RSC Advances
Paper
ꢂ1
nitrogen atmosphere (ow rate 100 mL min ) at a heating rate and di-n-butyltin dilaurate (256 mg, 0.405 mmol) in anhydrous
ꢁ
ꢂ1
ꢁ
of 10 C min . Samples for tensile testing were prepared by THF (4 mL) was stirred at 70 C under a N atmosphere for 4 h.
2
casting from distilled THF in a Petri dish made from poly- Aer cooling to room temperature, the reaction mixture was
tetrauoroethylene. Aer evaporation of solvent at room added to diethylether (40 mL). The white precipitate was
ꢁ
temperature for 24 h, the samples were further dried at 70 C for collected by centrifugation, washed with diethylether. The white
ꢁ
1
0–15 h. Tensile testing was conducted and recorded on tensile solid was dried under vacuum at 70 C for 15 h to give a color-
1
testing machine (EZ-LX, SHIMADZU) using rectangular lms less solid (1.08 g, 94%). H NMR (400 MHz, DMSO-d
6
, d, ppm):
(
ca. 0.3 mm (T) ꢀ 10 mm (W) ꢀ 40 mm (L)) with speed of 500 7.03 (s, 2H, NH), 3.70 (s, 4H, Si–CH
2
), 2.97 (br, 4H, N–CH ), 1.40
2
ꢂ1
13
mm min . Reported values of ultimate strength, strain at break (br, 4H, CH
2
), 1.25 (br, 4H, CH
2
), 0.11 (s, 6H, Si–CH
3
); C NMR
and Young's modulus (E) are average and standard deviations of (100 MHz, CDCl , d, ppm): 158.09 (C]O), 55.87 (Si–CH –O),
3
2
2
9
three samples.
41.31 (N–CH ), 30.22 (CH ), 26.59 (CH ), ꢂ5.65 (Si–CH ); Si
2
2
2
3
ꢂ1
NMR (80 MHz, DMSO-d , d, ppm) ꢂ1.21; FTIR (n, cm ): 3319,
6
2
928, 2857, 1687, 1526, 1290, 1233, 1136, 1040, 845, 777.
Materials
Methanol, tetrahydrofuran (THF) and di-n-butyltin dilaurate
were purchased from Wako Pure Chemical Industry (Osaka,
Japan). Bis(chloromethyl)dimethylsilane, 2,2-dimethyl-1,3-
propanediol, 1,6-hexamethylenediisocyanate, tolylene-2,4-
Synthesis of polyurethane 1b
A solution of tolylene-2,4-diisocyanate (697 mg, 4.00 mmol),
bis(hydroxymethyl)dimethylsilane (481 mg, 4.00 mmol) and di-
0
n-butyltin dilaurate (256 mg, 0.405 mmol) in anhydrous THF (4
diisocyanate, and methylenediphenyl-4,4 -diisocyanate were
ꢁ
mL) was stirred at 70 C under a N
2
atmosphere for 4 h. Aer
purchased from Tokyo Chemical Industry (Tokyo, Japan). All
the reagents were used without further purication. Anhydrous
THF was distilled over sodium. The monomer bis(hydrox-
ymethyl)dimethylsilane was prepared according to the litera-
cooling to room temperature, the reaction mixture was added to
methanol (40 mL). The white precipitate was collected by
centrifugation, washed with methanol. The white solid was
ꢁ
24,25
dried under vacuum at 90 C for 24 h to give a colorless solid
ture with a little modication.
1
(
715 mg, 61%). H NMR (400 MHz, DMSO-d
6
, d, ppm): 9.55 (s,
1
H, NH), 8.82 (s, 1H, NH), 7.49 (s, 1H, Ar–H), 7.21 (d, J ¼ 8.4 Hz,
Synthesis of bis(acetoxymethyl)dimethylsilane
1
H, Ar–H), 7.08 (d, J ¼ 8.4 Hz, 1H, Ar–H), 3.88 (d, J ¼ 3.6 Hz, 4H,
Bis(acetoxymethyl)dimethylsilane was prepared according to
13
Si–CH
2
), 2.14 (s, 3H, Ar–CH
3 3
), 0.20 (s, 6H, Si–CH ); C NMR
24,25
the previously reported procedure,
with some modications.
(100 MHz, DMSO-d , d, ppm): 156.34 (C]O), 155.52 (C]O),
6
The mixture of bis(chloromethyl)dimethylsilane (2.00 g, 12.7
mmol) and sodium acetate (3.14 g, 38.3 mmol) in DMF (25 mL)
1
5
38.27 (Ar), 137.52 (Ar), 131.21 (Ar), 126.59 (Ar), 115.86 (Ar),
29
6.52 (Si–CH –O), 18.12 (Ar–CH ), ꢂ4.65 (Si–CH ); Si NMR (80
2
3
3
ꢁ
was stirred at 100 C for 5 h. Aer cooling to room temperature,
ꢂ1
MHz, DMSO-d , d, ppm) ꢂ0.79; FTIR (n, cm ): 3302, 2918, 1701,
6
water (100 mL) was added to the reaction mixture. The aqueous
1
600, 1530, 1413, 1361, 1290, 1218, 1182, 1055, 1001, 850, 768.
layer was extracted with hexane (20 mL) ꢀ 4. The organic layer
2 4
was washed with brine, dried over Na SO . Solvents were
Synthesis of polyurethane 1c
removed under reduced pressure to give a colorless oil (2.56 g,
0
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1
A solution of methylenediphenyl-4,4 -diisocyanate (252 mg, 1.01
mmol), bis(hydroxymethyl)dimethylsilane (121 mg, 1.01 mmol)
and di-n-butyltin dilaurate (64.0 mg, 0.101 mmol) in anhydrous
9
4
9%). Mp: <ꢂ100 C; H NMR (400 MHz, CDCl , d, ppm): 3.84 (s,
3
13
H, Si–CH –O), 2.05 (s, 6H, O]C–CH ), 0.15 (s, 6H, Si–CH );
C
2
3
3
NMR (100 MHz, CDCl
3
, d, ppm): 172.10 (C]O), 55.75 (O]C–
).
ꢁ
THF (1 mL) was stirred at 70 C under a N
2
atmosphere for 4 h.
CH ), 21.06 (Si–CH
3
2
–O), ꢂ5.63 (Si–CH
3
Aer cooling to room temperature, the reaction mixture was
added to methanol (20 mL). The white precipitate was collected
by centrifugation, washed with methanol. The white solid was
Synthesis of bis(hydroxymethyl)dimethylsilane
Bis(hydroxymethyl)dimethylsilane was prepared according to
ꢁ
dried under vacuum at 90 C for 48 h to give a colorless solid
24,25
1
the previously reported procedure,
with some modications.
(332 mg, 89%). H NMR (400 MHz, DMSO-d , d, ppm): 9.46 (s,
6
A solution of bis(acetoxymethyl)dimethylsilane (4.10 g, 20.1
mmol) and conc. hydrochloric acid (0.5 mL) in methanol (100
mL) was stirred at 70 C for 24 h. Methanol was removed under
2
H, NH), 7.35 (d, J ¼ 8.4 Hz, 4H, Ar–H), 7.08 (d, J ¼ 8.4 Hz, 4H,
Ar–H), 3.86 (s, 4H, Si–CH ), 3.77 (s, 2H, Ar–CH –Ar), 0.16 (s, 6H,
); C NMR (100 MHz, DMSO-d , d, ppm): 155.56 (C]O),
38.15 (Ar), 136.39 (Ar), 129.84 (Ar), 119.23 (Ar–CH –Ar), 56.28
); Si NMR (80 MHz, DMSO-d , d, ppm)
2
2
ꢁ
13
Si–CH
1
3
6
reduced pressure. The crude product was puried by distillation
2
ꢁ
29
(
100 C, 2 mmHg) to give a colorless oil (2.21 g, 91%). Mp: ꢂ36
(Si–CH
2
), ꢂ4.72 (Si–CH
3
6
ꢁ
1
ꢂ1
C; H NMR (400 MHz, DMSO-d , d, ppm): 3.96 (t, J ¼ 4.4 Hz, 2H,
6
ꢂ0.79; FTIR (n, cm ): 3309, 2911, 1703, 1597, 1527, 1412, 1360,
1
3
OH), 3.22 (d, J ¼ 4.4 Hz, 4H, Si–CH ), 0.020 (s, 6H, Si–CH );
C
2
3
1310, 1239, 1200, 1056, 1018, 865, 843, 768.
NMR (400 MHz, DMSO-d
6
, d, ppm): 52.30 (Si–CH
2
), ꢂ5.25 (Si–
CH
3
).
Synthesis of polyurethane 2a
A solution of 1,6-hexamethylenediisocyanate (672 mg, 4.00
mmol), 2,2-dimethyl-1,3-propanediol (418 mg, 4.00 mmol) and
Synthesis of polyurethane 1a
A solution of 1,6-hexamethylenediisocyanate (672 mg, 4.00 di-n-butyltin dilaurate (256 mg, 0.405 mmol) in anhydrous THF
ꢁ
mmol), bis(hydroxymethyl)dimethylsilane (482 mg, 4.00 mmol) (4 mL) was stirred at 70 C under a N
2
atmosphere for 4 h. Aer
94804 | RSC Adv., 2016, 6, 94803–94808
This journal is © The Royal Society of Chemistry 2016