Macromolecules, Vol. 36, No. 16, 2003
Synthesis and Characterization of Copolymers 6153
Syn th esis of 1,2-Ben zen ed im eth a n ol (1). First, 1 L dry
Ta ble 1. Cop olym er iza tion Da ta a n d Rea ction Con d ition s
THF and 56 g (1.4 mol) LiAlH
4
were placed in a predried three-
for St-BMDO Cop olym er s
neck flask fitted with a dropping funnel, under argon. To this
was added 196 mL (1.2 mol) dimethyl phthalate in 300 mL of
THF dropwise with stirring. After completion of the addition
of dimethyl phthalate, the reaction contents were refluxed for
feed ratio
molar ratio)
runa BMDO St
copolymer composition
(molar ratio)
(
yield
(%) Mn × 10-4
BMDO
St
1
8 h. The mixture is hydrolyzed at ice temperature with 1.5 L
of water having 400 mL H SO . After extraction with diethyl
ether three times (each time 1 L of diethyl ether), the organic
phase was washed with NaHCO solution and then with water
and then dried over Na SO . Diethyl ether was evaporated off,
and the crude product was recrystallized from 1 L of CHCl
hexane 1:1 mixture giving 128 g (77%) of 1 as white crystals:
1
2
3
4
5
6
7
100
80
70
60
50
30
0
0
20
30
40
50
42
53
24
46
41
41
63
0.59
0.45
0.96
0.50
1.57
3.21
19.16
100
63
42
36
19
6
0
37
58
64
81
2
4
3
2
4
3
/
70
100
94
b
a
0
100
1
mp 64 °C. H NMR (200 MHz, CDCl
CH OH), 4.48 (s, -CH OH), 7.20 (s, 4H, Ar). C NMR (50
MHz, CDCl ): δ/ppm 63.69 (2C, -CH OH), 128.38, 129.52,
39.20 (6C, Ar).
Anal. Calcd (C
H, 7.75.
3
): δ/ppm 4.03 (s, 2H,
Monomer:benzyl bromide:CuBr:ligand ) 100:1:1:1 (molar
13
-
2
2
ratio); temperature ) 120 °C; time 72 h. b Temperature ) 110 °C.
3
2
1
benzyl bromide and 43 µL (0.2 mmol) of 1,1,4,7,7-pentameth-
yldiethylenetriamine were placed in a Schlenk tube under
argon. The mixture was degassed by two cycles of freeze-
pump-thaw and then placed in a preheated oil bath at 120
C for 72 h. The reaction mixture was dissolved in chloroform
and precipitated in MeOH-HCl. Purification of the copolymers
was done by dissolving in CHCl and reprecipitation in MeOH.
Drying of copolymers was done under vacuum at room tem-
perature until constant weight. Homopoly(BMDO) (PBMDO),
polystyrene (PS), and different copolymers of BMDO and St
were made by changing the molar ratio of the two monomers
in the feed, under similar reaction conditions as described
above. Details of the reaction conditions with monomer feed
ratios are given in Table 1.
Hyd r olysis of BMDO-Styr en e Cop olym er . First, 400
mg of copolymer (run 5, Table 1) was dissolved in a mixture
of 50 mL of KOH in methanol (5 wt %) and 30 mL of THF in
a round-bottom flask and was refluxed for 1 week. After this,
8
10 2
H O ): C, 69.55; H, 7.30. Found: C, 69.18;
Mass spectrum (EI): m/z 121 (4.75), 120 (100), 119 (82.43),
1
18 (1.55), 104 (10.15), 92 (20.86), 91 (56.98), 90 (3.01), 89
°
(
(
1.67), 79 (18.46), 78 (6.89), 77 (19.17), 65 (19.39), 51 (2.4), 44
1.07), 40 (29.57), 39 (6.39).
3
5
,6-Ben zo-2-(br om om eth yl)-1,3-d ioxep a n e (2). A mix-
ture of 117.44 g (0.85 mol) of 1, 167.51 g (0.85 mol) of
bromoacetaldehyde diethylacetal, and 900 mg of p-toluene-
sulfonic acid was heated at 120 °C for 8 h under argon in a
predried flask fitted with a Claisen bridge and dropping funnel
for collecting ethanol. When almost all the calculated amount
of ethanol was collected, the temperature of the reaction
mixture was raised to 160 °C under reduced pressure. The
crude product 2 was solidified on cooling the reaction mixture
to room temperature. The product was dissolved in CHCl
washed with NaHCO solution and water. After evaporation
3
and
3
of the solvent, crude product was recrystallized from 1.2 L
cyclohexane to give about 177 g (86%, white crystals) of 2.
5
mL of concentrated hydrochloric acid was added. The
mixture was extracted with chloroform and washed with
water. The solvent was evaporated under reduced pressure.
The remaining solid was dried under vacuum at room tem-
perature.
1
3
Mp: 98 °C. H NMR (200 MHz, CDCl
O) CHCH Br), 4.93 (s, 4H, C
.13 (t, 1H, J ) 5.12 Hz, (-CH O) CHCH Br), 7.16-7.27 (m,
H, Ar). C NMR (50 MHz, CDCl ): δ/ppm 31.45 (1C,
CH O-), 105.81 (1C,
3
): δ/ppm 3.46 (d, 2H, J
)
5.24 Hz, ((-CH
2
2
2
6
H
4
CH O-),
2
3
5
4
2
2
2
1
3
3
4
In str u m en ta tion . The molecular weights of the polymers
were determined by GPC using a Knauer system equipped
with two columns, PSS-SDV (linear, 10 µL, 60 × 0.8), a
differential refractive index detector, and a UV photometer
3
(-CH
2
2
O)
O)
2
2
CHCH
CHCH
2
2
Br), 71.74 (2C, C
6
H
2
(-CH
Br), 127.40, 127.67, 138.38 (6C, Ar).
Anal. Calcd (C10
11 2
H O
Br): C, 49.41; H, 4.56; Br, 32.87.
Found: C, 49.14; H, 4.76; Br, 29.75.
Mass spectrum (EI): m/z 244 (9.54), 242 (10.06), 150 (16.41),
using CHCl as eluent at a flow rate of 0.83 mL/min.
1
13
13
H (400.13 MHz), C (100.21 MHz), and C-DEPT NMR
1
9
6
49 (57.72), 121 (11.65), 119 (11.78), 105 (5.24), 104 (30.51),
3 (36.37), 92 (13.39), 91 (100), 90 (1.47), 89 (2.84), 77 (6.85),
5 (4.33), 43 (1.23).
spectra were recorded on a Bruker DRX-400 spectrometer.
1
Tetramethylsilane (TMS) was used as internal standard. H-
1
3
C correlation experiments were performed on a Bruker DRX-
5
,6-Ben zo-2-m eth ylen e-1,3-dioxepan e (BMDO) (3). First,
500 spectrometer, with a 5 mm multinuclear gradient probe
and using gs-HMQC and gs-HMBC pulse sequences. The
HMQC experiment was optimized for C-H coupling of 140 Hz,
with decoupling applied during acquisition; while the HMBC
experiment was optimized for coupling of 8 Hz, with decoupling
during acquisition. 2D NMR data were acquired with 2048
1
58.02 g (0.65 mol) of 2 and 78.55 g (0.65 mol) of t-BuOK were
allowed to react in the presence of 1 L of t-BuOH under argon
at 80 °C for 15 h. After this, 1 L of diethyl ether was added to
the reaction mixture. The insoluble material was removed by
passing through silica gel. The organic layer was dried over
Na
2
SO
4
, diethyl ether was removed and the crude liquid
2 1
points in t , and the number of increments for t was 256. A
obtained was distilled under reduced pressure to give a
colorless liquid which solidified to white crystals on standing,
total of four and eight scans were used for HMQC and HMBC
experiments respectively, and four dummy scans were used
for both the experiments. A relaxation delay of 1 s was used
for all 1D experiments and 2 s for all 2D experiments. Typical
experiment times were about 1.5 and 3.0 h for HMQC and
HMBC, respectively.
1
giving 82 g (77%) of 3; mp 44 °C. H NMR (200 MHz, CDCl
3
):
O-
, 7.05-7.08 (m, 2H, Ar), 7.21-7.23 (m, 2H, Ar). C (50 MHz,
CDCl ): δ/ppm 69.48 (1C, (-CH O) CdCH ), 71.99 (2C,
CH O-), 126.14, 127.38, 135.79 (6C, Ar), 164.21 (1C,
O) CdCH ).
Anal. Calcd (C10
H, 6.97.
2 2 2 6 4 2
δ/ppm 3.71 (s, 2H, (-CH O) CdCH ), 5.04 (s, 4H, C H CH
1
3
)
3
2
2
2
-
C
-CH
6
H
4
2
Mettler thermal analyzers having 851 TG and 821 DSC
modules were used for the thermal characterization of copoly-
mers. DSC scans were recorded in nitrogen atmosphere at a
heating rate of 10° C/min. Thermal stability was determined
by recording TG traces in nitrogen atmosphere (flow rate )
(
2
2
2
10 2
H O ): C, 74.06; H, 6.21. Found: C, 72.84;
Mass spectrum (EI): m/z 163 (100), 162 (2.9), 122 (5.84),
5
0 mL/min) using powdered samples. A heating rate of 10°
1
21 (73.12), 120 (71.1), 119 (65.41), 104 (22.02), 93 (6.63), 92
C/min and sample size of 10 ( 1 mg were used in each
experiment.
(6.92), 91 (4.91), 43 (58.59).
Hom o- a n d Cop olym er iza tion of BMDO a n d St. In
general, all homo- and copolymerization reactions were carried
out under argon in predried Schlenk tubes under ATRP
reaction conditions. In a typical copolymerization reaction (run
Resu lts a n d Discu ssion
5
, Table 1), 29 mg (0.2 mmol) of CuBr, 1.83 g (11.3 mmol) of
The BMDO monomer was synthesized by a slightly
modified version of the method of Grewe et al.16 The
BMDO, 1.3 mL (11.3 mmol) of styrene, 21 µL (0.2 mmol) of