Piezo-,pyro- and ferroelectricity of odd-numbered polyamides: poling in a soft state, structure-property relations, and electro-active properties

具有电活性的功能聚合物，如压电性、热释电性和铁电性，在换能器应用中非常有用，同时也给研究带来了挑战。奇数聚酰胺具有巨大的工业应用潜力。它们表现出优异的压电性热稳定性。不幸的是，由于固体聚酰胺膜中可用自由体积有限，因此很难将聚酰胺充分极化。在这个项目中，我们计划在高电场和可能的压力下，在软态(熔体或溶液)中极化奇数聚酰胺。我们的目标是获得这样的聚酰胺铁电薄膜，其中的极性酰胺基偶极子垂直于薄膜平面取向良好，并且表现出与应用相关的压电性和热释电性。我们将研究极化时的结构转变，以及相关极化参数与电活性性质之间的关系。此外，我们还将软态极化应用于其他铁电聚合物。

Functional polymers with electro-active properties such as piezo-, pyroand ferroelectricity are useful for transducer applications as well as challenging for research. Odd-numbered polyamides have significant potential for industrial applications. They exhibit excellent thermal stability of the piezoelectricity. Unfortunately, it is difficult to pole polyamides sufficiently because of the limited free volume available in solid polyamide films. In this project, we plan to polarize odd-numbered polyamides in a soft state (melt or solution) at high electric fields and possibly also under pressure. Our aim is to obtain ferroelectric polyamide films in which the polar amide-group dipoles are well oriented perpendicular to the film plane and which exhibit applications-relevant piezo- and pyroelectric properties. We will study structural transformations upon poling as well as relationships between relevant poling parameters and electro-active properties. Furthermore, we will apply soft-state poling to other ferroelectric polymers.