Charge trapping and conduction in γ irradiated isotactic polypropylene

How to Measure Polymer Degradation? An Analysis of Authors' Choices When Calculating the Carbonyl Index

“…The predominance of indoor degradation experiments (Figure b) is due to the need for better and more reliable assessment under accelerated and controlled conditions in a shorter period. ,,− These experiments provide experimental data to indicate optimal parameters for the best adjustment of products and processes that delay degradation and increase lifespan, improving recycling conditions and formulation. ,,− On the other hand, exposition to the weather in outdoor degradation experiments allows better prediction of how properties change as a function of degradation time in realistic conditions, although the experiments take longer. While indoor experimental conditions provide essential information and predictions regarding the behavior of materials under such controlled experimental conditions, laboratory experimental tests do not encompass all conditions of a true-to-life environment.…”

Temperature and trap distribution dependence of electrical tree growth characteristics in polypropylene/elastomer blends for recyclable cable insulation

“…7, which is proposed to be attributed to the appearance of dielectric relaxation process in PP. It has been reported that i-PP exhibits α relaxation at 75-80°C [43,44], where the relaxation of defects in the crystalline phase and the migration of defects in amorphous phase adjacent to the crystal regions are considered to occur [45]. The α relaxation process is accompanied by molecular chain movement or motion of segmental chains [46], and the relaxation time is longer than the carrier lifetime [47].…”

“…The α relaxation process is accompanied by molecular chain movement or motion of segmental chains [46], and the relaxation time is longer than the carrier lifetime [47]. As the molecule movement would lead to carrier de-trapping [44] and the relaxation of defects appears in the two-phase boundary, the PD at the interface between crystalline and amorphous regions is thought to be encouraged. Accordingly, the carbonisation caused by the PD becomes severe to form the pine shape tree and the conductivity increases in the tree channel, by which the electric field within the tree branch is reduced.…”

Charge transport behavior in gamma‐ray irradiated poly(ethylene terephthalate) estimated by surface potential decay

“…Min et al have reported that the number of trap centres in silicone rubber (SiR) increased firstly then decreased as the irradiation dose changed from 0 to 225 kGy [6]. The trap distribution in isotactic polypropylene (i‐PP) irradiated by gamma‐rays to a maximum dose of 100 kGy was studied by S. Mouaci et al, the increase in the number of traps with the irradiation has been revealed [7]. In short, it has been demonstrated that the change in chemical and physical structures of insulating polymer could result in the variation in charge transport behaviour, which would in turn affect the electrical performance of the insulating material in NPP [8].…”