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Mechano Optical Behavior of Novel Polymers for Capacitor MECHANO OPTICAL BEHAVIOR OF NOVEL POLYMERS FOR CAPACITOR APPLICATION DURING THEIR PROCESSING CYCLES A Dissertation Presented to The Graduate Faculty of the University of Akron In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Ido Offenbach September, 2016 MECHANO OPTICAL BEHAVIOR OF NOVEL POLYMERS FOR CAPACITOR APPLICATION DURING THEIR PROCESSING CYCLES Ido Offenbach Dissertation Approved: Accepted: ______________________________ ______________________________ Advisor Department Chair Dr. Mukerrem Cakmak Dr. Sadhan Jana ______________________________ ______________________________ Co-Advisor/Committee Member Dean of the College Dr. Robert A. Weiss Dr. Eric Amis ______________________________ ______________________________ Committee Member Interim Dean of the Graduate School Dr. Mark Soucek Chand Midha ______________________________ ______________________________ Committee Member Date Dr. Abraham Joy ______________________________ Committee Member Dr. Chrys Wesdemiotis ii ABSTRACT This work is a part of collaborative project between Multidisciplinary University Research Initiative (MURI) through which an advanced polymeric capacitor films for military applications were designed. Two of those novel polymers were PPOH (hydroxyl functionalized isotactic polypropylene with comonomer of 10-hydroxy-1-undecen) and PI(BTDA-DAH) (Polyimide 3,3',4,4'-benzophenone tetracarboxylic dianhydride and 1,6- diaminohexan). This dissertation focused on the effect of processing conditions on the mechano-optical behavior of PPOH and PI(BTDA-DAH). Firstly, the real-time mechano-optical behavior of PPOH containing 0.4 mol % comonomer and its comparison with unmodified polypropylene (PP) were studied in the partially molten state during processing cycle of heating, stretching, annealing, and cooling. It was revealed that the crystalline network dominated the material response during the processing cycle for both polymers. However, the presence of hydrogen bonding between the hydroxyl groups in PPOH was found to affect the structural evolution of the PPOH copolymer significantly more than compared to the PP homopolymer. Secondly, the real-time mechano-optical behavior of PI(BTDA-DAH) was studied in the glassy and the rubbery states as a function of processing temperature and stretching rate during uniaxial deformation. Thee regimes of stress optical behavior were revealed. First, at the early stage of deformation the stress optical rule is observed; birefringence linearly increased with a stress optical constant of 17.8 GPa-1 - regime I. Second, a iii deviation from linearity took place. At higher temperature and/or lower stretching rate the deviation is positive and the birefringence rapidly increases while the stress slowly increases- regime II. At lower temperature and/or higher stretching rate this deviation of linearity is negative- regime IIIa. Third, in cases where regime II is revealed, it was followed by a negative deviation of birefringence and reached a plateau while stress rapidly increased -regime IIIc. According to off-line characterization techniques: differential scanning calorimetry and wide-angle X-ray diffraction showed that the material remains amorphous during regime I and the early stage of regime II. By the end of regime II, a rapid increase in the crystallinity was observed. This implies stress induced crystallization associated with regime II. There was no significant change in the crystallinity with further stretching into regime III where the polymer chains reach to their finite extensibilities. Thirdly, the real-time infrared-mechano-optical behavior of PI(BTDA-DAH) during uniaxial deformation followed by relaxation was studied. The relaxation showed high dependency on the polymer structure pre-relaxation. Three regimes of stress optical behavior and stress reho (orientation function) behavior were revealed. At the early stage of deformation (regime I), birefringence and orientation function linearly decreased with a stress. At early stage of deformation in regime II, the birefringence and orientation function slowly decrease. These behaviors changed with the deformation level in regime II. At intermediate stage of the deformation in regime II, the birefringence and orientation function did not change while the stress rapidly decreases, and then birefringence and orientation function started slowly to increase, while the stress slowly decreased. At the high stage of the deformation in regime II, the birefringence and orientation function were slowly increased while the stress rapidly decreases, and then birefringence and orientation iv function rapidly increased while the stress slowly decreases. At the high stage of the deformation, regime III, the birefringence and orientation function were slowly increased while the stress rapidly decreased, and then birefringence slowly increased while the stress slowly decreased. It also was found that the birefringence and orientation function increased with enough relaxation time at all level of deformation in regime II. Fourthly, the real-time mechano-optical behavior of PI(BTDA-DAH) during biaxial deformation and their effect on dielectric properties was studied. It was found that during the biaxial stretching, the phenyl groups in the PI(BTDA-DAH) chains became parallel to the surface plane which reduced the polarizability of the polymer chain in the film thickness direction. As a result, the dielectric constant decreased with increasing in the stretching ratios. v DEDICATION This dissertation is dedicated to my parents Zeev and Ester Offenbach, who made me believe that the sky is the limit and encouraged me to never give up on dreams. vi ACKNOWLEDGEMENTS I would like to thank my academic advisor Dr. Mukerrem Cakmak for his continuous guidance, encouragement and trust. I am equally indebted to Dr. Robert A. Weiss for continuously motivating me throughout my research. I would also like to thank my dissertation committee members: Dr. Chyrs Wesdemiotis, Dr. Abraham Joy, and Dr. Mark Soucek for their guidance and taking time- off from their busy schedules. I would like to acknowledge our project collaborators, Dr. T.C. Mike Chung at the Pennsylvania State University and Dr. Gerege Sotzing, Dr. Rampi Ramprasad, Dr. Yang Cao, at the University of Connecticut, for useful discussions on several topics and highly productive collaboration. Thank you to Dr. Xuepei Yuan for synthesizing the hydroxyl-modified polypropylene copolymers; to Dr. Rui Aa and Gerege Terrich for synthesizing the PI(BTDA-DAH); and to JoAnne Ronzelle, Mattewos Teffri and Zongze Li for performing the dielectric measurements. Special thanks to Dr. Sahil Gupta for his ongoing advice, guidance and friendship. Thank you to my colleagues in the College of Polymer Science and Engineering for their support and assistance. vii I am grateful for the opportunity to have worked for the Office of Naval Research (ONR) on a Multidisciplinary University Research Initiative (MURI) grant (Contract No. N00014-10-1-0944). I am so very thankful to Wilhite family for their support, help and friendship in the last four years. I would like to thank my brother and my sister for always being there for me and for good advice. My wife, Effie, for her unconditional love and support. And to Pitzie, who came into our lives and changed our family. Thank you to my grandparents for all our good times and for all the memories that we share. And a big thank you to the Schuldiner family being my home away from home; especially to Dr. Ruth Schuldiner-Rosaler and Dr. Michael Schuldiner for their dedication to this dissertation. viii Table of Contents LIST OF TABLES ............................................................................................................ xiv LIST OF FIGURES ............................................................................................................ xv KEYWORDS .................................................................................................................. xxix LIST OF ABBREVIATIONS .......................................................................................... xxx CHAPTER I ......................................................................................................................... 1 INTRODUCTION ................................................................................................................ 1 LITERATURE REVIEW ..................................................................................................... 3 2.1 Energy Storage Systems .................................................................................................. 3 2.2 Types of Energy Storage Systems ................................................................................... 4 2.2.1 Battery ...................................................................................................................... 4 2.2.2 Fuel Cell ................................................................................................................... 5 2.2.3 Superconducting magnetic energy storage (SMES) ................................................ 5 2.2.4 Flywhell ................................................................................................................... 6 2.2.5 Capacitors ................................................................................................................ 6 2.3 Interaction of the dielectric constant and Light................................................................ 9 ix 2.3.1 Refractive
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