Polymer, Vol.39, No.2, 455-458, 1998
Annealing effects on crystal structure and ferroelectric properties in aromatic polyurethane
Annealing effects on ferroelectric properties of an aromatic polyurethane (m-xylene nonamethylene dicarbamate, PUMX-9) were studied. X-ray diffractometry showed that the crystallinity of PUMX-9 increased during annealing. Both quenched and annealed polyurethane samples showed a similar electric displacement (D) versus electric field (E) hysteresis loop. Furthermore, the remanent polarization obtained from the D-E loop was slightly changed by annealing. The experimental results suggest that the ferroelectric properties of this polyurethane arise not in the crystal phase but in a well-hydrogen-bonded amorphous phase which behaves like crystals with large numbers of defects. (C) 1997 Elsevier Science Ltd.