Ferroelectric behavior and polarization mechanism in odd‐odd polyamide 11,11

Abstract

ABSTRACT Ferroelectric and piezoelectric behavior in odd‐odd polyamide 11,11 are successfully detected for the first time. The maximum coercive field ( E c ) of 90 MV/m, and a remnant polarization ( P r ) of 40 mC/m 2 are obtained at room temperature. A piezoelectric strain coefficient ( d 33 ) value as high as −3.9 pC/N has been found in stretched polyamide 11,11 film. The structural change of samples before and after poling is investigated by wide‐angle X‐ray diffraction patterns, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The results indicate that the nature of the ferroelectricity originates from amide group dipoles in the γ ‐form crystal regions. Hysteresis behavior appears to result from the crystallites reversal mechanism. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52 , 1094–1099