K. Saito et al. / Reactive & Functional Polymers 73 (2013) 756–763
757
acetone (200 mL). Distilled water (200 mL) was then added to
2. Experimental
the solution, and the mixture was cooled to 0 °C. Into the solution
was added dropwise
a mixture of 28% aqueous ammonia
2.1. Materials
(473.0 mL, 776.0 mmol). The solution was warmed to 25 °C, and
stirring was maintained for an additional 12 h. After confirming
that the pH was approximately 8, the reaction solution was poured
into water. The white precipitate was collected, washed with THF,
and dried at 60 °C under reduced pressure for 12 h. Yield: 9.6 g
Dioxane and N-methylpyrrolidone (NMP) were dried over cal-
cium hydride (CaH2) and distilled under reduced pressure. Tetra-
hydrofuran (THF) was distilled from sodium-naphthalene under
nitrogen. Cesium fluoride (CsF) and lithium chloride (LiCl) were
dried at 180 °C for 12 h under reduced pressure before use. The
(34%). Mp 262 °C (DTA). FT-IR (KBr)
m 3340, 3176, 3110 (NAH
stretching), 1481 (C@N stretching), 797 (CACl) cmꢁ1 1H-NMR
.
compounds
4,40-oxydianiline
(ODA),
m-phenylenediamine
(DMSO-d6) d 7.12–7.20 (NH2) ppm. 13C-NMR (DMSO- d6) d 167.2,
(mPDA), and p-phenylenediamine (pPDA) were used after sublima-
tion, while o-tolidine (oTD) and 4,40-(9-fluorenylidene)dianiline
(BAFL) were purified via recrystallization from THF/hexane and
ethanol, respectively. The intermediate 2,4-diamino-6-chloro-
1,3,5-triazine (DACT) was prepared using the modified method re-
ported in the literature [21]. Other reagents and solvents were
used as received.
168.8 ppm.
2.5. Synthesis of 2,4-diamino-6-(N,N-dibutylamino)-1,3,5-triazine
(DABT)
In a three-necked flask equipped with a reflux condenser and a
magnetic stirrer, DACT (5.98 g, 41.0 mmol) was suspended in
400 mL of N,N-dimethylformamide (DMF). Next N,N-dibutylamine
(5.32 g, 41.0 mol) and potassium carbonate (5.69 g, 41.0 mol) were
added to the mixture in one portion, and the solution was stirred at
130 °C for 24 h under nitrogen. The resulting heterogeneous mix-
ture was poured into water, and the precipitate was collected by
filtration, dissolved in THF, and dried over MgSO4. Any inorganic
materials were then removed by filtration, and the filtrate was con-
centrated under reduced pressure to give a white solid, which was
purified by recrystallization from THF with hexane and dried at
60 °C under reduced pressure for 12 h to give white plate crystals.
2.2. Measurements
Fourier transform infrared (FT-IR) spectra were measured with
a Jasco IR-5500 (Jasco Co., Ltd.) using transmittance absorption
spectroscopy (KBr tablet method). Nuclear magnetic resonance
(NMR) analysis was performed on a Bruker AC-400P spectrometer
at 400 MHz for 1H and 100 MHz for 13C measurements. Deuterated
dimethylsulfoxide (DMSO-d6) was used as the solvent. Number
and weight average molecular weights (Mn and Mw) were mea-
sured via gel permeation chromatography (GPC) on a Tosoh HLC-
8120 GPC equipped with a consecutive polystyrene gel column
(TSK-GEL GMHHR-M and GMHHR-N) at 40 °C. NMP containing
0.01 mol/L lithium bromide was used as the eluent at a flow rate
of 1.0 mL/min. The column was calibrated using standard polysty-
rene samples. Thermal analyses were performed on a Seiko ther-
mal analyzer at heating rates of 10 °C/min for thermogravimetric
analysis (TGA; TG/DTA 7300) under air or nitrogen, and 20 °C/
min for differential scanning calorimetry (DSC; X-DSC 7000).
Yield 5.3 g (54%). FT-IR (KBr)
m
3323, 3157, 1680 (ANH2), 2959
(CAH stretching), 1433 (C@N of triazine) cmꢁ1
,
1H-NMR (DMSO-
d6) d 0.89 (t, 6H, ACH2CH3), 1.20–1.29 (m, 4H, ACH2CH3), 1.43–
1.51 (m, 4H, ACH2CH2CH3), 3.40 (t, 4H, ANCH2A), 6.03 (s, 4H,
ANH2) ppm. 13C-NMR (DMSO-d6) d 13.9, 19.7, 29.9, 45.2, 165.4,
167.0 ppm. Elemental Anal. Calcd for (C11H22N6): C:55.43 H:9.30
N:35.26%. Found: C:55.53 H:9.22 N:35.21%.
2.6. Synthesis of BDCT–DABT condensation product (BDCT–DABT)
2.3. Synthesis of 2-(N,N-dibutylamino)-4,6-dichloro-1,3,5-triazine
(BDCT)
In a two-necked flask equipped with a three-way stopcock and
a magnetic stirrer, DABT (0.238 g, 1.00 mmol), NMP (2 mL), and CsF
(0.152 g, 1.00 mmol) were placed under nitrogen. BDCT (0.277 g,
1.00 mmol) was slowly added using a syringe at 20 °C, and the
resultant solution was stirred at 120 °C for 12 h. The solution
was then cooled to room temperature and poured into water con-
taining NH3 aq. Next, the precipitate was dissolved in THF, dried
over MgSO4, and filtered. The solution was then evaporated in va-
cuo to give a white solid. Finally, the product was recrystallized
from hexane and dried at 60 °C for 12 h. The yield was 0.12 g
(36%). 1H-NMR (DMSO-d6) d 0.84–0.92 (m, 12H, ACH3), 1.21–1.28
(m, 8H, ACH2CH2CH3), 1.49–1.51 (m, 8H, ACH2CH2CH2A),
3.45–3.56 (t, 8H, ANACH2), 6.49 (s, 2H, NH2), 9.66 (1H, NH) ppm.
13C-NMR (DMSO-d6) d 13.7, 13.7, 13.8, 13.9, 19.4, 19.5, 19.6,
29.1.29.3, 29.5, 29.7, 45.2, 45.5, 45.9, 46.3, 163.5, 163.9, 164.4,
165.3, 167.2, 168.5 ppm.
In a three-necked flask equipped with a dropping funnel and a
magnetic stirrer, cyanuric chloride (CyC) (19.50 g, 98.00 mmol)
was dissolved in THF (100 mL) and then cooled to ꢁ10 °C. To this
solution was added dropwise N,N-dibutylamine (12.67 g,
98.00 mmol) and THF (70 mL). After stirring for 2 h, a solution of
Na2CO3 (5.61 g, 53.0 mol) in distilled water (60 mL) was added
dropwise at this temperature. After stirring for another 2 h, the
reaction solution was transferred to a separatory funnel and then
washed three times with saturated brine. The organic layer was
dried over MgSO4 and filtered. The filtrate was concentrated under
reduced pressure to give a viscous, colorless liquid mixed with
unreacted CyC as white solids, which was removed by filtration.
The separated liquid was purified by vacuum distillation
(b.p. = 107–108 °C/0.07 Torr). Yield 16.3 g (65.0%). FT-IR (KBr)
2953, 2933, 2873 (CAH stretching), 1439 (C@N stretching), 846
(CACl) cmꢁ1 1H-NMR (DMSO-d6) d 0.91 (t, 6H, ACH3), 1.26–1.32
m
2.7. Synthesis of PG of BDCT with various aromatic diamines
.
(m, 4H, ACH2CH2CH3), 1.52–1.56 (m, 4H, ACH2CH2CH2CH3), 3.52
(t, 4H, ANACH2) ppm. 13C-NMR (DMSO-d6) d 13.6, 19.3, 28.7,
47.1, 163.7, 168.7. Elemental Anal. Calcd for (C11H18Cl2N4):
C:47.66 H:6.55 N:20.21%. Found: C:47.78 H:6.39 N:20.29%.
Typical procedure: All glass vessels were heated in vacuo before
use, and filled with and handled in a stream of dry nitrogen. In a
two-necked flask equipped with a three-way stopcock, a reflux
condenser, and a magnetic stirrer, ODA (0.200 g, 1.00 mmol) was
dissolved in dry NMP (2 mL) at room temperature. To this solution,
BDCT (0.277 g, 1.00 mmol) and CsF (0.334 g, 2.20 mmol) were
added in that order. The mixture was stirred for 10 min, and then
the polymerization was performed at 150 °C for 6 h. Next, the poly-
merization solution was cooled to room temperature, and poured
2.4. Synthesis of DACT
In a three-necked flask equipped with a dropping funnel and a
magnetic stirrer, CyC (35.8 g, 194.0 mmol) was dissolved in