The University of Southern Mississippi The Aquila Digital Community Dissertations Spring 5-2016 Surface and Interfacial Design and Control of High Performing Thermoplastics: Polysulfones and Beyond Katrina Marie Knauer University of Southern Mississippi Follow this and additional works at: https://aquila.usm.edu/dissertations Part of the Physical Chemistry Commons, and the Polymer Chemistry Commons Recommended Citation Knauer, Katrina Marie, "Surface and Interfacial Design and Control of High Performing Thermoplastics: Polysulfones and Beyond" (2016). Dissertations. 344. https://aquila.usm.edu/dissertations/344 This Dissertation is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Dissertations by an authorized administrator of The Aquila Digital Community. For more information, please contact [email protected]. SURFACE AND INTERFACIAL DESIGN AND CONTROL OF HIGH PERFORMING THERMOPLASTICS: POLYSULFONES AND BEYOND by Katrina Marie Knauer A Dissertation Submitted to the Graduate School and the School of Polymers and High Performance Materials at The University of Southern Mississippi in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Approved: ________________________________________________ Dr. Sarah E. Morgan, Committee Chair Professor, School of Polymers and High Performance Materials ________________________________________________ Dr. Robert Y. Lochhead, Committee Member Professor, School of Polymers and High Performance Materials ________________________________________________ Dr. Sergei I. Nazarenko, Committee Member Professor, School of Polymers and High Performance Materials ________________________________________________ Dr. Derek L. Patton, Committee Member Associate Professor, School of Polymers and High Performance Materials ________________________________________________ Dr. Jeffrey S. Wiggins, Committee Member Associate Professor, School of Polymers and High Performance Materials ________________________________________________ Dr. Karen S. Coats Dean of the Graduate School May 2016 COPYRIGHT BY KATRINA MARIE KNAUER 2016 ABSTRACT SURFACE AND INTERFACIAL DESIGN AND CONTROL OF HIGH PERFORMING THERMOPLASTICS: POLYSULFONES AND BEYOND by Katrina Marie Knauer May 2016 The study of a class of materials almost always begins with the development of an understanding of properties in the bulk state. However, it is the study of surface critical phenomena that has led to a number of new important insights into polymer behavior. A systematic understanding of physical properties in the immediate vicinity of surface and interfacial layers, which cannot be deduced by simple extrapolation of bulk properties, is of significant importance for advancements in polymer applications where the interface drives performance such as in membranes, coatings, drug-delivery systems, medical devices, and composites. First, the surface and interfacial modification and characterization of sulfone polymers will be described (Part I). Much of what exists in molecular modeling and experimental literature explains the behavior of flexible or modified chains. There is still a lack of accepted models that adequately explain chain conformation, structural organization, and dynamics of semi-rigid and rigid rod polymers at surfaces and interfaces. The purpose of this research was to investigate the environmental and structural parameters that determine polymer chain conformation, organization, and dynamics at the polymer-air interface for a series of semi-rigid and rigid rod sulfone polymers cast from solution. Refined models of polysulfones (and by extension semi- ii rigid/rigid rod polymers) behavior at surfaces and interfaces were developed through combined experimental and simulation analysis. The second section of this work (Part II) will discuss the nanophase manipulation of polyisobutylene (PIB) based thermoplastic elastomers (TPE’s) and polyhedral oligomeric silsesquioxane (POSS) nanocomposites. The phase behavior and permeability of (PS-PIB)2-s-PAA miktoarm star terpolymers with varying volume fractions of PAA was investigated for potential applications as permselective TPE’s. Results of this work present the potential for design of novel microstructures for specific applications through precise control of architecture, composition, and interaction parameters of the components. Lastly, the rheological properties and crystallization kinetics of POSS filled polyphenylenesulfide (PPS) and polyetheretherketone (PEEK) nanocomposites were studied. The findings indicate the potential for improvements in melt viscosity and crystallization of high temperature thermoplastics with tailored POSS/polymer interactions. iii ACKNOWLEDGMENTS A great number of exceptional individuals were instrumental in the completion of this dissertation. Amongst them I’d like to acknowledge: My advisor , Dr. Sarah E. Morgan, for providing me with every opportunity to succeed and for your unfailing and whole-hearted guidance. Thank-you for constantly challenging me to be a better scientist, writer, and teacher. You have been such an incredible inspiration to me and I will be forever grateful for your mentorship. I could not have achieved my goals without you. I truly hope that you will remain a lifetime mentor to me and that I can continue to seek your guidance and advice throughout my career. Thank-you for everything; we did it! Dr. Jeffrey Wiggins for first recruiting me for the REU program at USM and for his unwavering support of my education and career choices. Thank-you for your guidance over the years and beautiful letters of recommendation. My committee members Dr. Sergei Nazarenko, Dr. Derek Patton, and Dr. Robert Locchead and other faculty members, such as Dr. Robson Storey, for their guidance and contribution to my education. Dr. Qi Wu for passing on his endless wisdom of polymer science and characterization to me. Thank-you for taking the time to train me in AFM, synthesis, spin coating, and numerous other aspects of my research. You were not only a mentor to me but became one of my best friends. I am so grateful to have met you. Financial Support which includes the Department of Education Graduate Assistance in Areas of National Need (GAANN) Fellowship Award #P200A120118, National Science Foundation International Research Experience for Students (IRES) in iv India Award #OISE-1132079, and National Science Foundation’s Experimental Program to Stimulate Competitive Research (EPSCoR) under Cooperative Agreement No. IIA1430364. Solvay Specialty Polymers for donation of materials, useful discussion, and for giving me the opportunity to complete an industrial internship and help me grow as a scientist. Hybrid Plastics for donation of materials and useful discussion. Rob Holler at the University of Alabama for kindly training me and assisting me in my XPS and WAXD characterization. Dr. John Ankner and Candice Halbert for their exceptional guidance and assistance with neutron reflectivity experiments at Oak Ridge National Laboratories. My colleagues in the Morgan Research Group (MoRG) for taking the time to read my papers, listen to my presentations, and for being a constant source of support as I wrote this dissertation. Thank-you Levi Moore, April Fogel, Pradipta Das, Ashleigh Bristol, Rene Cardona, and Mark Norman as well as MoRG alumni such as Dr. Sarah Exley and Dr. Mithun Battacharya. You have all played a pivotal role in my development and growth as a scientist. Thank-you for working late nights, making me laugh, and listening to me complain. I hope to remain friends with every single one of you and wish you all the best of luck with your PhD and future careers. My beautiful and amazing mother, Vicki Knauer-Blankenship, for being my ultimate inspiration and for teaching me to always take pride in my work. Thank-you for challenging me in every way and raising me to be the woman I am today. You have taught me to always give 100% to whatever task I am completing, whether it’s making a gift for a friend or staying up until two o’clock in the morning drawing fire ants on a v science fair poster. I love you with all my heart and I am immensely proud to be your daughter. My exceptional big sister, Tiffany Gispanski for being my role model and paving the way for me. Thank-you for letting me copy you as a child and follow you as an adult. You have inspired me in all aspects of life and challenge me to work harder and be better. Thank-you for protecting me and sticking up for me when I have been too scared and for being there for me through the good and bad times. I can’t wait for our future adventures together! My little sister, Karli Blankenship, for keeping me young and for making me feel like I can be a role model too. Thank-you for looking up to me and giving me the chance to be a big sister. Chelsey Martin for being my best friend and for always being on my side. Thank- you for the phone calls, the kind words, and for being a dork with me. I can’t wait to continue growing and learning together. Brian Donovan for being a pillar of support during my intense dissertation writing and one of my best friends and closest companions. Thank-you for listening to me complain, getting coffee with me at any time of day, and for talking me out of giving up. I hope that I can help you through this the way you have helped me. Maliha Syed for being the female presence and inspiration I needed through graduate school. Thank-you for proofreading my documents, critiquing my presentations,