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a
TABLE 1 Iodine-Transfer Radical Emulsion Polymerization of VAc
b
VAc/EIA/VA-044
(mol/mol/mol)
Temp.
Time
(h)
M
n (theory)
ꢂ3
Conv.
ꢁ
ꢀ 10ꢂ3 c
c
d
Run
( C)
(ꢀ10
)
M
n
M /M
w n
(%)
Emulsion
1
2
3
4
5
6
7
a
100/–/1
100/1/1
100/2/2
100/1/2
400/4/1
100/2/1
200/2/1
60
60
60
60
60
60
60
4
4
4
4
4
4
4
8.6
8.8
4.5
8.8
8.8
4.5
8.8
88.5
10.6
7.5
5.3
3.0
2.6
3.3
2.2
2.2
4.0
>99
>99
>99
>99
Stable
Stable
Stable
Stable
Unstable
Stable
Stable
12.0
5.1
9.6
>99
>99
16.4
Emulsion polymerizations conducted under the following conditions: [VAc]/[water] ¼ 1/3, wt/wt, PVA: 6 wt % aq. (15 wt % to VAc).
b
c
M
n (theory) ¼ MW of VAc ꢀ [VAc]
0
/[EIA]
relative to poly(styrene) standards.
Determined by H NMR (in CDCl ).
0
ꢀ conv. þ MW of EIA.
By SEC measurements in CHCl
3
d
1
3
performed using apparatus equipped with ALV/SO-SIPD de-
tector and ALV-7002 correlator. Particle size was measured
desired fraction was concentrated under vacuum to produce
a yellow oil with an 85% yield of 1.
ꢁ
at a scattering angle of 90 after temperature was controlled
1
8
5% yield. H NMR (200 MHz, CDCl ): 1.32 ppm (6H, d,
3
ꢁ
at 30 C. He-Ne laser (k ¼ 632.8 nm NEOARK NEO-30MS2)
AOCH(CH ) , J ¼ 6.3 Hz), 4.29 ppm (2H, s, ASCH C H ),
3
2
2 6 5
was used for light source. For the DLS measurements, 10 lL
5
.60–5.84 ppm (1H, hepted, AOCH(CH ) ), and 7.12–7.40
3 2
of emulsion samples were diluted with 20 mL of H O. The
2
2 6 5
ppm (5H, brm, ASCH C H ).
obtained auto-correlation function was analyzed by using
CONTIN program as well as the second-order cumulant
Synthesis of Ethyl 2-(benzylthiocarbonothioyl)
2
method to evaluate the variance l /C . Particle size distribu-
10
2
propionate (2)
2
tion was defined as 1 þ l /C , which roughly corresponds
1
2
3
3% yield: H NMR (200 MHz, CDCl ): 1.27 ppm (3H, t, 7.1
3
to the molecular weight distribution index. The obtained C
Hz, AOCH(CH )COOCH CH ), 1.62 ppm (3H, d, 7.0 Hz,
3
2
3
was transformed to the hydrodynamic radius (R ) by the
h
AOCH(CH )COOCH CH ), 4.22 ppm (2H, q, 7.2Hz,
3
2
3
Einstein-Stokes equation.
AOCH(CH )COOCH CH ), 4.40 ppm (2H,s, ASCH C H ), 5.74
3
2
3
2 6 5
ppm (1H, q, 7.0 Hz, AOCH(CH )COOCH CH ), and 7.16–7.60
ppm (5H, brm, ASCH C H ).
2 6 5
Iodine-Transfer Radical Emulsion Polymerization
H O (6.5 mL) and PVA (0.38 g, degree of saponification
2
3
2
3
8
9%) were mixed in a flask and put into a water bath at 60
ꢁ
Synthesis of Ethyl 2-(benzylthiocarbonothioylthio)
C and stirred for 40 min. EIA (29.7 mg, 0.139 mmol) and
VAc (1.2 g, 13.9 mmol) were added under nitrogen and
stirred for 1.5 h after the PVA was dissolved. Subsequently,
0
H
which time the reaction was continued for 4 h at 60 C.
Finally, the prepared PVAc emulsion was transferred to a
sample bottle (Run 2 in Table 1).
propionate (3)
1
3
3% yield: H NMR (200 MHz, CDCl
3
): 1.31 ppm (3H, t, 7.2
Hz, ASCH(CH )COOCH CH ), 1.64 ppm (3H, d, 7.3 Hz,
3
2
3
.045 g (0.139 mmol) of VA-044 was dissolved in 1.0 mL of
ASCH(CH )COOCH CH ), 4.24 ppm (2H, q, 7.2Hz, ASCH(CH )
3
2
3
3
2
O, and the aqueous solution added to the flask, after
ꢁ
COOCH CH ), 4.63 ppm (2H, s, ASCH C H ), 4.90 ppm (1H,
2 3 2 6 5
q, 7.3 Hz, ASCH(CH )COOCH CH ), and 7.26–7.46 ppm (5H,
3
2
3
brm, ASCH C H ).
2
6 5
Preparation of Xanthates and Trithiocarbonates
Synthesis of 2-Propylcarbonothioylthiomethylbenzene (1)
Dry toluene (33 mL, 10.8 mmol) was added to a flask of
TCDI (2.0 g, 19.2 mmol) and potassium hydroxide (0.03 g,
Synthesis of Ethyl 2-(2-Propylcarbonothioylthio)
propionate (4)
1
0
1
51% yield: H NMR (200 MHz, CDCl ): 1.29 ppm (3H, t, 7.3
3
Hz, ASCH(CH )COOCH CH ), 1.39 ppm (6H,
2
ꢀ
d,
3
2
3
0.53 mmol) that were added under nitrogen atmosphere. To
AOCH(CH ) , J ¼ 1.7 Hz, J ¼ 6.3 Hz), 1.56 ppm (3H, d, 7.3
3
2
2
1
the solution was added 2-propanol (95% purity, 0.82 mL,
Hz, ASCH(CH )COOCH CH ), 4.21 ppm (2H, q, 7.2Hz,
3
2
3
0
6
.64 g, and 19.2 mmol). The reaction mixture was heated to
0 C and stirred for 6 h. Then, the mixture was allowed to
ASCH(CH )COOCH CH ), 4.35 ppm (1H, q, 7.4 Hz,
3 2 3
ꢁ
ASCH(CH )COOCH CH ), and 5.74 ppm [1H, hepted,
3
2
3
cool to room temperature and left to stand, under nitrogen,
overnight. Benzyl mercaptane (99% purity, 1.26 mL, 1.33 g,
and 19.2 mmol) was added under nitrogen to the stirred
AOCH(CH ) ].
3
2
Synthesis of Ethyl 2-(ethylcarbonothioylthio)
ꢁ
9(b)
solution. The reaction mixture was heated to 60 C and
propionate (5)
1
stirred for 6 h before being left to cool to room temperature
overnight. The solution was filtrated and concentrated under
vacuum, and then subjected to gel permeation chromatogra-
phy (silica, 5% ethyl acetate in hexane as eluent). The
4% yield: H NMR (200 MHz, CDCl
3
): 1.29 ppm (3H, t, 7.1 Hz,
ASCH(CH )COOCH CH ), 1.42 ppm (3H, t, 7.1 Hz, AOCH CH ),
3
2
3
2
3
1.57 ppm (3H, d, 7.4 Hz, ASCH(CH )COOCH CH ), 4.21 ppm
(2H, q, 7.1Hz, ASCH(CH )COOCH CH ), 4.38 ppm (1H, q,
3
2
3
3
2
3
536
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2013, 51, 534–545