Solubilities of N -[(4-bromo-3,5-difluorine)-phenyl]maleimide in different organic solvents

Article abstract of DOI:10.1021/je1010054

N-[(4-Bromo-3,5-difluorine)phenyl]maleimide (BDPM) is a new monomer for polyreaction. Its corresponding solid-liquid equilibrium data provide essential support for industrial design and further theoretical studies. Using a laser detecting system, solubili

Full text of DOI:10.1021/je1010054

3
58
J. Chem. Eng. Data 2011, 56, 358–360
Solubilities of N-[(4-Bromo-3,5-difluorine)-phenyl]maleimide in Different Organic
Solvents
Yanxun Li, Xinding Yao, Li Xu, Tingliang Luo, and Guoji Liu*
College of Chemical and Energy Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China
N-[(4-Bromo-3,5-difluorine)phenyl]maleimide (BDPM) is a new monomer for polyreaction. Its corresponding
solid-liquid equilibrium data provide essential support for industrial design and further theoretical studies.
Using a laser detecting system, solubility data were measured for the title compound dissolved in different
organic solvents including N,N-dimethylformamide, dimethyl sulfoxide, 2-butanone, cyclohexanone, 1,4-
dioxane, and toluene at temperatures between (285.15 and 356.25) K. The solubility data were correlated
with the Apelblat equation and Buchowski-Ksiazczak λh equation. Both the Apelblat equation and the
Buchowski-Ksiazczak λh equation can regress the solubility data well.
Introduction
N-Substituted maleimide monomers, such as N-phenylmale-
imide (PM), N-hydroxyphenylmaleimide (HPM), and halogen-
substituted N-phenylmaleimide (XPM), are usually designed to
modify the thermal stability and fire resistance of organic matrix
1
-3
materials.
The polymers of PM and their derivatives have
values due to the rigid imide
been known to exhibit high T
rings in the backbones. Halogen-substituted PM polymers
possess the thermal stability from an imide ring and flame
retardancy from halides. The incorporation of fluorine atoms
or groups containing fluorine atoms) into polymer chains
increases the solubility, glass transition temperature (T ), and
g
4
,5
Figure 1. Structure of BDPM.
6
,7
the temperature of 293.15 K. Then, 0.88 g of toluene p-sulfonic
acid and an appropriate amount of p-dihydroxybenzene as an
inhibitor were added to the reaction flask; the mixture was
maintained for hours at the temperature of 383.15 K until no
water drops appear in the water separator. Toluene was removed
by vacuum distillation and then cooled to room temperature.
(
g
thermal stability of polymers in addition to decreasing moisture
absorption and dielectric constant.
N-[(4-Bromo-3,5-difluorine)phenyl]maleimide (BDPM, Fig-
ure 1) is a new XPM monomer with fluorine and bromine atoms
for polyreaction. BDPM was synthesized by the interaction of
8
BDPM [11.12 g, mp (470.45 to 470.85) K (measured by
1
differential scanning calorimetry), H NMR (CDCl
3
, 400 MHz)
4-bromo-3,5-difluoroaniline with maleic anhydride. Crude BDPM
δ: 7.13-7.18 (m, 2H, CH), 7.35-7.42 (m, 2H, ArH)] was
obtained by filtering, washing, and drying.
was gained after concentrating and filtrating. For the extensive
XPM polymer investigation, crude BDPM has to be purified
by crystallization. To select the suitable solvent used for
polymerization, the solubility data of BDPM in different solvents
are required.
Its mass fraction purity was more than 0.993, as determined
by high-performance liquid chromatography (HPLC). All of the
solvents (purchased from the Tianjin Kewei of China) used for
experiments were analytical reagent grade, and their mass
fraction purities were higher than 0.998. Distilled deionized
water of HPLC grade was used throughout.
In this article, solubility measurements of BDPM in pure
N,N-dimethylformamide, dimethyl sulfoxide, 2-butanone, cy-
clohexanone, 1,4-dioxane, and toluene at temperatures be-
tween (285.15 and 356.25) K were performed at atmospheric
pressure by a laser monitoring observation technique. Ex-
perimental data were correlated by the modified Apelblat
Apparatus and Procedure. The solubility of BDPM in six pure
solvents was measured by the method that was described in the
11-13
literature.
The experiments were carried out in a 50 mL
jacketed glass vessel with a magnetic stirrer. The temperature, with
an uncertainty of ( 0.05 K, was controlled by circulating water
through the outer jacket. To prevent the evaporation of the solvent,
a condenser vessel was introduced. The dissolution of the solute
was examined by the intensity of the laser beam that penetrated
through the suspension. The laser monitoring system (purchased
from Physics Department of Peking University) consisted of a laser
generator (type JD-3, China), a photoelectric switch (type model
9
,10
equation and the Buchowski-Ksiazczak λh equation.
Experimental Section
Materials. The N-[(4-bromo-3,5-difluorine)-phenyl]maleimide
was produced by ourselves. Portions of 80 mL of toluene, 15
mL of dimethylformamide (DMF), and 4.54 g of maleic
anhydride were put into a 250 mL four-mouth flask, respectively,
and then 8.00 g of 4-bromo-3,5-difluoroaniline was added to
three flasks in batches; the mixture was maintained for 1.5 h at
271, China), and a light intensity display. An electronic balance
(
Shimadzu AX200) with an uncertainty of ( 0.0001 g was used
for the mass measurements.
During the measurement, predetermined excess amounts of
solute and solvent of known masses were added to the jacket
*
Corresponding author. Phone: 86 0371 67781713. E-mail: guojiliu@
zzu.edu.cn.
1
0.1021/je1010054  2011 American Chemical Society
Published on Web 12/31/2010

Journal of Chemical & Engineering Data, Vol. 56, No. 2, 2011 359
Table 1. Mole Fraction Solubility of BDPM in Different Solvents at
Different Temperatures
2
2
2
T/K
x
i
·10
T/K
x
i
·10
T/K
1,4-Dioxane
287.65
i
x ·10
N,N-Dimethylformamide
Dimethyl Sulfoxide
2
2
3
3
3
3
3
3
3
3
3
3
3
3
3
3
89.45
93.65
00.83
05.65
08.85
17.55
20.45
22.95
25.25
33.55
37.65
42.65
46.65
50.75
53.35
56.25
2.08
2.28
2.69
3.01
3.24
3.98
4.26
4.52
4.77
5.82
6.43
7.22
7.94
8.76
9.32
10.00
289.35
293.65
297.05
301.45
305.95
309.45
314.05
318.15
324.55
328.05
333.65
338.85
342.55
346.05
349.35
355.95
1.16
1.31
1.43
1.61
1.84
2.02
2.31
2.60
3.14
3.48
4.06
4.73
5.27
5.80
6.37
7.68
1.22
1.33
1.46
1.60
1.83
2.06
2.30
2.81
3.18
3.42
4.08
4.64
5.13
5.58
6.39
7.59
290.65
293.85
297.15
302.05
306.25
310.05
317.15
321.65
324.45
330.85
335.35
339.15
342.25
347.25
353.65
2
89.75
99.25
03.5
08.75
13
-Butanone
Cyclohexanone
285.15
Toluene
2
2
3
3
3
3
3
3
3
3
3
3
3
3
3
3
0.86
1.12
1.28
1.49
1.70
1.87
2.02
2.20
2.37
2.57
2.96
3.26
3.60
3.90
4.11
4.32
1.29
1.51
1.67
1.91
2.21
2.59
2.95
3.42
3.70
4.11
4.62
5.15
5.72
6.90
7.51
8.23
291.05
296.35
299.15
302.95
306.05
310.15
315.95
321.05
325.15
330.65
334.45
340.75
343.55
348.45
350.65
354.45
0.31
0.37
0.41
0.47
0.53
0.61
0.75
0.89
1.03
1.24
1.40
1.75
1.92
2.26
2.44
2.76
Figure 2. Solubilities of BDPM in different solvents: 9, N,N-dimethylfor-
mamide; b, dimethyl sulfoxide; 2, 2-butanone; 1, cyclohexanone; f, 1,4-
dioxane; g, toluene. The line is well-fit of the experimental data calculated
with the modified Apelblat equation.
291.25
295.15
300.15
305.65
311.65
316.55
321.85
324.95
328.75
333.25
337.35
341.35
348.35
351.65
355.05
16.25
18.6
Table 2. Parameters of the Modified Apelblat Equation for BDPM
in Different Pure Solvents
21.75
24.25
27.05
31.95
35.25
38.85
41.55
43.5
5
solvent
A
B
C
10 rmsd
N,N-dimethylformamide
dimethyl sulfoxide
2-butanone
cyclohexanone
1,4-dioxane
-109.81
-118.21
-107.84
-109.85
-96.05
2980.7
2917.7
2369.4
2704.0
2181.1
2546.2
16.87
18.29
16.74
16.98
15.66
19.02
5.64
9.43
8.98
6.28
6.72
3.78
toluene
-122.46
45.25
the solubility of BDPM in pure N,N-dimethylformamide is
higher than that in the solvents of dimethyl sulfoxide, 2-bu-
tanone, cyclohexanone, and 1,4-dioxane.
To describe the solid-liquid equilibrium, the relationship
between solubility and temperature can be described as the
modified Apelblat equation
vessel. The contents of the vessel were stirred continuously for
0 min at a fixed temperature. Then, an additional solvent of
3
known mass was introduced to the cell. The dissolution of the
solute was monitored by a laser beam. When the solute dissolved
completely, the solution was clear, and the laser intensity that
penetrated through the solution attained its maximum. Other-
wise, the solute was believed not to be dissolved completely.
When the last solute just disappeared, the laser intensity
penetrating through the vessel reached a maximum, and the
solvent mass consumed was recorded. Together with the mass
of solute, the solubility would be obtained. The saturated mole
fraction solubility of BDPM can be determined from eq 1
B
T/K
ln(x) ) A +
+ C ln(T/K)
(2)
where A, B, and C are the empirical parameters. The experi-
mental data of mole fraction solubility in Table 1 were correlated
with eq 2. The results are shown in Figure 2.
The values of the three parameters, A, B, and C, together
with the root-mean-square deviations (rmsd’s), are listed in
Table 2. The rmsd is defined as
m /M
1
1
xi )
(1)
m /M + m /M
2
1
1
2
N
1/2
where m
1
and m
2
represent the masses of the solute and solvent
1
N
calc
2
and M and M
1
2
are the molecular weights of the solute and the
rmsd )
∑
(xi - xi)
(3)
{
}
i)1
solvent, respectively. All of the experiments were repeated three
times, and the solubility data were the average of experimental
results. Considering other factors, the relative uncertainty in the
measurement of the concentration of BDPM was within 0.5 %.
calc
where N is the number of experimental points, x
the solubility calculated, and x represents the experimental
i
i
represents
solubility values. As can be seen from Figure 2 and Table 2,
the correlation is satisfactory.
The another way to describe the solution behavior is the
Buchowski-Ksiazczak λh equation
Results and Discussion
The solubility data of BDPM in pure N,N-dimethylformamide,
dimethyl sulfoxide, 2-butanone, cyclohexanone, 1,4-dioxane, and
toluene are listed in Table 1. From Table 1, it can be seen that
at temperatures ranging from (285.15 and 356.25) K, the
solubility of BDPM increases with temperature in all six pure
solvents, and the BDPM is slightly soluble in toluene, while
λ(1 - x)
1
1
Tm
ln 1 +
) λh
-
(4)
[
]
(T
)
x

3
60 Journal of Chemical & Engineering Data, Vol. 56, No. 2, 2011
Table 3. Regression Result of the Buchowski-Ksiazczak λh
(2) Kita, Y.; Kishino, K.; Nakagawa, K. High-quality N-substituted
Equation for BDPM in Different Pure Solvents
maleimide for heat-resistant methacrylic resin. J. Appl. Polym. Sci.
1
997, 63, 1055–1062.
4
solvent
λ
h
10 rmsd
(
(
3) Matsumoto, A.; Kimura, T. Synthesis of heat- and solvent-resistant
polymers by radical polymerization of trifluoromethyl-substituted N-
phenylmaleimides. J. Appl. Polym. Sci. 1998, 68, 1703–1708.
N,N-dimethylformamide
dimethyl sulfoxide
0.46
0.56
0.40
0.51
0.51
0.33
5266.4
5387.8
7473.1
5455.5
5567.9
11086.2
10.42
8.08
2.65
8.78
6.80
2.20
4) Matsumoto, A.; Kubota, T.; Otsu, T. Radical polymerization of
N-(alkyl-substituted phenyl)maleimides: synthesis of thermally stable
polymers soluble in nonpolar solvents. Macromolecules 1990, 23,
2
-butanone
cyclohexanone
,4-dioxane
toluene
1
4
508–4513.
(
5) Otsu, T.; Matsumoto, A.; Kubota, T.; Mori, S. Reactivity in radical
polymerization of N-substituted maleimides and thermal stability of
the resulting polymers. Polym. Bull. 1990, 23, 43–50.
where λ and h are the empirical parameters, T is the absolute
temperature, x is the mole fraction solubility of BDPM, and T
is the melting temperature of BDPM, T ) 470.65 K. The
(6) Kita, Y.; Kanai, H.; Kishino, K. Preparation of N-(2,4,6-trihalophe-
nyl)maleimides as fire retardants and monomers. JP Patent 09194458,
m
m
1
997.
experimental data of mole fraction solubility in Table 1 were
correlated with eq 4, and the values of the two parameters λ
and h together with the rmsd’s are listed in Table 3; the
correlation is also satisfactory.
(
7) Ryttel, A. N-(p-bromophenyl)maleimide and its copolymers with alkyl
methacrylates. Angew. Makromol. Chem. 1999, 267, 67–72.
8) Mokhtar, S. M.; Abd-Elaziz, S. M.; Gomaa, F. A. Synthesis
characterizations and properties of a new fluoro-maleimide polymer.
J. Fluorine Chem. 2010, 131, 616–620.
9) Wang, Z. Z.; Wang, J. K.; Zhang, M. J.; Dang, L. P. Solubility of
Erythromycin A Dihydrate in Different Pure Solvents and Acetone +
Water Binary Mixtures Between 293 and 323 K. J. Chem. Eng. Data
(
(
Conclusions
Using the laser monitoring observation technique, the solubil-
ity of BDPM in pure N,N-dimethylformamide, dimethyl sul-
foxide, 2-butanone, cyclohexanone, 1,4-dioxane, and toluene
as a function of temperature was determined in this study.
Depending on Tables 1 to 3 and Figure 2, some conclusions
can be obtained: (1) The solubilities of BDPM in all selected
solvents increase with increasing temperature. (2) The solubility
of BDPM increases with the solvents in the order: toluene,
2
006, 51, 1062–1065.
(10) Yao, X. D.; Li, X. B.; Li, Y. X.; Luo, T. L.; Liu, G. J. Solubilities of
N-[(4-Bromo-3,5-difluorine)phenyl]-acrylamide in Benzene, Methanol,
Pyridine, Ethanol, Acetonitrile,and Toluene at Temperatures between
(
284.65 and 348.95) K. J. Chem. Eng. Data 2010, 55, 1434–1436.
(11) Han, Y.; Wang, Z. Z. Solubility of Fluorene in Benzene, Chloroform,
Acetone, 1-Propanol, Isobutanol, and Methylbenzene from (283 to 323)
K. J. Chem. Eng. Data 2009, 54, 148–149.
(
12) Liu, Y.; Wang, J. K.; Wang, X.; Liu, P.; Pang, F. Solubility of
Valsartan in Different Organic Solvents and Ethanol + Water Binary
Mixtures from (278.15 to 313.15) K. J. Chem. Eng. Data 2009, 54,
2-butanone, dimethyl sulfoxide, 1,4-dioxane, cyclohexanone, and
9
86–988.
N,N-dimethylformamide. (3) Both the Apelblat equation and
the λh equation can regress the solubility data well. (4) The
solubility measured in this study can be used as the solvent for
the polymerization of BDPM.
(
13) Yan, F. Y.; Chen, L.; Liu, D. Q.; SiMa, L. F.; Chen, M. J.; Shi, H.;
Zhu, J. X. Solubility of (+)-(S)-2-(6-Methoxynaphthalen-2-yl) Pro-
panoic Acid in Acetone, Methanol, Ethanol, Propan-2-ol, and Ethyl
Ethanoate at Temperatures between (278 and 320) K. J. Chem. Eng.
Data 2009, 54, 1117–1119.
Literature Cited
(
1) Chung, C. M.; Ahn, K. D. Synthesis and thermal modification of
Received for review October 7, 2010. Accepted December 23, 2010.
JE1010054
N-substituted functional polymaleimides. Macromol. Symp. 1997, 118,
4
85–491.