Ferroelectric switching characteristics and crystal structure of nylon 11

Abstract

The time domain measurement of polarization reversal is made for melt-quenched, uniaxially-drawn and annealed Nylon 11 samples by applying a stepwise electric field. The amount of reversed polarization of an as-drawn sample is almost independent of the field strength above 80MVm-1 and gives a value of ca. 50mCm-2. The switching time is proportional to a power of the field strength. Annealing above 100°C causes a marked increase in switching time but does not change the amount of reversed polarization. X-ray study shows that annealing results in a change in crystal structure from a pseudohexagonal phase containing distorted conformation into an all-trams triclinic phase. Such a structural change enlarges the potential barrier against the chain rotation to result in the increase in the switching time.