1
038
M. H. Stenzel and T. P. Davis
2
(2-Oxo-1,3,2-dioxaphospholoyl) Ethyl Acrylate
chromatographic pump operating at room temperature, an inline ERC-
3
415 degasser unit, a 10ADVP Shimadzu autoinjector with a stepwise
A 1.5 L five-necked reaction vessel was equipped with a mechanical
stirrer, pressure equalizing dropping funnel, thermometer, condenser,
drying tube, and dry air flow to introduce oxygen and minimize the
polymerization side reaction. The vessel was charged with 23.25 g
injection control motor with an accuracy of ± 1 µL, a column set
that consisted of a PL 5.0 µm bead size guard column and a set of
3
4
5
3
× 5.0 µm PL linear columns (10 , 10 , and 10 Å), and a DRI
◦
detector. THF (40 C) was used as a continuous phase at a flow
rate of 1 mL min . The columns were calibrated with commercial
linear polystyrene standards. Polymer analyte solutions were prepared
with 2.5 mg mL polymer, and sample injection volumes of 50 µL
were used.
(
0.20 mol) of 2-hydroxyethyl acrylate, 22.4 g (0.22 mol) of anhydrous
−
1
triethylamine, and 300 mL of dry tetrahydrofuran (THF). The reac-
◦
tion mixture was then cooled to −30 C with a dry ice/acetone bath
−
1
and 28.74 g (0.20 mol) of 2-chloro-2-oxo-1,3,2-dioxaphospholane in
1
50 mL of THF was added dropwise over a period of 2 h. After the addi-
tion of the 2-chloro-2-oxo-1,3,2-dioxaphospholane, the mixture was
allowed to heat up to room temperature and then heated at 40 C for
Casting Technique
◦
[
17]
a further 2 h. Finally, the reaction mixture was cooled with an ice/water
bath to <5 C and the triethylammonium hydrochloride was removed by
The casting method was described elsewhere.
◦
precipitation. The filtrate was stabilized with a free radical inhibitor and
THF was removed by rotary evaporation under a reduced pressure. The
product was obtained as a yellow oil in quantitative yield. δH (CDCl3)
References
[1] T. A. Horbett, Hydrogels in Medicine and Pharmacy 1986 (CRC
4
.3–4.5 (8 H), 5.7–6.5 (3 H).
Press: New York, NY).
[
2] (a) J. Watanabe, T. Eriguchi, K. Ishihara, Biomacromolecules
002, 3, 1375. (b) K. Ishihara, N. P. Ziats, B. P. Tierney,
N. Nakabayashi, J. Anderson, J. Biomed. Mat. Res. 1991, 25,
397.
3] A. L. Lewis, Colloids Surf. B 2000, 18, 261.
2
-Acryloyloxy Ethyl Phosphorylcholine
2
The ring opening reaction of 2-(2-oxo-1,3,2-dioxaphospholoyl) ethyl
acrylate with triethylamine was carried out in a high pressure reactor.
2
1
[
-(2-Oxo-1,3,2-dioxaphospholoyl) ethyl acrylate (41.1 g, 0.185 mol)
◦
[4] (a) R. Langer, J. P. Vacanti, Science 1993, 260, 920. (b)
R. Langer, J. P. Vacanti, Sci. Am. 1999, 280, 86.
[5] G. Widawski, M. Rawieso, B. François, Nature 1994, 369, 397.
[6] O. Pitois, B. François, Colloid Polym. Sci. 1999, 277, 574.
was dissolved in 900 mL of dry acetonitrile and cooled to −20 C for
the addition of trimethylamine (0.23 mol).The mixture was then reacted
◦
at 60 C for 12 h before cooling to room temperature for removal of the
◦
reactor. The mixture was then cooled at −20 C for at least 24 h to allow
[
7] O. Karthaus, N. Maruyama, X. Cieren, M. Shimomura,
H. Hasegawa, T. Hashimoto, Langmuir 2000, 16, 6071.
8] O. Pitois, B. François, Eur. Phys. J. B 1999, 8, 225.
9] M. H. Stenzel, Aust. J. Chem. 2002, 55, 239.
crystallization of the monomer. The precipitate was collected by filtra-
◦
tion, rinsed with acetone, and dried under vacuum at 40 C for 2–3 h.
The monomer was obtained as a clean white precipitate in 47% yield
[
[
(
Found: C 43.6, H 7.92, N 4.2, P 9.3%. C10H20NO6P requires C 46.6,
H 7.8, N 4.5, P 10.0%). δH (D2O) 3.22 (s, 9 H), 3.68 (m, 2 H), 4.17 (m,
H), 4.26 (b, 2 H), 4.41 (m, 2 H), 6.0–6.5 (3 H).
[
[
10] T. P. Le, G. Moad, E. Rizzardo, S. H. Thang, International
Patent WO 9801478, 1998.
11] P. Vana, J. F. Quinn, T. P. Davis, C. Barner-Kowollik, Aust. J.
Chem. 2002, 55, 425.
2
Polymerization
[
[
[
12] K. Ishihara, T. Ueda, N. Nakabayashi, Polym. J. 1990, 22, 355.
13] Y. Seo, Y. J. Li, T. Nakaya, Macromol. Rep. 1995, A32, 999.
14] (a) R. T. A. Mayadunne, E. Rizzardo, J. Chiefari, Y. K. Chong,
G. Moad, S. H. Thang, Macromolecules 1999, 32, 6977. (b)
R. T. A. Mayadunne, E. Rizzardo, J. Chiefari, J. Krstina,
G. Moad, A. Postma, S. H. Thang, Macromolecules 2000,
The macroRAFT agent was prepared from styrene and benzyldithioben-
[
10]
zoate according to a procedure described elsewhere.
Polystyrene
−
1
macroRAFT agent (1.0 g, Mn 32 000 g mol ) and AIBN (4.0 mg)
were dissolved in DMF (30 mL), while APC (1.0 g) was dissolved in
methanol (5 mL). Both solutions were mixed together and purged with
◦
nitrogen. The mixture was immersed in a waterbath at 60 C for 24 h.
3
3, 243.
The conversion was determined by NMR (chloroform/methanol, 2 : 1)
or gravimetrically after purification of the polymer by dialysis against
water using regenerated cellulose tubular membrane.
[
15] C. Barner-Kowollik, T. P. Davis, J. P. A. Heuts, M. H. Stenzel,
P. Vana, M. Whittaker, J. Polym. Sci., Part A: Polym Chem.
2
003, 41, 365.
[
16] P. Vana, T. P. Davis, C. Barner-Kowollik, Macromol. Theory
Simul. 2002, 11, 823.
Gel Permeation Chromatography
Gel permeation chromatography was performed on a modular sys-
tem comprised of the following: a GBC LC1120 high-pressure liquid
[17] M. Stenzel-Rosenbaum, T. P. Davis, A. G. Fane, V. Chen, Angew.
Chem. Int. Ed. 2001, 40, 3428.