ผศ.ดร.วราวุฒิ ตัง้ พสุธาดล
ภาควิชาเคมี คณะวิทยาศาสตร์
จุฬาลงกรณ์มหาวิทยาลัย
varawut.t@chula.ac.th
2
Bioplastics
 Poly(lactic acid)
 Polylactide
 Poly(L-lactic acid)
 Poly-L-lacide
 Poly(D-lactic acid)
 Poly-D-lacide
 Other 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)
O
O
HO
OH
CH3
L-Lactic acid
HO
OH
CH3
D-Lactic acid
4
Poly(lactic acid) or polylactide
O
Polycondensation
HO CH C OH
CH3
catalyst
O
H
O CH C OH + H2O
n
CH3
lactic acid
O
H3C
O
O
Lactide
PLA
CH3
O
Ring-opening
polymerization
catalyst
O
H
O
CH
CH3
C
OH
n
PLA
or polylactide
5
O
HO CH C OH
CH3
lactic acid
dehydration
reduce pressure
80ฐC, 4h
damp LA
esterification
N2, titanium butoxide,
170ฐC, 1h
PLA oligomer
O
H
polycondens ation
reduce pressure
170ฐC, 5h
O CH C OH + (n-1) H2O
n
CH3
PLA
6
 Mechanism of metal catalyzed esterification
Ti4+

O
HO CH C OH
CH3
R OH
O
HO CH C O R
CH3
7
 Mechanism of metal catalyzed ring-opening
polymerization
M+
O
R OH
O
CH3
O
R O
H3C
O
Lactide
O
H
C C O
CH3
O
H
C C O
CH3
8
Key reaction conditions for making
polyesters:
(that you can also play with)
 Temperature
 Vacuum (dehydration process)
 Catalyst
 Recommended paper:
T. Maharana, B. Mohanty, Y.S. Negi, Progress in Polymer
Science 34 (2009) 99–124
9
10
By Worapob Kitpanitch
Program of Petrochemistry and Polymer Science
graduated in May 2012
11
Literature review
O
O
C CH
CH 3 O
CH C
O
CH C
x
O CH 2 CH2 CH 2 CH2 O
z
y
PLBM
Benzoyl peroxide
O
C
O
CH CH
CH 3 O
C
O
x
CH C
O CH 2 CH2 CH 2 CH2 O
y
Park, E.S. et al. Journal of Applied Polymer Science, 2003, 90, 1802-1807.
z
12
Literature review
O
CH 3
C
CH O
O
+
n
PLA
O
CH 2 CH2 O
+
O
n
poly(ethylene glycol) diacrylate
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.
13
I.Synthesis of PLLA-diol
O
OH
HO C
O
O
CH OH
CH 3
Lactic acid
HO
Polycondensation
O
H O CH C O
CH3 n
1,4-butanediol
C CH O H
n
CH 3
H 2O
PLLA-diol
 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
Zeng, J.B. et al. Ind. Eng. Chem. Res. 2009, 48, 1706-1711.
14
1H
NMR spectrum of PLLA-diol
a
O
O
HO CH C O CH C
CH 3
CH3
O
f
O
O
O
b
C CH O
CH 3
e
n
a
d
C CH OH
n
CH 3
c
b
c
d
7.5
7.0
6.5
6.0
5.5
5.0
4.5
e
f
4.0
3.5
3.0
2.5
2.0
1.5 ppm
15
II.Methacrylated-endcapped PLLA
(a)
CH2
CH2
H3C C
C CH3
C O C
O
HO
O
C CH O H
CH3
n
O
80°C
CH2
O
HO
C CH3
+
C CH O
C
CH3
nO
O
C C
H2 C
PLLA-Meth
PLLA
H3 C
OH
Methacrylic acid
CH2
CH2
(b)
O
O
O
H O CH C O
CH3
n
PLLA-diol
C CH O H
n
CH3
CH2
CH2
H3 C C
C CH3
C O C
O
O
80°C
O
O
H3 C C
C O CH C
O
CH 3
O
O
n
PLLA-diMeth
+
H 3C
H 2C
O
C C
OH
Methacrylic acid
C CH O C
CH 3
nO
C CH3
16
Degree of substitution (DS)
Effect of mole ratios (PLLA:Meth) on the degree of methacrylate substitution on
PLLA chain end (reaction time = 24 h, reaction temperature = 80 °C)
100
90
80
70
60
50
40
30
20
10
0
1:5
1:10
1:20
1:40
1:60
Mole ratios of PLLA:Meth
1:80
17
1H
NMR spectrum of PLLA-MA
O
HO
7.00
O a
C CH
C CH O
CH 3
n
6.80
6.60
b
O
CH C OH
6.40
6.20
decrease
a b
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5 ppm
18
III.Crosslinking of PLLA
CH 2
(a)
O
HO
C
C
C CH O
CH3
CH3
O
initiator
HO
C
C CH O
nO
CH3
PLLA-Meth
C
CH 2
CH3
nO
PLLA network
(b)
CH2
CH2
O
C CH 3
O
H 3C C
C
O CH C
O
CH 3
O
O
C
CH O
CH 3
n
H2C
initiator
C
O
C
H3C
nO
PLLA-diMeth
C
O
C
O CH C
O
CH 3
O
O
n
C CH O
CH 3
C
nO
PLLA network
O
O
O
O
Thermal crosslinking
 The functionalized PLLA was mixed with 10 wt% BPO in chloroform
 The mixture was poured into a circular mold (3 mm high and 6 mm in
diameter) and kept at room temperature for 24 h
 The mixture was heated at 150 °C for 1 h
CH 2
CH 3
19
Degree of gel content
Chloroform
immersion 24 h
Thermal crosslinking
Gel content = 60%
20
By Piyachai Khomein
Department of Chemistry, Faculty of Science, CU
graduated in May 2012
21
Positively-charged PLA
O
H
O
O
PLA
O
N
H
n
O
Cl
H
O
GTMAC
By Piyachai Khomein
Department of Chemistry
O
O
O
OH
n
Positively-charged PLA
N
Cl
22
Positively-charged PLA
Hydrophilicity determination of PLA+ films
Sample (Mn)
Degree of
substitution
Contact 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°
23
End-Functionalized PLA
O
H
O
O
H
n
OH
O
O
H
O
O
O
O n
Lu, D. D.; Yang, L. Q.; Zhou, T. H.; Lei, Z. Q., European Polymer Journal 2008, 44 (7), 2140-2145.
O
H3C
O
O
O
11
A
H
n
H 3C
O
O
O
3
B
Kobori, Y.; Iwata, T.; Doi, Y.; Abe, H., Biomacromolecules 2004, 5 (2), 530-536.
H
n
24
End-Functionalized PLA
O
H
O
PEG
O
O
O
O
O
Ouchi, T.; Kontani, T.; Ohya, Y., Polymer 44 (2003), 3927-3933
PLA
n