Piezoelectric Properties and Ferroelectric Hysteresis Effects in Unaxially Stretched Nylon-11 Films

摘要

Uniaxilly stretched Nylon-11 films (obtained by melt-pressing and quenching in ice-water, were poled up to 900 KV/cm at 75 deg C for 30 min. Both piezoelectric strain constant, d sub 31, and piezoelectric stress constant, e sub 31, were found to increase with poling fields. The values reach a plateau at fields of 800 KV/cm. Under identical poling conditions (500 KV/cm; 75 deg C) d sub 31 was found to be approx. 25% greater than that observed for unoriented films in previous studies while the value for e sub 31 was found to be approx. 85% greater than that for the unoriented films. Static switching experiments were conducted for uniaxially stretched Nylon 11 films, initially prepared by quenching or slow cooling from the melt. Both films exhibited ferroelectric hysteresis behavior in d sub 31 and e sub 31 indicating that both the quenched and slow cooled points of Nylon-11 are ferroelectric. X-ray diffraction studies for the plasticized and uniaxially stretched slow cooled films indicate that the crystallites may be reorienting in a way consistent with dipole alignment in field direction. (Author)