synthesis methods of poly(lactic acid)
DESCRIPTION
Synthesis methods of poly(lactic acid). ผศ.ดร. วรา วุฒิ ตั้งพสุธาดล ภาควิชาเคมี คณะวิทยาศาสตร์ จุฬาลงกรณ์มหาวิทยาลัย [email protected]. Poly(lactic acid) Polylactide Poly( L -lactic acid) Poly- L - lacide Poly( D -lactic acid) Poly- D - lacide - PowerPoint PPT PresentationTRANSCRIPT
Synthesis methods of poly(lactic acid)
ผศ.ดร. วราวุฒิ ต้ังพสธุาดล ภาควชิาเคมี คณะวทิยาศาสตร์
จุฬาลงกรณ์มหาวทิยาลัย[email protected]
2
BioplasticsPoly(lactic acid)PolylactidePoly(L-lactic acid)Poly-L-lacidePoly(D-lactic acid)Poly-D-lacideOther polyesters: poly(glycolic acid), poly(butylene
succinate), poly(butylene adipate terephthalate), poly(ethylene terephthalate) etc.
3
Poly(L-lactic acid) vs Poly(D-lactic acid)
HO
CH3
O
OH
L-Lactic acid
HOO
OHCH3
D-Lactic acid
4
Poly(lactic acid) or polylactide
HO CH C
O
OH H O CH C
O
OHPolycondensation
lactic acid
n+ H2O
PLA
CH3 CH3catalyst
O
OO
O
CH3
H3C
Ring-opening polymerization
Lactide
H O CHCH3
C
O
OH
PLA
catalyst n
or polylactide
5
HO CH C
O
OH
H O CH C
O
OH
dehydration
lactic acid
n+ (n-1) H2O
PLA
CH3
CH3
reduce pressure80ฐC, 4h
esterification
N2, titanium butoxide,170ฐC, 1h
polycondensationreduce pressure
170ฐC, 5h
damp LA
PLA oligomer
6
Mechanism of metal catalyzed esterification
HO CH C
O
OHCH3
Ti4+
R OH
HO CH C
O
OCH3
R
7
Mechanism of metal catalyzed ring-opening polymerization
O
OO
O
CH3
H3C
Lactide
R OH
M+
R O C
OHCCH3
O C
OHCCH3
O-
8
Key reaction conditions for making polyesters: (that you can also play with)
TemperatureVacuum (dehydration process)Catalyst
Recommended paper:T. Maharana, B. Mohanty, Y.S. Negi, Progress in Polymer Science 34 (2009) 99–124
9
End-Functionalized PLA-PLA with new properties
10
Crosslinkable PLABy Worapob KitpanitchProgram of Petrochemistry and Polymer Sciencegraduated in May 2012
11
Literature review
C
O
CH CH C
O
O CH
CH3
C
O
O CH2 CH2 CH2 CH2 Ox y z
C
O
CH CH C
O
O CH
CH3
C
O
O CH2 CH2 CH2 CH2 Ox y z
PLBM
Benzoyl peroxide
Park, E.S. et al. Journal of Applied Polymer Science, 2003, 90, 1802-1807.
12
Literature review
Irgacure 651(2,2-dimethoxy-2-
phenylacetophenone)
UV at 365 nm
Brown, C.D. et al. Journal of Biomaterials Science, Polymer Edition, 2005, 16, 189-201.
PLA
OCHC
O CH3
n
+OO CH2 CH2 O
O
poly(ethylene glycol) diacrylaten
+
13
I.Synthesis of PLLA-diol
Zeng, J.B. et al. Ind. Eng. Chem. Res. 2009, 48, 1706-1711.
L-lactic acid was heated to 80 °C under reduced pressure for 3 h 1.5 mol% 1,4-butanediol and 0.1 mol% TNBT were added The reaction was heated up to 160 °C under reduced pressure for 5 h and then continued at
180 °C for 5 h The resulting polymer was purified by dissolving in chloroform and precipitating in MeOH The white product of PLLA was obtained and dried by vacuum at room temperature
CHO C
O
On
PLLA-diol
O CH OC
O
n
Lactic acid
OHCHCHO
O
HOOH
1,4-butanediol
CH3 CH3CH3
Polycondensation H2OHH
14
1H NMR spectrum of PLLA-diol
1.51.52.02.02.52.53.03.03.53.54.04.04.54.55.05.05.55.56.06.06.56.57.07.07.57.5
CHO C
O
On
O CH OC
O
nCH3
CH3C
C
O
CH OHCH3
O
CHHOCH3
e
f
a
b d
c
ef
a
c
b
d
ppm
15
II.Methacrylated-endcapped PLLA
CHO C
O
On
PLLA-diol
O CH OC
O
nCH3
CH3
CH C
O
On
PLLA-diMeth
O CH OC
O
nC
O
C
CH2
H3CO
C
O
C CH3
CH2
H3C CC O C
C CH3
CH2
O O
CH2
CH3CH3
n
PLLA
C CO
OH
H3C
H2C
+
H3C CC O C
C CH3
CH2
O O
CH2
Methacrylic acid
OCHCHO
O
CH3
HH
Hn
PLLA-Meth
OCHCHO
O
CH3
C
O
C CH3
CH2
C CO
OH
H3C
H2C+
Methacrylic acid
80°C
80°C
(a)
(b)
16
Effect of mole ratios (PLLA:Meth) on the degree of methacrylate substitution on PLLA chain end (reaction time = 24 h, reaction temperature = 80 °C)
1:5 1:10 1:20 1:40 1:60 1:800
102030405060708090
100
Mole ratios of PLLA:Meth
Deg
ree
of s
ubst
itutio
n (D
S)
17
1.51.52.02.02.52.53.03.03.53.54.04.04.54.55.05.05.55.56.06.06.56.57.07.07.57.5
1H NMR spectrum of PLLA-MA
nOCHCHO
O
CH3
CO
CH CH CO
OHa b
a b
ppm
6.206.206.406.406.606.606.806.807.007.00
decrease
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III.Crosslinking of PLLA
Thermal crosslinking
The functionalized PLLA was mixed with 10 wt% BPO in chloroformThe mixture was poured into a circular mold (3 mm high and 6 mm in
diameter) and kept at room temperature for 24 hThe mixture was heated at 150 °C for 1 h
O
O O
O
(a)
(b)
OCHCHO
O
CH3n
C
O
C
CH2
CH3
PLLA-Meth
CHCH3
C
O
On
PLLA-diMeth
O CHCH3
OC
O
nC
O
C
CH2
H3CO
C
O
C CH3
CH2
initiator
initiatorOCHCHO
O
CH3n
C
O
CCH3
PLLA network
CH2
CHCH3
C
O
On
PLLA network
O CHCH3
OC
O
nC
O
CO
C
O
CCH3H3C
CH2H2C
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Degree of gel content
Thermal crosslinking
Chloroform immersion 24 h
Gel content = 60%
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Positively-charged PLABy Piyachai KhomeinDepartment of Chemistry, Faculty of Science, CUgraduated in May 2012
21
Positively-charged PLA
PLA GTMAC Positively-charged PLA
O
OOH
Hn
O NCl O
OO
OHN ClO
OH
n
By Piyachai KhomeinDepartment of Chemistry
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Hydrophilicity determination of PLA+ films
Sample (Mn)Degree of
substitutionContact angle
PLLA(2,978) - 57±2°
p-PLLA(2,945) 11.6 55±2°
p-PLLA(2,079) 23.7 56±1°
p-PLLA(3,135) 59.3 51±1°
p-PLLA(2,029) 76.5 45±4°
P-PLLA(2,838) 90.0 47±1°
Positively-charged PLA
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End-Functionalized PLA
O
OOH
Hn
O OO
O
O
HOH
O
n
Lu, D. D.; Yang, L. Q.; Zhou, T. H.; Lei, Z. Q., European Polymer Journal 2008, 44 (7), 2140-2145.
O
OO
Hn
H3C O
OO
Hn
OH3C
311
A B
Kobori, Y.; Iwata, T.; Doi, Y.; Abe, H., Biomacromolecules 2004, 5 (2), 530-536.
24
Ouchi, T.; Kontani, T.; Ohya, Y., Polymer 44 (2003), 3927-3933
OO
O
nO
O
OO
H
PEG PLA
End-Functionalized PLA