JOURNAL OF
POLYMER SCIENCE
ORIGINAL ARTICLE
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exclusion chromatography (SEC) was carried out at 40 C on a
TOSOH HLC-8220 system (Tosoh corporation, Tokyo, Japan)
equipped with three consecutive polystyrene gel columns [TSK-
gels (bead size, exclusion limited molecular weight); super-
AW4000 (6 μm, > 4 × 105), super-AW3000 (4 μm, > 6 × 104),
and super-AW2500 (4 μm, > 2 × 103)] and refractive index and
ultraviolet detectors. This system was operated using DMF con-
diol-1: 1H NMR (400 MHz, DMSO-d6, δ, ppm): 1.36 (s, 9H),
3.59–3.35 (m, 2H), 3.96–3.74 (m, 1H), 4.66 (t, J = 5.9 Hz, 1H),
5.05 (d, J = 6.3 Hz, 1H). 13C NMR (100 MHz, DMSO-d6, δ,
ppm): 28.27, 64.31, 72.88, 80.55, 172.46. FT-IR (neat, cm−1):
1728, 2940, 2990, 3420.
diol-2: 1H NMR (400 MHz, DMSO-d6, δ, ppm): 1.02 (dd,
J = 6.6, 2.2 Hz, 6H), 3.38 (dd, J = 11.1, 6.2 Hz, 1H), 3.58–3.46
(m, 1H), 3.89–3.73 (m, 2H), 4.57 (t, J = 5.8 Hz, 1H), 5.36 (d,
J = 5.6 Hz, 1H), 7.32 (d, J = 7.9 Hz, 1H). 13C NMR (100 MHz,
DMSO-d6, δ, ppm): 22.84, 40.35, 64.48, 73.41, 171.53. FT-IR
(neat, cm−1): 1539, 1640, 2880, 2940, 2980, 3290, 3400.
taining 10 mM LiBr as the eluent at a flow rate of 0.5 mL min−1
.
Polystyrene standards were used for the calibration. Differential
scanning calorimetry (DSC) was carried out with a Seiko Instru-
ment DSC-6200 (Seiko Instrument Inc, Chiba, Japan) using an
aluminum pan under nitrogen flow at a heating rate of 10 ꢀC
min−1. Thermogravimetric analysis (TGA) was performed on
TG/DTA6200 thermal analyzer (Seiko Instrument Inc, Chiba,
Japan) with aluminum pan under nitrogen flow at a heating rate
of 10 ꢀC min−1. The mechanical properties of thin films (approxi-
mately 130 μm) were evaluated on a Shimadzu EZ Test EZ-LX
(SHIMADZU CORPORATION, Kyoto, Japan) at a crosshead speed
of 200 mm/min. Young’s modulus was estimated by the initial
rising slope of stress–strain curve. The film was cut into
dumbbell-shaped test pieces according to the Japan Indus-
trial Standards (JIS) K6251, No.7, and the tensile tests were
repeated at least four times to obtain the average values.
Geometry optimized energy was estimated by using density
functional theory (DFT) calculation with B3LYP/6-31G* method
(Wavefunction, Inc., Spartan’06 Windows version 1.1.0).
Synthesis of 1-phenylethane-1,2-diol (diol-3)
The heterogeneous mixture of styrene oxide (6.0 g, 50 mmol)
distillated water (100 mL) was refluxed for 24 h. Then, water
was evaporated in rotary and the residue dissolved in ethyl
acetate. Organic phase was dried on Mg2SO4, filtrated, and
concentrated. Toluene (500 mL) was added and kept in refrig-
erator for overnight to perform recrystallization. Obtained
white crystals was filtered and dried in vacuum at 100 ꢀC
overnight to yield 90%.
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diol-3: H NMR (400 MHz, DMSO-d6, δ, ppm): 3.40 (t, J = 5.9 Hz,
2H), 4.51 (dd, J = 10.3, 5.9 Hz, 1H), 4.67 (t, J = 5.8 Hz, 1H), 5.17
(d, J = 4.2 Hz, 1H), 7.35–7.14 (m, 5H). 13C NMR (100 MHz,
DMSO-d6, δ, ppm): 68.04, 74.37, 126.80, 127.30, 128.33, 143.95.
FTIR (neat, cm−1): 1345, 1454, 2865, 2930, 3200.
Materials
Synthesis of 3,4-dihydroxy-1-octylpyrrolidine-2,5-dione
(diol-4)
L-tartaric acid (25 g, 166.5 mmol) and octylamine (27.5 mL,
Tert-butyl acrylate, N-isopropyl acrylamide and potassium
permanganate (KMnO4) were purchased from FUJIFILM
Wako Pure Chemical Corporation (Osaka, Japan). Styrene
oxide, L-tartaric acid, n-octylamine, benzyltriethylammonium
chloride (TEBAC), dibutyltin dilaurate (DBTDL), methylene-
diphenyl 4,40-diisocyanate (MDI), and HDI were purchased
from Tokyo Chemical Industry C., Ltd. (Tokyo, Japan). All
other solvents were purchased from KANTO Chemical Co.,
INC. (Tokyo, Japan) and used as received without further
purification unless otherwise described.
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(166.5 mmol) in 250 mL of p-xylene were refluxed at 150 C
for 24 h. The reaction mixture was cooled to ambient tempera-
ture and to resulting crystalline product, excess amount of
hexane was added and stirred for 30 min, then filtered off.
After successive washing with portions of hexane until the
color of crystalline becomes light-yellow, then dried in vac-
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uum at 100 C overnight to yield 95%.
diol-4: 1H NMR (400 MHz, DMSO-d6, δ, ppm): 0.81 (dd,
J = 8.7, 5.0 Hz, 3H), 1.55–0.99 (m, 12H), 3.41–3.16 (m, 2H),
4.27 (s, 2H), 6.20 (br, 2H). 13C NMR (100 MHz, DMSO-d6, δ,
ppm): 14.44, 22.58, 26.66, 27.56, 29.04, 31.71, 38.16, 74.86,
175.20. FTIR (neat, cm−1): 1465, 1534, 1646, 2879, 2934,
2984, 3370.
Synthesis of tert-butyl 2,3-dihydroxypropanoate (diol-1)
and 2,3-dihydroxy-N-isopropylpropanamide (diol-2)
TEBAC (13.7 g, 60 mmol) and KMnO4 (9.5 g, 60 mmol) were
mixed in acetone (400 ml) and the mixture were stirred at
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r.t. for 3 h, then cooled to 0 C. To this mixture, a solution of
tert-Butyl acrylate or N-isopropyl acrylamide (50 mmol) in
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100 ml acetone was added dropwise over 15 min at 0 C and
stirred for 10 min after addition completed. Aqueous solution
of NaHSO3 (25 g, 240 mmol in 100 mL water) was added in
one portion to quench the reaction mixture, then filtered
through Celite by washing with acetone. Acetone in the filtrate
was evaporated and the aqueous residue was extracted with
excess ethyl acetate. The organic phase was dried (MgSO4),
filtered, and solvent evaporated. The crude oily product was
purified by column chromatography (silica gel, hexane: ethyl
acetate (2:1 for diol-1) to yield 50% as colorless oil and (silica
gel, hexane: ethyl acetate (1:1 for diol-2)) to yield 60% as
light-yellow oil).
Synthesis of Poly(urethane)s from Vicinal Diol and
Diisocyanate
As described in Scheme 2, the polymers were synthesized in
the solution of DMF, which was dried over 4 Å molecular
sieves overnight. Briefly, the diol compound (3 mmol) and dibu-
tyltin dilaurate (DBTDL) (36 μL, 0.06 mmol) were dissolved in
half amount of total reaction solvent. To this solution MDI
(3 mmol) or HDI (3 mmol) in DMF (1.5 mL) was added,
then the mixture was degassed by nitrogen cycles. The
polymerization was performed under nitrogen at 60 ꢀC for
24 h. All of the polymers were precipitated in the mixture
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JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2019