Journal of Polymer Science Part B: Polymer Physics, Vol.37, No.6, 531-538, 1999
Polarized infrared spectra of poled aromatic polyamide films
In connection with ferroelectric behavior of aromatic polyamides poled at a high electric field, polarized infrared spectra were studied in poled films of crystalline and amorphous aromatic polyamides consisting of ring systems to elucidate the relation between the orientation of polar groups and the ferroelectric polarization. The infrared spectra revealed that the C=O and N-H bonds oriented preferably along the poling direction in both crystalline and amorphous polyamides. The crystallinity of the crystalline polyamide increased with poling. In the amorphous polyamide, strong intermolecular hydrogen bonding is closely related to the retention of ferroelectric polarization in the frozen state of molecular motions below the glass transition temperature.