Novel Polyamides Based on 2-Trifluoromethyl-4,4 -diaminodiphenylether
J. Chin. Chem. Soc., Vol. 49, No. 5, 2002 933
purified by distillation und e r reduced pressure over calcium
hydride and stored over 4Å molecular sieves. Commercially
available anhydrous calcium chloride (CaCl2) was dried un-
der reduced pressure at 150 C for 6 h prior to use.
(KBr): 3421, 3399 (N H stretch), 1263, 1228, 1155, 1103
1
cm-1 (C O and C F stretch). H NMR (400 MHz, DMSO-
d6): = 6.919, 6.912 (1H, Hc), 6.764-6.793 (1H, He), 6.663-
6.711 (3H, Hb,d), 6.557-6.596 (2H, Ha), 5.242 (2H, N HB),
4.859 (2H, N HA). 13C NMR (100 MHz, DMSO-d6):
=
Synthesis of Monomer
148.02 (C4), 145.53 (C5), 144.60 (C1), 144.24 (C8), 123.81
(C11, quartet, 1JC-F = 271 Hz), 120.69 (C10), 119.95 (C6, quar-
2-Trifluoromethyl-4,4 -dinitrodiphenylether (1)
2
tet, JC-F = 30 Hz), 119.09 (C3), 118.69 (C9), 114.89 (C2),
4-Nitrophenol (20.87 g, 0.15 mol) and 2-chloro-5-
nitrobenzotrifluoride (33.83 g, 0.15 mol) were first dissolved
in 80 mL of DMAc in a 300-mL flask with stirring. After the
mixture was completely dissolved, potassium carbonate (21
g, 0.15 mol) was added to it in one portion. After 30 min of
stirring at room temperature, the mixture was heated at 100
C for 12 h. The obtained mixture was poured into 440 mL of
methanol/water (volume ratio 10/1) to give a solid, which
was collected, washed thoroughly with methanol and hot wa-
ter, and dried under vacuum at 60 C (53.61 g, 98%). The
crude product was recrystallized from DMF/methanol to give
fine, pale-cream crystals (44.49 g, 83%).
110.82 (C7, quartet, 3JC-F = 5 Hz). Anal. Calcd for C13H11F3N2O:
C, 58.21; H, 4.13; N, 10.44. Found: C, 58.25; H, 3.79; N,
10.70.
11
F3C
a b
32
c
76
A
H2N
B
NH2
1
54
8
O
10 9
e
d
Synthesis of Polymers
A typical example of polycondensation is described as
follows. A mixture of 0.536 g (2 mmol) of diamine 2, 0.612 g
(2 mmol) of 3c, 0.12 g of CaCl2, 1.0 mL of Py, 1.2 mL of TPP
and 2.0 mL of NMP was heated while being stirred at 100 C
for 3 h. At the end of the reaction, the obtained polymer sol u -
tion was trickled into 400 mL of stirred methanol. The stringy
polymer was washed thoroughly with hot water and metha -
nol, collected by filtration and dried at 100 C under reduced
pressure. The product obtained was 1.06 g. The inherent vis-
cosity of the polymer 4c was 1.12 dL/g, measured with a
polymer concentration of 0.5 g/dL in DMAc at 30 C. Other
polymers were synthesized in a similar manner.
Dinitro compound 1: mp 82-83 C by differential scan-
ning calorimetry (DSC) at a scan rate of 10 C/min. IR (KBr):
1533, 1336 ( NO2 stretch), 1290, 1257, 1199, 1145, 1120
cm-1 (C F and C O stretch). 1H NMR (400 MHz, DMSO-d6):
= 8.545-8.576 (2H, Hc,d), 8.344-8.388 (2H, Ha), 7.437-
7.474 (3H, Hb,e). 13C NMR (100 MHz, DMSO-d6): = 159.84
(C4), 158.00 (C5), 144.46 (C1), 143.30 (C8), 130.27 (C9),
126.50 (C2), 123.57 (C7, quartet, 3JC-F = 5 Hz), 122.13 (C11,
1
quartet, JC-F = 272 Hz), 121.10 (C10), 120.82 (C6, quartet,
2JC-F = 32 Hz), 120.11 (C3). Anal. Calcd for C13H7F3N2O5: C,
47.57; H, 2.15; N, 8.54. Found: C, 47.54; H, 1.94; N, 8.98.
Measurements
11
a b
32
c
Elemental analyses were run in a Perkin-Elmer Model
2400 C,H,N analyzer. IR spectra were recorded on a Horiba
F3C
76
1
54
8
O2N
O
NO2
1
Fourier-Transform Infrared Spectrometer FTIR-720. H and
10 9
13C NMR spectra were determined on a Jeol EX-400 FT-
NMR spectrometer. Inherent viscosities of all polymers were
determined at 0.5 g/dL concentration using a Cannon-Fenske
viscometer at 30 C. Differential scanning calorimeter (DSC)
traces were measured on a TA Instruments DSC 2010 at the
rate of 15 C/min in flowing nitrogen (40 cm3/min). Thermo-
gravimetry analysis (TGA) was conducted with a TA Instru-
ment TGA 2050. Experiments were carried out on 10 2 mg
samples heated in flowi n g nitrogen or air (100 cm3/min) at a
heating rate of 20 C/min. An Instron Universal Tester Model
1130 with a load cell 5 kg was used to study the stress-strain
behavior of the sample. A gauge of 2 cm and a strain rate of 5
cm/min were used for this study. Measurements were per-
formed at room temperature with film specimens (0.5 cm
e
d
2-Trifluoromethyl-4,4 -diaminodiphenylether (2)
To a suspension solution of the purified dinitro com-
pound 1 (30 g, 0.0914 mol) and 10% Pd/C (0.2 g) in ethanol
(150 mL), hydrazine monohydrate (15 mL) was added
dropwise to the stirred mixture at 70 C within 1 h. After
complete addition, the mixture was heated at the reflux tem-
perature for another 2 h. The reaction solution was filtered
hot to remove Pd/C, and the filtrate was then distilled to re-
move the solvent. The crude product was purified by recrys-
tallization from ethanol to give pale-cream crystals (25.2 g,
84%).
Diamine 2: mp 112-113 C by DSC (10 C/min). IR