Langmuir
Article
reactions and separations but also for a wide range of
engineering and biomedical applications. In lithium-ion and
lithium−oxygen batteries, sulfone-based electrolytes are more
useful than other common electrolytes such as ethylene
carbonate due to their high ion conductivity, stability toward
electrochemical oxidation, nonflammability, and low volatil-
reaction was quenched with saturated NaHCO
the mixture was washed with a saturated solution of sodium chloride.
3
solution (10 mL), and
The organic layer was dried over MgSO and concentrated at reduced
4
pressure. The crude product was purified by column chromatography
(
8
acetone/hexane 1:2), which afforded a colorless oil (yield: 2.80 g,
1
5%). H NMR (500 MHz, CDCl ): δ (ppm) = 6.18 (s, 1H), 5.68 (s,
3
1
H), 5.59 (m, 1H), 3.47−3.15 (m, 4H), 2.53 (m, 2H), 1.96 (s, 3H).
1
8−22
ity.
Divinyl sulfones have been used as water-soluble cross-
13
C NMR (125 MHz, CDCl ): δ (ppm) = 166.1, 135.3, 127.3, 69.9,
3
linking agents in the preparation of biomaterials, including
5
2
6.7, 49.5, 29.0, 18.1. ESI-MS (M + Na): calcd for 204.05, found
04.05.
23,24
extracellular matrixes and hyaluronic acid-based hydrogels.
Sulfones demonstrate the properties of inflammation inhibitors
Synthesis of Poly(3-sulfolanyl methacrylate) (PSMA). Compound
2 (0.400 g, 1.92 mmol), 2-cyano-2-propyl benzodithioate (CPBD)
1.74 mg, 7.84 μmol), and 2,2′-azobis(2-methylpropionitrile) (AIBN)
0.258 mg, 1.57 μmol) were dissolved in DMSO (1.2 mL). After being
degassed using 3 freeze−pump−thaw cycles, the reaction mixture was
stirred for 24 h at 60 °C. The reaction was quenched in liquid
nitrogen. The polymer solution was precipitated in methanol, filtered,
and tumor cell growth inhibitors; thus, they are advantageous in
25,26
(
(
medical adhesive applications.
Polymers containing sul-
fones, such as poly(ether sulfone), are mechanically stable
materials throughout broad pH and temperature ranges and are
often used as membrane filtration materials. These polymer
membranes exhibit water permeation and low protein fouling
due to the sulfone moieties, indicating that the sulfonyl groups
impart hydrophilic properties to material surfaces. Surprisingly,
however, there has been no focused research on the sulfone as a
surface functional group, even though it fits all of the criteria
useful to provide biocompatibility to material surfaces: charge
neutral, hydrophilic, hydrogen bond accepting, not hydrogen
bond donating.
We report the synthesis of three methacrylate polymers
containing sulfone side chains: sulfolane, methylsulfone, and
ethylsulfone. The thermal properties of these polymers were
investigated using differential scanning calorimetry (DSC) and
themogravimetric analysis (TGA). The surface wetting proper-
ties and the effects of the sulfone structure were determined
using contact angle analysis of spin-coated silicon wafer-
supported thin polymer films.
rinsed with acetone and then dried at reduced pressure (yield: 0.301 g,
1
7
2
5%). H NMR (500 MHz, CDCl ): δ (ppm) = 5.34 (br, 2H), 3.65−
3
.96 (br, 4H), 2.62−2.14 (br, 2H), 2.10−1.39 (br, 2H), 1.20−0.634
(br, 3H).
Synthesis of 2-(Methylsulfonyl)ethyl Methacrylate (3). 2-
(Methylsulfonyl)ethanol (1.12 g, 9.06 mmol) dissolved in dry
chloroform (15 mL) was added to triethylamine (2.06 g, 19.9
mmol) at room temperature. The solution was cooled to 0 °C, and
methacryloyl chloride (1.04 g, 9.97 mmol) was added slowly. The
reaction mixture was stirred for 30 min at 0 °C, allowed to warm to
room temperature, and stirred for 30 min. The reaction was quenched
with saturated NaHCO3 solution (10 mL), and the mixture was
washed with a saturated solution of sodium chloride. The organic layer
was dried over MgSO and concentrated at reduced pressure. The
4
crude product was purified by column chromatography (acetone/
1
hexane 1:3), which afforded a colorless oil (yield: 1.24 g, 71%). H
NMR (500 MHz, CDCl
): δ (ppm) = 6.14 (s, 1H), 5.66 (s, 1H), 4.62
3
(
3
t, J = 5.75 Hz, 2H), 3.39 (t, J = 5.75 Hz, 2H), 3.00 (s, 3H), 1.96 (s,
H). 13C NMR (125 MHz, CDCl ): δ (ppm) = 166.6, 135.4, 127.0,
3
EXPERIMENTAL SECTION
■
58.2, 54.0, 42.3, 18.3. ESI-MS (M + Na): calcd for 215.05, found
215.05.
Materials and Synthesis. 2-(Methylsulfonyl)ethanol (98%), 2,2′-
azobis(2-methylpropionitrile) (98%), and 2-cyano-2-propyl benzodi-
thioate (>97%) were purchased from Sigma-Aldrich. Butadiene
sulfone (sulfolene, 98%), methacryloyl chloride (95%), and all
solvents were purchased from Acros Organics. 2-(Ethylsulfonyl)-
ethanol (95%) was purchased from Oakwood Chemical. Triethyl-
amine was purchased from Fisher Scientific. All reactions were carried
out under nitrogen atmosphere, and all solvents were dehydrated by
standard methods. The progress of reactions was monitored using thin
layer chromatography (TLC) and detected using UV (254 nm) and
staining with an ethanol solution of phosphomolybdic acid (5%).
Products were purified by column chromatography with silica gel 60
Synthesis of Poly(2-(methylsulfonyl)ethyl methacrylate) (PMSE-
MA). Compound 3 (0.400 g, 2.08 mmol), 2-cyano-2-propyl
benzodithioate (CPBD) (1.84 mg, 8.33 μmol), and 2,2′-azobis(2-
methylpropionitrile) (AIBN) (0.274 mg, 1.67 μmol) were dissolved in
DMSO (0.6 mL). After being degassed using three freeze−pump−
thaw cycles, the reaction mixture was stirred for 24 h at 60 °C. The
reaction was quenched in liquid nitrogen. The polymer solution was
precipitated in methanol, filtered, rinsed with acetone, and then dried
at reduced pressure (yield: 0.280 g, 70%). 1H NMR (500 MHz,
CDCl ): δ (ppm) = 4.252 (br, 2H), 3.51 (br, 2H), 3.17 (br, 3H),
3
2.04−1.43 (br, 2H), 1.29 (br, 2H), 1.09−0.657 (br, 3H).
(
240−400 mesh). Nuclear magnetic resonance spectra were recorded
Synthesis of 2-(Ethylsulfonyl)ethyl Methacrylate (4). 2-
(Ethylsulfonyl)ethanol (1.00 g, 7.24 mmol) dissolved in dry
chloroform (15 mL) was added to triethylamine (1.61 g, 15.9
mmol) at room temperature. The solution was cooled to 0 °C, and
methacryloyl chloride (0.829 g, 7.97 mmol) was added slowly. The
reaction mixture was stirred for 30 min at 0 °C, allowed to warm to
room temperature, and stirred for 30 min. The reaction was quenched
with saturated NaHCO3 solution (10 mL), and the mixture was
washed with saturated solution of sodium chloride. The organic layer
with a 500 MHz Bruker spectrometer using chloroform-d and DMSO-
d6 solvents. Chemical shifts (δ) are expressed in parts per million
downfield from tetramethylsilane using the solvent resonance as the
internal standard. Mass spectral data were obtained at the University of
Massachusetts Mass Spectrometry Center.
Synthesis of 3-Hydroxysulfolane (1). Butadiene sulfone (20.0 g,
.169 mol) was dissolved in 2 N NaOH (42 mL) and stirred for 24 h
0
at room temperature. The reaction was quenched with 12 N HCl
solution (7.0 mL) and then concentrated at reduced pressure. The
crude product was purified by column chromatography (acetone/
was dried over MgSO and concentrated at reduced pressure. The
4
crude product was purified by column chromatography (acetone/
1
1
hexane 1:1), which afforded a colorless solid (yield: 20.1 g, 87%). H
hexane 1:3), which afforded a colorless oil (yield: 0.588 g, 39%). H
NMR (500 MHz, CDCl ): δ (ppm) = 4.70 (m, 1H), 3.41−3.09 (m,
NMR (500 MHz, CDCl ): δ (ppm) = 6.13 (s, 1H), 5.66 (s, 1H), 4.61
3
3
4
H), 2.99 (br, 1H), 2.39 (m, 2H). EI-MS (M + H): calcd for 137.02,
(t, J = 6.00 Hz, 2H), 3.34 (t, J = 6.00 Hz, 2H), 3.08 (q, J = 7.25 Hz,
2H), 1.96 (s, 3H), 1.42 (s, 3H). 13C NMR (125 MHz, CDCl ): δ
found 137.11.
3
Synthesis of 3-Sulfolanyl Methacrylate (2). Compound 1 (2.20 g,
6.2 mmol) dissolved in dry chloroform (10 mL) was added to
(ppm) = 166.6, 135.4, 126.9, 58.0, 51.1, 48.5, 18.1, 6.49. EI-MS (M +
H): calcd for 206.06, found 206.02.
1
triethylamine (3.63 g, 35.6 mmol) at room temperature. The solution
was cooled to 0 °C, and methacryloyl chloride (1.85 g, 17.8 mmol)
was added slowly. The reaction mixture was stirred for 30 min at 0 °C,
allowed to warm to room temperature, and stirred for 30 min. The
Synthesis of Poly(2-(methylsulfonyl)ethyl methacrylate) (PESE-
MA). Compound 4 (0.294 g, 1.43 mmol), 2-cyano-2-propyl
benzodithioate (CPBD) (1.26 mg, 5.71 μmol), and 2,2′-azobis(2-
methylpropionitrile) (AIBN) (0.187 mg, 1.14 μmol) were dissolved in
7
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Langmuir 2016, 32, 765−771