Functional Polyesters from ω-Carboxy Fatty Acids
Biomacromolecules, Vol. 11, No. 1, 2010 261
CH3], 274 (9), 259 (100) [M+
The biotransformation of oleic acid was also conducted in a 3-L
Bioflo3000 fermentor (New Brunswick Scientific Co., U.S.A.) in fed-
batch culture. The conversion medium above was used except for
addition of 0.05% antifoam 204 (Sigma) and 0.5% oleic acid. The
culture was grown at 30 °C at 900 rpm, with aeration rate of 1.5 vvm.
After 12 h fermentations (growth phase), the biotransformation phase
was started by feeding oleic acid at 2 mL/L. Glucose (500 g/L) as
cosubstrate was fed continuously at 1.2 g/L/h. During the biotransfor-
mation phase, the pH was maintained at 7.6 automatically by addition
of 4 mol/L NaOH solution and dissolved oxygen was controlled at
about 60%. To avoid excessive foaming, antifoam 204 was added as
needed. Every 12 h, a 5 mL aliquot from fermentation media was
withdrawn to determine cell growth, glucose concentration, depletion
of the fatty acid, and diacid production.
Extraction and Purification of Fermentation Products. Fermenta-
tion broths of oleic acid and erucic acid were acidified to pH 1.0 with
HCl and extracted twice with diethyl ether. To avoid epoxy ring-opening
during acidification, the fermentation broth of 9,10-epoxy stearic acid
was slowly acidified to pH 3.0 with 5 N HCl and then extracted with
diethyl ether. Diethyl ether was removed by rotoevaporation that gave
a light yellow solid for all products from oleic acid, erucic acid, and
9,10-epoxy stearic acid. The crude product (4 g), dissolved in diethyl
ether, was separated into components with a Biotage SP1 Flash
Chromatography system (Biotage Inc., A Dynax Corp. Company,
U.S.A.). Separations were performed using a Biotage SI 40+M column
(150 × 40 mm ID; 100 g KP-Sil silica; 40-63 µm particle size; flow
rate: 25-50 mL/min). The mobile phase consisted of n-hexane/diethyl
ether mixtures that were run in gradient mode with compositions ranging
from 30 to 80% diethyl ether in 10 column volumes (CVs) at 30 mL/
min flow rate. Fractions were monitored at 220 and 280 nm by UV
detection. Unreacted fatty acid substrate eluted first and then R,ω-diacid
eluted in the second peak. Fractions in the second peak showing a single
band on TLC plate were pooled and concentrated by rotoevaporation
that gave a white powder. The purity of ω-carboxyl OA, ω-carboxyl
EA, and ω-carboxyl epoxy SA used in polymerizations was >99%
(GC-MS).
[M+
-
CH3OH
-
-
(CH3)2COO(CH2)7CHO], 201 (5) [(CH3)2COO(CH2)7CHO+], 169 (4)
[CH3COO(CH2)7C+], 155 (44) [CHO(CH2)CO+], 137 (12), 109 (18),
73 (53) [TMSi+], 55 (11) [C4H7+], 31 (9) [CH3O+].
Novozym 435-Catalyzed Condensation Polymerizations
between ω-Carboxy Fatty Acids and Diols. Reactions were performed
in a parallel synthesizer (AdvantageTM 2050, Argonaut) both in-bulk
and in diphenyl ether at 90 °C. Unsaturated and epoxidized R,ω-diacids
(1.0 mmol) and diol (1.0 mmol) were transferred into reactor tubes of
the parallel synthesizer and, then, 10%-by-wt N435 (i.e., 1%-by-wt
CALB) relative to monomer was added. For solution polymerizations,
1 mL diphenyl ether was added. Control reactions without addition of
N435 were also performed in parallel. Vacuum (10 mmHg) was applied
after 2 h. To follow the progress of polymerizations, aliquots were
withdrawn at 2, 6, 12, 24, 36, and 48 h. Reactions were terminated by
addition of cooled chloroform and N435 was removed by filtration.
Filtrates were concentrated at 50 °C under vacuum to remove
chloroform and then directly (i.e., without fractionation by precipitation)
1
analyzed by gel permeation chromatography (GPC) and H and 13C
NMR. Alternatively, the concentrated filtrate solutions were added into
magnetically stirred cold methanol. Precipitated polymers were filtered,
were washed three times with cold methanol, and were dried in vacuo
overnight at 50 °C.
Polyester from ω-Carboxyl OA and 1,3-Propanediol
1
(Poly(ω-carboxyl OA-co-PD)). Yield: 80%. H NMR (10.7 mg in 0.7
mL CDCl3; ppm): 5.2-5.35 (2H, m, dCH-CH2-), 4.05 (4H, m, -(CO)-
O-CH2-), 2.23 (4H, t, -CH2-CO-), 1.8-2.0 (6H, m, dCH-CH2-, -(CO)-
O-CH2-CH2-), 1.45-1.6 (4H, m, -CH2-CH2-CO-), 1.1-1.35 (16H, m,
-CH2-). 13C NMR (76.8 mg in 0.7 mL CDCl3; ppm): 173.7 (CdO),
129.8 (dCH-), 60.8 (-CH2O-), 34.2, 29.7, 29.2, 29.1, 28.1, 27.2, 24.9.
Polyester
from
ω-Carboxyl
OA
and
1,8-Octanediol
1
(Poly(ω-carboxyl OA-co-OD)). Yield: 79%. H NMR (10 mg in 0.7
mL CDCl3; ppm): 5.3-5.4 (2H, m, dCH-CH2-), 4.05 (4H, m, -(CO)-
O-CH2-), 2.35 (4H, t, -CH2-CO-), 1.9-2.1 (4H, m, dCH-CH2-),
1.5-1.7 (8H, m, -CH2-CH2-(CO)-O-CH2-CH2-), 1.2-1.4 (24H, m,
-CH2-). 13C NMR (80 mg in 0.7 mL CDCl3; ppm): 173.9 (CdO), 129.8
(dCH-), 64.3 (-CH2O-), 34.3, 29.6, 29.2, 29.1, 28.6, 27.1, 25.8, 24.9.
Polyester from ω-Carboxyl OA and 1,16-Hexadecanediol
ω-Carboxyl OA. Yield: 95% (from crude mixture of diethyl ether
extracted products); mp 66-68 °C. 1H NMR (9.8 mg in 0.7 mL CDCl3;
ppm): 5.3-5.4 (2H, m, dCH-CH2-), 2.35 (4H, t, -CH2-CO-), 1.9-2.1
(4H, m, dCH-CH2-), 1.6 (4H, m, -CH2-CH2-CO-), 1.2-1.4 (16H, m,
-CH2-). 13C NMR (63.5 mg in 0.7 mL CDCl3; ppm): 180.7 (CdO),
129.8 (dCH-), 34.1, 29.6, 29.1, 29.0, 28.9, 27.1, 24.6. IR (KBr; cm-1):
1691 (s, CdO), 725 (m, CdC, cis-form). MS for dimethyl ester of
1
(Poly(ω-carboxyl OA-co-HD)). Yield: 89%. H NMR (8.3 mg in 0.7
mL CDCl3) (ppm): 5.3-5.4 (2H, m, dCH-CH2-), 4.05 (4H, m, -(CO)-
O-CH2-), 2.30 (4H, t, -CH2-CO-), 1.9-2.1 (4H, m, dCH-CH2-),
1.5-1.7 (8H, m, -CH2-CH2-(CO)-O-CH2-CH2-), 1.1-1.4 (40H, m,
-CH2-). 13C NMR (81.9 mg in 0.7 mL CDCl3; ppm): 173.7 (CdO),
129.7 (dCH-), 64.3 (-CH2O-), 34.3, 29.6, 29.5, 29.4, 29.2, 29.1, 29.0,
28.9, 28.6, 27.1, 25.8, 24.9.
ω-carboxyl OA, m/z (rel int, %): 340 (5) [M+], 308 (49) [M+
-
CH3OH], 276 (90) [M+ - 2CH3OH], 248 (18) [M+ - 2CH3OH -
CO], 234 (7) [M+ - 2CH3OH - CO - CH2], 165 (19) [M+ - CH3OH
- CH3OOC(CH2)6], 151 (27), 109 (37), 95 (31), 81 (100), 69 (48)
[C5H9+], 55 (81) [C4H7+], 41 (63) [C3H5+].
Polyester
from
ω-Carboxyl
EA
and
1,8-Octanediol
1
(Poly(ω-carboxyl EA-co-OD)). Yield: 79%. (a) H NMR (7.5 mg in
0.7 mL CDCl3; ppm): 5.3-5.4 (2H, m, dCH-CH2-), 4.05 (4H, m,
-(CO)-O-CH2-), 2.33 (4H, t, -CH2-CO-), 2.0 (4H, m, dCH-CH2-),
1.5-1.7 (8H, m, -CH2-CH2-(CO)-O-CH2-CH2-), 1.2-1.4 (32H, m,
-CH2-). 13C NMR (CDCl3; 75 mg in 0.7 mL ppm): 173.9, 173.8 (CdO),
129.9, 129.7 (dCH-), 64.2 (-CH2O-), 34.3, 29.7, 29.6, 29.54, 29.51,
29.4, 29.3, 29.2, 29.1, 29.06, 28.6, 27.2, 27.1, 25.8, 24.9.
ω-Carboxyl EA. Yield: 70% (from crude mixture of diethyl ether
extracted products); mp 71-73 °C. 1H NMR (10.3 mg in 0.7 mL
CDCl3; ppm): 5.3-5.4 (2H, m, dCH-CH2-), 2.33 (4H, t, -CH2-CO-),
1.9-2.1 (4H, m, dCH-CH2-), 1.6 (4H, m, -CH2-CH2-CO-), 1.2-1.4
(24H, m, -CH2-). 13C NMR (63.5 mg in 0.7 mL CDCl3; ppm): 180.4,
180.5 (CdO), 130.0, 129.7 (dCH-), 34.1, 29.7, 29.6, 29.57, 29.53,
29.5, 29.4, 29.3, 29.2, 29.1, 29.0, 27.2, 27.1, 24.6. IR (KBr; cm-1):
1691 (s, CdO), 725 (m, CdC, cis-form). MS for dimethyl ester of
Polyester from ω-Carboxyl Epoxy SA and 1,8-Octanediol
1
(Poly(ω-carboxyl epoxy SA-co-OD)). Yield: 60%. H NMR (10.0 mg
in 0.7 mL CDCl3; ppm): 4.05 (4H, m, -(CO)-O-CH2-), 2.9 (2H, bs,
-CH-, cis-epoxide), 2.29 (4H, t, -CH2-CO-), 1.2-1.7 (36H, m, -CH2-).
13C NMR (82.7 mg in 0.7 mL CDCl3; ppm): 173.8 (CdO), 64.2
(-CH2O-), 57.1 (-CH-, cis-epoxide), 34.2, 29.3, 29.1, 29.0, 28.9, 27.7,
26.5, 25.7, 24.8.
ω-carboxyl EA, m/z (rel int, %): 396 (0.7) [M+], 364 (8) [M+
-
CH3OH], 332 (13) [M+ - 2CH3OH], 304 (4) [M+ - 2CH3OH - CO],
290 (2) [M+ - 2CH3OH - CO - CH2], 165 (8), 151 (13), 109 (32),
95 (56), 81 (68), 69 (69) [C5H9+], 55 (100) [C4H7+], 41 (39) [C3H5+].
ω-Carboxyl Epoxy SA. Yield: 92% (from crude mixture of diethyl
ether extracted products); mp 85-86 °C. 1H NMR (10.0 mg in 0.7 mL
CDCl3) (ppm): 2.92 (2H, bs, -CH-, cis-epoxide), 2.35 (4H, t, -CH2-
CO-), 1.2-1.8 (24H, bm, -CH2-). 13C NMR (50.6 mg in 0.7 mL CDCl3;
ppm): 180.1 (CdO), 57.3 (-CH-, cis-epoxide), 34.0, 29.2, 29.1, 28.9,
27.6, 26.4, 24.5. MS for TMSi-ether dimethyl ester derivative of
ω-carboxyl epoxy SA, m/z (rel int, %): 429 (2) [M+ - CH3O], 413 (2)
Unlike the above copolymerizations, reaction of 1,18-octadecanedioic
acid (ω-carboxyl SA) with 1,8-octanediol was performed in a 250 mL
flask with addition of toluene using an azeotrope at 90 °C. 1,18-
Octadecanedioic acid (20 mmol) and 1,8-octanediol (20 mmol) were
transferred into a flask with 100 mL toluene and 10%-by-wt N435.
Vacuum (200-250 mmHg) was applied after 2 h. To follow the
progress of polymerizations, aliquots were withdrawn at 2, 6, 12, 24,
36, and 48 h. As above, an aliquot that was not precipitated was used