Malleability of highly cross-linked polymers – an investigation of the topology freezing phenomenon of Vitrimers via static and dynamic means and its relevance for the solution of technological challenges

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Vitrimers are a new class of polymers that combine the malleable character of thermoplastics with the extraordinary mechanical performances of highly cross-linked thermosets. The huge advantage of Vitrimers is, even though they are cross-linked, i.e. their molecular state being far beyond a structural percolation threshold, that they can be repaired, reshaped or even recycled. This is because of the presence of switchable molecular bonds. Hence, Vitrimers are not only sustainable, but also enable new perspectives on processing technologies, e.g. via repeated forming processes, as well as opportunities to enhance the lifetime and durability of polymer applications in service. However, from an engineering point of view, making use of the exciting Vitrimer properties currently lacks the understanding of the underlying physical and physio-chemical mechanisms. This is even more important in the case of Vitrimer-based composite materials, when additional physical and chemical interactions come into play, e.g. between fibres and a Vitrimer matrix. Within this research proposal, the early-stage postdoc and applicant to the Walter Benjamin programme aims to, independently and self-coordinated, contribute to a better understanding of Vitrimers as sustainable polymer and polymer composite solutions. This shall be done by a systematic investigation and elucidation of the processes that are responsible for the malleability, foremost by quasi-static and dynamic (including kinetic) means of thermo-physical properties, using a model Vitrimer system. Thereby, the applicant focusses on interdisciplinary research at the interface between materials science, engineering and physics.