Water-based suspension of Polymer Nanoclay - SMARTech

179 Pages·2007·5.56 MB·English

Water-based suspension of Polymer Nanoclay
Composite Prepared via Miniemulsion
Polymerization
A Thesis
Presented to
The Academic Faculty
by
Zhaohui Tong
In Partial Fulfillment
of the Requirements for the Degree
Doctor of Philosophy
School of Chemical and Biomolecular Engineering
Georgia Institute of Technology
December 2007
Water-based suspension of Polymer Nanoclay
Composite Prepared via Miniemulsion
Polymerization
Approved by:
Dr. Yulin Deng, Advisor Dr. Jeffery S. Hsieh
School of Chemical and Biomolecular School of Chemical and Biomolecular
Engineering Engineering
Georgia Institute of Technology Georgia Institute of Technology
Dr. J. Carson Meredith Dr. Timothy Patterson
School of Chemical and Biomolecular School of Mechanical Engineering
Engineering Georgia Institute of Technology
Georgia Institute of Technology
Dr. Howard (Jeff) L. Empie
School of Chemical and Biomolecular
Engineering
Georgia Institute of Technology
Date Approved: October 11, 2007
To my husband Guanghui Lan and my son,Jesse
and
To my parents Duanxiang Tong and Hexiang Long,
iii
ACKNOWLEDGEMENTS
There are many people who have helped me through my graduation education. First,
I would like to thank my adviser, Dr. Yulin Deng, for providing me instruction,
dedication, support, and encouragement through the entire PhD studying. I am also
grateful for all of my committee members. Dr. Howard (Jeff) L. Empie, Dr. Jeffery
S. Hsieh and Dr. J. Carson Meredith give me an invaluable source of advice and
support for my research. I appreciate that Dr.Timothy Patterson takes his time to
serve as one of my committee members for my defense and keep my science sound.
I also thank Dr. Joseph Schork who is one of my committee members for my PhD
proposal, and his advice and guidance are very important input of this research.
Next, I would like to thank all of my lab colleagues Dr. Zegui Yan, Dr. Qunhui
Sun, Dr. Yunlin Zhao, Dr. Myungchul Park, Ying, Delong, Zhengzhi, Seyoung,
Jihoon, Kim and Brett for the assistance for my lab work. I also thank Ms. Yolande
Berta, Dr. Yong Ding and Mr. Shaobo Pan for their help for the TEM and SEM
training and measurements. The fellowship from IPST member companies and the
support from NSF(Grant Number CTS-0244371) is gratefully acknowledged.
Then, sincerely thanks go to Ms. Janet L. Webb for her grammar check of my
dissertation. I also enjoy talking with her at all the time.
Finally, I would like to thank my family. I am deeply indebted to my lovely hus-
band, guanghui Lan, for his always understanding, support, love and encouragement
during my PhD studying and spend the hardest and happiest time in my life with
me together, and my lovely son, jesse, for always bringing me the most happiness
in my life. I would like to thank my parents, for their love, understanding and en-
couragement. This dissertation is especially for my lovely father, who has given me
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his deepest love and provides me the freedom to do everything I like. In addition,
Sincerely thanks go to my two brothers, who take their responsibility for taking care
of my parents and support me at all the time. I also thank my parents-in-law to take
care of my son for almost one year during my graduation study.
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TABLE OF CONTENTS
DEDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . iv
LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
LIST OF ABBREVIATIONS AND SYMBOLS . . . . . . . . . . . . . xii
SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
I INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
II BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Water-based barrier coating . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.1 Development of coating technology . . . . . . . . . . . . . . 5
2.1.2 Waterborne Coating . . . . . . . . . . . . . . . . . . . . . . 8
2.1.3 Water-based barrier paper coating . . . . . . . . . . . . . . . 12
2.2 Emulsion and miniemulsion polymerization . . . . . . . . . . . . . . 15
2.2.1 Emulsion polymerization . . . . . . . . . . . . . . . . . . . . 15
2.2.2 Miniemulsion polymerization . . . . . . . . . . . . . . . . . . 21
2.3 Polymer nanoclay composite . . . . . . . . . . . . . . . . . . . . . . 36
2.3.1 Surface modification of nanoclay . . . . . . . . . . . . . . . . 38
2.3.2 Synthesis methods of polymer nanoclay hybrid . . . . . . . . 41
2.3.3 Properties of polymer nanoclay composite . . . . . . . . . . . 44
2.3.4 The characterization of polymer nanolcay composite . . . . . 45
2.4 Synthesisofpolymernanocompositeswithsymmetricandasymmetric
morphologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
2.4.1 Synthesis of polymer encapsulated nanoparticle composite . . 49
2.4.2 Synthesisofpolymernanocompositewithanasymmetricstruc-
ture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
III PROBLEM ANALYSIS AND OBJECTIVES . . . . . . . . . . . . 55
3.1 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
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3.1.1 The synthesis of a stable water-based latex of polystyrene en-
capsulated nanoclay composite . . . . . . . . . . . . . . . . . 56
3.1.2 The impact of reaction conditions on final latex stability, en-
capsulation degree and the intercalation or exfoliation degree
of nanoclay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.1.3 The fundamental understanding of the impact of nanoclay on
the styrene miniemulsion polymerization kinetics . . . . . . . 57
3.1.4 The impact of nanoclay on the properties of polystyrene(PS)
and polystyrene butylacrylate (PSBA) copolymer films . . . 57
3.2 Approach determination . . . . . . . . . . . . . . . . . . . . . . . . 57
3.2.1 Surface modification of clay . . . . . . . . . . . . . . . . . . . 58
3.2.2 Sythesis method determination . . . . . . . . . . . . . . . . . 59
IV THE APPROACHES SCREENING TO SYNTHESIZE A STA-
BLE WATER-BASED SUSPENSION OF POLYMER MMT-KSF
COMPOSITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
4.2 Experiment, Result and Discussion . . . . . . . . . . . . . . . . . . . 65
4.2.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
4.2.2 Miniemulsion polymerization . . . . . . . . . . . . . . . . . . 66
4.2.3 High solid miniemulsion polymerization . . . . . . . . . . . . 67
4.2.4 Miniemulsion polymerization with initiator grafting on the
clay surface . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
4.2.5 Conventional emulsion polymerization . . . . . . . . . . . . . 70
4.2.6 Seeded emulsion polymerization . . . . . . . . . . . . . . . . 71
4.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
4.4 Recommendation - screening clay varieties . . . . . . . . . . . . . . . 72
V SYNTHESISOFWATER-BASEDPOLYSTYRENE-NANOCLAY(NSC)
COMPOSITE SUSPENSION VIA MINI-EMULSION POLYMER-
IZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
5.2 Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.2.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
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5.2.2 Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.2.3 Characterizations . . . . . . . . . . . . . . . . . . . . . . . . 79
5.3 Result and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 80
5.3.1 Modification and dispersion of NSC . . . . . . . . . . . . . . 80
5.3.2 Distribution of the clay in water and oil phase . . . . . . . . 81
5.3.3 Effect of hexadecane co-stabilizer on the particle size and final
latex stability . . . . . . . . . . . . . . . . . . . . . . . . . . 83
5.3.4 Effect of nanoclay particles on polymerization conversion . . 83
5.3.5 Characterization morphology and stability of the latex in the
presence of pristine saponite or pre-modified saponite . . . . 84
5.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
VI POLYSTYRENEENCAPSULATEDNANOSAPONITECOMPOS-
ITE LATEX VIA MINIMEULSION POLYMERIZATION AND
THEIR MORPHOLOGIES . . . . . . . . . . . . . . . . . . . . . . . . 90
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.2 Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.2.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.2.2 Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
6.2.3 Characterization . . . . . . . . . . . . . . . . . . . . . . . . . 95
6.3 Result and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 95
6.3.1 Modification and dispersion of nanosaponite . . . . . . . . . 95
6.3.2 Morphologyofpolystyreneencapsulatedorgano-saponitecom-
posite latex . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
6.3.3 Morphologies of final latex particles . . . . . . . . . . . . . . 102
6.4 The mechanism to form a variety of morphologies of polystyrene/SSC
composite latex particles via miniemulsion polymerization . . . . . . 105
6.4.1 Theformationofhemisphericalpolystyrene/nanoclaycompos-
ite particles via a single-step miniemulsion polymerization us-
ing Nano-saponite particles as a template . . . . . . . . . . . 107
6.4.2 The mechanisms for the formation of hemispherical particles
in the absence and the presence of nanosaponite . . . . . . . 111
6.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
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VIIKINETICSOFMINIEMUSLIONPOLYMERIZATIONOFSTYRENE
IN THE PRESENCE OF ORGANOCLAY . . . . . . . . . . . . . 118
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
7.2 Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
7.2.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
7.2.2 Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
7.2.3 Characterization . . . . . . . . . . . . . . . . . . . . . . . . . 122
7.2.4 Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
7.3 Result and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 123
7.3.1 Styrene miniemulsion kinetics in the absence and the presence
of different clay contents . . . . . . . . . . . . . . . . . . . . 123
7.3.2 Polymerizationparametersbeforeandafterminiemulsionpoly-
merization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
7.3.3 Theeffectsofnanoclaychemistryandsizeontheminiemulsion
polymerization of styrene . . . . . . . . . . . . . . . . . . . . 132
7.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
VIIITHE THERMALANDPHYSICALPROPERTIESOFPOLYSTYRENE
ANDPOLYSTYRENE-BUTYLACRYLATE COPOLYMERNANOS-
APONITE COMPOSITE FILMS . . . . . . . . . . . . . . . . . . . . 136
8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
8.2 Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
8.2.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
8.2.2 Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
8.3 Result and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 140
8.3.1 Physical properties of composite films . . . . . . . . . . . . . 140
8.3.2 Thermal properties of composite films . . . . . . . . . . . . . 142
8.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
IX OVERALL CONCLUSIONS AND RECOMMENDATIONS . . . 147
9.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
9.2 Future work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
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REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
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