scholarly journals Influence of Ramped Compression on the Dielectric Behavior of the High-Voltage Epoxy Composites

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3150
Author(s):  
Muhammad Bilal Iqbal ◽  
Abraiz Khattak ◽  
Asghar Ali ◽  
M. Hassan Raza ◽  
Nasim Ullah ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dissipation Factor ◽  
Dielectric Behavior ◽  
Mechanical Stresses ◽  
Dielectric Characteristics ◽  
Polymeric Insulators ◽  
Basic Characteristics ◽  
Service Application ◽  
Micro Silica

The emergence of micro and nano-based inorganic oxide fillers with optimal filler-loadings further enhances the required insulation characteristics of neat epoxy. During manufacturing and service application, insulators and dielectrics face mechanical stresses which may alter their basic characteristics. Keeping this in mind, the facts’ influence of mechanical stresses and fillers on dielectric properties of polymeric insulators of two epoxy/silica composites were fabricated and thoroughly analyzed for dielectric characteristics under ramped mechanical compressions relative to the unfilled sample. Before compression, epoxy nanocomposites exhibited responses having an average dielectric constant of 7.68 with an average dissipation factor of 0.18. After each compression, dielectric properties of all samples were analyzed. The dissipation factor and the dielectric constant trends of each sample are plotted against a suitable frequency range. It was observed that after the successive compressions up to 25 MPa, the dielectric properties of epoxy micro-silica composites were highly affected, having an average final dielectric constant of 9.65 times that of the uncompressed sample and a dissipation factor of 2.2 times that of the uncompressed sample, and these were recorded.

scholarly journals DIELECTRIC BEHAVIOR OF NANO BARIUM TITANATE FILLED POLYMERIC COMPOSITES

2013 ◽  
Vol 22 ◽  
pp. 1-10 ◽  
Author(s):  
A. PRATAP ◽  
N. J. JOSHI ◽  
P. B. RAKSHIT ◽  
G. S. GREWAL ◽  
V. SHRINET
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Barium Titanate ◽  
Polymer Composites ◽  
Hydrothermal Process ◽  
Volume Resistivity ◽  
Polymeric Composites ◽  
Ceramic Materials ◽  
Dissipation Factor ◽  
Dielectric Behavior

Rapid growth of electronic industry requires development of new materials that combine the high dielectric constant intrinsic to ferroelectric ceramic materials with easy processing characteristics of polymers. Ceramic-polymeric composites possess interesting properties for a variety of electronic applications including passive electronic devices. In fact, polymer-ceramic materials have drawn lot attention for use in microelectronic packaging, because they can give higher performance with lower cost, size and weight. In this work, attempts are made to prepare ceramic polymer composites followed by characterization of dielectric properties. The Barium Titanate ceramic powders are synthesized using the hydrothermal process. Crystal structure and crystallite size of particles are determined using X-ray diffraction. Silane treatment is carried out on Barium Titanate powder to increase its compatibility with polymer, followed with preparation of ceramic polymer composites. Epoxy and polyvinyledene fluoride (PVDF) polymers are used as matrices for preparation of the composites. The proportion of nanopowder is varied from 60 to 90 wt%. Dielectric properties such as volume resistivity, dielectric constant, dissipation factor are evaluated. Results indicate that the dielectric constant and dissipation factor vary between 18 -140 and 0.01 to 0.09, respectively as the relative ratio of polymer and silane modified Barium Titanate is varied. Specifically, at 90 wt% of 0.1 wt% silane modified Barium Titanate, the highest dielectric constant of 140 along with dissipation factor of 0.07 is obtained in the epoxy based system.

scholarly journals Dielectric properties of natural Borneo woods: Keranji, Kayu Malam, and Kumpang

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7815-7827
Author(s):  
Elammaran Jayamani ◽  
Md Rezaur Rahman ◽  
Sinin Hamdan ◽  
Muhammad Idris Kyari ◽  
Muhammad Khusairy Bin Bakri ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Physical Properties ◽  
Potassium Carbonate ◽  
Treatment Method ◽  
Dissipation Factor ◽  
Dielectric Behavior ◽  
Impedance Analyzer ◽  
Heat Treated ◽  
Structure Density

The dielectric behavior and properties of three types of Sarawak woods, under various conditions (untreated, alkaline treated, potassium carbonate treated, and heat treated), were investigated and discussed. The dielectric constant, loss, and dissipation factor tests were conducted via a dielectric impedance analyzer. The results revealed that the dielectric properties decreased in relation to an increase in frequency. With considerations to the treatment method, the highest dielectric constant values for the untreated samples were found in Kumpang wood, the highest dielectric constant values for the heat-treated samples and potassium carbonate treated samples were found in Keranji wood, and the highest dielectric constant values for sodium hydroxide treated samples were found in Kayu Malam wood. Therefore, it was evident that the physical properties, e.g., internal structure, density, moisture, temperature, etc., could affect the dielectric behavior and properties of the wood materials.

Influence of Ca-Doping on Structural, Magnetic and Dielectric Properties of Ba3Co2-xCaxFe24O41 Hexaferrite Powders

2015 ◽  
Vol 241 ◽  
pp. 226-236 ◽  
Author(s):  
Neha Solanki ◽  
Rajshree B. Jotania
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Sol Gel ◽  
Calcium Content ◽  
Combustion Method ◽  
Dielectric Behavior ◽  
Dielectric Parameters ◽  
Ca Doping ◽  
Auto Combustion ◽  
Magnetic And Dielectric Properties

Influence of Ca substitution on structural, magnetic and dielectric properties of Ba3Co2-xCaxFe24O41(where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), prepared by Sol-Gel auto-combustion method, has been investigated in present studies. The obtained powder was sintered at 950 oC for 4 hrs. in the static air atmosphere. Structural analysis of Ca-doped Ba3Co2-xCaxFe24O41powders revealed pure Z-type hexaferrite phase at low temperature. The frequency dependent dielectric constant (Єʹ) and magnetic properties such as remanent magnetization (Mr), saturation magnetization (Ms) and coercivity (Hc) were studied. It is observed that coercivity increased gradually with increase in calcium content. The real dielectric constant (Єʹ) and dielectric loss tangent (tan δ) were studied in the frequency range of 20Hz to 2MHz. The dielectric parameters for all samples show normal dielectric behavior as observed in hexaferrites. Contents of Paper

Effect of Nb2O5 Content on Microstructure and Dielectric Properties of Ba2-2xNa1-xNb5O15-5x/2 Ceramics

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1273-1278 ◽  
Author(s):  
Peng Wang ◽  
Joon Hyung Lee ◽  
Jeong Joo Kim ◽  
Sang Hee Cho ◽  
Hee Young Lee
Keyword(s):  
Phase Transformation ◽  
Dielectric Properties ◽  
Transformation Temperature ◽  
Tungsten Bronze ◽  
Dielectric Behavior ◽  
Phase Transformation Temperature ◽  
Microstructure Development ◽  
Dielectric Characteristics ◽  
Optically Transparent ◽  
Second Phases

The effect of Nb 2 O 5 content on the microstructure development and the dielectric characteristics of tungsten-bronze-structured polycrystalline Ba 2 Na 1 Nb 5 O 15 (BNN) ceramics was studied. The compositions of stoichiometry, Nb 2 O 5–deficient and Nb 2 O 5–excess BNN were prepared and sintered at 1250 °C for 2 h in oxygen. We report the development of second phases, microstructure and dielectric behavior of polycrystalline BNN ceramics, which was not reported ever. The Nb 2 O 5 content affect lattice constant of the sintered body, which contributed to the change of phase transformation temperature. The stoichiometric BNN showed the lowest densification, while an optically transparent sample was obtained in Nb 2 O 5–excess highly dense sample.

scholarly journals Investigation of the dielectric properties of copolymers based on 2,3,4,5,6-pentafluorostyrene, styrene, 4-fluoro-α-methylstyrene and α-methylstyrene

2019 ◽  
Vol 60 (12) ◽  
pp. 87-90
Author(s):  
Ignat S. Dolgin ◽  
◽  
Pyotr P. Purygin ◽  
Yury P. Zarubin ◽  
◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Signal Generator ◽  
Frequency Signal ◽  
Current Frequency ◽  
Dielectric Characteristics ◽  
Methyl Styrene

Three new copolymers based on fluorine-containing derivatives of styrene and α-methylstyrene were obtained. According to the results of the previous stages of the study, copolymers based on styrene derivatives have improved dielectric properties compared to polystyrene and a copolymer of styrene and α-methyl styrene. The dielectric constant ε and dielectric loss tangent tanδ were measured for the initial and synthesized samples of styrene – α-methyl styrene copolymer at Samara Electromechanical Plant OJ-SC (Samara city, Russia). All measurements of dielectric characteristics were carried out at an alternating current frequency of 10 GHz on a pressed copolymer tablet with a diameter of 10 and a thickness of 3 mm. During the experiment, a measuring stand was used, consisting of a high-frequency signal generator G4-83, an electronically counting frequency meter Ch3-54 with a frequency converter YaZCh-43, a measuring amplifier U2-4; low-frequency signal generator G3-109; measuring unit FKDG 418151.002. The results obtained indicate high values of the dielectric constant. For samples of copolymers of α-methylstyrene – 4-fluoro-α-methylstyrene and styrene – 4-fluoro-α-methylstyrene, values of 4.63 and 4.21, respectively, were obtained. These dielectric permittivity values are superior not only to samples previously obtained during the experiment, but also to some other compounds that are widely used in industry. In particular, the dielectric constant of lavsan, which is used in the manufacture of capacitors, is 3.1-3.3. The improved dielectric constant values are probably related to the high-quality composition of the copolymer. Samples of the copolymer containing 4-fluoro-α-methylstyrene are significantly superior to the copolymer with 2,3,4,5,6-pentafluorostyrene for this characteristic. The values of the dielectric loss tangent are in the range from 8.74∙10−4 to 37.4∙10−4. Given the dielectric characteristics of the synthesized copolymers, we can conclude that there are good prospects for the use of fluorine-containing styrene copolymers. The obtained values of permittivity and dielectric loss tangent indicate a good possible competitiveness of new materials based on new copolymers. In the future, it is planned to study a number of other physicochemical properties of these materials in order to obtain the most complete spectrum of their characteristics.

Effects of thermal annealing on the dielectric properties of Pb(Zn1/3Nb2/3)O3-based ceramics

1999 ◽  
Vol 14 (5) ◽  
pp. 1683-1685 ◽  
Author(s):  
Feng Xia ◽  
Xi Yao
Keyword(s):  
Dielectric Constant ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Thermal Annealing ◽  
Wall Motion ◽  
Relative Dielectric Constant ◽  
Domain Wall Motion ◽  
Dissipation Factor ◽  
Diffusion Factor ◽  
Maximum Dielectric Constant

Pb(Zn1/3Nb2/3)O3-based ceramics were thermally annealed at 700–900 °C for 4 h. Both the relative dielectric constant and dissipation factor in the vicinity of transition temperature were increased when the specimens were thermally annealed at 700–900 °C, but the diffusion factor was decreased. After thermal annealing, the maximum dielectric constant Km was increased from about 11,000 to 26,000. These phenomena can be related to the domain wall motion and the elimination of internal stress.

Dielectric properties of Ba0.97Bi0.02TiO3–Ba1−xMgxSn0.02Ti0.98O3 composite ceramics

2016 ◽  
Vol 30 (29) ◽  
pp. 1650363
Author(s):  
Jing wang ◽  
Guijuan Rong ◽  
Liangbin Hao ◽  
Lan Gao ◽  
Haiyan Cheng ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Breakdown Strength ◽  
Dielectric Strength ◽  
Dielectric Behavior ◽  
Composite Ceramics ◽  
Solid State Method ◽  
Composition Formula ◽  
State Method ◽  
Mg Content

A wet solid-state method was used in this work to produce [Formula: see text]–[Formula: see text] materials. By using core-shell structure nanocubic [Formula: see text] (BMST) decorated [Formula: see text] (BBT) assemblies, a composite capacitor with improved dielectric constant and enhanced breakdown strength was successfully fabricated in contrast with the composite ferroelectric [Formula: see text]–[Formula: see text] (BBT–BST) ceramic. With increasing Mg content, the ceramic capacitors display a stronger performance in its dielectric behavior. The best dielectric properties were obtained in the composition [Formula: see text] = 0.007 with the dielectric constant above 65,000. The dielectric strength of the ceramics was measured by a withstanding voltage tester. The best dielectric strength was achieved in the composition [Formula: see text] = 0.007 with [Formula: see text] = 5.455 kV/mm.

Dielectric Properties of Importance in Operations of Post-harvest of Sorghum

2017 ◽  
Vol 13 (4) ◽  
Author(s):  
Caciano P. Z. Noreña ◽  
Carlos E. Lescano-Anadón
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Moisture Content ◽  
Loss Factor ◽  
Dissipation Factor ◽  
Post Harvest ◽  
Moisture Contents ◽  
And Storage

Abstract The knowledge of electrical properties and their relationship with moisture content is of great importance in operations of post-harvest and storage in grains. The dielectric properties of sorghum samples were studied at different moisture contents and temperatures (25 at 41 °C), at frequencies of 1 and 10 kHz. In order to measure changes in the capacitance and dissipation factor of the samples, the method of impedance bridge was used. Both the dielectric constant and the dielectric loss factor of the samples increased with increasing moisture content and temperature; however, they decreased with increasing frequency. Models were proposed to relate the dielectric properties to either the moisture (exponential and polynomial) or temperature (linear).

scholarly journals Development of a dielectric ceramic based on diatomite-titania part two: dielectric properties characterization

Cerâmica ◽  
1998 ◽  
Vol 44 (287-288) ◽  
pp. 136-140
Author(s):  
Jamilson Pinto Medeiros ◽  
Elcio Correia de Souza Tavares ◽  
Uilame Umbelino Gomes ◽  
Wilson Acchar
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Temperature Coefficient ◽  
Sintering Temperature ◽  
Dielectric Strength ◽  
Dissipation Factor ◽  
Insulation Resistance ◽  
Dielectric Ceramic ◽  
Dc Voltage ◽  
Titania Content

Dielectric properties of sintered diatomite-titania ceramics are presented. Specific capacitance, dissipation factor, quality factor and dielectric constant were determined as a function of sintering temperature, titania content and frequency; the temperature coefficient of capacitance was measured as a function of frequency. Besides leakage current, the dependence of the insulation resistance and the dielectric strength on the applied dc voltage were studied. The results show that diatomite-titania compositions can be used as an alternative dielectric.

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