Study of trap structure of thermally polarized polyimide

Gaur, M. S.; Ramlal,; Tiwari, R.K.

doi:10.1002/app.35679

Cited by 11 publications

(16 citation statements)

References 25 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These ketone groups not only contribute to permanent dipole moment but also act as localized trapping centers. The trapped charges are considered to be released from these trapping centers due to dipolar motion [17][18]. The Differential scanning Callorimetery (DSC) thermographs of PEEK [50 μm thickness] studied by H.M. Li et al [19] also confirmed occurrence of glass transition temperature (T g ) around 145°C.…”

Section: Resultsmentioning

confidence: 80%

Dielectric behavior of polyetheretherketone (PEEK) using TSDC technique

Kalia

Sharma

2012

J Polym Res

View full text Add to dashboard Cite

The dielectric relaxation behavior of Polyetheretherketone (PEEK) has been investigated by using thermally stimulated discharge current (TSDC) technique. The dependence of TSDC characteristics of PEEK on poling temperature (T P ) [50-200°C], poling field (E P ) [200-500 kV/cm], storage time (t S ) [2-120 hrs] and various thicknesses 25 μm, 50 μm and 75 μm have been investigated in the temperature range [60-230°C]. The TSDC spectra shows a prominent maxima around glass transition temperature (T g ) i.e. at 143°C named as α-peak and the other peak is observed around 200°C named as β-peak. The α-dipolar relaxation is taking place because of the movement of ketone (>C 00) dipoles linked to the main chain. The β-peak is attributed to the space charges. It is observed that the magnitude of α-peak increases with the increase in poling field. The peak current and area under the α-peaks are found to be diminished with the increase of storage time (t s ) for electrets. The amplitude of α-peak decreases with the increase in thickness. The activation energies for PEEK sample at different conditions in the present work are found to be 0.38 eV-1.70 eV. The values of activation energy (U) and preexponential factor (C o ) for α-relaxation are determined using Bucci plot method and support the nature of the relaxations.

show abstract

Section: Resultsmentioning

confidence: 80%

Dielectric behavior of polyetheretherketone (PEEK) using TSDC technique

Kalia

Sharma

2012

J Polym Res

View full text Add to dashboard Cite

show abstract

“…40 And it has been proposed that intensity and location of the peaks in TSDC spectrum are regarded as significant parameters in thermal relaxation process. The SC detrapping is a dual process that both molecular motion to lower the capturing capability of traps and thermal excitation for the charge carriers will lead to the escapes of SC from traps.…”

Section: Tsdc Characteristicmentioning

confidence: 99%

Polarization and space charge performance in PVDF with MPB composition BCZT doped composite films

Liu

Lin

et al. 2017

J of Applied Polymer Sci

View full text Add to dashboard Cite

The morphotropic phase boundary composition 47(Ba 0.7 Ca 0.3 )TiO 3 -0.53Ba(Zr 0.2 Ti 0.8 )O 3 (calcium barium zirconate titanate, BCZT) were doped in poly(vinylidene fluoride) matrix by solution casting method. The effect of BCZT particles on polarization characteristics of composite films were investigated through dielectric spectra, hysteresis, and thermally stimulated discharge current measurements. It reveals that relative dielectric constant, remnant polarization, and energy storage density gradually increase and reach the maximum value with 39 at 100 Hz, 1.17 lC/cm 2 , and 3.69 J/cm 3 at the concentration of 20 vol % BCZT. The Gaussian method was employed to decompose thermally stimulated discharge current composite peaks and an approximate model was used to analyze the activation energy levels of these films. The results indicated that the introduction of BCZT is effective for the charge carrier traps and activation energy distribution in the relaxation process of composite films. The decreased molecular movements, and increased interfaces formed between the BCZT grains and the poly(vinylidene fluoride) matrix may be responsible for these performances. And a new relaxation peak appeared at about 370 K in composites when BCZT concentration exceeded 20 vol %, which was considered to be caused by the ferroelectric-paraelectric phase transition of BCZT.

show abstract

“…Dielectric polymer films have been widely used for insulating and electrical materials as their excellent physical, chemical and charge storage properties [1][2][3]. Polyimide (PI) is one of the representative polymers for dielectric application, which possesses remarkable performance, such as outstanding heat resistance, good mechanical properties, electrical properties and stability.…”

Section: Introductionmentioning

confidence: 99%