Ferroelectric Behavior and Polarization Mechanism in Odd-Odd Polyamide 11,11

摘要

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 23.9 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.