The Influence of Fabrication Parameters on the Piezoelectric and Ferroelectric Responses of Poly(pelargonamide) Membranes

Abstract

Synthesized poly(pelargonamide) membranes are shown to be a ferroelectric polymeric material based on the demonstration of the D‐E hysteresis curves of the oriented and unoriented samples. Dipole switching required a lower electric field excitation with increasing stretching ratio caused by a better orientation of the dipoles upon the uniaxial stretching of the membranes. The ferroelectric response of the samples could be greatly enhanced by uniaxial cold‐drawn. When T was >Tg , and d31 was kept constant then e31 increased non‐linearly with Pr for the samples within the range of the stretching ratio. However, both d31 and e31 increased nonlinearly with Pr for the samples within the range of the stretching ratio if T < Tg. Scanning electron microscopy photographs illustrate the stretching and poling effects on the packing of the macrofibrils of the specimens. The origin of the piezoelectric response of the poly(pelargonamide) membranes was considered to account for the effect of the dipoles reorientation under the electric field poling and was evidenced by polarized infrared spectroscopy examinations.