The dielectric behavior of cyano-substituted polyimides

الملخص EN

A number of amorphous polyimides containing polar functional groups, cyano group, have been synthesized and investigated for potential use as high temperature piezoelectric sensors.

The piezoelectric constants are related to the polarization.

The remanent polarization and hence piezoelectric response of a material is determined by dielectric relaxation strength which is the difference in dielectric constant at the glass transition temperature vicinity.

The intent of this work is to clarify the mechanism and key components required for developing piezoelectricity in amorphous polymers and further to apply this understanding in designing a unique high temperature piezoelectric polyimide.

In this paper, experimental investigations of dielectric constant of piezoelectric cyano -substituted polyimides have been tested as a function of temperature to measure the dielectric relaxation strength in the glass transition temperature region.