advisor : assoc. prof. dr. sarawut rimdusit co-advisor: dr. suchada tragoonwichian polymer...
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Advisor : Assoc. Prof. Dr. Sarawut Rimdusit
Co-advisor: Dr. Suchada Tragoonwichian
Polymer Engineering Laboratory
Department of Chemical Engineering
Faculty of Engineering
Chulalongkorn University
Bangkok 10330, Thailand
by
Sunanta Klayposri
Controlled Molecular Weight Polycarbonate
Synthesis from Melt Transesterification of
Bisphenol-A and Diphenyl Carbonate
* C
CH3
CH3
O C
O
O *
n
Carbonate Group
• An important class of engineering thermoplastics.
• Containing recurring carbonate groups (-O-CO-C-)
in the main chain.
• The most popular PC is based on bisphenol-A.
Polycarbonate (PC)
Ref.: L. A. Utracki, “Commercial Polymer Blends,” Chapman & Hall, London, (1998). p.85.2
Properties of Polycarbonate
• High impact resistanceIzod, notched impact strength = 850 J m-1
• High heat resistanceMaximum use temperature = 100-135C
• Optical clarityLight transmittance, initial 85 % and after 3 yr 82 %
• Dimensional stability Tensile modulus = 2.38 GPa
Flexural modulus = 2.34 GPa
• Good electrical resistance
Ref.: D. J. Brunelle, “Encyclopedia of Polymer Science and Technology,” John Wiley & Sons, Inc., 2006J. E. Mark, “Polymer Data Handbook,” Oxford University Press, Inc., 1999.
3
Applications of Polycarbonate
• Optical Media
• Automotive Part
• Bottles & Packaging
• Electrical Part
• Glazing & Sheet
• Safety & Healthcare
• Diffuser Sheets for LCD Screens
Ref.: http://www.plasticseurope.org/, http://www.lgdow.com/products/application.htm, http://www.bayer.co.th/webphp/eng/production.php
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Linear and Branched Polycarbonate
Linear Polycarbonate
OH
O
Branched Polycarbonate
monomers having two different
functional groups react through
condensation polymerization.
monomers having two different
functional groups react through
condensation polymerization, one
having at least 3-functional sites.
DPC
BPA
55.
Branched Polycarbonate
Mw = 5,000 g/mole
OH
O
DPC
BPA
Mw= Mc = 5,000 g/mole
Ref.: R. Dobkowski., Rheol Acta., 34, 578-585(1995).6.
Properties of Branched Polycarbonate
• Melt flow indexBranched polycarbonate ; Melt flow index = 2.5 g/10minLinear polycarbonate ; Melt flow index = 12.2 g/10min
• Optical clarityLight transmittance;Branched polycarbonate; 1 mm thick 88 %, 2 mm thick 87% and
4 mm thick 84%Linear polycarbonate; 3 mm thick 89 %
• Enhanced shear sensitivities Strong shear thinning
• Good processability from high melt strengthExtrusion blow molding, Injection stretch blow molding
Ref.: D. Karlik, H.P. Brack, H. Verhoogt, J.P. Lemmon, J.H. Kamps, W.L. Sederel, J.M.D. Goossens, U.S. Patent 6,504,002 B1 (2003).
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1. To synthesize polycarbonate prepolymer with a critical molecular weight (Mc) of at least 5,000 to be used as PC precursor for further branched PC preparation.
2. To investigate the optimum conditions for the PC prepolymer preparation.
Objectives
8
Experimental Method
BPA DPC
Nitrogen Tank Vacuum PumpHeater
Trap
9
Stirrer
Gel Permeation Chromatography
Controller
PumpRefractive Index Detector
Column Container
Ref.: http://www.waters.com/waters/nav.htm?cid=10167568&locale=en_TH 10
Pores
Small permeating molecules
Large excluded molecules
Results & Discussion
HO C
CH3
CH3
OH O C O
O
n n
2n-1
Bisphenol-A Diphenyl Carbonate
Linear Polycarbonate Phenol
Melt Transesterification of Linear Polycarbonate
12
C O C
CH3
CH3
O C O
O
n
O
O
OH
175
180
185
190
195
200
205
0
100
200
300
400
500
600
700
800
0 50 100 150 200 250
Temperature
Pressure
Tem
pe
ratu
re(o
C)
Press
ure
(mm
Hg
)
Reaction Time(min)
760 mmHg
100 mmHg180oC
200oC
Synthesis Conditions of PC; without a Catalyst
13
FT-IR Spectra of Linear Polycarbonates
Commercial PC(Wonderilte110)
As-synthesized PC
5001000150020002500300035004000
Ab
so
rba
nc
e
Wavenumber (cm-1)
C-H (Aromatic ring) (1506,757)
C-H (Methyl groups) (2969)
O- (C=O)-O (Carbonyl)) (1773)
C=C (aromatic ring)(1602,1465)
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Molecular Weight Profile of Synthesized PC without a Catalyst @ DPC:BPA 1.05:1.00
15
0
0.5
1
1.5
2
2.5
0 50 100 150 200 250
Mo
lecu
lar
Wei
gh
t (M
w x
10
4)
Reaction Time (min)
Molecular Weight Profile of Synthesized PC without a Catalyst @ DPC:BPA 1.26:1.00
16
0
0.2
0.4
0.6
0.8
1
0 50 100 150 200 250
Mo
lec
ula
r W
eig
ht
(Mw
x104)
Reaction Time (min)
Molecular Weight Profile of Synthesized PC without a Catalyst at Various
DPC/BPA Mole Ratios
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0
0.5
1
1.5
2
2.5
0 50 100 150 200 250
DPC:BPA 1.05:1.00
DPC:BPA 1.26:1.00
Mo
lecu
lar
Wei
gh
t (
Mw
x 1
04)
Reaction Time (min)
DSC Thermograms of PC Products
Heating rate at 10oC/min
MwTg
(oC)
2,747
10,599
13,144
14,475
101
130
133
136
18
40 60 80 100 120 140 160 180 200
Mw 14,475
Mw 2,747
Mw 10,599
Mw 13,144
Hea
t F
low
(m
W)
Exo
Up
Temperature (oC)
Conclusions
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The obtained FTIR absorption bands suggested the formation of PC by condensation of BPA with DPC.
The reaction of PC prepolymer of varied Mw could be performed at 200oC without adding catalyst, and by varying mole ratio of DPC/BPA reactants.
The PC prepolymer prepared using the initial DPC/BPA mole ratio of 1.26:1.00 was found to be appropriate for the preparation of the PC precursor to provide a molecular weight in a range that suitable for branched PC production.
The Tg significantly increased with increasing molecular weight of the synthesized PC.
Innovation and Technology Department, PTT
Phenol Co., Ltd.
Higher Education Research Promotion and
National Research University Project of Thailand
Office of the Higher Education Commission
(AM1076A).
Acknowledgements
20
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Diphenyl Carbonate (DPC)
• Molecular weight; 214.216 g/mol
• Comonomer for BPA polycarbonate
• White solid (flakes)
• Melting point 78oC
• Boiling point 320oC
• Methods for DPC synthesis Transesterification of DMC to DPC Oxidative carbonylation of phenol
O C O
O
Structural formula of DPC
11Ref.: www.inchem.org, W. B. Kim, U. A. Joshi, and J. S. Lee, Ind. Eng. Chem. Res., 43, 1897-1914(2004).
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Branching Agent: THPE
HO
CH3
OH
OHStructure formula
Formula; C20H18O3
Molecular weight; 306.355 g/mol
Melting point; 246-248oC
Physical form; solid
Ref.: www.chemicalbook .com /Chemicalproductproperties_EN_CB7458874.htm12
1,1,1,-tris(4-hydroxyphenyl)ethane (THPE)
232
Branching Agent Branching Agent
Structure formula
OHO
O
O
HO
HO
Formula; C9H6O6
Molecular weight; 210.14 g/mol
Purity; ≥98%
Melting point; 240-245 °C
Solubility; 83 g/l (30 °C)
Ref.: www.biotechsci.co.th www.indiamart.com
Trimellitic acid
2413
S. P. Kim and J. S. Lee (1999)
Literature Reviews
Synthesis of branched polycarbonate and properties of blends with linear polycarbonate
Results:
15Ref.: S.P. Kim, J.S. Lee, S.H. Kim, B.H. Lee, S.H. Kim, and W.G. Kim, Ind. Eng. Chem. Res., 5, 268-273(1999).
At 0.35 mol% of THPE- Aromatic proton peaks;(THPE) not detected.At 2 mol% of THPE- Aromatic proton peaks;(THPE) at 6.6-6.7 ppm.- Methyl proton peaks; (THPE) at 1.65 ppm.- Hydroxyl groups;(BPA+THPE) at 4.9 ppm.
1H NMR Spectra of branching agent
26
Md. M. Islam et al. (2011)
Literature Reviews
Synthesis and characterization of branched bisphenol-Apolycarbonates functionalized with siloxane
• At high frequencies, the
branched PC exhibited more
pronounced shear thinning
than BPA-PC (linear).
Complex viscosity curves
Results:
21Ref.: Md.M. Islam, D.W. Seo, H.H. Jang, Y.D. Lim, K.M. Shin, and W.G. Kim, Macromol. Res., 19,1278-1286(2011).
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Literature ReviewsM. Y. Lyu et al. (2001)Study of mechanical and rheological behaviors of linear and branched polycarbonates blends Complex viscosity curves of linear and branched polycarbonates blends
Temperature at 260oC Temperature at 280oCRef.: M. Y. Lyu, J. S. Lee, and Y. Pae, J. Appl. Polym. Sci., 80, 1814-1824(2001).
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19
Temperature at 300oC
Results:
• The viscosities increase as the
content of the branched
polycarbonate increases in the
blends at each measured
temperature.
• The temperature increases from
260 to 300oC, the viscosities
decrease and the range of the
shear rate for Newtonian regions
increases.
Ref.: M. Y. Lyu, J. S. Lee, and Y. Pae, J. Appl. Polym. Sci., 80, 1814-1824(2001).
2920
Literature ReviewsC. Liu and C. Li (2004)Influence of long-chain in branching on linear viscoelastic flow properties and dielectric relaxation of polycarbonates
Characteristics of the polycarbonates studied
COOH
COOH
HOOC
PC-B2
N
H
O
OH
CH3
OH
CH3
PC-B1 PC-B3
Ref.: C. Liu, C. Li, P. Chen, J. He, and Q. Fan, J. Appl. Polym. Sci., 45, 2803-2812(2004).
HO C CH3
OH
OH 3016
17
Results:
• Branched PC exhibits higher zero shear viscosity, more significant shear thinning, and much longer relaxation time than linear PC.
•The observed behaviors resulted from additional molecular chain entanglement of LCBs.
Ref.: C. Liu, C. Li, P. Chen, J. He, and Q. Fan, J. Appl. Polym. Sci., 45, 2803-2812(2004).
- Different branching agent may result in different degree of branching.
- Degree of branching inversely depends on the chain length of branches thus the flow behaviors of the branched PC.
PC-B3PC-B2PC-B1PC-L
Effect of LCBs on the storage modulus for linear PC-L
and branched PC-Bs
Results:
• LCB PC shows greater
elasticity of melt e.g. storage
modulus, than SCB PC.
Ref.: C. Liu, C. Li, P. Chen, J. He, and Q. Fan, J. Appl. Polym. Sci., 45, 2803-2812(2004).18
1. To synthesize branched polycarbonate based on melt transesterification of diphenyl carbonate (DPC) and bisphenol-A (BPA).
2. To investigate effects of operating conditions and branching agents on physical, mechanical, and thermal properties of as-synthesized polycarbonate.
3. To recommend the academic data and technical data for the branched polycarbonate production using DPC and BPA.
Objectives
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1. Studying on the preparation of branched polycarbonate from BPA and DPC by melt transesterification.
2. Parameters to be studied. - Synthesis conditions
Temp. range: 180-300○C, P = 100 mmHg - Branching agents: 3 types;
1,1,1-tris(4-hydroxyphenyl)ethane, Trimellitic
acid, and 3,3-Bis(3-methyl-4-hydroxyphenyl) oxyindole
3. Synthesize branched polycarbonate by using Na2CO3 as branch-inducing catalyst.
Scopes of Study
2334
Scopes of Study
4. Characterize physical, mechanical and thermal properties of the as-synthesized branched polycarbonate.
- Chemical structure- Molecular weight- Rheological properties- Optical properties- Glass transition temp, Degradation
temp- Dynamic mechanical behaviors
2435
5. Benchmarking the obtained properties with commercial grades upon PPCL’s recommendation if applicable.
6. Summarizing the optimum processing condition and suitable branching agents of branched PC production based on the reaction of DPC with BPA.
Scopes of Study
2536
Experimental Method
BPA DPC
Nitrogen Tank Vacuum PumpHeater
Trap
26
Stirrer Branching Agent
37
Na2CO3
Sample Characterization
Thermal properties
Mechanical propertiesPhysical properties
• Glass transition temperature• Thermal degradation temperature
• Tensile properties• Storage and loss modulus
• Viscosity• Molecular weight• Chemical structure
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