Thermally stimulated currents in polyethylene and ethylene–vinyl-acetate copolymers

Abstract

Articles you may be interested inStudy on thermal properties and crystallization behavior of electron beam irradiated ethylene vinyl acetate (EVA)/waste tyre dust (WTD) blends in the presence of polyethylene graft maleic anhydride (PEgMAH) AIP Conf.Thermally stimulated depolarization current studies of poly(ethylene oxide) and poly(ethylene oxide) complexed with potassium thiocyanate Thermally stimulated currents (TSC) from polyethylene and ethylene-vinyl-acetate copolymers with a variety of vinyl-acetate contents have been investigated using a TSC technique with x-ray irradiation. Five main TSC peaks, which we believe are due to trapped carriers, were observed in these polymers. The detrapping of carriers is closely related to molecular-chain motions, and trapping sites are assigned to physical defects such as cavities formed by local arrangements of molecular chains rather than carbonyl groups. One of the TSC peaks is associated with traps in the amorphous region, one with traps in the boundary region between the amorphous and the crystalline regions, i.e., in the folded region, and another with traps in the crystalline region. The TSC spectrum from the dipole of the vinyl-acetate unit under a bias field shows a TSC peak accompanied by a current inversion. The average effective dipole moment for the vinyl-acetate unit was determined to be about 1.8 D from a TSC analysis.PACS numbers: 72.20.Jv, 71.5S.Ht, 61.80.Cb a The DSC was measured at the heating rate of 10 K/min.

Thermally stimulated depolarization current behavior of polyethylene/poly(vinyl acetate) blends: Effect of blending

“…Many TSDC reports have been published for pure PE 15–17. As discussed previously, the thermograms in this case are characterized by a small peak or hump around 50–60°C and a well‐defined, broad peak around 80°C.…”

Thermally stimulated discharge current studies of corona polarized pristine and swift heavy ion irradiated kapton-H polyimide

“…However, the appearance of peak P 2 in abnormal current direction is due to the complex nature of the tsd current behavior of coronapoled polymers. The normal and the abnormal current behavior can be explained from the model proposed by T. Mizutani et al [10]. The distribution of injected homocharges (q s,t ) and field strength (E s,t ) in the negative corona charged sample during tsd current measurement is represented in figure 2.…”

“…Corona charging method for obtaining induced polarization (corona electret) in polymeric materials has been widely used because of its ease and speed at which polymers can be polarized [9][10][11][12]. Charging current during corona charging has been found much more than that obtained by applying the same potential to metal-polymer-metal sample.…”

“…The excess charge supplied by the ions either resides in surface traps or injected and trapped into the bulk of the material [9]. The nature of traps and their association with different dielectric relaxation processes can be investigated by releasing these charge carriers from their traps using tsd current technique [9][10][11][13][14][15]. The number, location and shape of different current maxima appearing in the tsd current spectrum arising from the detrapping of charges provide deep insight into the molecular origin of space charge and other relaxation processes [15].…”

Electrical properties of polymers: space‐charge behaviour in insulating polymers under high‐voltage direct current

“…The TSC and TL without preceding X‐ray irradiation are also measured under the same conditions. Therefore, the difference between these two TSC (or TL) values is due to the thermal release of trapped carriers 15. Figure 14 shows typical TSC and TL spectra of LDPE with and without X‐ray irradiation.…”