Experimentelle und theoretische Untersuchungen zur Ringöffnungspolymerisation von nachwachsenden cyclischen Estern durch N-Donor-Zinkkomplexe

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The use of polymer materials enables our modern way of life. Due to the inexorable depletion and exploding costs of fossil resources and growing landfill sites, the need for ecological polymers has never been more exigent. Our society requires new advanced materials which can be produced by sustainable versatile tools. We target the ultimate catalyst which marries the two complementary polymerisation methods of ring-opening polymerisation (ROP) and atom transfer polymerisation (ATRP). Both polymerisation methods are essential techniques for the sustainable synthesis of modern block-copolymers as intelligent high-performance materials. This innovative union has not been realised yet although urgently needed for the general substitution of petrochemical plastics. The superior catalyst is based on iron complexes since this element offers sufficient Lewis acidity (for ROP) and one-electron redox chemistry (for ATRP) by being at the same time sustainable, biocompatible and available. Until now, there is a significant lack of understanding of the mechanisms using iron complexes.In this project, we aim to develop an iron(II)-based high-performance ATRP catalyst and an iron(III)-based high-performance ROP catalyst - both combined within one single system. The monomer scope for both methods will be expanded towards novel renewable monomers. We will first address both methods separately for a fundamental understanding. The catalyst development follows intelligent design principles with theoretical feedback from the first catalyst generation. Then, we design a dual-functional catalyst where the redox-control between both oxidation states allows to switch between the polymerisation methods. On the larger perspective, multi-component block-copolymers are built up for modern polymer architectures. In summary, we target to develop by comprehensive design the ultimate sustainable polymerisation catalyst as multifunctional redox-controlled tool.