Poly(ethyleneoxyd) networks: synthesis, network structure and crystallization

• Applicants: Professor Dr. Jörg Kreßler; Professor Dr. Detlef Reichert
• Subject Area: Polymer Materials ; Experimental and Theoretical Physics of Polymers ; Preparatory and Physical Chemistry of Polymers
• Term: from 2013 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 245736274

The aim of the previous project was to obtain a molecular picture of the polymer crystallization in PEO networks and its obstruction by the presence of the network structures. We are planning to continue these works in a 2nd period. A main topic will be to study the effect of dissolved slats on the crystallization behavior and the ionic conductivity. This will be achieved by SAXS and WAXS experiments which will deliver a detailed picture of the structures and a phase diagram. NMR line-shape analysis and CODEX experiments will provide insight into the molecular mobility of the PEO chains in the crystallites of the doped polymer that will be correlated with the ionic conductivity. A second emphasis will be the syntheses of PEO networks with ionic connection points, realized by the alkylation of the triazole rings. It is very likely that these materials will have rather different properties, in particular related to the crystallization behavior that will be investigated by x-ray scattering and solid-state NMR. Ionic conductivity as measured by impedance spectroscopy will be related to the diffusion behavior of the ions, obtained from PFG NMR. At the end, we are planning to investigate the effect of mechanical deformation (stretching) on the crystallization behavior. We expect a phase transition of the helical structure of the PEO crystals into the zick-zack conformation that can be detected by WAXS. Temperature depended NMR experiments will provide insight into the molecular mobility of the stretched networks.

• DFG Programme: Research Grants