Thermal piezoelectric stability of poled uniaxially-and biaxially-oriented poly(vinylidene fluoride

Abstract
The long term stability of biaxially-oriented poly(vinylidene fluoride) has been examined. In isothermal aging from a few minutes to a Few months, log e vs. time shifts between 6O°C at 88°C are characterized to have an activation energy of 1.2 eV. Data on uniaxial poled commercial film shows agreement with this result. Long term room temperature stability of pyroelectricity over a 10 year span augmented other elevated temperature data in supporting the conclusion that thermally activated processes should not be a factor in device reliability.