Gamma irradiation effect on chain segment motion and charge detrapping in polyamide 610

Gamma irradiation effect on the chain segment motion and charge detrapping in polyamide 610 was investigated by means of thermally stimulated depolarization current (TSDC), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and gel fraction. There are four current peaks (named alpha, rho(1), rho(2) and rho(3) peak, respectively) in TSDC spectra of polyamide 610. The alpha peak corresponds to the glass transition, the rho(1) peak is attributed to space charge trapped in the amorphous phase, the rho(2) peak is originated from space charge trapped in the interphase between crystalline and amorphous regions and the rho(3) peak is originated from space charge trapped in crystalline phase. With the increase of irradiation dose from 1.5 to 2 MGy, rho(1) and rho(2) peaks gradually merge into one single peak. With the increase of irradiation dose the degree of crosslinking in amorphous phase is more than that in interphase and then the trap depth of interphase is gradually close to that of amorphous phase. By analyzing the characteristic parameters of these peaks, it is found that gamma irradiation can reduce the mobility of chain segments and increase structural defects in polyamide 610. In addition, irradiation increases the stability of trapped charge in both amorphous phase and interphase, but not affecting the stability of trapped charge in crystalline phase. (C) 2011 Elsevier Ltd. All rights reserved.