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Synthesis and Optimization of Emulsion Polymers

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Synthesis and Optimization of Emulsion Polymers SYNTHESIS AND OPTIMIZATION OF EMULSION POLYMERS A Thesis presented to the Faculty of California Polytechnic State University, San Luis Obispo In Partial Fulfillment of the Requirements for the Degree Master of Science in Polymers and Coatings Science by Daisy Jauregui March 2016 © 2016 Daisy Jauregui ALL RIGHTS RESERVED ii COMMITTEE MEMBERSHIP TITLE: Synthesis and Optimization of Emulsion Polymers AUTHOR: Daisy Jauregui DATE SUBMITTED: March 2016 COMMITTEE CHAIR: Raymond H. Fernando, Ph.D. Professor of Chemistry, Director of Polymers and Coatings Program COMMITTEE MEMBER: Andres W. Martinez, Ph.D. Assistant Professor of Chemistry and Biochemistry COMMITTEE MEMBER: Philip Costanzo, Ph.D. Associate Professor of Chemistry and Biochemistry iii ABSTRACT Synthesis and Optimization of Emulsion Polymers Daisy Jauregui Synthetic latex or resin is perhaps the most important component of any paint formulation. As the binder, it holds all ingredients in a paint together and is responsible for film formation. Various latexes are used in industry though acrylic resins have shown to impart superior paint properties. This project is concerned with the synthesis of an acrylic latex. Various emulsion polymerization processes were used including semi-batch, starved- feed, and in-situ seeded in the attempt to produce a stable latex that can be used in a broader study concerning the syneresis and rheology mechanisms of latex/thickener systems. In addition, this project investigates the optimization of the emulsion polymerization teaching lab used in the Polymers and Coatings masters program. Here, a batch emulsion polymerization process was studied and various particle stability aspects altered to produce a stable latex with minimum coagulum. iv ACKNOWLEDGMENTS I would first like to thank my committee, Dr. Raymond Fernando, Dr. Andres Martinez, and Dr. Philip Costanzo for all your support and guidance. I would also like to thank the Cal Poly Bill Moore Fellowship Endowment, Arthur C. Edward Endowment, the Kenneth N. Edwards Western Coatings Technology Center, and the Polymers and Coatings graduate program. Special thanks to industrial supporters Dr. Jeff Stubbs, Mr. Howard Killilea, and Dr. Gary Dombrowski. Lastly, I would like to thank James Casabar, Richard Morrison, Jake Thomas, and Travis Smith. v TABLE OF CONTENTS Page LIST OF TABLES……………………………………………………………………….ix LIST OF FIGURES……………………………………………………………………...x CHAPTER 1. INTRODUCTION ............................................................................................... 1 1.1 Project Objectives ........................................................................................ 1 1.2 Fundamentals of Polymerization ................................................................. 1 1.2.1 Polymerization Methods ....................................................................... 2 1.2.2 Polymerization Techniques .................................................................. 5 1.3 Emulsion Polymerization ............................................................................. 7 1.3.1 Components of Emulsion Polymerization ............................................. 7 1.3.1.1 Continuous Medium ....................................................................... 8 1.3.1.2 Surfactants .................................................................................... 8 1.3.1.2.1 Surfactant Classification ......................................................... 9 1.3.1.2.2 Surfactant Selection ............................................................. 11 1.3.1.3 Monomers .................................................................................... 11 1.3.1.3.1 Monomer Selection ............................................................... 12 1.3.1.3.2 Monomer End-Use Applications ........................................... 13 1.3.1.4 Initiator ......................................................................................... 14 vi 1.3.1.5 Other Additives ............................................................................ 14 1.3.2 Emulsion Polymerization Mechanism ................................................. 15 1.3.2.1 Particle Nucleation (Stage I) ........................................................ 16 1.3.2.2 Particle Growth (Stage II) ............................................................ 19 1.3.2.3 Stage III ....................................................................................... 20 1.3.3 Emulsion Polymerization Processes .................................................. 20 1.3.3.1 Batch ........................................................................................... 21 1.3.3.2 Semi-Batch .................................................................................. 22 1.3.4 In-Situ Seeded Emulsion Polymerization ........................................... 22 1.3.5 Polymer Composition .......................................................................... 23 1.3.6 Particle Stability .................................................................................. 26 1.3.6.1 Coagulation ................................................................................. 29 2 EXPERIMENTAL METHODS ........................................................................... 32 2.1 Instrumental Methods and Analysis ........................................................... 32 2.1.1 Solids Content .................................................................................... 32 2.1.2 DLS ..................................................................................................... 33 2.1.3 DSC .................................................................................................... 33 2.1.4 NMR .................................................................................................... 33 2.2 Acrylic Latex Synthesis .............................................................................. 34 vii 2.2.1 Semi-batch Polymerization (Latex 1) .................................................. 35 2.2.2 Starved-feed Polymerization (Latexes 2-3) ........................................ 36 2.2.3 In-situ Seeded Polymerization (Latexes 4-6) ...................................... 38 2.3 Optimization of Emulsion Polymerization Teaching Lab ............................ 41 2.3.1 Original Teaching Lab ........................................................................ 41 2.3.2 Modification of Synthetic Batch Setup ................................................ 43 2.3.3 Change of Surfactant to SDS ............................................................. 44 2.3.4 Change of Surfactant to SLS .............................................................. 45 3 RESULTS AND DISCUSSION ......................................................................... 47 3.1 Acrylic Latex Synthesis .............................................................................. 47 3.1.1 Solids .................................................................................................. 49 3.1.2 Particle Size ........................................................................................ 49 3.1.3 Glass Transition Temperature ............................................................ 51 3.1.4 Copolymer Composition ..................................................................... 52 3.2 Optimization of Chem 547 Emulsion Polymerization Lab .......................... 54 4 CONCLUSIONS AND FUTURE WORK ........................................................... 60 REFERENCES .................................................................................................... 62 viii LIST OF TABLES Table Page Table 1. Literature values of monomer properties ............................................... 34 Table 2. Synthetic reagents and amounts for Latexes 1 and 2 ........................... 34 Table 3. Synthetic reagents and amounts for Latex 3 ......................................... 38 Table 4. Synthetic reagents and amounts for Latexes 4-6 .................................. 39 Table 5. Synthetic reagents and amounts for Latexes A-C ................................. 42 Table 6. Synthetic reagents and amounts for Latexes D-H ................................. 45 Table 7. Synthetic reagents and amounts for Latexes J1-J2 ............................... 46 Table 8. Target monomer compositions and properties for Latexes 1-6 ............. 48 Table 9. Names of latexes synthesized ............................................................... 49 Table 10. Solids content data .............................................................................. 49 Table 11. Particle size data ................................................................................. 51 Table 12. Glass transition temperature data ........................................................ 51 Table 13. Copolymer Composition data .............................................................. 52 Table 14. Coagulation data .................................................................................. 56 ix LIST OF FIGURES Figure Page Figure 1. Synthesis of Nylon 6,6 ............................................................................ 3 Figure 2. FRP Initiation .......................................................................................... 4 Figure 3. FRP Propagation .................................................................................... 5 Figure 4. Structure of SDS ................................................................................... 10 Figure 5. Decomposition
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