Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2011 Pmma Carbon Nanotube Nanocomposite Foams for Energy Dissipation Applications Kristin Kynard Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY FAMU-FSU COLLEGE OF ENGINEERING PMMA CARBON NANOTUBE NANOCOMPOSITE FOAMS FOR ENERGY DISSIPATION APPLICATIONS By KRISTIN KYNARD A Thesis submitted to the Department of Industrial and Manufacturing Engineering in partial fulfillment of the requirements for the degree of Master of Science Degree Awarded: Summer Semester, 2011 The members of the committee approve the thesis of Kristin Kynard defended on June 30, 2011. _______________________________________ Changchun Zeng Professor Directing Thesis _______________________________________ Okenwa Okoli Committee Member _______________________________________ Arda Vanli Committee Member Approved: _____________________________________ Chuck Zhang, Chair, Department of Industrial and Manufacturing Engineering _____________________________________ John Collier, Interim Dean, FAMU-FSU College of Engineering The Graduate School has verified and approved the above-named committee members. ii For the many blessings God has bestowed upon me: to my mother, Margaret for encouraging to continue; to my sister, Charita for the constant guidance and advice; and my wonderful friends for pushing me and supporting me through all the ups and downs…On to the next chapter iii ACKNOWLEDGEMENTS I would to acknowledge all of the wonderful people who have provided guidance and motivation during the journey to complete this research. First, I would to thank my committee members. To Dr. Changchun Zeng, my major professor, thank you for your constant guidance and patience during this process. I would also like to thank Dr. Okenwa Okoli and Dr. Arda Vanli for their support and guidance by serving on my committee members. I appreciate the entire faculty and staff of the Department of Industrial and Manufacturing Engineering and High Performance Materials Institute (HPMI) for their support. In particular, I would like recognize Dr. Jin-Gyu Park, Mr. Jerry Horne, Mr. Jim Horne, Mr. Frank Allen and Ms. Judy Gardner for their continued assistance with many aspects of my research. I would like to express my appreciation to National Nuclear Security Administration (NNSA) for providing the financial support for this work. Moreover, I would like to thank those who helped me with various aspects of this project. I would especially like to thank Dr. Zhenhua Chen for help with the foaming procedure and testing.. In addition, thank you to Dr. Jhunu Chatterjee for training me on TA Instruments for mechanical property testing and William Garrett Sullivan for providing training on the Shimadzu AGS-J. Thank you to Nemat Hossieny, Wei Wei (Thomas) Yang, Quyet Do, Chase Knight, Tarik Dickens, Micah McCrary Dennis, and Lambert Parker for training and helping fabricate my nanocomposite and nanocomposite foams. Finally, I would like to show my gratitude to my friends and colleagues at Florida State University, as well as my family for their unwavering support. iv TABLE OF CONTENTS LIST OF TABLES ..................................................................................................................... VII LIST OF FIGURES ................................................................................................................. VIII ABSTRACT .................................................................................................................................. X CHAPTER ONE ........................................................................................................................... 1 INTRODUCTION......................................................................................................................... 1 1.1 BACKGROUND ............................................................................................................ 1 1.2 PROBLEM STATEMENT ........................................................................................... 1 1.3 OBJECTIVES ................................................................................................................ 2 CHAPTER TWO .......................................................................................................................... 3 LITERATURE REVIEW ............................................................................................................ 3 2.1 POLYMER NANOCOMPOSITES ............................................................................. 3 2.1.1 CARBON NANOTUBES ....................................................................................... 4 2.1.1.1 STRUCTURE AND MORPHOLOGY OF CARBON NANOTUBES ..... 4 2.1.1.2 PROPERTIES OF CNTS ............................................................................ 6 2.1.2 CARBON NANOTUBE REINFORCED NANOCOMPOSITES ......................... 7 2.1.3 PROCESSING METHODS OF POLYMER NANOCOMPOSITES .................... 8 2.1.3.1 SOLUTION BLENDING .......................................................................... 9 2.1.3.2 MELT BLENDING ................................................................................... 9 2.1.3.3 IN SITU POLYMERIZATION ................................................................ 10 2.2 POLYMER NANOCOMPOSITE FOAMS .............................................................. 10 2.2.1 FUNDAMENTAL PROCESSES OF FOAMING ............................................... 11 2.2.2 CELL NUCLEATION AND GROWTH.............................................................. 11 2.2.3 PHYSICAL FOAMING BY CO2 ......................................................................... 14 2.2.4 RETROGRADE VITRIFICATION ..................................................................... 15 2.2.5 FOAMING TECHNIQUES: BATCH FOAMING AND CONTINUOUS FOAMING ............................................................................................................ 16 2.2.6 EFFECT OF NANOPARTICLES ON FOAM MORPHOLOGY AND PROPERTIES ....................................................................................................... 17 2.3 COMPRESSIVE AND ENERGY DISSIPATION PROPERTIES OF POLYMER FOAM ........................................................................................................................... 17 2.3.1 GENERAL BEHAVIOR OF POLYMER FOAM UNDER COMPRESSION .... 18 2.3.2 TOUGHNESS AS INDICATION OF ENERGY DISSIPATION CAPABILITIES ............................................................................................................................... 19 2.3.3 COMPRESSIVE AND ENERGY ABSORBING PROPERTIES OF POLYMER AND POLYMER CNT FOAM ............................................................................ 21 CHAPTER THREE .................................................................................................................... 26 EXPERIMENTAL APPROACH .............................................................................................. 26 3.1 MATERIALS AND RESOURCES ............................................................................ 26 v 3.2 POLYMER NANOCOMPOSITE SYNTHESIS ...................................................... 26 3.3 FOAMING PROCESS ................................................................................................ 28 3.4 CHARACTERIZATION AND TESTING ................................................................ 28 CHAPTER FOUR ....................................................................................................................... 30 RESULTS AND DISCUSSION ................................................................................................. 30 4.1 NANOCOMPOSITE SYNTHESIS ............................................................................ 30 4.2 FOAMABILITY OF POLYMER NANOCOMPOSITES ....................................... 31 4.2.1 EXPANSION RATIO ........................................................................................... 31 4.3 MORPHOLOGY OF POLYMER NANOCOMPOSITE FOAMS......................... 36 4.3.1 EFFECT OF CNT CONCENTRATION ON FOAM MORPHOLOGY ............. 36 4.3.2 EFFECT OF PROCESSING CONDITIONS ON FOAM MORPHOLOGY ...... 38 4.4 COMPRESSIVE AND ENERGY ABSORBING PROPERTIES OF POLYMER FOAMS ......................................................................................................................... 40 CHAPTER FIVE ........................................................................................................................ 43 CONCLUSION AND RECOMMENDATIONS ...................................................................... 43 5.1 CONCLUSION ............................................................................................................ 43 5.2 RECOMMENDATIONS ............................................................................................ 43 REFERENCES ............................................................................................................................ 45 BIOGRAPHICAL SKETCH ..................................................................................................... 51 vi LIST OF TABLES 2.1 COMPARISON OF CARBON NANOTUBE PROPERTIES TO TYPICAL FILLERS.......6 2.2 FACTORS WHICH AFFECT FOAM PROCESSING AT DIFFERENT STAGES ............11 2.3 MECHANICAL PROPERTIES OF PU AND PU NANOCOMPOSITE FOAMS ..............22 4.1 PHOTOOS OF BULK AND FOAMED SAMPLES ............................................................32