Ferroelectric and pyroelectric behaviors in poly(glycolic acid)

Abstract

Ferro and pyroelectric behavior was observed in poly(glycolic acid) (PGA) consisting of dipoles along the chain direction. The pyro- and piezoelectric (dt) constants in poled sample (Tp = 150 °C; tp = 3 min; Ep = 50 MV m-1) were 32 μC m-2 K-1 and 15 pC N-1, respectively, at room temperature. Such large constants may be due to polar structure formed by poling. D-E hysteresis loop was observed above 100 °C. Remanent polarization and coercive electric field were 70 mC m-2 and 40 MV m-1 at 120 °C, respectively. It can be seen from IR, XRD, and polarizing microscope data that remanent polarization mainly results from the orientation in the amorphous chain by a high electric field.