17th November 2017

Research

Welcome to the research pages of the UnterlassLab. Our research interests are centered around advanced polymer materials, i.e. high-performance polymers (HPPs).

HPPs are polymer materials showing outstanding properties such as excellent thermal and chemical resistance, mechanical performance, insulating behavior and radiation stability, all at low specific weight. Therefore, they are found in numerous high-tech applications, in e.g. airplanes, cell phones and cars.

For achieving certain properties in HPPs we place special efforts on the design of the monomeric units. This involves the synthesis of (often novel) molecularly rigid monomers. Such monomers are mostly aromatic/heteroaromatic. The monomer syntheses we perform are therefore typically involving classical reaction towards aromatic compounds, e.g. substitution reactions of aromatic compounds and cross-couplings.   

Crystalline polymers, especially crystalline HPPs are another core interest of our group: The outstanding properties of HPPs can be even further enhanced with increasing crystallinity. For HPPs, crystallinity can however often not be influenced anymore once the polymer is formed.

We are therefore developing non-classical polymer syntheses, where high crystallinity can already be achieved during polymerization, e.g. hydrothermal polymerization (HTP) and solid-state polymerizations (SSP). These techniques are less harmful than classical approaches: HTP uses water as solvent and SSP does not require solvents at all.

Both HTP and SSP involve crystalline monomers, i.e. co-monomers pre-organized in a monomer salt crystal. In such precursor crystals, the co-monomers are interacting via various non-covalent interactions (NCIs), which overall leads to crystallographically fascinating patterns. For designing these systems we focus on crystal engineering approaches, and their study involves both crystallography and crystal growth – both topics that we are passionate about!

Highly crystalline polymers often show morphologies that reflect their high interchain order, and non-classical polymerizations also typically lead to intriguing morphologies that strongly vary from morphologies obtained by conventional techniques. We could for instance obtain flower-shaped polyimide micro-particles by HTP, and synthesize angular polyimide particles via SSP. We study polymer morphology by several optical and electron microscopy techniques.