Synthesis of Sulfo-Phenylated Terphenylenes: Molecules, Polymers and Copolymers by Thomas Joseph Gilbert Skalski M.Sc. (Chimie), Université de Montréal, Québec, Canada, 2013 M.Sc. (Chimie), Université de Lille 3, Villeneuve d’Ascq, France, 2010 B.Sc (Chimie), Faculté des Sciences Jean Perrin, Lens, France, 2008 Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Department of Chemistry Faculty of Science ©Thomas Skalski 2019 SIMON FRASER UNIVERSITY Spring 2019 Copyright in this work rests with the author. Please ensure that any reproduction or re-use is done in accordance with the relevant national copyright legislation. Approval Name: Thomas Joseph Gilbert Skalski Degree: Doctor of Philosophy Title: Synthesis of Sulfo-Phenylated Terphenylenes: Molecules, Polymers and Copolymers Examining Committee: Chair: Robert Brittron Professor Steven Holdcroft Senior Supervisor Professor Hua-Zhong (Hogan) Yu Supervisor Professor Jeff Warren Supervisor Assistant Professor Peter Wilson Internal Examiner Associate Professor Cathleen Crudden External Examiner Professor Chemistry Queen’s University Date Defended/Approved: April 16th, 2019 ii Abstract This thesis reports the synthesis and study of a new class of fluorine-free, acid-bearing polymers for potential usage in proton exchange membrane fuel cells. The polymers were prepared via the synthesis of a pre-sulfonated monomer, followed by homo- and co- polymerization by [4+2] Diels-Alder cycloaddition. Molecular structures were determined by mass spectrometry, infrared spectroscopy, 1H NMR and 2D COSY spectroscopies, and single crystal X-ray diffraction. Disulfonated tetracyclone and tetrasulfonated bistetracyclone molecules were used to synthesize two model compounds to determine the potential isomers present. Tetrasulfonated bistetracyclone was polymerized with 1,4-diethynylbenzene co-monomer. + The resultant polymer, sPPP-HNEt3 , was prepared with a high molecular weight and converted into its acid form, prior to casting as a membrane. The membranes possessed a high ion exchange capacity (IEC) of 3.49 meq/g and a proton conductivity of 118 mS/cm at room temperature and at 95% relative humidity (RH), respectively, four and a half time superior as the current benchmark NRE 211®. The polymer film was found to become soluble during exposure to aggressive oxidative solutions no significant chemical changes were observed. The final part of this work focused on increasing the polymer film stability by judiciously tuning the hydrophilic content of the polymer. A family of random-copolymers was prepared based on the above monomers. The parameters for polymerization were studied and the optimal conditions were found using size exclusion chromatography to determine molecular weight. The measured IEC for these copolymers correlated well with the theoretical IEC, ranging from 1.86 to 3.50 meq/g. The conductivity of these polymers at 80°C and 95% RH was found to reach 338 mS/cm. Fuel cell tests were performed using the membranes and provided a peak power density of 770 mW/cm2. Keywords: Prefunctionalized monomers; Hydrocarbon polymer; polyphenylenes Diels-Alder Cycloaddition; Electrophilic aromatic substitution; Proton- exchange membranes; Fuel cells; 1H NMR polymer characterization ; ion- exchange membranes iii Dedication To my soulmate Benita, my parents Hervé & Véronique, and my grandmother Paulette who have supported and believed in me and allowed me to be where I stand today. To the great scientist who claimed, “don’t add too many benzene rings, you might decrease the oxidative durability of the polymer backbone”. For those few who did not believe in me: the Maréchal Cambronne said it all. iv Acknowledgements All of this work would not have be possible without the great help and guidance from my senior supervisor Prof. Steven Holdcroft who accepted my application into his group in 2012. He gave me the opportunity to work in a new field, he supported my ideas, and he allowed me to do my research. I am thankful for his patience, his endless help, and the motivation he provided throughout the years, and for the relaxing moments we had after our successes. I thank and acknowledge the following people: My supervisory committee members, Prof. Hogan Hu and Prof. Jeffrey Warren for their supervision, advice and motivation to help me to finish these projects. Dr. Timothy J. Peckham, ex-lab manager of the team who was always there to talk, and to provide advice, motivation and jokes throughout the years. All my professors and teachers at SFU, especially Prof. Vance William and Daniel Leznoff, who were patient and enhanced my curiosity for research through their classes. Professor Barbara Frisken and Eric Schlibi from the Department of Physics, SFU, for help in characterizing our materials using the X-ray facility at SFU and Docteur Sandrine Lyonnard for the neutron scattering studies performed in Grenoble, France. SFU staff members, Nathalie Fournier, Amber Schroeder, Jen Jackson, Shirley Purdon, and Hamel Tailor. Drs. Julie Lunniss, Uwe Kreis, and Dev Sharma, who were always there and helpful during my teaching duties; and members of the teaching laboratory, Paul Saunders, Pingping Zhang, and Paul Mulyk. Members of the mass spectrometry and nuclear magnetic resonance group: Drs. Hongwen Chen, Yilin (Colin) Zhang, Andrew Lewis, and Eric Ye. Members of the “Centre Régionale de Spectrometrie de Masse de l’Université de Montréal”, including Dr Alexandra Furtos-Matei and Marie-Christine Tang for their help characterizing difficult compounds. v Members of the Catalysis Research for Polymer Electrolyte Fuel Cells (CARPE FC) network: Dr. Kunal Karan of the University of Calgary, and Dr. Gillian Goward of McMaster University. Some of my best friends whom I met at SFU: Dr. Takashi Mochizuki, for his help in the characterization of polymer membranes. Dr. Hsu-Feng Lee, my true friend. Dr Chi (Ben) Zhang for the great times we had in and outside the lab, and for his advice during my PhD studies. Dr. Thomas Weissbach, who showed me that patience and perseverance are the two masterpieces in graduate school. Dr. David Novitski, a true helping friend, always there for anything and everything. Dr. Jiantao Fan, with whom I did great chemistry for three years and who showed me the side of the AEM-FC. Dr. Benjamin Britton, for the nights and weekends he spent running fuel cell tests on my materials. Owen Thomas who showed me the way in the laboratory when I arrived and gave me precious advice on my projects. Ania Sergeenko for her help and teaching me XRD, which I wanted to learn for years. Patrick Fortin, a true supporting friend and brew master, who gave me the virus of brewing. Mike Adamski, my friend and co-worker, who succeeded in a part of my project I didn’t have the time to do, and who helped me to compile all the data at the end of my studies. The current members of the Holdcroft group and those who have left, including Lukas Metzler and Elizabeth Kitching for all the fun time we had together. My current and past family, from France and my second family in Vancouver for their love, support, motivation and proof reading, despite the fact that this thesis was not one of their favourite books on the nightstand. vi Table of Contents Approval ............................................................................................................................. ii Abstract ............................................................................................................................. iii Dedication ......................................................................................................................... iv Acknowledgements ........................................................................................................... v Table of Contents ............................................................................................................. vii List of Tables ..................................................................................................................... xi List of Figures .................................................................................................................. xii List of Acronyms ........................................................................................................... xviii Chapter 1. Introduction ............................................................................................... 1 1.1. History of the Fuel Cell ........................................................................................... 1 1.2. Polymer Electrolyte Membranes ............................................................................ 3 1.2.1. Proton Exchange Membrane for Fuel Cell (PEM-FC) ..................................... 4 1.2.2. Perfluorosulfonated acid ionomer PEMs ......................................................... 4 1.2.3. Non-Fluorinated PEMs .................................................................................... 6 1.2.4. Poly(phenylene) PEMs .................................................................................... 7 1.3. Electrochemistry of PEMFCs ................................................................................. 9 1.3.1. Proton Transport Mechanism .......................................................................... 9 1.4. Degradation: Oxidative Stability ........................................................................... 11 1.5. Synthetic routes ..................................................................................................