Research


Sequence controlled polymerization




 
One of the last frontiers in polymer science is the development of efficient protocols towards sequence controlled materials. By choosing specific sequences, macromolecules are generated that can form protein-like tertiary structures or that simply contain specific information by using the sequences as a chemical code. Sequence controlled materials can be obtained via multiblock copolymer synthesis, or via a sequence of single monomer insertions. Both types can be accessed via controlled radical polymerization techniques. The first relies on continuous reinitiation of polymerizations and thus requires CRP methods of very high efficiency and livingness. The latter yields monodisperse materials and thus requires sophisticated separation techniques in order to isolate the desired product from a polydisperse crude mixture.

Both materials are synthesized in the PRD group through contemporary CRP methods in combination with state-of-the-art purification methods. Often, microreactors are used for synthesis to increase the preciseness of the synthesis protocols.


Microreactor technology

 

Microreactor flow synthesis has in recent years matured into a significant technique to perform organic reactions in research laboratories worldwide. Microreactors allow for synthesis of materials in a broad window of conditions and feature distinct advantages such as ideal heat transfer, high reproducibility and inherently simple scale-up of reactions. In the PRD group, we focus on the synthesis of precision polymers in flow. Application of flow techniques towards polymer reactions opens an avenue for scaling up of complex reactions and concomitantly increases the efficiency of reactions. In this manner, classical click-transformations can be largely accelerated and CRP method can be driven to higher conversions while retaining a high livingness of the processes.

Controlled PPV polymerization

 

Poly(p-phenylene vinylene)s (PPVs) are one of the most important classes of materials in the area of organic semiconductors and find use in applications ranging from light-emitting diodes to imaging in biomedical context. The synthesis of PPV (and derivatives) is possible on significant scale, yet to date no efficient methodologies exist to control polymerizations with respect to endgroup functionality, dispersity or average molecular weight. To overcome this hurdle – and thus to make this type of materials available for the construction of tailor-made macromolecular architectures – advances are made in the PRD group to develop controlled PPV synthesis methods. Therefore, anionic polymerizations, but also the so-called precursor routes are explored in a combined theoretical and experimental approach.