 and p-Tolyl
isocyanate as a Model Reaction
Before studying polyaddition of 2 and diisocyanate, we inves-
tigated the oxazolidone ring formation of 2 and p-tolylisocya-
nate as
a
model reaction (Scheme 3). When
2
and
ꢀ
p-tolylisocyanate was stirred with 20 mol % of LiBr at 160 C
for 2 h in NMP, the oxazolidone ring formation was confirmed
1
from H NMR spectrum of the crude compound. This reaction
almost proceeded without side reaction and the correspond-
ing oxazolidone compound was obtained in 95% NMR yield
by 1H NMR measurement. The oxazolidone compound was
isolated by recrystallization with diethyl ether in 60% yield.
These results suggest that the oxazolidone ring formation of 2
and p-tolylisocyanate which is monofunctional isocyanate
might smoothly proceed without side reaction.
Polyaddition of 2 and Diisocyanate
Polyaddition of 2 and MDI carried out with 20 mol % of
LiBr as a catalyst at 120 ꢀC for 2 h in NMP on the basis of
a model reaction of 2 and p-tolyl isocyanate. As a result, a
white solid was obtained in 86% yield as a methanol insol-
uble part (Table 1, run 1). The polymer was soluble in
many typical organic solvents such as chloroform, dichloro-
methane, NMP, and cyclohexanone. The number-averaged
molecular weight (Mn) and the polydispersity (Mw/Mn) of
the obtained polymer were 5100 and 12.4, respectively.
Mw/Mn was broader than we expected. FTIR analysis of the
polymer showed two strong absorptions at 1710 and 1750
cm21 (Fig. 1). The latter absorption was attributed with
carbonyl group of the desired oxazolidone structure.
According to previous work on synthesis of poly(oxazoli-
done),10–14 it was reported that isocyanurate was generated
by cyclotrimerization of isocyanate as a side reaction. In the
current system, the corresponding side reaction was pre-
sumed to form isocyanurate, which caused the presence of
the other absorption at 1710 cm21. In this condition, as
shown in Scheme 4(a), isocyanurate having three isocyanate
groups might form by cyclotrimerization of diisocyanate. In
addition, as shown in Scheme 4(b,c), the isocyanate group
of isocyanurate reacted with epoxide or another isocyanate
to form oxazolidone or isocyanurate, respectively. It could
explain the broader dispersity may be due to a branched
structure of isocyanurate formed in main chain.
FIGURE 2 FTIR spectra of poly(oxazolidone) obtained at (a) 100
ꢀC, (b) 120 ꢀC, (c) 160 ꢀC, and (d) 180 ꢀC.
1H NMR (CDCl3): d 5 7.76 (m, 2H), 7.36–7.62 (m, 6H), 7.05
(s, 8H), 3.81 (m, 2H), 3.11 (dd, 2H), 2.88 (m, 4H), 2.54 (m,
2H), 2.26 (s, 6H).
Polyaddition
A typical polyaddition procedure is described below. 2 (556 mg,
2.0 mmol), methylenediphenyl 4,40-diisocyanate (500 mg,
2.0 mmol), and LiBr (18 mg, 0.2 mmol) were placed in a Schlenk
reaction tube. The flask was evacuated and then filled with nitro-
gen gas. NMP (2.0 mL) was added to flask under nitrogen atmos-
phere. The mixture was stirred at 160 ꢀC for 2 h. Then, the
reaction mixture was cooled to room temperature and poured
into 200 mL of methanol. The resulting precipitate was collected
by centrifugation, and purified by reprecipitation from NMP–
methanol systems two times. The obtained polymer was dried at
ꢀ
100 C in vacuo to afford 82% yield. The Mn and Mw/Mn were
2600 g mol21 and 2.02, respectively.
1H NMR (CDCl3): d 5 7.83 (br, 2H), 7.65 (br, 2H), 7.16–7.50
(br, 6H), 6.92–7.15 (br, 6H), 3.88–3.60 (br, 4H), 3.29–3.03(br,
2H), 2.77–2.62 (m, 4H), 2.60–2.35 (m, 2H).
To control the formation of isocyanurate, we examined the
polyaddition with various conditions such as concentration,
TABLE 2 Polyaddition of 2 and Various Diisocyanatesa
Yieldb (%)
Mn
Mw/Mn
c
c
Run
Diisocyanate
Temperature (ꢀC)
NMP (mL)
LiBr (mol %)
1
2
3
PDI
160
160
200
2.0
2.0
2.0
10
10
10
59
81
61
1,700
NDd
1.91
NDd
4.26
HMDI
HMDI
2,400
a
c
Reaction conditions: reaction time 5 2 h.
Methanol-insoluble part.
Estimated by GPC analysis (eluent : DMF, polystyrene standards).
ND, not determined.
b
d
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insoluble in many typical organic solvents such as chloro-
form, tetrahydrofuran, and DMSO. On the other hand, the
polymers prepared at 120–180 ꢀC were 81–85% yield,
Mn 5 2700–4100, and Mw/Mn 5 2.00–8.52. Polydispersities
of the polymers obtained at 120 and 140 ꢀC were much
broader, whereas those of the polymers obtained 160 and
ꢀ
180 C were a narrow dispersity. Figure 2ꢀshows FTIR spec-
tra of the polymers obtained at 120–180 C. In the IR spec-
trum of the polymers obtained 100 ꢀC, the peak at 1710
cm21
, assignable to isocyanurate moiety, was strongly
appeared [Fig. 2(a)]. Increasing the reaction temperature,
the absorption of isocyanurate fꢀor oxazolidone is reduced
and hardly observed at 160–180 C. Therefore, it was possi-
ble to prevent the formation of isocyanurate by the polyad-
FIGURE 3 TGA curves of poly(oxazolidone)s obtained with
MDI (open circle), HMDI (open triangle), and PDI (open square)
and networked polymer obtained with MDI (filled circle).
ꢀ
dition at high reaction temperature (>160 C).
The polyadditions with HMDI and PDI carried out as well as
the polyaddition with MDI. The conditions and results were
summarized in Table 2. The polymer obtained with PDI was
59% yield, Mn 5 1700, and Mw/Mn 5 1.91. On the other
hand, in the polyaddition with HMDI, the polymerization
solution was gelation and the insoluble polymer was formed.
As a result of polyaddition carried out by raising to 200 ꢀC,
the soluble polymer was obtained with 61% yield,
Mn 5 2400, Mw/Mn 5 4.26. This phenomenon was probably
due to the reactivity of aliphatic isocyanate. It had been
known that the reactivity of aliphatic isocyanate was lower
than that of aromatic isocyanate. When using HMDI, isocya-
nurate structure might form preferentially because 160 ꢀC
was too low in the formation of oxazolidone.
catalyst amount, and temperature. The conditions and results
are summarized in Table 1. As a result, the polymers were
obtained in 52–92% yield. The Mn’s and Mw/Mn’s of the
obtained polymers were 1800–4200 and 1.63–4.51, respec-
tively (Table 1, runs 2–5). Mw/Mn was a narrow with
decreasing concentration. As a result of FTIR spectra of these
polymers, the polymers obtained in 2.0–8.0 mL of NMP
showed weaker the absorptions of isocyanurate as compared
with the polymers obtained in 1.0 or 1.5 mL of NMP. It
might be necessary to polymerize in suitable concentration
to control the formation of isocyanurate.
We examined the amount of LiBr on the polyaddition behav-
ior (Table 1, runs 6–8). The polymers were obtained in 51–
82% yield. The Mn’s and Mw/Mn’s of the obtained polymers
were 2400–2600 and 2.02–2.50, respectively. As a result of
FTIR analysis of the polymer, there was a tendency that the
absorptions of the isocyanurate weaken as the amount of
LiBr increases. In particular, it was hardly observed in the
polymer obtained with 10 mol % of LiBr. However, absorp-
tion of isocyanurate appeared in the case of the polyaddition
with 20 mol % of LiBr. Thus, using 10 mol % of LiBr, it was
possible to prevent the formation of isocyanurate.
Thermal and Optical Properties of Polyoxazolidones
The heat resistance of these oxazolidone polymers was eval-
uated by TG/DTA. Figure 3 shows typical TGA curves for the
polymers obtained from 2 with various isocyanates. From
TG/DTA curves, the corresponding Td5 and Td10 (5 and 10%
weight loss temperature, respectively) and the char yield at
500 ꢀC were determined and listed in Table 3. It is that, in
all the cases, the resulting polymers exhibited high thermal
stability. In particular, utilization of diisocyanate having aro-
matic group resulted in the higher thermal stability of the
corresponding polymers than the polymer obtained with dii-
socyanate having only aliphatic group. The glass transition
temperature (Tg) of the polymers was examined by DSC
analysis. While Tg of the soluble polymer prepared with 2
The polyadditions carried out in range from 100 to 180 ꢀC
(Table 1, runs 9–12). In the case of polyaddition at 100 ꢀC,
the mixture lost its fluidity after 2 h and obtained in 70%
yield as a methanol insoluble part. The polymer was
TABLE 3 Thermal Properties of Polymers Obtained from 2 and Various Diisocyanatesa
Run
Diisocyanate
Td5 (ꢀC)
Td10 (ꢀC)
Charc Yield (%)
a
a
b
Tg (ꢀC)
1d
2e
3g
4
MDI
MDI
HMDI
PDI
333
343
300
295
360
363
322
331
198
NDf
NDf
NDf
29
57
15
36
a
e
f
Determined by TGA under N2.
Table 1, run 9.
b
c
Determined by DSC under N2.
Char yield at 500 ꢀC under N2.
Glass transition temperature was not detected (<250 ꢀC).
g
Table 2, run 3.
d
Table 1, run 8.
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isocyanurate formed preferentially at 100 ꢀC, oxazolidone
formed preferentially at 160 ꢀC. In the thermal stability of
the obtained polymers, Td5 and Td10 were 300–361 and
322–378 ꢀC, respectively. The polymers possessed relatively
high thermal stability. Tg of the polymer prepared with 2
and MDI was higher than Tg of the polymer prepared with
bisphenol A diglycidyl ether and MDI. The introduction of
the fluorene skeleton is found to contribute to the thermal
stability of poly(oxazolidone). All polymers had good trans-
parency in a visible region. The transmittances were higher
than 80% at 450 nm.
FIGURE 4 Transmittance of poly(oxazolidone) obtained with
REFERENCES AND NOTES
MDI (solid line), HMDI (dotted line), and PDI (dashed line).
1 G. P. Speranza, W. J. Peppel, J. Org. Chem. 1958, 23, 1922–
1924.
and MDI was 198 ꢀC, Tg of the networked polymer was not
observed in range from 50 to 250 ꢀC. Previously, we
reported on the networked polymer consist of isocyanurate
skeleton.15–17 In previous report, Tg of the networked poly-
2 J. E. Herweh, J. Org. Chem. 1968, 33, 4029–4033.
ꢀ
3 M. Zilic, A. Sendijarevic´, V. Sendijarevic´, J. Polym. Sci. Part
A: Polym. Chem. 1989, 27, 1843–1851.
4 J. E. Herweh, W. J. Kauffman, Tetrahedron Lett. 1971, 12,
809–812.
ꢀ
mers was not observed in range from 50 to 300 C similarly
to the polymer obtained in this work. Therefore, isocyanu-
rate formed in polymer is found to affect to Tg of poly(oxazo-
lidone). Tg of the polymer prepared with 2 and MDI were
compared with Tg of the polymer prepared with diglycidyl
ether of bisphenol A and MDI.13 While Tg of the latter was
134 C, Tg of the former was 198 C. Thus, the introduction
of the fluorene skeleton is found to contribute to the thermal
stability of poly(oxazolidone).
5 A. Sendijarevic´, V. Sendijarevic´, J. Polym. Sci. Part A: Polym.
Chem. 1987, 25, 151–170.
ꢀ
6 Sehovic´, H.; A. Sendijarevic´, V. Sendijarevic´, J. Polym. Sci.
Part A: Polym. Chem. 1987, 25, 2729–2736.
7 S. H. Eldin, A. Renner, J. Appl. Polym. Sci. 1990, 41, 1505–
1516.
ꢀ
ꢀ
8 P. I. Kordomenos, J. E. Kresta, Macromolecules 1981, 14,
1434–1437.
9 P. I. Kordomenos, J. E. Kresta, K. C. Frisch, Macromolecules
1987, 20, 2077–2083.
Figure 4 illustrated the UV–vis spectra of the prepared sample
films in the wavelength region ranging from 200 to 800 nm.
The polymers were dissolved in NMP to prepare 10 wt % sol-
utions. The solution was filtered through membrane filter and
casted on a glass plate. The plate was dried in a drying oven
at 100 ꢀC for 12 h and further dried at 120 ꢀC for 12 h in
vacuo. All polymers had good transparency in a visible region.
The transmittances were higher than 80% at 450 nm.
10 S. R. Sandler, F. Berg, G. Kitazawa, J. Appl. Polym. Sci.
1965, 9, 1994–1996.
11 Y. Iwakura, S. Izawa, F. Hayano, J. Polym. Sci. Part A-1:
Polym. Chem. 1966, 4, 751–760.
12 R. R. Dileone, J. Polym. Sci. Part A-1: Polym. Chem. 1970, 8,
609–615.
13 J. E. Herweh, W. Y. Whitmore, J. Polym. Sci. Part A-1:
Polym. Chem. 1970, 8, 2759–2773.
14 N. Kinjo, S. Numata, T. Koyama, T. Narahara, J. Appl.
Polym. Sci. 1983, 28, 1729–1741.
SUMMARY
15 M. Moritsugu, A. Sudo, T. Endo, J. Polym. Sci. Part A:
Polym. Chem. 2011, 49, 5186–5191.
Poly(oxazolidone)s containing fluorene moiety were synthe-
sized by polyaddition of 9,9-diglycidyl fluorene and various
diisocyanates under various conditions. As a result of the
polyaddition, it was found that isocyanurate formed by
cyclotrimerization of isocyanate group. In particular, while
16 M. Moritsugu, A. Sudo, T. Endo, J. Polym. Sci. Part A:
Polym. Chem. 2012, 50, 4365–4367.
17 M. Moritsugu, A. Sudo, T. Endo, J. Polym. Sci. Part A:
Polym. Chem. 2013, 51, 2631–2637.
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JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2014, 00, 000–000