Thermal depolarization current study of polystyrene composites containing mica flakes

Tanaka, Toshiaki; Hayashi, Shoryo; Hirabayashi, Shoji; Shibayama, Kyōichi

doi:10.1063/1.325097

Cited by 31 publications

(8 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The enhancement of depolarization current in composites in comparison to the amorphous matrix material observed in some cases [50,51] is usually explained by the Maxwell-Wagner polarization mechanism [6,42]. A similar effect is observed in our samples as well (see Figs.…”

Section: (E*)ll-2 L = Vl(e )I1-2ai + V2(e )I1-2ai O0)supporting

confidence: 87%

“…Interpretation of the TSD curves of previously dried (polarized at 120 ~ is simpler in the sense that water has a negligible effect, but it is complicated by the presence of space charge polarization which has proven to be important in semicrystalline polymers such as polyethylene and polyethylene terephthalate [48,49] and in composites such as mica filled epoxy resin and mica filled polystyrene [50,51] or glass fiber filled polypropylene [52]. Semicrystalline polymers exhibit one or more relaxation transitions in the premelting range, which are related to the molecular superstructure and morphology.…”

Section: (E*)ll-2 L = Vl(e )I1-2ai + V2(e )I1-2ai O0)mentioning

confidence: 99%

See 1 more Smart Citation

DC dielectric study of polyethylene/CaCO3 composites

Bánhegyi¹,

Hedvig²,

Karasz

1988

Colloid & Polymer Sci

View full text Add to dashboard Cite

The dielectric properties of composite samples prepared by polymerizing ethylene on the surface of filler are compared to those of mechanical mixtures consisting of CaCO3 and ultra high molecular weight polyethylene. After presenting the normalized master curves of AC dispersion and loss measured at different relative humidities, the field strength dependence of the 50 Hz AC and DC responses were studied. With one exception, the effect is small. Thermally stimulated polarization (TSP) and depolarization (TSD) curves are presented; the peak appearing on the TSP curves of the samples stored under ambient conditions is interpreted as a result of water desorption. The high temperature DC conductivity and the depolarization current density are higher in the composites and mechanical mixtures than in the matrix. The dielectric properties of the wet filler particles were calculated from the measured composite and matrix data using various mixture formulae. The results can be understood and interpreted if the dielectric properties of adsorbed water are described by the cluster theory of dielectric relaxation.

show abstract

Section: (E*)ll-2 L = Vl(e )I1-2ai + V2(e )I1-2ai O0)supporting

confidence: 87%

Section: (E*)ll-2 L = Vl(e )I1-2ai + V2(e )I1-2ai O0)mentioning

confidence: 99%

DC dielectric study of polyethylene/CaCO3 composites

Bánhegyi¹,

Hedvig²,

Karasz

1988

Colloid & Polymer Sci

View full text Add to dashboard Cite

show abstract

“…The changing slope of the semilogarithmically plotted depolarization current-temperature curves in the a, peak region is consistent with the changing activation energies observed on the polarization current curves, thus they also reflect the change of the trap-distribution. In earlier TSD studies of mica filled epoxy resin (40), mica filled polystyrene (41). glass filled polypropylene (32), silica and zeolite filled ethylene-propylene rubber (42), and in CaC03 filler polyethylene (1 7) the depolarization current proved to be higher in the composite than in the matrix resin.…”

Section: Discussionmentioning

confidence: 94%

“…glass filled polypropylene (32), silica and zeolite filled ethylene-propylene rubber (42), and in CaC03 filler polyethylene (1 7) the depolarization current proved to be higher in the composite than in the matrix resin. This phenomenon has been explained in terms of the interfacial polarization effect (40,41) and is due to the conductivity difference between the components. This effect, however, cannot explain the decrease of conductivity and depolarization currents in the a, range, observed in our systems containing untreated filler.…”

Section: Discussionmentioning

confidence: 99%

AC and DC dielectric properties of some polypropylene/calcium carbonate composites

Bánhegyi

Karasz

Petrovìć³

1990

Polymer Engineering & Sci

View full text Add to dashboard Cite

AC dielectric properties and thermally stimulated polarization (TSP) and depolarization (TSD) currents were studied in a series of CaCO3‐filled polypropylene composites. The filler content (0 to 50 weight percent) and the average particle size (3.0 to 16.1 μm) at constant filler content (30 weight percent) were varied in separate groups of samples. In a third group of samples the filler (20 to 40 weight percent) was surface treated with stearates. The AC dielectric behavior of composites containing untreated fillers is largely determined by a small amount of adsorbed water. Upon heating, the dielectric properties show maxima (increasing with decreasing frequency) which disappear on cooling. In the case of stearate‐treated fillers the dielectric loss level is higher, the dispersion and loss curves on heating reflect a combination of dipolar and protonic processes with water desorption. In the dry state the onset of an audio frequency relaxation process is observed in the pre‐melting zone. The thermally stimulated currents of the composites containing treated and untreated fillers are also different. In the case of the untreated fillers the TSP curves show maxima indicating water desorption which are increasingly intense and roughly exponential with filler content. The high temperature conductivity and the intensity of the pre‐melting depolarization peak pass through a minimum as a function of filler content. Above 20 weight percent filler content the activation energy of high temperature conductivity decreases. In the case of the surface treated samples, the thermally stimulated response is different for “wet” and dried samples. The dry samples exhibit a relaxation between the amorphous and crystalline transitions of the matrix polymer which is probably due to interfacial relaxation caused by the enhanced surface conductivity of the stearate‐treated fillers.

show abstract

“…TANAKA et al [20] have also suggested t h a t the number of traps is closely related to the change of the molecular structure in the vicinity of the poly(pyromel1itimide) film surface by the high temperature. TANAKA et al [20] have also suggested t h a t the number of traps is closely related to the change of the molecular structure in the vicinity of the poly(pyromel1itimide) film surface by the high temperature.…”

Section: Ptwtoelectret Statementioning

confidence: 99%

The photoelectret state in kapton polyimide film. II. The effect of intensity of illumination and the autophotoelectret state

Quamara¹,

Bhardwaj²,

Pillai

et al. 1983

Acta Polymerica

View full text Add to dashboard Cite

The photoelectret state in Kapton polyimide film as a function of intensity of illumination has been investigated using visible light and ultraviolet radiation. Experiments were carried out both with as-received and heat treated Kapton samples. The photoelectret charge is observed to increase with the intensity of illumination tending towards saturation which is in accordance with the reciprocity law. The nature of decay curves shows the presence of shallow and deep trap levels in Kapton. Ultraviolet radiations were found more efficient for photopolarization than visible light. Heat treatment results in reduction of photoelectret: charge which: may: be; due t o the decrease in the number of traps owing to high temperature aging. The autophotoelectret state has also been investigated in Kapton. This study is useful for exploring the possibilities of using Kapton in electrophotographic process and solar energy conversion devices. Der Photoelektret-Zustand in Kapton(Po1yimid)-Filmen. 11. Der Einflup der lntensitat der Beleuchtung und der Autophotoelektret-ZustandDer Photoelektretzustand in Polyimidfilmen (Kapton) wurde in Abhangigkeit von der Intensitat der Beleuchtung mit sichtbarem und UV-Licht untersucht. Die Photoelektret-Ladung nimmt mit der Beleuchtungsintensitat zu und erreicht eine Sattigung in Ubereinstimmung mit dem Reziprozititatsgesetz. Die Zerfallskurven deuten auf die Existenz von flachen und tiefen Haftstellen (Traps) im Kapton hin. Ultraviolettstrahlung erwies sich hinsichtlich der Photopolarisation als wirksamer als sichtbares Licht. Warmebehandlung der Filme fuhrt zu einer Verringerung der Photoelektretladung, was auf einer Abnahme der Anzahl der Haftstellen beruhen kann. Weiter wurde der Autophotoelektretzustand im Kapton untersucht. Die Untersuchungen sind fur Anwendungen von Kapton in der Elektrophotographie und bei der Umwandlung von Solarenergie von Interesse. @omoa~ze~mpemnoe cocmomue e Kanmonoebix (nonuuwudmcx) nJzenKax. Vacmb I I . BJcumue unmencuenocmu oceetqenus u a e m o~o m o s~e~m p e m n o e cocmomme bfCCneAOBaH0 @OTO3JIeKTpeTHOe COCTORHHe B IIOJIAAMHnHbIX IIJIeHHaX (KBIITOH) B 3aBHCHMOCTH OT HHTeHCHBHOCTHOCBeIQeHHR C BAnHMbIM EI Ya)-CBeTOM. (DOT03neKTPeTHbIfi 3apfIn

show abstract

Thermal depolarization current study of polystyrene composites containing mica flakes

Cited by 31 publications

References 9 publications

DC dielectric study of polyethylene/CaCO3 composites

DC dielectric study of polyethylene/CaCO3 composites

AC and DC dielectric properties of some polypropylene/calcium carbonate composites

The photoelectret state in kapton polyimide film. II. The effect of intensity of illumination and the autophotoelectret state

Contact Info

Product

Resources

About