Technische Universität München Fakultät für Chemie Fachgebiet Molekulare Katalyse Functionalized Hybrid Silicones – Catalysis, Synthesis and Application Sophie Luise Miriam Putzien Vollständiger Abdruck der von der Fakultät für Chemie der Technischen Universität München zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) genehmigten Dissertation. Vorsitzender: Univ.-Prof. Dr. M. Schuster Prüfer der Dissertation: 1. Univ.-Prof. Dr. F. E. Kühn 2. Univ.-Prof. Dr. O.Nuyken (i.R.) Die Dissertation wurde am 16.02.2012 bei der Technischen Universität München eingereicht und durch die Fakultät für Chemie am 08.03.2012 angenommen. The following dissertation was prepared between April 2009 and March 2012 at the Chair of Inorganic Chemistry, Department of Molecular Catalysis of the Technische Universität München. I would like to express my deep gratitude to my academic supervisor Prof. Dr. Fritz E. Kühn for his support and confidence and the freedom of scientific research. This work was supported by a research grant from the BASF Construction Chemicals GmbH, Trostberg, Germany. Acknowledgement I would like to express my sincere gratitude to Prof. Dr. Oskar Nuyken and Dr. Eckhart Louis for their ongoing support and their undamped enthusiasm for my research topic. They supported this work with many inspiring discussions, new ideas and critical questions. I thank the BASF Construction Chemicals GmbH, Trostberg, for giving me the opportunity to work on an industrial cooperation project. Especially, I would like to thank Dr. Simone Klapdohr and Dr. Burkhard Walther, who accompanied this project from the industrial perspectice, for their support and the nice time I had in Trostberg during the application technological tests. I am very grateful to Prof. Dr. James Crivello for his support with the photopolymerization experiments and the very nice and fruitful time at the Rensselaer Polytechnic Institute. I would like to thank all the colleagues at the Technische Universität München for the nice working atmosphere. Especially, I thank my lab mate Simone Hauser for the very comfortable lab climate, for her friendly and polite nature, for various inspiring conversations, also besides chemistry, and for solving small computer problems. I also thank the lab neighbors from the east-west corridor, Jenny Ziriakus, Christina Müller, Philipp Altmann and Stefan Huber, for the nice time we spent together, especially during the coffee breaks, and for their generosity concerning chemicals. Many thanks also to the colleagues from the Si-Institute, Dr. Peter Gigler, Dr. Stefanie Riederer and Dr. Daniel Canella for many inspiring discussions concerning silicon chemistry and to Dr. Manuel Högerl and Dr. Magnus Buchner for the maintainance of the NMR spectrometer. All technicians at the TUM, especially Georgeta Krutsch for NMR experiments and Thomas Schröferl for GC-MS, are gratefully acknowledged. Furthermore, I am grateful to Dr. Marianne Hanzlik for performing several TEM measurements. I also thank the technicians at the BASF in Trostberg, especially Andrea Schneider and Andreas Brey for their support during the application technological tests. Many thanks go to Prof. Dr. Peter Härter, Tobias Kubo and Peter Richter who made the supervision of the practical courses in Weihenstephan almost a pleasure. Furthermore, I am very grateful to the secretaries of the Chair of Inorganic Chemistry for their excellent support with respect to all bureaucratic issues. Additionally, I thank the TUM graduate school for unbureaucratic financial support. My bachelor students Simone Keller and Hannah Weinzierl are gratefully achnowledged for their enthusiastic and energetic contribution to my research. Finally and most of all, I would like to thank my mother and my boyfriend for their perpetual support, patience and trust! Contents Contents 1. Introduction .......................................................................................................... 1 1.1 Hydrosilylation ......................................................................................................... 1 1.2 Polysilalkylene Siloxanes as Hybrid Silicones ......................................................... 2 1.3 Objectives of this Work ............................................................................................ 5 2. Catalysis ............................................................................................................... 6 2.1 Platinum Catalysts and Reaction Mechanism ......................................................... 6 2.2 Test and Comparison of Different Hydrosilylation Catalysts .................................... 8 2.3 PtO2 as Heterogeneous Hydrosilylation Catalyst ................................................... 11 2.4 Hydrosilylation of Isopropenyl Compounds ........................................................... 21 2.4.1 Mechanistic Models for the Hydrosilylation of Allyl Compounds ..................... 22 2.4.2 General Observations ..................................................................................... 24 2.4.3 Kinetic Considerations .................................................................................... 25 2.4.4 Scope and Limits of the Reaction ................................................................... 27 2.4.5 Deuteration Experiments and Mechanistic Proposal....................................... 30 3. Synthesis and Functionalization of Hybrid Silicones ...................................... 36 3.1 State of the Art ....................................................................................................... 36 3.2 Synthesis of Si-H-terminated Hybrid Silicones ...................................................... 41 3.3 Functionalization of Hybrid Silicones ..................................................................... 52 3.3.1 Functionalization with Alcohols ....................................................................... 52 3.3.2 Functionalization with Epoxides ...................................................................... 55 3.3.3 Functionalization with Amines ......................................................................... 56 3.3.4 Functionalization with (Meth)acrylates ............................................................ 58 3.3.5 Functionalization with Anhydrides ................................................................... 59 3.3.6 Functionalization with Trialkoxysilanes ........................................................... 60 3.3.7 Functionalization with Acetates ....................................................................... 61 3.3.8 Functionalization with Ether Groups ............................................................... 63 3.3.9 Functionalization with Aliphatic, Cycloaliphatic or Aromatic Groups ............... 65 3.3.10 Further Functionalizations ............................................................................. 66 Contents 4. Stability of Differently-substituted Silicon-containing Model Compounds .... 68 5. Synthesis and Application of Functionalized Hybrid Silicones ...................... 71 5.1 Epoxy-functional Hybrid Silicones ......................................................................... 72 5.1.1 Photochemical Curing of Epoxy-functional Hybrid Silicones ........................... 72 5.1.2 Thermal Curing of Epoxy-functional Hybrid Silicones ..................................... 88 5.2 Preparation and Thermal Curing of Amino-functional Hybrid Silicones ................. 94 5.3 Preparation and Curing of Trimethoxysilyl-functional Hybrid Silicones................ 107 6. Summary and Conclusion ............................................................................... 119 7. Experimental ..................................................................................................... 123 7.1 General ................................................................................................................ 123 7.2 Comparison of Different Hydrosilylation Catalysts ............................................... 123 7.3 Hydrosilylation of Isopropenyl Compounds ......................................................... 126 7.4 Synthesis of Different SiH-terminated Hybrid Silicones ....................................... 131 7.5 Test Reactions for the Functionalization of SiH-terminated Hybrid Silicones ...... 136 7.6 Determination of the Stability of Different Model Compounds ............................. 148 7.7 Synthesis and Photochemical Curing of Epoxy-functional Hybrid Silicones ........ 148 7.8 Thermal Curing of Epoxy-functional Hybrid Silicones .......................................... 154 7.9 Synthesis and Curing of Amino-terminated Hybrid Silicones .............................. 156 7.10 Synthesis and Curing of Trimethoxysilyl-terminated Hybrid Silicones ............... 161 References ............................................................................................................ 165 Abbreviations Abbreviations and Trade Names Å Ångstroem AAS atomic absorption spectroscopy Ac acetate Aerosil® 812S fumed silica AGE allyl glycidyl ether Ancamine® K54 2,4,6-tris-dimethylaminomethylphenol Anti-terra® U80 wetting and dispersing additive Ar Aryl Araldite® 2047-1 cold curing two-part methacrylate adhesive Barytmehl N barite flour BDDVE 1,4-butandiol divinyl ether BHT butylated hydroxytoluene (2,6-di-tert-butyl-p-cresol) BNT-CAT® 440 dibutyltin diketonate br broad Bu butyl t-bu tertiary butyl Byk® 057 defoamer Byk® 354 leveling