Dielectric Properties of Piezoelectric Polyimides

Molecular modeling and dielectric measurements are used to identify mechanisms governing piezoelectric behavior in polyimides such as dipole orientation during poling and degree of piezoelectricity achievable. Molecular modeling on polyimides containing pendant, polar nitrile (CN) groups has been completed to determine their remanent polarization. Experimental investigation of dielectric properties evaluated as a function of temperature and frequency has substantiated numerical predictions. With this information, we are able to suggest changes in the molecular structures which will improve the piezoelectric response.