Application of the Measurement of the Dielectric Constant and Loss Angle to the Study of the Structure of Vulcanizates Loaded with Carbon Blacks

1952 ◽  
Vol 25 (3) ◽  
pp. 533-548
Author(s):  
P. Thirion ◽  
R. Chasset
Keyword(s):  
Dielectric Constant ◽  
Carbon Black ◽  
The Other ◽  
Rubber Matrix ◽  
Loss Angle ◽  
Colloidal Structure ◽  
Dielectric Absorption ◽  
Dielectric Loss Angle ◽  
Dielectric Constant And Loss ◽  
The Matrix

Abstract In the case of vulcanizates containing carbon black the variation curves of dielectric loss angle as a function of temperature enable the Debye type absorption occurring in the rubber matrix to be distinguished from a supplementary absorption little influenced by variations in temperature and frequency which is characteristic of blacks possessing a structure. The experimental results obtained indicate no difference in physical or chemical state between the matrix occupying the space between the particles of black in a loaded mix and the vulcanizate of the corresponding pure rubber mix. The supplementary losses on the other hand seem to be closely related to the effects of structure in loaded mixes imagined by Mullins to explain the mechanical behavior of these mixes: they decrease very rapidly by elongation or swelling and give rise to various phenomena of hysteresis. It would seem that dielectric absorption could advantageously be applied as a nondestructive test revealing the colloidal structure of rubber mixes based on carbon black. Moreover the dielectric constant would enable information to be obtained on the form factor and the orientation of the particles or agglomerates of particles of black in mixes on the basis of a theory assimilating these particles (or agglomerates) to condenser armatures.

Swelling Behavior of Rubbers Compounded with Reinforcing Pigments

1959 ◽  
Vol 32 (3) ◽  
pp. 825-843 ◽  
Author(s):  
B. B. S. T. Boonstra ◽  
Eli M. Dannenberg
Keyword(s):  
Carbon Black ◽  
Fumed Silica ◽  
Crosslink Density ◽  
The Other ◽  
Rubber Matrix ◽  
Volume Loading ◽  
Precipitated Silica ◽  
Bound Rubber ◽  
Equilibrium Swelling ◽  
The Matrix

Abstract Equilibrium swelling data are presented for vulcanizates of natural rubber, SBR 1500, butyl rubber, neoprene, and nitrile rubber containing fumed silica, precipitated silica, precipitated calcium metasilicate, hard clay and carbon black. Swelling media are chloroform, benzene, hexane, and acetone. It is observed that certain fillers, particularly carbon black, cause a reduction in the swelling of the rubber matrix which is commensurate with the volume loading of the filler. This effect is not specific for a particular solvent or elastomer. When a series of loadings of a filler shows this effect of reducing the matrix swelling in one solvent, it is also shown by the swelling data for the other solvents, but not to the same degree. The system SBR-benzene was studied to determine from the bound rubber measurements and the equilibrium swelling data for the corresponding vulcanizates the number of crosslinks per cubic centimeter in the unvulcanized and vulcanized states. It appears that the number of crosslinks estimated in the bound rubber gel is much too small to account for the increase in crosslink density in the rubber matrix that is caused by the presence of carbon black in the vulcanizate.

Photokapazitiver Effekt und Lumineszenz unter IR-Bestrahlung

1964 ◽  
Vol 19 (4) ◽  
pp. 454-458 ◽  
Author(s):  
Frank Matossi ◽  
Dieter Siebert
Keyword(s):  
Dielectric Constant ◽  
Energy Band ◽  
Infrared Radiation ◽  
Band Model ◽  
Loss Angle ◽  
Capacitance Change ◽  
Effect Change ◽  
Conduction Electrons ◽  
Dielectric Constant And Loss ◽  
Uv Excitation

The photocapacitive effect (change of dielectric constant and loss angle by uv-radiation) is modified by additional infrared radiation either during or after uv excitation. This is investigated in some detail for a phosphor with photodielectric effect where the capacitance change is essentially due to polarization of filled traps. There are indications for the influence of reversible occupation changes among traps. Results with a phosphor whose capacitance change is due to conduction electrons are not yet conclusive with respect to a detailed energy band model; they show, however, that both conduction band and valence band participate in the processes.

scholarly journals Dielectric and Microwave Properties of Siloxane Rubber/Carbon Black Nanocomposites and Their Correlation

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Omar A. Al-Hartomy ◽  
Falleh Al-Solamy ◽  
Ahmed Al-Ghamdi ◽  
Nikolay Dishovsky ◽  
Vladimir Iliev ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Carbon Black ◽  
Relative Permittivity ◽  
Filler Content ◽  
Microwave Properties ◽  
Loss Angle ◽  
Shielding Effectiveness ◽  
Frequency Range ◽  
Dielectric Loss Angle

In this paper, the dielectric and microwave properties of carbon black/siloxane rubber-based nanocomposites have been investigated in the frequency range from 1 GHz till 12 GHz according to the content of carbon black and the frequency. It has been established that the increasing frequency and filler content lead to an increase in the relative permittivity and tangent of dielectric loss angle. At higher filler content, the effects become more pronounced, especially those upon dielectric loss. It has been also established that there are two well-distinguished areas in all dependences of microwave properties on frequency and filler content increasing. The first is between 1 and 8 GHz wherein the reflection and attenuation of microwaves do not change considerably with frequency and filler content alternation while shielding effectiveness worsens. The second area is between 8 and 12 GHz wherein the reflection and attenuation of microwaves increase drastically with the increasing frequency and filler content. Shielding effectiveness improves, too. It has been established that in all cases the degree of correlation between dielectric and microwave properties evaluated on the basis of the coefficients of correlation calculation is perfect.

Online Electrical Conductivity as a Measure to Characterize the Carbon Black Dispersion in Oil Containing Rubber Compounds with a Different Polarity of Rubber

2004 ◽  
Vol 77 (5) ◽  
pp. 815-829 ◽  
Author(s):  
H. H. Le ◽  
I. Prodanova ◽  
S. Ilisch ◽  
H.-J. Radusch
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Conductivity Measurement ◽  
Infiltration Rate ◽  
Rubber Matrix ◽  
Electrical Conductivity Measurement ◽  
Infiltration Process ◽  
The Matrix ◽  
Polar Oil ◽  
Carbon Black Dispersion

Abstract The influence of viscosity, polarity of the rubber matrix and the types and contents of extender oil on the carbon black dispersion has been characterized using the online electrical conductivity measurement. A corresponding change of the online conductivity with the rubber infiltration and extent of carbon black dispersion has been observed. The infiltration rate increases with increasing polarity and decreasing viscosity of the rubber matrix, whereby the matrix polarity shows a stronger effect than the viscosity. The oil addition accelerates the infiltration process. This is caused by the reduction of the matrix viscosity and the intensification of the filler-matrix interaction. Oil addition affects the carbon black dispersion in non-polar rubber much more than in polar rubber. Furthermore, in non-polar rubber, polar oil shows a stronger effect than non-polar oil.

scholarly journals Effects of additional amount of carbon micro-coils on the dielectric properties of its composite sheet

2014 ◽  
Vol 38 (1) ◽  
pp. 39-47
Author(s):  
Meherun Nessa
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Relative Dielectric Constant ◽  
Loss Angle ◽  
Composite Sheet ◽  
Dielectric Parameters ◽  
Dielectric Loss Angle ◽  
Additional Amount ◽  
Academy Of Sciences

The morphology and dielectric properties of carbon micro-coils (CMC) composite sheet wereexamined. Frequency dependence of dielectric parameters; dielectric loss angle (?), dielectric losstangent (tan?) and relative dielectric constant ( ?r) were measured on single and double-helixcomposite sheet. It was found that these parameters of CMC/polysilicone composites extensivelychanged with the additional amount of CMC with polysilicone resine. It was also observed that thehigher additional amount (wt%) of CMC is appropriate for high response. DOI: http://dx.doi.org/10.3329/jbas.v38i1.20210 Journal of Bangladesh Academy of Sciences, Vol. 38, No. 1, 39-47, 2014

scholarly journals Study of dielectric properties of 4-methylstyrene and α-methylstyrene copolymer films with different molar ratio of initial monomers

2019 ◽  
Vol 58 (6) ◽  
pp. 55-58
Author(s):  
Ignat S. Dolgin ◽  
◽  
Pyotr P. Purygin ◽  
Yury P. Zarubin ◽  
◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Methylene Chloride ◽  
Molar Ratio ◽  
Loss Angle ◽  
Electrical Capacitance ◽  
Copolymer Films ◽  
Laboratory Conditions ◽  
Dielectric Loss Angle ◽  
Material Sample

Two new copolymers of 4-methylstyrene and α-methylstyrene were obtained by the emulsion polymerization method according to the previously described and tested method in the course of the experiment in laboratory conditions. The molar ratio of the starting monomers of 4-methylstyrene and α-methylstyrene was 9: 2 and 10: 1, respectively, in each material sample. The structure of the copolymers obtained was confirmed by IR and 1H NMR spectroscopy. Under laboratory conditions, three prototypes of each copolymer film were obtained from the solution. A sample of the copolymer was dissolved in methylene chloride was applied on a smooth glass substrate. After complete evaporation of the solvent, the film was separated from the substrate. The thickness of the films for each copolymer sample was 20, 30, and 50 microns. In the course of further experimentation, these samples were examined for the values of dielectric constant and tangent of dielectric loss angle. The basis of this experiment used a resonant method of measurement. The presented method is based on the variation of conductivity due to a change in the electrical capacitance of the oscillating circuit. In this experiment, the magnitude of the electrical capacitance and the tangent of the dielectric loss angle were measured. Based on the value of the capacitance and the parameters of the film sample to be measured, it is possible to calculate the dielectric constant. From the data obtained it can be seen that with increasing film thickness, dielectric constant values decrease. However, the indicators of the tangent of dielectric loss angle increase. With an increase in the measurement frequency, a slight decrease in the dielectric constant is observed, and the value of the tangent of the dielectric loss angle decreases nonlinearly. In addition, it should be noted that the samples of 4-methylstyrene-α-methylstyrene copolymer films with a molar ratio of starting monomers of 10: 1 have a higher dielectric constant, along with lower values of the dielectric loss tangent. From this it follows that samples with a lower proportion of α-methylstyrene in their structure have better dielectric characteristics compared with their counterparts with a high content of α-methylstyrene.

scholarly journals Synthesis of constructive-technological decisions of regulation of working capacitance of cables of industrial networks

2021 ◽  
pp. 44-49
Author(s):  
G.V. Bezprozvannych ◽  
I.A. Kostiukov ◽  
O.A. Pushkar
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Effective Dielectric Constant ◽  
Protective Film ◽  
Loss Angle ◽  
Twisted Pair ◽  
Industrial Networks ◽  
The Past ◽  
Dielectric Loss Angle ◽  
Physical Level

Introduction. Over the past 10 years, the number of industrial networks has more than doubled. At the physical level, all industrial technology networks are based on twisted pair. Purpose. Synthesis of constructive-technological decisions of regulation of electric capacitance of the insulated conductor at a stage of manufacturing of twisted pair of cables of industrial networks. Methodology. The method of secondary charges to determine the capacitance of the insulated conductor by varying the thickness of the solid and foamed polyethylene insulation. Practical value. Effective regulation is provided on the basis of the obtained dependencies of the effective dielectric constant, the tangent of the dielectric loss angle and the capacitance of the insulated conductor on the degree of foaming and the thickness of the protective film of two-layer insulation. At a degree of porosity of 40 %, the dielectric constant decreases by 25 %, the tangent of the dielectric loss angle – by 33 %, the electrical capacitance of the insulated conductor – by 20 %.

Low Temperature Hydrothermal Synthesis and Sintering of Ba0.6Sr0.4TiO3

2008 ◽  
Vol 368-372 ◽  
pp. 53-55
Author(s):  
Yun Fei Fu ◽  
Pei Feng Zhang ◽  
Hui Qing Fan ◽  
Xiu Li Chen
Keyword(s):  
Dielectric Constant ◽  
Low Temperature ◽  
Room Temperature ◽  
Hydrothermal Process ◽  
Dielectric Anomaly ◽  
Loss Angle ◽  
Synthesis Mechanism ◽  
Dielectric Constant And Loss ◽  
Different Temperatures ◽  
Bst Ceramics

Ba0.6Sr0.4TiO3 nanopowders (~ 80 nm in size) were prepared by low temperature hydrothermal process. The process and synthesis mechanism were discussed in detail. Furthermore, the powders were pressed into disc-shaped pellets and sintered at different temperatures. The frequency dependence of the dielectric constant and loss angle tangent of the sintered BST ceramics are measured from room temperature to 500°C and a diffuse dielectric anomaly by the dielectric relaxation was found.

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