Electret properties of polyetherimides: Influence of water content and comparison with other high-temperature polymer films

Abstract

In this comparative study, the charge storage performance of commercial high-temperature polymer films was evaluated and correlated with their chemical structure. Isothermal surface potential decay measurements after annealing periods at 90°C revealed that amorphous polyetherimide (PEI) films showed the best charge storage behavior. Polyimide films showed reduced charge storage performance, whereas sulfur-containing polymer films are not suitable as electrets due to their fast charge decay. Additionally, the effect of water content in PEI films in the range of 0.02-0.79 wt.-% was studied. Increasing amounts of water decreased the charge storage properties proportionally, but only by a relatively smaller amount: the highest investigated water content of 0.79 wt.-% reduced the charge by only 30%. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA,.