Electrets based on cellular and fibrous structures
Prof. Volker Altstädt (Polymeric Materials)
Within the scope of the Collaborative Research Center, work is focused on high temperature
elecret materials. Among other things, elecret properties of commercial high temperature
polymer films were investigated during the period reported. In the process, polyetherimide
(PEI) turned out to be one of the best materials in terms of potential for charge coupling.
Based upon this finding, new fluorinated polyetherimides were synthesized and polymers
with excellent electret properties were found. Since porous structures significantly slow
charge decay, cellular PEI systems were produced by physical foaming and biaxial
stretching of particle-containing films. The electret properties could thereby be improved
In the continuation of the subproject, the main focus of the scientific objective will be on
summarizing the interrelationships between morphology and electret properties.
REM image of the fractured surface of a foamed PEEK film with the corresponding 3D X-ray
Dr. Reiner Giesa (Macromolecular Chemistry I)
Prof. Hans-Werner Schmidt (Macromolecular Chemistry I)
Scanning electron micrograph of the fractured surface of a foamed PEEK film. A 3D-X-ray image of a small sample strip is included.