Dielectric loss of poly(vinylidene fluoride) at low temperatures and effect of poling on the low temperature loss

Abstract

Abstract Dielectric constant and loss of poly(vinylidene fluoride) (PVDF) were measured at 20 Hz. 110 Hz and 1 kHz in the temperatures ranging from 4.2 K to 300 K. Dielectric loss peaks (1 kHz) were observed respectively at 75 K (δ peak) for melt-crystallized PVDF with form I1 crystals and at 18 K (e peak) for rolled PVDF with oriented form 1 crystals. Activation energies were evaluated to be 12.6 and 1.9 kJ/mol for δ and e respectively. The height of e loss peak is suppressed by poling the sample at a rather low poling field. suggesting that the dipolar orientation in the form I crystal accompanying reduction of crystal detects occurs at the early stage of poling process.