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 pCN−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 mCm−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.