Effect of polarization temperature on the chain segment motion and space charge detrapping in polyamide 610 film electrets

摘要

The effect of polarization temperature on the chain segment motion and charge trapping and detrapping in polyamide 610 films has been investigated by means of thermally stimulated depolarization current (TSDC) and wide-angle X-ray diffraction (WAXD). A small part of the amorphous phase of quenched polyamide 610 changes into the crystalline state with increasing polarization temperature. There are three current peaks (named α,ρ _1, and ρ _2 peak, respectively) in the TSDC spectra. The peak corresponds to the glass transition, the ρ _1 peak is attributed to space charge trapped in the amorphous phase, and interphase between crystalline and amorphous phases, and the ρ _2 peak originates from space charge trapped in the crystalline phase. By analyzing the characteristic parameters of these peaks, it was found that the increase of polarization temperature induced a decrease of the chain segment mobility and promoted the creation of structural traps in polyamide 610. The decrease of the chain segment mobility in the amorphous phase made the intensity of the peak weak and the activation energy increased. The higher the polarization temperature, the higher the degree of crystallinity and the more charge carriers trapped in the crystalline phase. So, the increase of polarization temperature made the intensity of the ρ _2 peak strong and increased the stability of trapped charge in the crystalline phase. The increase of polarization temperature also made the intensity of the ρ _1 peak strong and decreased the stability of trapped charge in the amorphous phase and interphase.