Piezoelectric properties of irradiation-crosslinked polypropylene ferroelectrets

Abstract

The cellular irradiation-cross-linked polypropylene films treated by a hot-press process are corona charged to be piezoelectric. For the samples charged at room temperature, quasistatic piezoelectric d33 coefficients up to 400pC∕N are obtained. The d33 coefficients are slightly dependent on pressure in the range up to 50kPa. The d33 values decrease to 30% when the samples are exposed to 90°C for 1day; a preaging treatment improves the thermal stability of d33. The dominant drift path of the detrapped charges is from one void surface to the adjacent void surface through the bulk of the solid.