Novel Polyoxymethylene Copolymers: Chemistry and Application Scope of Concatenated and Multi-Block Oligomers with Polyacetal Segments Von der Fakultät für Mathematik, Informatik und Naturwissenschaften der RWTH Aachen University zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation vorgelegt von Matthias Hoffmann, M.Sc. aus Bergheim Berichter: Privatdozent, Dr. rer. nat. Thomas E. Müller Professor, Dr. rer. nat. Walter Leitner Tag der mündlichen Prüfung: 07.05.2018 Diese Dissertation ist auf den Internetseiten der Universitätsbibliothek verfügbar. “Il y établit que nous ne pesons qu’avec le feccurs des mots; que les langues font de véritables méthoads analytiques; que l’alg’ebre la pius simple, la plus exacte & la mieux adaptée a son objet de toutes les maniéres de s’enoneer, est á-la-fois une langue & une méthode analytique; enfin que l’art de raifonnesse reduit d une langue bien faite” – Abbé de Condillac “We think only through the medium of words. – Languages are true analytical meth- ods. – Algebra, which is adapted to its purpose in every species of expression, in the most simple, most exact, and best manner possible, is at the same time a language and analytical method. – The art of reasoning is nothing more than a language well ar- ranged” – Abbé de Condillac Dissertation, Matthias Hoffmann, 2017 I Curriculum vitae Contact & personal information Name Matthias Hoffmann Address 52072 Aachen, Lousbergstrasse 5, Germany Cell phone + 49 151 70085110 E-mail [email protected] Nationality German Education and training Dates March 2012 – February 2017 Title to be awarded Dr rer. nat. Awarding body RWTH Aachen University Work group CAT Catalytic Centre, ITMC, RWTH Aachen University Mentor Dr. Thomas E. Müller Dates October 2009 – February 2012 Title of qualification awarded M.Sc. Chemie Specialisation Catalysis and synthesis Master thesis Synthesis of Monomers from Lignin (Group of Prof. Welton, Imperial College London) Awarding body RWTH Aachen University Dates October 2006 – September 2009 Title of qualification awarded B.Sc. Chemistry Bachelor thesis Synthesis of half-open substituted ruthenocenes (Group of Prof. Salzer, RWTH Aachen University) Awarding body RWTH Aachen University Dates August 1996 – June 2005 Title of qualification awarded Allgemeine Hochschulreife (A – levels) Principal subjects Chemistry, Mathematics, English and History Awarding body Erftgymnasium Bergheim, Germany II Dissertation, Matthias Hoffmann, 2017 I hereby declare that this thesis is my own original work, and that it has not been submitted anywhere else for any award. Wherever contributions of others are involved, every effort was made to indicate this clearly with due reference to the literature and acknowledgement of col- laborative research. Additionally, I hereby declare that I have recognised and followed the principles for ensuring good scientific praxis of RWTH Aachen, University. _______________________ _____________________ (Place, date) (Signature) Dissertation, Matthias Hoffmann, 2017 III The experimental part of this work has been carried out at CAT Catalytic Center, Institut für Technische und Makromolekulare Chemie (ITMC) of RWTH Aachen University between March 2012 and March 2016 in close collaboration with Covestro Deutschland AG (formerly Bayer Material Science) under the supervision of PD Dr. Thomas E. Müller (March 2012 to February 2017). IV Dissertation, Matthias Hoffmann, 2017 Parts of this thesis have been published or publications are in preparation: Conference contributions 10/2014 Matthias Hoffmann, Henning Vogt, Thomas E. Müller, 7th Green Solvents Conference, Dresden, poster presentation: “The design of new sustainable polyesters” 10/2014 Matthias Hoffmann, Henning Vogt, Thomas E. Müller, ProcessNet-Jahrestagung, Aachen, poster presentation: “The design of formaldehyde-based polymers beyond POM” 03/2014 Matthias Hoffmann, Henning Vogt, Thomas E. Müller, 47. Jahrestreffen Deutscher Katalytiker, Weimar, poster presentation: “In situ-infrared study on the ring-opening insertion of trioxane” Publications Matthias Hoffmann, Claudia Bizzari, Walter Leitner and Thomas E. Müller, Insight into the Reaction Pathways of Trioxane Polymerisation (in preparation) Matthias Hoffmann, Walter Leitner and Thomas E. Müller, Polyoxymethylene Diacetate Oligomers: Synthesis, Properties and Fuel Application (in preparation) Matthias Hoffmann, Walter Leitner and Thomas E. Müller, Poly(acetalester): Synthesis, Properties and Application Scope (in preparation) Matthias Hoffmann, Matthias Leven, Walter Leitner and Thomas E. Müller, Multi-Block POM-PEG and POM-PPG Copolymers: Synthesis and Mechanism (in preparation) Matthias Hoffmann, Matthias Leven, Walter Leitner and Thomas E. Müller, Multi-Block POM-PEG and POM-PPG Copolymers: Synthesis, Properties and Application Scope (in preparation) Patents Matthias Hoffmann, Henning Vogt, Walter Leitner, Thomas Ernst Müller, Christoph Gürtler, Method for Producing Polyacetal-Polyesters from Cyclic Anhydrides and Aldehydes, WO 2015/135948 A1 (PCT/EP2015/054974). Dissertation, Matthias Hoffmann, 2017 V Acknowledgements First and foremost, I would like to express my gratitude to my supervisor PD Dr. Thomas E. Müller, for the interesting project, excellent working conditions, superb scientific discussion and ongoing support. Moreover, I would like to thank him for allowing me to gather first teaching experiences by allowing me to supervise a trainee chemistry technician, by letting me support his lecture and by letting me occasionally give lectures for him in the rare case that he was not available himself. This opportunity strengthened my commitment in pursuing a career in academia. Further, I want to thank Dr. Henning Vogt, Dr. Matthias Leven and Dr. Claudia Bizzari for their support and our scientific discussions. For their excellent support in case of equipment, analytical devices, practical questions, and analytical services, would like to thank Volker Marker, Alexandra Keldenich and Mario Krautschick. My thanks go to the staff of CAT Catalytic Center and the ITMC for excellent analytical ser- vices (Corinna Stork, Hannelore Eschmann, Ines Bachmann-Remy and Wolfgang Falter) and outstanding craftsmanship (Ralf Thelen, Stefan Aey and Thomas Müller). Dr. Willy Offer- manns and Günter Wirtz, I would like to thank for their excellent IT support. I would like to thank Diana Schillings for the work she performed for me, while I supervised her in the laboratory for six months, as part of her education as chemistry technician. Daniel Schikowski, whom I supervised during his research and supported, while he wrote his bache- lor thesis, is greatly acknowledged for his hard work, leading to excellent results that are pre- sented in Chapter 5 of this thesis. I would like to thank all current and former members of CAT Catalytic Center for a great time and working atmosphere for the time of my doctoral studies. I would like to thank my family and parents for their support and love. Last but not least, I would like to thank my wife for her advice on the English language, for her general support in life, for her love and for being amazing. VI Dissertation, Matthias Hoffmann, 2017 Abstract The thesis at hand various different topics regarding the synthesis and properties of polyoxymethylene (POM) oligomers and copolymers. POM is an engineering plastics, that finds widespread applications. The general interest in POM polymers remains high, as formaldehyde can be produced from sustainable feedstocks. The present thesis is divided into 5 main chapters. Chapter 1 gives an overview on the history behind POM polymers, their application as materials, the cationic homopolymerisation of tri- oxane, the cationic copolymerisation of trioxane with other comonomers. Also the sus- tainability of formaldehyde and its polymers are discussed. In Chapter 2, the ring- opening reaction of trioxane in the presence of acetic anhydride is discussed as a model reaction for the initial phase of the trioxane homopolymerisation. In situ IR spectros- copy was used as a tool to monitor the kinetic profile of multiple reactions performed with different Brønsted acidic and Lewis acidic catalysts. The role of these catalysts is discussed in the context of the mechanism of the ring-opening reaction of trioxane with acetic anhydride. Chapter 3 entails the synthesis of a series of low molecular weight oxymethylene diacetates. The crystallinity, melting- and crystallisation temperature of these compounds were determined. The effect of the composition of oxymethylene diacetate mixtures on their thermal properties is discussed in general. Moreover, the findings are discussed in the context of sustainable fuel applications for POM oligo- mers with relatively low molecular weight. In Chapter 4, the synthesis, thermal proper- ties and the application of poly(acetalester) are discussed. Poly(acetalester) are novel and sustainable copolymers of trioxane and cyclic anhydride. The monomers are co- polymerised in the presence of an open chain anhydride as chain transfer agent to achieve molecular weight control. Multiple aspects, like average length of oxymeth- ylene segments, formation of cyclic poly(acetalester) as side products and the introduc- tion of reactive moieties in the copolymer chain are discussed. In Chapter 5, the syn- thesis, the mechanism and the thermal properties of multi-block POM-PEG copoly- mers are discussed. The control of the copolymer composition and the connection to their